HCl in massive star-forming regions across various scales

Affiliations: 1 2 lennart-boehm.de [email protected] ✉ Tracing Chlorine Isotopes Across the Milky Way A Large Scale Survey of Hydrogen Chloride in Star-Forming Regions Arshia M. Jacob2, Friedrich Wyrowski2, Karl M. Menten2, Ashley T. Barnes1, Katharina Immer1 HCl IN ALL TARGETS! Lennart Böhm1,2 Lennart Böhm, ESO IMPRS PhD student SCAN ME! Böhm, L. et al., in prep., Tracing chlorine isotopes across the Milky Way Elia, D. et al. (2021). The Hi-GAL compact source catalogue–II. The 360° catalogue of clump physical properties. MNRAS, 504(2), 2742-2766. Giannetti, A. et al.(2014). ATLASGAL-selected massive clumps in the inner Galaxy-I. CO depletion and isotopic ratios. A&A, 570, A65. Kobayashi, C., Karakas, A. I., & Umeda, H. (2011). The evolution of isotope ratios in the Milky Way Galaxy. MNRAS, 414(4), 3231-3250. Maas, Z. G., & Pilachowski, C. A. (2021). The Galactic Chemical Evolution of Chlorine. AJ, 161(4), 183. Möller, T., Endres, C., & Schilke, P. (2017). eXtended CASA line analysis software suite (XCLASS). A&A, 598, A7. Neufeld, D. A., & Wolfire, M. G. (2009). The chemistry of interstellar molecules containing the halogen elements. ApJ, 706(2), 1594. Neufeld, D. A. et al. (2021). The Chemistry of Chlorine-Bearing Species in the Diffuse Interstellar Medium, and New SOFIA/GREAT* Observations of HCl+. ApJ, 917(2), 104. Reid, M. J. et al. (2019). Trigonometric parallaxes of high-mass star-forming regions: our view of the Milky Way. ApJ, 885(2), 131. References: CHLORINE: PROBING THE ISM SURVEYING HCl WHAT WE STILL DON'T KNOW SCATTERED, NO TREND OUTFLOWS? CONTACT Image credit: apex-telescope.org H2 H2 e hω Cl+ HCl+ Cl H2Cl+ HCl hω e e e Chlorine isotopes probe the nucleosynthesis history of massive star-forming regions and their enrichment of the ISM: ‣35Cl and 37Cl are produced in core-collapse supernovae (CCSNe) and the weak s-process in massive stars (Maas & Pilachowski, 2021) ‣The 35Cl/37Cl ratio in a CCSN varies with factors such as initial mass, metallicity, and explosion properties (Maas & Pilachowski, 2021) ‣Galactic chemical evolution models predict the isotopic ratio to vary with metallicity, hence tracing the nucleosynthesis history of a galaxy (Kobayashi et al. 2010) 28 massive star-forming regions across the Milky Way ‣bright sub-mm continuum sources (Hi-Gal catalogue; Elia et al., 2021) ‣Galactocentric radii between to (Reid et al., 2019) ‣selected from the HyGAL and PRISMAS surveys on hydrides 0.1 kpc 10 kpc and the SEPIA660 receiver •single-pixel, sideband separated heterodyne •native resolution: ‣smoothed to 0.03 km s−1 0.5 km s−1 1. How abundant is HCl across the inner Galaxy? 2. Is there widespread line of sight absorption in the Galactic arms? 3. What physical and excitation conditions does HCl trace? 4. Are variations of the 35Cl/37Cl ratio a localized phenomenon, or does a galactic trend exist? ‣Is the isotopic ratio linked to supernova remnants? APEX 12m sub-mm telescope at 5104 m, Llano de Chajnantor HPBW: 10.1′ ′ HCl 37 HCl 35 covers 2 x 7.9 GHz atmospheric H O absorption! 2 typical weather conditions of our observations Figure Credit: Neufeld & Wolfire (2009) Dashed lines: 10 times higher CR ionization rate deeper surface HCl traces dense cores Chemical evolution across the depths of a cloud HCl and to some degree translucent gas 0 –2 Av [mag] –4 log (abundance/elemental) –6 0 2 4 6 8 10 A typical HCl line profile in our sample consists of 1. a narrow core component 2. a broad, often offset outflow component 70 80 130 0.00 0.25 1.00 2 3 4 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.25 0.50 0.75 1.00 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 G029.954–00.016 Tmb [K] dN dυ[cm−2 km s−1] υLSR [km s−1] CH3OCH3 (?) & CH3CN (?) outflow wing outflow wing υLSR [km s−1] υsys theoretical HFS line intensity 624.977821 GHz625.918756 GHz 2 4 3 G029.954–00.016 0.50 0.75 90 100 110 120 70 80 13090 100 110 120 APEX 12m sub-mm telescope hyperfine structure (HFS) deconvolved column density profile In summary, 11 of the 28 targeted sources showed only emission line profiles (including one tentative detection). 17 had one or more additional absorption components, often rendering analyses difficult. From these observations, we could derive the isotopic ratio in two ways: from the XCLASS line profile models, incl. sources with well separated, or no absorption components from the integrated intensity ratio, where we cut out contaminants and have to discard sources with absorption line profile modeled with XCLASS 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.05 0.10 0.15 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 W43 MM1 0.15 Tmb [K] dN dυ[cm−2 km s−1] 3 υLSR [km s−1] υLSR [km s−1] 70 80 130 90 100 110 120 70 80 130 90 100 110 120 W 43 MM-1 CH3OCH3 (?) & CH3CN (?) dominant absorption 0.10 0.05 0.00 4 5 1 2 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) °10 0 10 20 30 40 50 vLSR [km s°1] 0.0 0.5 1.0 dN dv[cm°2 km s°1] £1013 °10 0 10 20 30 40 50 vLSR [km s°1] £1013 HGAL 000.546–00.852 offset absorption υLSR [km s−1] –10 0 50 10 20 30 40 υLSR [km s−1] –10 0 50 10 20 30 40 HGAL 000.545–00.852 CH3OCH3 (?) & CH3CN (?) emission from core Tmb [K] dN dυ[cm−2 km s−1] 1 1.0 0.5 0.0 4 5 2 3 4 6 8 10 Tmb [K] SO+ H35Cl (1°0) H37Cl (1°0) °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] 0 1 2 3 dN dv[cm°2 km s°1] £1013 °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] £1013 IRAS 12326–6245 CH3OCH3 (?) & CH3CN (?) υLSR [km s−1] υLSR [km s−1] –70 –60 –10 –50 –40 –30 –20 –70 –60 –10 –50 –40 –30 –20 IRAS 12326–6245 outflow SO + massive outflow emission from core 3 Tmb [K] dN dυ[cm−2 km s−1] 4 2 1 0 6 10 8 The line profiles toward some targets show massive outflows: Some show offset absorption: And some even show dominant absorption: a characteristic zigzag pattern HCl has been detected in 27 massive star-forming regions. ‣The observed emission often traces strong outflows ‣Complex line profiles (emission with absorption) renders modeling the spectral line profiles difficult We find an average chlorine isotopic ratio of [H35Cl]/[H37Cl] = 2.6 ± 0.8. ‣The ratio shows no systemic trend with galactocentric distance. ‣Chlorine isotopic ratios have been observed for the first time in the Galactic center, where they are higher, but still agree with CCSN models (Maas & Pilachowski, 2021). ‣Currently, it remains unclear whether the ratio is higher for targets in the vicinity of SNRs. We plan to analyze the physical and excitation conditions traced by HCl. For this, we are exploring HCl’s spatial distribution, especially in outflows to disentangle both components: ‣Mapping HCl toward IRAS 12326–6245 and its massive outflow RA (J2000) Dec (J2000) [K km s–1] 12h35m42s 39s 36s 33s 30s –62°02'00" 03'00" 20" 40" 100 80 60 40 20 work in progress First look at the HCl (1–0) map outflow Photodissociation model predictions for the abundances of chlorine-bearing (and fluorine-bearing) species relative to the elemental abundances across the depths of an interstellar cloud Chlorine-bearing molecules have diagnostic properties due to chlorine’s unique chemistry ‣Most interstellar chlorine is contained in ≤6 species ‣Chlorine is primarily ionized (IPCl = 12.968 eV < IPH) and highly reactive ‣The chemical network is initialized by the exothermic (D0(HCl+) > D0(H2)) reaction Cl+ + H2 → HCl+ Chemical network displaying the most relevant gas-phase formation and destruction pathways for chlorine chemistry in the ISM. Based on Fig. 3, Neufeld et al. (2021) Neufeld & Wolfire (2009) We used XCLASS (Möller, Endres & Schilke, 2017) to model the observed line profiles. XCLASS assumes LTE and optimizes a number of source parameters per component. While we left column density, isotopic ratio and line width open, we constrained ‣the source size, , (verified with ATLASGAL), ‣the rotational temperature, Trot = Tdust, (from ATLASGAL), ‣and the velocity offset, < 1 km s–1, for the core component. - and the number of components have been determined from H13CO (7–6), covered in the lower sideband -or CO isotopologues (Giannetti et al., 2014) θs= 20′ ′ υoff υLSR + predictions for the solar neighborhood from Galactic chemical evolution models (Kobayashi et al., 2011) R1 R2 Affiliations: 1 2 lennart-boehm.de [email protected] ✉ Tracing Chlorine Isotopes Across the Milky Way A Large Scale Survey of Hydrogen Chloride in Star-Forming Regions Arshia M. Jacob2, Friedrich Wyrowski2, Karl M. Menten2, Ashley T. Barnes1, Katharina Immer1 HCl IN ALL TARGETS! Lennart Böhm1,2 Lennart Böhm, ESO IMPRS PhD student SCAN ME! Böhm, L. et al., in prep., Tracing chlorine isotopes across the Milky Way Elia, D. et al. (2021). The Hi-GAL compact source catalogue–II. The 360° catalogue of clump physical properties. MNRAS, 504(2), 2742-2766. Giannetti, A. et al.(2014). ATLASGAL-selected massive clumps in the inner Galaxy-I. CO depletion and isotopic ratios. A&A, 570, A65. Kobayashi, C., Karakas, A. I., & Umeda, H. (2011). The evolution of isotope ratios in the Milky Way Galaxy. MNRAS, 414(4), 3231-3250. Maas, Z. G., & Pilachowski, C. A. (2021). The Galactic Chemical Evolution of Chlorine. AJ, 161(4), 183. Möller, T., Endres, C., & Schilke, P. (2017). eXtended CASA line analysis software suite (XCLASS). A&A, 598, A7. Neufeld, D. A., & Wolfire, M. G. (2009). The chemistry of interstellar molecules containing the halogen elements. ApJ, 706(2), 1594. Neufeld, D. A. et al. (2021). The Chemistry of Chlorine-Bearing Species in the Diffuse Interstellar Medium, and New SOFIA/GREAT* Observations of HCl+. ApJ, 917(2), 104. Reid, M. J. et al. (2019). Trigonometric parallaxes of high-mass star-forming regions: our view of the Milky Way. ApJ, 885(2), 131. References: CHLORINE: PROBING THE ISM SURVEYING HCl WHAT WE STILL DON'T KNOW SCATTERED, NO TREND OUTFLOWS? CONTACT Image credit: apex-telescope.org H2 H2 e hω Cl+ HCl+ Cl H2Cl+ HCl hω e e e Chlorine isotopes probe the nucleosynthesis history of massive star-forming regions and their enrichment of the ISM: ‣35Cl and 37Cl are produced in core-collapse supernovae (CCSNe) and the weak s-process in massive stars (Maas & Pilachowski, 2021) ‣The 35Cl/37Cl ratio in a CCSN varies with factors such as initial mass, metallicity, and explosion properties (Maas & Pilachowski, 2021) ‣Galactic chemical evolution models predict the isotopic ratio to vary with metallicity, hence tracing the nucleosynthesis history of a galaxy (Kobayashi et al. 2010) 28 massive star-forming regions across the Milky Way ‣bright sub-mm continuum sources (Hi-Gal catalogue; Elia et al., 2021) ‣Galactocentric radii between to (Reid et al., 2019) ‣selected from the HyGAL and PRISMAS surveys on hydrides 0.1 kpc 10 kpc and the SEPIA660 receiver •single-pixel, sideband separated heterodyne •native resolution: ‣smoothed to 0.03 km s−1 0.5 km s−1 1. How abundant is HCl across the inner Galaxy? 2. Is there widespread line of sight absorption in the Galactic arms? 3. What physical and excitation conditions does HCl trace? 4. Are variations of the 35Cl/37Cl ratio a localized phenomenon, or does a galactic trend exist? ‣Is the isotopic ratio linked to supernova remnants? APEX 12m sub-mm telescope at 5104 m, Llano de Chajnantor HPBW: 10.1′ ′ HCl 37 HCl 35 covers 2 x 7.9 GHz atmospheric H O absorption! 2 typical weather conditions of our observations Figure Credit: Neufeld & Wolfire (2009) Dashed lines: 10 times higher CR ionization rate deeper surface HCl traces dense cores Chemical evolution across the depths of a cloud HCl and to some degree translucent gas 0 –2 Av [mag] –4 log (abundance/elemental) –6 0 2 4 6 8 10 A typical HCl line profile in our sample consists of 1. a narrow core component 2. a broad, often offset outflow component 70 80 130 0.00 0.25 1.00 2 3 4 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.25 0.50 0.75 1.00 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 G029.954–00.016 Tmb [K] dN dυ[cm−2 km s−1] υLSR [km s−1] CH3OCH3 (?) & CH3CN (?) outflow wing outflow wing υLSR [km s−1] υsys theoretical HFS line intensity 624.977821 GHz625.918756 GHz 2 4 3 G029.954–00.016 0.50 0.75 90 100 110 120 70 80 13090 100 110 120 APEX 12m sub-mm telescope hyperfine structure (HFS) deconvolved column density profile In summary, 11 of the 28 targeted sources showed only emission line profiles (including one tentative detection). 17 had one or more additional absorption components, often rendering analyses difficult. From these observations, we could derive the isotopic ratio in two ways: from the XCLASS line profile models, incl. sources with well separated, or no absorption components from the integrated intensity ratio, where we cut out contaminants and have to discard sources with absorption line profile modeled with XCLASS 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.05 0.10 0.15 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 W43 MM1 0.15 Tmb [K] dN dυ[cm−2 km s−1] 3 υLSR [km s−1]υLSR [km s−1] 70 80 13090 100 110 12070 80 13090 100 110 120 W 43 MM-1 CH3OCH3 (?) & CH3CN (?) dominant absorption 0.10 0.05 0.00 4 5 1 2 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) °10 0 10 20 30 40 50 vLSR [km s°1] 0.0 0.5 1.0 dN dv[cm°2 km s°1] £1013 °10 0 10 20 30 40 50 vLSR [km s°1] £1013 HGAL 000.546–00.852 offset absorption υLSR [km s−1] –10 05010 20 30 40 υLSR [km s−1] –10 05010 20 30 40 HGAL 000.545–00.852 CH3OCH3 (?) & CH3CN (?) emission from core Tmb [K] dN dυ[cm−2 km s−1] 1 1.0 0.5 0.0 4 5 2 3 4 6 8 10 Tmb [K] SO+ H35Cl (1°0) H37Cl (1°0) °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] 0 1 2 3 dN dv[cm°2 km s°1] £1013 °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] £1013 IRAS 12326–6245 CH3OCH3 (?) & CH3CN (?) υLSR [km s−1]υLSR [km s−1] –70 –60 –10–50 –40 –30 –20 –70 –60 –10–50 –40 –30 –20 IRAS 12326–6245 outflow SO+ massive outflow emission from core 3 Tmb [K] dN dυ[cm−2 km s−1] 4 2 1 0 6 10 8 The line profiles toward some targets show massive outflows: Some show offset absorption: And some even show dominant absorption: a characteristic zigzag pattern HCl has been detected in 27 massive star-forming regions. ‣The observed emission often traces strong outflows ‣Complex line profiles (emission with absorption) renders modeling the spectral line profiles difficult We find an average chlorine isotopic ratio of [H35Cl]/[H37Cl] = 2.6 ± 0.8. ‣The ratio shows no systemic trend with galactocentric distance. ‣Chlorine isotopic ratios have been observed for the first time in the Galactic center, where they are higher, but still agree with CCSN models (Maas & Pilachowski, 2021). ‣Currently, it remains unclear whether the ratio is higher for targets in the vicinity of SNRs. We plan to analyze the physical and excitation conditions traced by HCl. For this, we are exploring HCl’s spatial distribution, especially in outflows to disentangle both components: ‣Mapping HCl toward IRAS 12326–6245 and its massive outflow RA (J2000) Dec (J2000) [K km s–1] 12h35m42s39s36s33s30s –62°02'00" 03'00" 20" 40" 100 80 60 40 20 work in progress First look at the HCl (1–0) map outflow Photodissociation model predictions for the abundances of chlorine-bearing (and fluorine-bearing) species relative to the elemental abundances across the depths of an interstellar cloud Chlorine-bearing molecules have diagnostic properties due to chlorine’s unique chemistry ‣Most interstellar chlorine is contained in ≤6 species ‣Chlorine is primarily ionized (IPCl = 12.968 eV < IPH) and highly reactive ‣The chemical network is initialized by the exothermic (D0(HCl+) > D0(H2)) reaction Cl+ + H2 → HCl+ Chemical network displaying the most relevant gas-phase formation and destruction pathways for chlorine chemistry in the ISM. Based on Fig. 3, Neufeld et al. (2021) Neufeld & Wolfire (2009) We used XCLASS (Möller, Endres & Schilke, 2017) to model the observed line profiles. XCLASS assumes LTE and optimizes a number of source parameters per component. While we left column density, isotopic ratio and line width open, we constrained ‣the source size, , (verified with ATLASGAL), ‣the rotational temperature, Trot = Tdust, (from ATLASGAL), ‣and the velocity offset, < 1 km s–1, for the core component. - and the number of components have been determined from H13CO (7–6), covered in the lower sideband -or CO isotopologues (Giannetti et al., 2014) θs= 20′ ′ υoff υLSR + predictions for the solar neighborhood from Galactic chemical evolution models (Kobayashi et al., 2011) R1 R2 Affiliations: 1 2 lennart-boehm.de [email protected] ✉ Tracing Chlorine Isotopes Across the Milky Way A Large Scale Survey of Hydrogen Chloride in Star-Forming Regions Arshia M. Jacob2, Friedrich Wyrowski2, Karl M. Menten2, Ashley T. Barnes1, Katharina Immer1 HCl IN ALL TARGETS! Lennart Böhm1,2 Lennart Böhm, ESO IMPRS PhD student SCAN ME! Böhm, L. et al., in prep., Tracing chlorine isotopes across the Milky Way Elia, D. et al. (2021). The Hi-GAL compact source catalogue–II. The 360° catalogue of clump physical properties. MNRAS, 504(2), 2742-2766. Giannetti, A. et al.(2014). ATLASGAL-selected massive clumps in the inner Galaxy-I. CO depletion and isotopic ratios. A&A, 570, A65. Kobayashi, C., Karakas, A. I., & Umeda, H. (2011). The evolution of isotope ratios in the Milky Way Galaxy. MNRAS, 414(4), 3231-3250. Maas, Z. G., & Pilachowski, C. A. (2021). The Galactic Chemical Evolution of Chlorine. AJ, 161(4), 183. Möller, T., Endres, C., & Schilke, P. (2017). eXtended CASA line analysis software suite (XCLASS). A&A, 598, A7. Neufeld, D. A., & Wolfire, M. G. (2009). The chemistry of interstellar molecules containing the halogen elements. ApJ, 706(2), 1594. Neufeld, D. A. et al. (2021). The Chemistry of Chlorine-Bearing Species in the Diffuse Interstellar Medium, and New SOFIA/GREAT* Observations of HCl+. ApJ, 917(2), 104. Reid, M. J. et al. (2019). Trigonometric parallaxes of high-mass star-forming regions: our view of the Milky Way. ApJ, 885(2), 131. References: CHLORINE: PROBING THE ISM SURVEYING HCl WHAT WE STILL DON'T KNOW SCATTERED, NO TREND OUTFLOWS? CONTACT Image credit: apex-telescope.org H2 H2 e hω Cl+ HCl+ Cl H2Cl+ HCl hω e e e Chlorine isotopes probe the nucleosynthesis history of massive star-forming regions and their enrichment of the ISM: ‣35Cl and 37Cl are produced in core-collapse supernovae (CCSNe) and the weak s-process in massive stars (Maas & Pilachowski, 2021) ‣The 35Cl/37Cl ratio in a CCSN varies with factors such as initial mass, metallicity, and explosion properties (Maas & Pilachowski, 2021) ‣Galactic chemical evolution models predict the isotopic ratio to vary with metallicity, hence tracing the nucleosynthesis history of a galaxy (Kobayashi et al. 2010) 28 massive star-forming regions across the Milky Way ‣bright sub-mm continuum sources (Hi-Gal catalogue; Elia et al., 2021) ‣Galactocentric radii between to (Reid et al., 2019) ‣selected from the HyGAL and PRISMAS surveys on hydrides 0.1 kpc 10 kpc and the SEPIA660 receiver •single-pixel, sideband separated heterodyne •native resolution: ‣smoothed to 0.03 km s−1 0.5 km s−1 1. How abundant is HCl across the inner Galaxy? 2. Is there widespread line of sight absorption in the Galactic arms? 3. What physical and excitation conditions does HCl trace? 4. Are variations of the 35Cl/37Cl ratio a localized phenomenon, or does a galactic trend exist? ‣Is the isotopic ratio linked to supernova remnants? APEX 12m sub-mm telescope at 5104 m, Llano de Chajnantor HPBW: 10.1′ ′ HCl 37 HCl 35 covers 2 x 7.9 GHz atmospheric H O absorption! 2 typical weather conditions of our observations Figure Credit: Neufeld & Wolfire (2009) Dashed lines: 10 times higher CR ionization rate deeper surface HCl traces dense cores Chemical evolution across the depths of a cloud HCl and to some degree translucent gas 0 –2 Av [mag] –4 log (abundance/elemental) –6 0 2 4 6 8 10 A typical HCl line profile in our sample consists of 1. a narrow core component 2. a broad, often offset outflow component 70 80 130 0.00 0.25 1.00 2 3 4 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.25 0.50 0.75 1.00 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 G029.954–00.016 Tmb [K] dN dυ[cm−2 km s−1] υLSR [km s−1] CH3OCH3 (?) & CH3CN (?) outflow wing outflow wing υLSR [km s−1] υsys theoretical HFS line intensity 624.977821 GHz625.918756 GHz 2 4 3 G029.954–00.016 0.50 0.75 90 100 110 120 70 80 13090 100 110 120 APEX 12m sub-mm telescope hyperfine structure (HFS) deconvolved column density profile In summary, 11 of the 28 targeted sources showed only emission line profiles (including one tentative detection). 17 had one or more additional absorption components, often rendering analyses difficult. From these observations, we could derive the isotopic ratio in two ways: from the XCLASS line profile models, incl. sources with well separated, or no absorption components from the integrated intensity ratio, where we cut out contaminants and have to discard sources with absorption line profile modeled with XCLASS 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.05 0.10 0.15 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 W43 MM1 0.15 Tmb [K] dN dυ[cm−2 km s−1] 3 υLSR [km s−1]υLSR [km s−1] 70 80 13090 100 110 12070 80 13090 100 110 120 W 43 MM-1 CH3OCH3 (?) & CH3CN (?) dominant absorption 0.10 0.05 0.00 4 5 1 2 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) °10 0 10 20 30 40 50 vLSR [km s°1] 0.0 0.5 1.0 dN dv[cm°2 km s°1] £1013 °10 0 10 20 30 40 50 vLSR [km s°1] £1013 HGAL 000.546–00.852 offset absorption υLSR [km s−1] –10 05010 20 30 40 υLSR [km s−1] –10 05010 20 30 40 HGAL 000.545–00.852 CH3OCH3 (?) & CH3CN (?) emission from core Tmb [K] dN dυ[cm−2 km s−1] 1 1.0 0.5 0.0 4 5 2 3 4 6 8 10 Tmb [K] SO+ H35Cl (1°0) H37Cl (1°0) °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] 0 1 2 3 dN dv[cm°2 km s°1] £1013 °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] £1013 IRAS 12326–6245 CH3OCH3 (?) & CH3CN (?) υLSR [km s−1]υLSR [km s−1] –70 –60 –10–50 –40 –30 –20 –70 –60 –10–50 –40 –30 –20 IRAS 12326–6245 outflow SO+ massive outflow emission from core 3 Tmb [K] dN dυ[cm−2 km s−1] 4 2 1 0 6 10 8 The line profiles toward some targets show massive outflows: Some show offset absorption: And some even show dominant absorption: a characteristic zigzag pattern HCl has been detected in 27 massive star-forming regions. ‣The observed emission often traces strong outflows ‣Complex line profiles (emission with absorption) renders modeling the spectral line profiles difficult We find an average chlorine isotopic ratio of [H35Cl]/[H37Cl] = 2.6 ± 0.8. ‣The ratio shows no systemic trend with galactocentric distance. ‣Chlorine isotopic ratios have been observed for the first time in the Galactic center, where they are higher, but still agree with CCSN models (Maas & Pilachowski, 2021). ‣Currently, it remains unclear whether the ratio is higher for targets in the vicinity of SNRs. We plan to analyze the physical and excitation conditions traced by HCl. For this, we are exploring HCl’s spatial distribution, especially in outflows to disentangle both components: ‣Mapping HCl toward IRAS 12326–6245 and its massive outflow RA (J2000) Dec (J2000) [K km s–1] 12h35m42s39s36s33s30s –62°02'00" 03'00" 20" 40" 100 80 60 40 20 work in progress First look at the HCl (1–0) map outflow Photodissociation model predictions for the abundances of chlorine-bearing (and fluorine-bearing) species relative to the elemental abundances across the depths of an interstellar cloud Chlorine-bearing molecules have diagnostic properties due to chlorine’s unique chemistry ‣Most interstellar chlorine is contained in ≤6 species ‣Chlorine is primarily ionized (IPCl = 12.968 eV < IPH) and highly reactive ‣The chemical network is initialized by the exothermic (D0(HCl+) > D0(H2)) reaction Cl+ + H2 → HCl+ Chemical network displaying the most relevant gas-phase formation and destruction pathways for chlorine chemistry in the ISM. Based on Fig. 3, Neufeld et al. (2021) Neufeld & Wolfire (2009) We used XCLASS (Möller, Endres & Schilke, 2017) to model the observed line profiles. XCLASS assumes LTE and optimizes a number of source parameters per component. While we left column density, isotopic ratio and line width open, we constrained ‣the source size, , (verified with ATLASGAL), ‣the rotational temperature, Trot = Tdust, (from ATLASGAL), ‣and the velocity offset, < 1 km s–1, for the core component. - and the number of components have been determined from H13CO (7–6), covered in the lower sideband -or CO isotopologues (Giannetti et al., 2014) θs= 20′ ′ υoff υLSR + predictions for the solar neighborhood from Galactic chemical evolution models (Kobayashi et al., 2011) R1 R2 Affiliations: 1 2 lennart-boehm.de [email protected] ✉ Tracing Chlorine Isotopes Across the Milky Way A Large Scale Survey of Hydrogen Chloride in Star-Forming Regions Arshia M. Jacob2, Friedrich Wyrowski2, Karl M. Menten2, Ashley T. Barnes1, Katharina Immer1 HCl IN ALL TARGETS! Lennart Böhm1,2 Lennart Böhm, ESO IMPRS PhD student SCAN ME! Böhm, L. et al., in prep., Tracing chlorine isotopes across the Milky Way Elia, D. et al. (2021). The Hi-GAL compact source catalogue–II. The 360° catalogue of clump physical properties. MNRAS, 504(2), 2742-2766. Giannetti, A. et al.(2014). ATLASGAL-selected massive clumps in the inner Galaxy-I. CO depletion and isotopic ratios. A&A, 570, A65. Kobayashi, C., Karakas, A. I., & Umeda, H. (2011). The evolution of isotope ratios in the Milky Way Galaxy. MNRAS, 414(4), 3231-3250. Maas, Z. G., & Pilachowski, C. A. (2021). The Galactic Chemical Evolution of Chlorine. AJ, 161(4), 183. Möller, T., Endres, C., & Schilke, P. (2017). eXtended CASA line analysis software suite (XCLASS). A&A, 598, A7. Neufeld, D. A., & Wolfire, M. G. (2009). The chemistry of interstellar molecules containing the halogen elements. ApJ, 706(2), 1594. Neufeld, D. A. et al. (2021). The Chemistry of Chlorine-Bearing Species in the Diffuse Interstellar Medium, and New SOFIA/GREAT* Observations of HCl+. ApJ, 917(2), 104. Reid, M. J. et al. (2019). Trigonometric parallaxes of high-mass star-forming regions: our view of the Milky Way. ApJ, 885(2), 131. References: CHLORINE: PROBING THE ISM SURVEYING HCl WHAT WE STILL DON'T KNOW SCATTERED, NO TREND OUTFLOWS? CONTACT Image credit: apex-telescope.org H2 H2 e hω Cl+ HCl+ Cl H2Cl+ HCl hω e e e Chlorine isotopes probe the nucleosynthesis history of massive star-forming regions and their enrichment of the ISM: ‣35Cl and 37Cl are produced in core-collapse supernovae (CCSNe) and the weak s-process in massive stars (Maas & Pilachowski, 2021) ‣The 35Cl/37Cl ratio in a CCSN varies with factors such as initial mass, metallicity, and explosion properties (Maas & Pilachowski, 2021) ‣Galactic chemical evolution models predict the isotopic ratio to vary with metallicity, hence tracing the nucleosynthesis history of a galaxy (Kobayashi et al. 2010) 28 massive star-forming regions across the Milky Way ‣bright sub-mm continuum sources (Hi-Gal catalogue; Elia et al., 2021) ‣Galactocentric radii between to (Reid et al., 2019) ‣selected from the HyGAL and PRISMAS surveys on hydrides 0.1 kpc 10 kpc and the SEPIA660 receiver •single-pixel, sideband separated heterodyne •native resolution: ‣smoothed to 0.03 km s−1 0.5 km s−1 1. How abundant is HCl across the inner Galaxy? 2. Is there widespread line of sight absorption in the Galactic arms? 3. What physical and excitation conditions does HCl trace? 4. Are variations of the 35Cl/37Cl ratio a localized phenomenon, or does a galactic trend exist? ‣Is the isotopic ratio linked to supernova remnants? APEX 12m sub-mm telescope at 5104 m, Llano de Chajnantor HPBW: 10.1′ ′ HCl 37 HCl 35 covers 2 x 7.9 GHz atmospheric H O absorption! 2 typical weather conditions of our observations Figure Credit: Neufeld & Wolfire (2009) Dashed lines: 10 times higher CR ionization rate deeper surface HCl traces dense cores Chemical evolution across the depths of a cloud HCl and to some degree translucent gas 0 –2 Av [mag] –4 log (abundance/elemental) –6 0 2 4 6 8 10 A typical HCl line profile in our sample consists of 1. a narrow core component 2. a broad, often offset outflow component 70 80 130 0.00 0.25 1.00 2 3 4 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.25 0.50 0.75 1.00 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 G029.954–00.016 Tmb [K] dN dυ[cm−2 km s−1] υLSR [km s−1] CH3OCH3 (?) & CH3CN (?) outflow wing outflow wing υLSR [km s−1] υsys theoretical HFS line intensity 624.977821 GHz625.918756 GHz 2 4 3 G029.954–00.016 0.50 0.75 90 100 110 120 70 80 13090 100 110 120 APEX 12m sub-mm telescope hyperfine structure (HFS) deconvolved column density profile In summary, 11 of the 28 targeted sources showed only emission line profiles (including one tentative detection). 17 had one or more additional absorption components, often rendering analyses difficult. From these observations, we could derive the isotopic ratio in two ways: from the XCLASS line profile models, incl. sources with well separated, or no absorption components from the integrated intensity ratio, where we cut out contaminants and have to discard sources with absorption line profile modeled with XCLASS 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.05 0.10 0.15 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 W43 MM1 0.15 Tmb [K] dN dυ[cm−2 km s−1] 3 υLSR [km s−1]υLSR [km s−1] 70 80 13090 100 110 12070 80 13090 100 110 120 W 43 MM-1 CH3OCH3 (?) & CH3CN (?) dominant absorption 0.10 0.05 0.00 4 5 1 2 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) °10 0 10 20 30 40 50 vLSR [km s°1] 0.0 0.5 1.0 dN dv[cm°2 km s°1] £1013 °10 0 10 20 30 40 50 vLSR [km s°1] £1013 HGAL 000.546–00.852 offset absorption υLSR [km s−1] –10 05010 20 30 40 υLSR [km s−1] –10 05010 20 30 40 HGAL 000.545–00.852 CH3OCH3 (?) & CH3CN (?) emission from core Tmb [K] dN dυ[cm−2 km s−1] 1 1.0 0.5 0.0 4 5 2 3 4 6 8 10 Tmb [K] SO+ H35Cl (1°0) H37Cl (1°0) °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] 0 1 2 3 dN dv[cm°2 km s°1] £1013 °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] £1013 IRAS 12326–6245 CH3OCH3 (?) & CH3CN (?) υLSR [km s−1]υLSR [km s−1] –70 –60 –10–50 –40 –30 –20 –70 –60 –10–50 –40 –30 –20 IRAS 12326–6245 outflow SO+ massive outflow emission from core 3 Tmb [K] dN dυ[cm−2 km s−1] 4 2 1 0 6 10 8 The line profiles toward some targets show massive outflows: Some show offset absorption: And some even show dominant absorption: a characteristic zigzag pattern HCl has been detected in 27 massive star-forming regions. ‣The observed emission often traces strong outflows ‣Complex line profiles (emission with absorption) renders modeling the spectral line profiles difficult We find an average chlorine isotopic ratio of [H35Cl]/[H37Cl] = 2.6 ± 0.8. ‣The ratio shows no systemic trend with galactocentric distance. ‣Chlorine isotopic ratios have been observed for the first time in the Galactic center, where they are higher, but still agree with CCSN models (Maas & Pilachowski, 2021). ‣Currently, it remains unclear whether the ratio is higher for targets in the vicinity of SNRs. We plan to analyze the physical and excitation conditions traced by HCl. For this, we are exploring HCl’s spatial distribution, especially in outflows to disentangle both components: ‣Mapping HCl toward IRAS 12326–6245 and its massive outflow RA (J2000) Dec (J2000) [K km s–1] 12h35m42s39s36s33s30s –62°02'00" 03'00" 20" 40" 100 80 60 40 20 work in progress First look at the HCl (1–0) map outflow Photodissociation model predictions for the abundances of chlorine-bearing (and fluorine-bearing) species relative to the elemental abundances across the depths of an interstellar cloud Chlorine-bearing molecules have diagnostic properties due to chlorine’s unique chemistry ‣Most interstellar chlorine is contained in ≤6 species ‣Chlorine is primarily ionized (IPCl = 12.968 eV < IPH) and highly reactive ‣The chemical network is initialized by the exothermic (D0(HCl+) > D0(H2)) reaction Cl+ + H2 → HCl+ Chemical network displaying the most relevant gas-phase formation and destruction pathways for chlorine chemistry in the ISM. Based on Fig. 3, Neufeld et al. (2021) Neufeld & Wolfire (2009) We used XCLASS (Möller, Endres & Schilke, 2017) to model the observed line profiles. XCLASS assumes LTE and optimizes a number of source parameters per component. While we left column density, isotopic ratio and line width open, we constrained ‣the source size, , (verified with ATLASGAL), ‣the rotational temperature, Trot = Tdust, (from ATLASGAL), ‣and the velocity offset, < 1 km s–1, for the core component. - and the number of components have been determined from H13CO (7–6), covered in the lower sideband -or CO isotopologues (Giannetti et al., 2014) θs= 20′ ′ υoff υLSR + predictions for the solar neighborhood from Galactic chemical evolution models (Kobayashi et al., 2011) R1 R2 Affiliations: 1 2 lennart-boehm.de [email protected] ✉ Tracing Chlorine Isotopes Across the Milky Way A Large Scale Survey of Hydrogen Chloride in Star-Forming Regions Arshia M. Jacob2, Friedrich Wyrowski2, Karl M. Menten2, Ashley T. Barnes1, Katharina Immer1 HCl IN ALL TARGETS! Lennart Böhm1,2 Lennart Böhm, ESO IMPRS PhD student SCAN ME! Böhm, L. et al., in prep., Tracing chlorine isotopes across the Milky Way Elia, D. et al. (2021). The Hi-GAL compact source catalogue–II. The 360° catalogue of clump physical properties. MNRAS, 504(2), 2742-2766. Giannetti, A. et al.(2014). ATLASGAL-selected massive clumps in the inner Galaxy-I. CO depletion and isotopic ratios. A&A, 570, A65. Kobayashi, C., Karakas, A. I., & Umeda, H. (2011). The evolution of isotope ratios in the Milky Way Galaxy. MNRAS, 414(4), 3231-3250. Maas, Z. G., & Pilachowski, C. A. (2021). The Galactic Chemical Evolution of Chlorine. AJ, 161(4), 183. Möller, T., Endres, C., & Schilke, P. (2017). eXtended CASA line analysis software suite (XCLASS). A&A, 598, A7. Neufeld, D. A., & Wolfire, M. G. (2009). The chemistry of interstellar molecules containing the halogen elements. ApJ, 706(2), 1594. Neufeld, D. A. et al. (2021). The Chemistry of Chlorine-Bearing Species in the Diffuse Interstellar Medium, and New SOFIA/GREAT* Observations of HCl+. ApJ, 917(2), 104. Reid, M. J. et al. (2019). Trigonometric parallaxes of high-mass star-forming regions: our view of the Milky Way. ApJ, 885(2), 131. References: CHLORINE: PROBING THE ISM SURVEYING HCl WHAT WE STILL DON'T KNOW SCATTERED, NO TREND OUTFLOWS? CONTACT Image credit: apex-telescope.org H2 H2 e hω Cl+ HCl+ Cl H2Cl+ HCl hω e e e Chlorine isotopes probe the nucleosynthesis history of massive star-forming regions and their enrichment of the ISM: ‣35Cl and 37Cl are produced in core-collapse supernovae (CCSNe) and the weak s-process in massive stars (Maas & Pilachowski, 2021) ‣The 35Cl/37Cl ratio in a CCSN varies with factors such as initial mass, metallicity, and explosion properties (Maas & Pilachowski, 2021) ‣Galactic chemical evolution models predict the isotopic ratio to vary with metallicity, hence tracing the nucleosynthesis history of a galaxy (Kobayashi et al. 2010) 28 massive star-forming regions across the Milky Way ‣bright sub-mm continuum sources (Hi-Gal catalogue; Elia et al., 2021) ‣Galactocentric radii between to (Reid et al., 2019) ‣selected from the HyGAL and PRISMAS surveys on hydrides 0.1 kpc 10 kpc and the SEPIA660 receiver •single-pixel, sideband separated heterodyne •native resolution: ‣smoothed to 0.03 km s−1 0.5 km s−1 1. How abundant is HCl across the inner Galaxy? 2. Is there widespread line of sight absorption in the Galactic arms? 3. What physical and excitation conditions does HCl trace? 4. Are variations of the 35Cl/37Cl ratio a localized phenomenon, or does a galactic trend exist? ‣Is the isotopic ratio linked to supernova remnants? APEX 12m sub-mm telescope at 5104 m, Llano de Chajnantor HPBW: 10.1′ ′ HCl 37 HCl 35 covers 2 x 7.9 GHz atmospheric H O absorption! 2 typical weather conditions of our observations Figure Credit: Neufeld & Wolfire (2009) Dashed lines: 10 times higher CR ionization rate deeper surface HCl traces dense cores Chemical evolution across the depths of a cloud HCl and to some degree translucent gas 0 –2 Av [mag] –4 log (abundance/elemental) –6 0 2 4 6 8 10 A typical HCl line profile in our sample consists of 1. a narrow core component 2. a broad, often offset outflow component 70 80 130 0.00 0.25 1.00 2 3 4 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.25 0.50 0.75 1.00 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 G029.954–00.016 Tmb [K] dN dυ[cm−2 km s−1] υLSR [km s−1] CH3OCH3 (?) & CH3CN (?) outflow wing outflow wing υLSR [km s−1] υsys theoretical HFS line intensity 624.977821 GHz625.918756 GHz 2 4 3 G029.954–00.016 0.50 0.75 90 100 110 120 70 80 13090 100 110 120 APEX 12m sub-mm telescope hyperfine structure (HFS) deconvolved column density profile In summary, 11 of the 28 targeted sources showed only emission line profiles (including one tentative detection). 17 had one or more additional absorption components, often rendering analyses difficult. From these observations, we could derive the isotopic ratio in two ways: from the XCLASS line profile models, incl. sources with well separated, or no absorption components from the integrated intensity ratio, where we cut out contaminants and have to discard sources with absorption line profile modeled with XCLASS 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.05 0.10 0.15 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 W43 MM1 0.15 Tmb [K] dN dυ[cm−2 km s−1] 3 υLSR [km s−1] υLSR [km s−1] 70 80 130 90 100 110 120 70 80 130 90 100 110 120 W 43 MM-1 CH3OCH3 (?) & CH3CN (?) dominant absorption 0.10 0.05 0.00 4 5 1 2 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) °10 0 10 20 30 40 50 vLSR [km s°1] 0.0 0.5 1.0 dN dv[cm°2 km s°1] £1013 °10 0 10 20 30 40 50 vLSR [km s°1] £1013 HGAL 000.546–00.852 offset absorption υLSR [km s−1] –10 0 50 10 20 30 40 υLSR [km s−1] –10 0 50 10 20 30 40 HGAL 000.545–00.852 CH3OCH3 (?) & CH3CN (?) emission from core Tmb [K] dN dυ[cm−2 km s−1] 1 1.0 0.5 0.0 4 5 2 3 4 6 8 10 Tmb [K] SO+ H35Cl (1°0) H37Cl (1°0) °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] 0 1 2 3 dN dv[cm°2 km s°1] £1013 °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] £1013 IRAS 12326–6245 CH3OCH3 (?) & CH3CN (?) υLSR [km s−1] υLSR [km s−1] –70 –60 –10 –50 –40 –30 –20 –70 –60 –10 –50 –40 –30 –20 IRAS 12326–6245 outflow SO + massive outflow emission from core 3 Tmb [K] dN dυ[cm−2 km s−1] 4 2 1 0 6 10 8 The line profiles toward some targets show massive outflows: Some show offset absorption: And some even show dominant absorption: a characteristic zigzag pattern HCl has been detected in 27 massive star-forming regions. ‣The observed emission often traces strong outflows ‣Complex line profiles (emission with absorption) renders modeling the spectral line profiles difficult We find an average chlorine isotopic ratio of [H35Cl]/[H37Cl] = 2.6 ± 0.8. ‣The ratio shows no systemic trend with galactocentric distance. ‣Chlorine isotopic ratios have been observed for the first time in the Galactic center, where they are higher, but still agree with CCSN models (Maas & Pilachowski, 2021). ‣Currently, it remains unclear whether the ratio is higher for targets in the vicinity of SNRs. We plan to analyze the physical and excitation conditions traced by HCl. For this, we are exploring HCl’s spatial distribution, especially in outflows to disentangle both components: ‣Mapping HCl toward IRAS 12326–6245 and its massive outflow RA (J2000) Dec (J2000) [K km s–1] 12h35m42s39s36s33s30s –62°02'00" 03'00" 20" 40" 100 80 60 40 20 work in progress First look at the HCl (1–0) map outflow Photodissociation model predictions for the abundances of chlorine-bearing (and fluorine-bearing) species relative to the elemental abundances across the depths of an interstellar cloud Chlorine-bearing molecules have diagnostic properties due to chlorine’s unique chemistry ‣Most interstellar chlorine is contained in ≤6 species ‣Chlorine is primarily ionized (IPCl = 12.968 eV < IPH) and highly reactive ‣The chemical network is initialized by the exothermic (D0(HCl+) > D0(H2)) reaction Cl+ + H2 → HCl+ Chemical network displaying the most relevant gas-phase formation and destruction pathways for chlorine chemistry in the ISM. Based on Fig. 3, Neufeld et al. (2021) Neufeld & Wolfire (2009) We used XCLASS (Möller, Endres & Schilke, 2017) to model the observed line profiles. XCLASS assumes LTE and optimizes a number of source parameters per component. While we left column density, isotopic ratio and line width open, we constrained ‣the source size, , (verified with ATLASGAL), ‣the rotational temperature, Trot = Tdust, (from ATLASGAL), ‣and the velocity offset, < 1 km s–1, for the core component. - and the number of components have been determined from H13CO (7–6), covered in the lower sideband -or CO isotopologues (Giannetti et al., 2014) θs= 20′ ′ υoff υLSR + predictions for the solar neighborhood from Galactic chemical evolution models (Kobayashi et al., 2011) R1 R2 Affiliations: 1 2 lennart-boehm.de [email protected] ✉ Tracing Chlorine Isotopes Across the Milky Way A Large Scale Survey of Hydrogen Chloride in Star-Forming Regions Arshia M. Jacob2, Friedrich Wyrowski2, Karl M. Menten2, Ashley T. Barnes1, Katharina Immer1 HCl IN ALL TARGETS! Lennart Böhm1,2 Lennart Böhm, ESO IMPRS PhD student SCAN ME! Böhm, L. et al., in prep., Tracing chlorine isotopes across the Milky Way Elia, D. et al. (2021). The Hi-GAL compact source catalogue–II. The 360° catalogue of clump physical properties. MNRAS, 504(2), 2742-2766. Giannetti, A. et al.(2014). ATLASGAL-selected massive clumps in the inner Galaxy-I. CO depletion and isotopic ratios. A&A, 570, A65. Kobayashi, C., Karakas, A. I., & Umeda, H. (2011). The evolution of isotope ratios in the Milky Way Galaxy. MNRAS, 414(4), 3231-3250. Maas, Z. G., & Pilachowski, C. A. (2021). The Galactic Chemical Evolution of Chlorine. AJ, 161(4), 183. Möller, T., Endres, C., & Schilke, P. (2017). eXtended CASA line analysis software suite (XCLASS). A&A, 598, A7. Neufeld, D. A., & Wolfire, M. G. (2009). The chemistry of interstellar molecules containing the halogen elements. ApJ, 706(2), 1594. Neufeld, D. A. et al. (2021). The Chemistry of Chlorine-Bearing Species in the Diffuse Interstellar Medium, and New SOFIA/GREAT* Observations of HCl+. ApJ, 917(2), 104. Reid, M. J. et al. (2019). Trigonometric parallaxes of high-mass star-forming regions: our view of the Milky Way. ApJ, 885(2), 131. References: CHLORINE: PROBING THE ISM SURVEYING HCl WHAT WE STILL DON'T KNOW SCATTERED, NO TREND OUTFLOWS? CONTACT Image credit: apex-telescope.org H2 H2 e hω Cl+ HCl+ Cl H2Cl+ HCl hω e e e Chlorine isotopes probe the nucleosynthesis history of massive star-forming regions and their enrichment of the ISM: ‣35Cl and 37Cl are produced in core-collapse supernovae (CCSNe) and the weak s-process in massive stars (Maas & Pilachowski, 2021) ‣The 35Cl/37Cl ratio in a CCSN varies with factors such as initial mass, metallicity, and explosion properties (Maas & Pilachowski, 2021) ‣Galactic chemical evolution models predict the isotopic ratio to vary with metallicity, hence tracing the nucleosynthesis history of a galaxy (Kobayashi et al. 2010) 28 massive star-forming regions across the Milky Way ‣bright sub-mm continuum sources (Hi-Gal catalogue; Elia et al., 2021) ‣Galactocentric radii between to (Reid et al., 2019) ‣selected from the HyGAL and PRISMAS surveys on hydrides 0.1 kpc 10 kpc and the SEPIA660 receiver •single-pixel, sideband separated heterodyne •native resolution: ‣smoothed to 0.03 km s−1 0.5 km s−1 1. How abundant is HCl across the inner Galaxy? 2. Is there widespread line of sight absorption in the Galactic arms? 3. What physical and excitation conditions does HCl trace? 4. Are variations of the 35Cl/37Cl ratio a localized phenomenon, or does a galactic trend exist? ‣Is the isotopic ratio linked to supernova remnants? APEX 12m sub-mm telescope at 5104 m, Llano de Chajnantor HPBW: 10.1′ ′ HCl 37 HCl 35 covers 2 x 7.9 GHz atmospheric H O absorption! 2 typical weather conditions of our observations Figure Credit: Neufeld & Wolfire (2009) Dashed lines: 10 times higher CR ionization rate deeper surface HCl traces dense cores Chemical evolution across the depths of a cloud HCl and to some degree translucent gas 0 –2 Av [mag] –4 log (abundance/elemental) –6 0 2 4 6 8 10 A typical HCl line profile in our sample consists of 1. a narrow core component 2. a broad, often offset outflow component 70 80 130 0.00 0.25 1.00 2 3 4 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.25 0.50 0.75 1.00 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 G029.954–00.016 Tmb [K] dN dυ[cm−2 km s−1] υLSR [km s−1] CH3OCH3 (?) & CH3CN (?) outflow wing outflow wing υLSR [km s−1] υsys theoretical HFS line intensity 624.977821 GHz625.918756 GHz 2 4 3 G029.954–00.016 0.50 0.75 90 100 110 120 70 80 13090 100 110 120 APEX 12m sub-mm telescope hyperfine structure (HFS) deconvolved column density profile In summary, 11 of the 28 targeted sources showed only emission line profiles (including one tentative detection). 17 had one or more additional absorption components, often rendering analyses difficult. From these observations, we could derive the isotopic ratio in two ways: from the XCLASS line profile models, incl. sources with well separated, or no absorption components from the integrated intensity ratio, where we cut out contaminants and have to discard sources with absorption line profile modeled with XCLASS 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.05 0.10 0.15 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 W43 MM1 0.15 Tmb [K] dN dυ[cm−2 km s−1] 3 υLSR [km s−1] υLSR [km s−1] 70 80 130 90 100 110 120 70 80 130 90 100 110 120 W 43 MM-1 CH3OCH3 (?) & CH3CN (?) dominant absorption 0.10 0.05 0.00 4 5 1 2 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) °10 0 10 20 30 40 50 vLSR [km s°1] 0.0 0.5 1.0 dN dv[cm°2 km s°1] £1013 °10 0 10 20 30 40 50 vLSR [km s°1] £1013 HGAL 000.546–00.852 offset absorption υLSR [km s−1] –10 0 50 10 20 30 40 υLSR [km s−1] –10 0 50 10 20 30 40 HGAL 000.545–00.852 CH3OCH3 (?) & CH3CN (?) emission from core Tmb [K] dN dυ[cm−2 km s−1] 1 1.0 0.5 0.0 4 5 2 3 4 6 8 10 Tmb [K] SO+ H35Cl (1°0) H37Cl (1°0) °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] 0 1 2 3 dN dv[cm°2 km s°1] £1013 °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] £1013 IRAS 12326–6245 CH3OCH3 (?) & CH3CN (?) υLSR [km s−1] υLSR [km s−1] –70 –60 –10 –50 –40 –30 –20 –70 –60 –10 –50 –40 –30 –20 IRAS 12326–6245 outflow SO + massive outflow emission from core 3 Tmb [K] dN dυ[cm−2 km s−1] 4 2 1 0 6 10 8 The line profiles toward some targets show massive outflows: Some show offset absorption: And some even show dominant absorption: a characteristic zigzag pattern HCl has been detected in 27 massive star-forming regions. ‣The observed emission often traces strong outflows ‣Complex line profiles (emission with absorption) renders modeling the spectral line profiles difficult We find an average chlorine isotopic ratio of [H35Cl]/[H37Cl] = 2.6 ± 0.8. ‣The ratio shows no systemic trend with galactocentric distance. ‣Chlorine isotopic ratios have been observed for the first time in the Galactic center, where they are higher, but still agree with CCSN models (Maas & Pilachowski, 2021). ‣Currently, it remains unclear whether the ratio is higher for targets in the vicinity of SNRs. We plan to analyze the physical and excitation conditions traced by HCl. For this, we are exploring HCl’s spatial distribution, especially in outflows to disentangle both components: ‣Mapping HCl toward IRAS 12326–6245 and its massive outflow RA (J2000) Dec (J2000) [K km s–1] 12h35m42s39s36s33s30s –62°02'00" 03'00" 20" 40" 100 80 60 40 20 work in progress First look at the HCl (1–0) map outflow Photodissociation model predictions for the abundances of chlorine-bearing (and fluorine-bearing) species relative to the elemental abundances across the depths of an interstellar cloud Chlorine-bearing molecules have diagnostic properties due to chlorine’s unique chemistry ‣Most interstellar chlorine is contained in ≤6 species ‣Chlorine is primarily ionized (IPCl = 12.968 eV < IPH) and highly reactive ‣The chemical network is initialized by the exothermic (D0(HCl+) > D0(H2)) reaction Cl+ + H2 → HCl+ Chemical network displaying the most relevant gas-phase formation and destruction pathways for chlorine chemistry in the ISM. Based on Fig. 3, Neufeld et al. (2021) Neufeld & Wolfire (2009) We used XCLASS (Möller, Endres & Schilke, 2017) to model the observed line profiles. XCLASS assumes LTE and optimizes a number of source parameters per component. While we left column density, isotopic ratio and line width open, we constrained ‣the source size, , (verified with ATLASGAL), ‣the rotational temperature, Trot = Tdust, (from ATLASGAL), ‣and the velocity offset, < 1 km s–1, for the core component. - and the number of components have been determined from H13CO (7–6), covered in the lower sideband -or CO isotopologues (Giannetti et al., 2014) θs= 20′ ′ υoff υLSR + predictions for the solar neighborhood from Galactic chemical evolution models (Kobayashi et al., 2011) R1 R2 Affiliations: 1 2 lennart-boehm.de [email protected] ✉ Tracing Chlorine Isotopes Across the Milky Way A Large Scale Survey of Hydrogen Chloride in Star-Forming Regions Arshia M. Jacob2, Friedrich Wyrowski2, Karl M. Menten2, Ashley T. Barnes1, Katharina Immer1 HCl IN ALL TARGETS! Lennart Böhm1,2 Lennart Böhm, ESO IMPRS PhD student SCAN ME! Böhm, L. et al., in prep., Tracing chlorine isotopes across the Milky Way Elia, D. et al. (2021). The Hi-GAL compact source catalogue–II. The 360° catalogue of clump physical properties. MNRAS, 504(2), 2742-2766. Giannetti, A. et al.(2014). ATLASGAL-selected massive clumps in the inner Galaxy-I. CO depletion and isotopic ratios. A&A, 570, A65. Kobayashi, C., Karakas, A. I., & Umeda, H. (2011). The evolution of isotope ratios in the Milky Way Galaxy. MNRAS, 414(4), 3231-3250. Maas, Z. G., & Pilachowski, C. A. (2021). The Galactic Chemical Evolution of Chlorine. AJ, 161(4), 183. Möller, T., Endres, C., & Schilke, P. (2017). eXtended CASA line analysis software suite (XCLASS). A&A, 598, A7. Neufeld, D. A., & Wolfire, M. G. (2009). The chemistry of interstellar molecules containing the halogen elements. ApJ, 706(2), 1594. Neufeld, D. A. et al. (2021). The Chemistry of Chlorine-Bearing Species in the Diffuse Interstellar Medium, and New SOFIA/GREAT* Observations of HCl+. ApJ, 917(2), 104. Reid, M. J. et al. (2019). Trigonometric parallaxes of high-mass star-forming regions: our view of the Milky Way. ApJ, 885(2), 131. References: CHLORINE: PROBING THE ISM SURVEYING HCl WHAT WE STILL DON'T KNOW SCATTERED, NO TREND OUTFLOWS? CONTACT Image credit: apex-telescope.org H2 H2 e hω Cl+ HCl+ Cl H2Cl+ HCl hω e e e Chlorine isotopes probe the nucleosynthesis history of massive star-forming regions and their enrichment of the ISM: ‣35Cl and 37Cl are produced in core-collapse supernovae (CCSNe) and the weak s-process in massive stars (Maas & Pilachowski, 2021) ‣The 35Cl/37Cl ratio in a CCSN varies with factors such as initial mass, metallicity, and explosion properties (Maas & Pilachowski, 2021) ‣Galactic chemical evolution models predict the isotopic ratio to vary with metallicity, hence tracing the nucleosynthesis history of a galaxy (Kobayashi et al. 2010) 28 massive star-forming regions across the Milky Way ‣bright sub-mm continuum sources (Hi-Gal catalogue; Elia et al., 2021) ‣Galactocentric radii between to (Reid et al., 2019) ‣selected from the HyGAL and PRISMAS surveys on hydrides 0.1 kpc 10 kpc and the SEPIA660 receiver •single-pixel, sideband separated heterodyne •native resolution: ‣smoothed to 0.03 km s−1 0.5 km s−1 1. How abundant is HCl across the inner Galaxy? 2. Is there widespread line of sight absorption in the Galactic arms? 3. What physical and excitation conditions does HCl trace? 4. Are variations of the 35Cl/37Cl ratio a localized phenomenon, or does a galactic trend exist? ‣Is the isotopic ratio linked to supernova remnants? APEX 12m sub-mm telescope at 5104 m, Llano de Chajnantor HPBW: 10.1′ ′ HCl 37 HCl 35 covers 2 x 7.9 GHz atmospheric H O absorption! 2 typical weather conditions of our observations Figure Credit: Neufeld & Wolfire (2009) Dashed lines: 10 times higher CR ionization rate deeper surface HCl traces dense cores Chemical evolution across the depths of a cloud HCl and to some degree translucent gas 0 –2 Av [mag] –4 log (abundance/elemental) –6 0 2 4 6 8 10 A typical HCl line profile in our sample consists of 1. a narrow core component 2. a broad, often offset outflow component 70 80 130 0.00 0.25 1.00 2 3 4 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.25 0.50 0.75 1.00 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 G029.954–00.016 Tmb [K] dN dυ[cm−2 km s−1] υLSR [km s−1] CH3OCH3 (?) & CH3CN (?) outflow wing outflow wing υLSR [km s−1] υsys theoretical HFS line intensity 624.977821 GHz625.918756 GHz 2 4 3 G029.954–00.016 0.50 0.75 90 100 110 120 70 80 13090 100 110 120 APEX 12m sub-mm telescope hyperfine structure (HFS) deconvolved column density profile In summary, 11 of the 28 targeted sources showed only emission line profiles (including one tentative detection). 17 had one or more additional absorption components, often rendering analyses difficult. From these observations, we could derive the isotopic ratio in two ways: from the XCLASS line profile models, incl. sources with well separated, or no absorption components from the integrated intensity ratio, where we cut out contaminants and have to discard sources with absorption line profile modeled with XCLASS 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.05 0.10 0.15 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 W43 MM1 0.15 Tmb [K] dN dυ[cm−2 km s−1] 3 υLSR [km s−1] υLSR [km s−1] 70 80 130 90 100 110 120 70 80 130 90 100 110 120 W 43 MM-1 CH3OCH3 (?) & CH3CN (?) dominant absorption 0.10 0.05 0.00 4 5 1 2 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) °10 0 10 20 30 40 50 vLSR [km s°1] 0.0 0.5 1.0 dN dv[cm°2 km s°1] £1013 °10 0 10 20 30 40 50 vLSR [km s°1] £1013 HGAL 000.546–00.852 offset absorption υLSR [km s−1] –10 0 50 10 20 30 40 υLSR [km s−1] –10 0 50 10 20 30 40 HGAL 000.545–00.852 CH3OCH3 (?) & CH3CN (?) emission from core Tmb [K] dN dυ[cm−2 km s−1] 1 1.0 0.5 0.0 4 5 2 3 4 6 8 10 Tmb [K] SO+ H35Cl (1°0) H37Cl (1°0) °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] 0 1 2 3 dN dv[cm°2 km s°1] £1013 °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] £1013 IRAS 12326–6245 CH3OCH3 (?) & CH3CN (?) υLSR [km s−1] υLSR [km s−1] –70 –60 –10 –50 –40 –30 –20 –70 –60 –10 –50 –40 –30 –20 IRAS 12326–6245 outflow SO + massive outflow emission from core 3 Tmb [K] dN dυ[cm−2 km s−1] 4 2 1 0 6 10 8 The line profiles toward some targets show massive outflows: Some show offset absorption: And some even show dominant absorption: a characteristic zigzag pattern HCl has been detected in 27 massive star-forming regions. ‣The observed emission often traces strong outflows ‣Complex line profiles (emission with absorption) renders modeling the spectral line profiles difficult We find an average chlorine isotopic ratio of [H35Cl]/[H37Cl] = 2.6 ± 0.8. ‣The ratio shows no systemic trend with galactocentric distance. ‣Chlorine isotopic ratios have been observed for the first time in the Galactic center, where they are higher, but still agree with CCSN models (Maas & Pilachowski, 2021). ‣Currently, it remains unclear whether the ratio is higher for targets in the vicinity of SNRs. We plan to analyze the physical and excitation conditions traced by HCl. For this, we are exploring HCl’s spatial distribution, especially in outflows to disentangle both components: ‣Mapping HCl toward IRAS 12326–6245 and its massive outflow RA (J2000) Dec (J2000) [K km s–1] 12h35m42s39s36s33s30s –62°02'00" 03'00" 20" 40" 100 80 60 40 20 work in progress First look at the HCl (1–0) map outflow Photodissociation model predictions for the abundances of chlorine-bearing (and fluorine-bearing) species relative to the elemental abundances across the depths of an interstellar cloud Chlorine-bearing molecules have diagnostic properties due to chlorine’s unique chemistry ‣Most interstellar chlorine is contained in ≤6 species ‣Chlorine is primarily ionized (IPCl = 12.968 eV < IPH) and highly reactive ‣The chemical network is initialized by the exothermic (D0(HCl+) > D0(H2)) reaction Cl+ + H2 → HCl+ Chemical network displaying the most relevant gas-phase formation and destruction pathways for chlorine chemistry in the ISM. Based on Fig. 3, Neufeld et al. (2021) Neufeld & Wolfire (2009) We used XCLASS (Möller, Endres & Schilke, 2017) to model the observed line profiles. XCLASS assumes LTE and optimizes a number of source parameters per component. While we left column density, isotopic ratio and line width open, we constrained ‣the source size, , (verified with ATLASGAL), ‣the rotational temperature, Trot = Tdust, (from ATLASGAL), ‣and the velocity offset, < 1 km s–1, for the core component. - and the number of components have been determined from H13CO (7–6), covered in the lower sideband -or CO isotopologues (Giannetti et al., 2014) θs= 20′ ′ υoff υLSR + predictions for the solar neighborhood from Galactic chemical evolution models (Kobayashi et al., 2011) R1 R2 Affiliations: 1 2 lennart-boehm.de [email protected] ✉ Tracing Chlorine Isotopes Across the Milky Way A Large Scale Survey of Hydrogen Chloride in Star-Forming Regions Arshia M. Jacob2, Friedrich Wyrowski2, Karl M. Menten2, Ashley T. Barnes1, Katharina Immer1 HCl IN ALL TARGETS! Lennart Böhm1,2 Lennart Böhm, ESO IMPRS PhD student SCAN ME! Böhm, L. et al., in prep., Tracing chlorine isotopes across the Milky Way Elia, D. et al. (2021). The Hi-GAL compact source catalogue–II. The 360° catalogue of clump physical properties. MNRAS, 504(2), 2742-2766. Giannetti, A. et al.(2014). ATLASGAL-selected massive clumps in the inner Galaxy-I. CO depletion and isotopic ratios. A&A, 570, A65. Kobayashi, C., Karakas, A. I., & Umeda, H. (2011). The evolution of isotope ratios in the Milky Way Galaxy. MNRAS, 414(4), 3231-3250. Maas, Z. G., & Pilachowski, C. A. (2021). The Galactic Chemical Evolution of Chlorine. AJ, 161(4), 183. Möller, T., Endres, C., & Schilke, P. (2017). eXtended CASA line analysis software suite (XCLASS). A&A, 598, A7. Neufeld, D. A., & Wolfire, M. G. (2009). The chemistry of interstellar molecules containing the halogen elements. ApJ, 706(2), 1594. Neufeld, D. A. et al. (2021). The Chemistry of Chlorine-Bearing Species in the Diffuse Interstellar Medium, and New SOFIA/GREAT* Observations of HCl+. ApJ, 917(2), 104. Reid, M. J. et al. (2019). Trigonometric parallaxes of high-mass star-forming regions: our view of the Milky Way. ApJ, 885(2), 131. References: CHLORINE: PROBING THE ISM SURVEYING HCl WHAT WE STILL DON'T KNOW SCATTERED, NO TREND OUTFLOWS? CONTACT Image credit: apex-telescope.org H2 H2 e hω Cl+ HCl+ Cl H2Cl+ HCl hω e e e Chlorine isotopes probe the nucleosynthesis history of massive star-forming regions and their enrichment of the ISM: ‣35Cl and 37Cl are produced in core-collapse supernovae (CCSNe) and the weak s-process in massive stars (Maas & Pilachowski, 2021) ‣The 35Cl/37Cl ratio in a CCSN varies with factors such as initial mass, metallicity, and explosion properties (Maas & Pilachowski, 2021) ‣Galactic chemical evolution models predict the isotopic ratio to vary with metallicity, hence tracing the nucleosynthesis history of a galaxy (Kobayashi et al. 2010) 28 massive star-forming regions across the Milky Way ‣bright sub-mm continuum sources (Hi-Gal catalogue; Elia et al., 2021) ‣Galactocentric radii between to (Reid et al., 2019) ‣selected from the HyGAL and PRISMAS surveys on hydrides 0.1 kpc 10 kpc and the SEPIA660 receiver •single-pixel, sideband separated heterodyne •native resolution: ‣smoothed to 0.03 km s−1 0.5 km s−1 1. How abundant is HCl across the inner Galaxy? 2. Is there widespread line of sight absorption in the Galactic arms? 3. What physical and excitation conditions does HCl trace? 4. Are variations of the 35Cl/37Cl ratio a localized phenomenon, or does a galactic trend exist? ‣Is the isotopic ratio linked to supernova remnants? APEX 12m sub-mm telescope at 5104 m, Llano de Chajnantor HPBW: 10.1′ ′ HCl 37 HCl 35 covers 2 x 7.9 GHz atmospheric H O absorption! 2 typical weather conditions of our observations Figure Credit: Neufeld & Wolfire (2009) Dashed lines: 10 times higher CR ionization rate deeper surface HCl traces dense cores Chemical evolution across the depths of a cloud HCl and to some degree translucent gas 0 –2 Av [mag] –4 log (abundance/elemental) –6 0 2 4 6 8 10 A typical HCl line profile in our sample consists of 1. a narrow core component 2. a broad, often offset outflow component 70 80 130 0.00 0.25 1.00 2 3 4 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.25 0.50 0.75 1.00 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 G029.954–00.016 Tmb [K] dN dυ[cm−2 km s−1] υLSR [km s−1] CH3OCH3 (?) & CH3CN (?) outflow wing outflow wing υLSR [km s−1] υsys theoretical HFS line intensity 624.977821 GHz625.918756 GHz 2 4 3 G029.954–00.016 0.50 0.75 90 100 110 120 70 80 13090 100 110 120 APEX 12m sub-mm telescope hyperfine structure (HFS) deconvolved column density profile In summary, 11 of the 28 targeted sources showed only emission line profiles (including one tentative detection). 17 had one or more additional absorption components, often rendering analyses difficult. From these observations, we could derive the isotopic ratio in two ways: from the XCLASS line profile models, incl. sources with well separated, or no absorption components from the integrated intensity ratio, where we cut out contaminants and have to discard sources with absorption line profile modeled with XCLASS 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.05 0.10 0.15 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 W43 MM1 0.15 Tmb [K] dN dυ[cm−2 km s−1] 3 υLSR [km s−1] υLSR [km s−1] 70 80 130 90 100 110 120 70 80 130 90 100 110 120 W 43 MM-1 CH3OCH3 (?) & CH3CN (?) dominant absorption 0.10 0.05 0.00 4 5 1 2 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) °10 0 10 20 30 40 50 vLSR [km s°1] 0.0 0.5 1.0 dN dv[cm°2 km s°1] £1013 °10 0 10 20 30 40 50 vLSR [km s°1] £1013 HGAL 000.546–00.852 offset absorption υLSR [km s−1] –10 05010 20 30 40 υLSR [km s−1] –10 05010 20 30 40 HGAL 000.545–00.852 CH3OCH3 (?) & CH3CN (?) emission from core Tmb [K] dN dυ[cm−2 km s−1] 1 1.0 0.5 0.0 4 5 2 3 4 6 8 10 Tmb [K] SO+ H35Cl (1°0) H37Cl (1°0) °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] 0 1 2 3 dN dv[cm°2 km s°1] £1013 °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] £1013 IRAS 12326–6245 CH3OCH3 (?) & CH3CN (?) υLSR [km s−1]υLSR [km s−1] –70 –60 –10–50 –40 –30 –20 –70 –60 –10–50 –40 –30 –20 IRAS 12326–6245 outflow SO+ massive outflow emission from core 3 Tmb [K] dN dυ[cm−2 km s−1] 4 2 1 0 6 10 8 The line profiles toward some targets show massive outflows: Some show offset absorption: And some even show dominant absorption: a characteristic zigzag pattern HCl has been detected in 27 massive star-forming regions. ‣The observed emission often traces strong outflows ‣Complex line profiles (emission with absorption) renders modeling the spectral line profiles difficult We find an average chlorine isotopic ratio of [H35Cl]/[H37Cl] = 2.6 ± 0.8. ‣The ratio shows no systemic trend with galactocentric distance. ‣Chlorine isotopic ratios have been observed for the first time in the Galactic center, where they are higher, but still agree with CCSN models (Maas & Pilachowski, 2021). ‣Currently, it remains unclear whether the ratio is higher for targets in the vicinity of SNRs. We plan to analyze the physical and excitation conditions traced by HCl. For this, we are exploring HCl’s spatial distribution, especially in outflows to disentangle both components: ‣Mapping HCl toward IRAS 12326–6245 and its massive outflow RA (J2000) Dec (J2000) [K km s–1] 12h35m42s 39s 36s 33s 30s –62°02'00" 03'00" 20" 40" 100 80 60 40 20 work in progress First look at the HCl (1–0) map outflow Photodissociation model predictions for the abundances of chlorine-bearing (and fluorine-bearing) species relative to the elemental abundances across the depths of an interstellar cloud Chlorine-bearing molecules have diagnostic properties due to chlorine’s unique chemistry ‣Most interstellar chlorine is contained in ≤6 species ‣Chlorine is primarily ionized (IPCl = 12.968 eV < IPH) and highly reactive ‣The chemical network is initialized by the exothermic (D0(HCl+) > D0(H2)) reaction Cl+ + H2 → HCl+ Chemical network displaying the most relevant gas-phase formation and destruction pathways for chlorine chemistry in the ISM. Based on Fig. 3, Neufeld et al. (2021) Neufeld & Wolfire (2009) We used XCLASS (Möller, Endres & Schilke, 2017) to model the observed line profiles. XCLASS assumes LTE and optimizes a number of source parameters per component. While we left column density, isotopic ratio and line width open, we constrained ‣the source size, , (verified with ATLASGAL), ‣the rotational temperature, Trot = Tdust, (from ATLASGAL), ‣and the velocity offset, < 1 km s–1, for the core component. - and the number of components have been determined from H13CO (7–6), covered in the lower sideband -or CO isotopologues (Giannetti et al., 2014) θs= 20′ ′ υoff υLSR + predictions for the solar neighborhood from Galactic chemical evolution models (Kobayashi et al., 2011) R1 R2 Affiliations: 1 2 lennart-boehm.de [email protected] ✉ Tracing Chlorine Isotopes Across the Milky Way A Large Scale Survey of Hydrogen Chloride in Star-Forming Regions Arshia M. Jacob2, Friedrich Wyrowski2, Karl M. Menten2, Ashley T. Barnes1, Katharina Immer1 HCl IN ALL TARGETS! Lennart Böhm1,2 Lennart Böhm, ESO IMPRS PhD student SCAN ME! Böhm, L. et al., in prep., Tracing chlorine isotopes across the Milky Way Elia, D. et al. (2021). The Hi-GAL compact source catalogue–II. The 360° catalogue of clump physical properties. MNRAS, 504(2), 2742-2766. Giannetti, A. et al.(2014). ATLASGAL-selected massive clumps in the inner Galaxy-I. CO depletion and isotopic ratios. A&A, 570, A65. Kobayashi, C., Karakas, A. I., & Umeda, H. (2011). The evolution of isotope ratios in the Milky Way Galaxy. MNRAS, 414(4), 3231-3250. Maas, Z. G., & Pilachowski, C. A. (2021). The Galactic Chemical Evolution of Chlorine. AJ, 161(4), 183. Möller, T., Endres, C., & Schilke, P. (2017). eXtended CASA line analysis software suite (XCLASS). A&A, 598, A7. Neufeld, D. A., & Wolfire, M. G. (2009). The chemistry of interstellar molecules containing the halogen elements. ApJ, 706(2), 1594. Neufeld, D. A. et al. (2021). The Chemistry of Chlorine-Bearing Species in the Diffuse Interstellar Medium, and New SOFIA/GREAT* Observations of HCl+. ApJ, 917(2), 104. Reid, M. J. et al. (2019). Trigonometric parallaxes of high-mass star-forming regions: our view of the Milky Way. ApJ, 885(2), 131. References: CHLORINE: PROBING THE ISM SURVEYING HCl WHAT WE STILL DON'T KNOW SCATTERED, NO TREND OUTFLOWS? CONTACT Image credit: apex-telescope.org H2 H2 e hω Cl+ HCl+ Cl H2Cl+ HCl hω e e e Chlorine isotopes probe the nucleosynthesis history of massive star-forming regions and their enrichment of the ISM: ‣35Cl and 37Cl are produced in core-collapse supernovae (CCSNe) and the weak s-process in massive stars (Maas & Pilachowski, 2021) ‣The 35Cl/37Cl ratio in a CCSN varies with factors such as initial mass, metallicity, and explosion properties (Maas & Pilachowski, 2021) ‣Galactic chemical evolution models predict the isotopic ratio to vary with metallicity, hence tracing the nucleosynthesis history of a galaxy (Kobayashi et al. 2010) 28 massive star-forming regions across the Milky Way ‣bright sub-mm continuum sources (Hi-Gal catalogue; Elia et al., 2021) ‣Galactocentric radii between to (Reid et al., 2019) ‣selected from the HyGAL and PRISMAS surveys on hydrides 0.1 kpc 10 kpc and the SEPIA660 receiver •single-pixel, sideband separated heterodyne •native resolution: ‣smoothed to 0.03 km s−1 0.5 km s−1 1. How abundant is HCl across the inner Galaxy? 2. Is there widespread line of sight absorption in the Galactic arms? 3. What physical and excitation conditions does HCl trace? 4. Are variations of the 35Cl/37Cl ratio a localized phenomenon, or does a galactic trend exist? ‣Is the isotopic ratio linked to supernova remnants? APEX 12m sub-mm telescope at 5104 m, Llano de Chajnantor HPBW: 10.1′ ′ HCl 37 HCl 35 covers 2 x 7.9 GHz atmospheric H O absorption! 2 typical weather conditions of our observations Figure Credit: Neufeld & Wolfire (2009) Dashed lines: 10 times higher CR ionization rate deeper surface HCl traces dense cores Chemical evolution across the depths of a cloud HCl and to some degree translucent gas 0 –2 Av [mag] –4 log (abundance/elemental) –6 0 2 4 6 8 10 A typical HCl line profile in our sample consists of 1. a narrow core component 2. a broad, often offset outflow component 70 80 130 0.00 0.25 1.00 2 3 4 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.25 0.50 0.75 1.00 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 G029.954–00.016 Tmb [K] dN dυ[cm−2 km s−1] υLSR [km s−1] CH3OCH3 (?) & CH3CN (?) outflow wing outflow wing υLSR [km s−1] υsys theoretical HFS line intensity 624.977821 GHz625.918756 GHz 2 4 3 G029.954–00.016 0.50 0.75 90 100 110 120 70 80 13090 100 110 120 APEX 12m sub-mm telescope hyperfine structure (HFS) deconvolved column density profile In summary, 11 of the 28 targeted sources showed only emission line profiles (including one tentative detection). 17 had one or more additional absorption components, often rendering analyses difficult. From these observations, we could derive the isotopic ratio in two ways: from the XCLASS line profile models, incl. sources with well separated, or no absorption components from the integrated intensity ratio, where we cut out contaminants and have to discard sources with absorption line profile modeled with XCLASS 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) 70 80 90 100 110 120 130 vLSR [km s°1] 0.00 0.05 0.10 0.15 dN dv[cm°2 km s°1] £1013 70 80 90 100 110 120 130 vLSR [km s°1] £1013 W43 MM1 0.15 Tmb [K] dN dυ[cm−2 km s−1] 3 υLSR [km s−1] υLSR [km s−1] 70 80 130 90 100 110 120 70 80 130 90 100 110 120 W 43 MM-1 CH3OCH3 (?) & CH3CN (?) dominant absorption 0.10 0.05 0.00 4 5 1 2 3 4 5 Tmb [K] H35Cl (1°0) H37Cl (1°0) °10 0 10 20 30 40 50 vLSR [km s°1] 0.0 0.5 1.0 dN dv[cm°2 km s°1] £1013 °10 0 10 20 30 40 50 vLSR [km s°1] £1013 HGAL 000.546–00.852 offset absorption υLSR [km s−1] –10 05010 20 30 40 υLSR [km s−1] –10 05010 20 30 40 HGAL 000.545–00.852 CH3OCH3 (?) & CH3CN (?) emission from core Tmb [K] dN dυ[cm−2 km s−1] 1 1.0 0.5 0.0 4 5 2 3 4 6 8 10 Tmb [K] SO+ H35Cl (1°0) H37Cl (1°0) °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] 0 1 2 3 dN dv[cm°2 km s°1] £1013 °70 °60 °50 °40 °30 °20 °10 vLSR [km s°1] £1013 IRAS 12326–6245 CH3OCH3 (?) & CH3CN (?) υLSR [km s−1]υLSR [km s−1] –70 –60 –10–50 –40 –30 –20 –70 –60 –10–50 –40 –30 –20 IRAS 12326–6245 outflow SO+ massive outflow emission from core 3 Tmb [K] dN dυ[cm−2 km s−1] 4 2 1 0 6 10 8 The line profiles toward some targets show massive outflows: Some show offset absorption: And some even show dominant absorption: a characteristic zigzag pattern HCl has been detected in 27 massive star-forming regions. ‣The observed emission often traces strong outflows ‣Complex line profiles (emission with absorption) renders modeling the spectral line profiles difficult We find an average chlorine isotopic ratio of [H35Cl]/[H37Cl] = 2.6 ± 0.8. ‣The ratio shows no systemic trend with galactocentric distance. ‣Chlorine isotopic ratios have been observed for the first time in the Galactic center, where they are higher, but still agree with CCSN models (Maas & Pilachowski, 2021). ‣Currently, it remains unclear whether the ratio is higher for targets in the vicinity of SNRs. We plan to analyze the physical and excitation conditions traced by HCl. For this, we are exploring HCl’s spatial distribution, especially in outflows to disentangle both components: ‣Mapping HCl toward IRAS 12326–6245 and its massive outflow RA (J2000) Dec (J2000) [K km s–1] 12h35m42s 39s 36s 33s 30s –62°02'00" 03'00" 20" 40" 100 80 60 40 20 work in progress First look at the HCl (1–0) map outflow Photodissociation model predictions for the abundances of chlorine-bearing (and fluorine-bearing) species relative to the elemental abundances across the depths of an interstellar cloud Chlorine-bearing molecules have diagnostic properties due to chlorine’s unique chemistry ‣Most interstellar chlorine is contained in ≤6 species ‣Chlorine is primarily ionized (IPCl = 12.968 eV < IPH) and highly reactive ‣The chemical network is initialized by the exothermic (D0(HCl+) > D0(H2)) reaction Cl+ + H2 → HCl+ Chemical network displaying the most relevant gas-phase formation and destruction pathways for chlorine chemistry in the ISM. Based on Fig. 3, Neufeld et al. (2021) Neufeld & Wolfire (2009) We used XCLASS (Möller, Endres & Schilke, 2017) to model the observed line profiles. XCLASS assumes LTE and optimizes a number of source parameters per component. While we left column density, isotopic ratio and line width open, we constrained ‣the source size, , (verified with ATLASGAL), ‣the rotational temperature, Trot = Tdust, (from ATLASGAL), ‣and the velocity offset, < 1 km s–1, for the core component. - and the number of components have been determined from H13CO (7–6), covered in the lower sideband -or CO isotopologues (Giannetti et al., 2014) θs= 20′ ′ υoff υLSR + predictions for the solar neighborhood from Galactic chemical evolution models (Kobayashi et al., 2011) R1 R2