Streamers and winds: shaping the chemistry of protostellar disks
Abstract
"Observations of protostellar disks suggest that planets formation may start early, in disks of ≤105 yr. The physical and chemical properties of young disks are strongly influenced by the intense and variable accretion/ejection activity, and by the interaction with the environment. The disk gains mass rapidly from the infalling envelope, as well as from accretion streamers. Because of the high accretion rate, young disks are warm and the snowlines are pushed outwards, with important implications for the growth of dust grains and the composition of the nascent planets. Accretion streamers and the shocks occurring where the streamer hits the disk, can drastically alter the disk's kinematical structure, mass budget, stability, and chemical composition. In addition, recent models and observations suggest that disk-winds can transport large grains from the inner disk to the envelope. The possible fallback of the grains in the outer disk regions would then promote dust growth and mixing in the disk, with crucial effects on the formation and composition of planets. I will review the physical and chemical properties of protostellar disks, and how these are affected by environmental and accretion/ejection processes."
Full text
Streamers and winds: shaping the chemistry of protostellar disks Linda Podio — INAF - Osservatorio Astrofisico di Arcetri
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets ALMA provided evidence of planet formation in disks with ages of 105 yr Class 0 and I disks are massive enough to form planets Tychoniec et al. 2020 Rings and gaps in young disks (Class I) mmdust grains in the envelope & disk of Class I Kwon et al. 2009 Miotello et al. 2014 Galametz et al. 2019 Planets form in protostellar disks Sheehan et al. 2018 Segura-Cox et al. 2020 Maureira et al. 2024 GY 91 - Class I
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets What are the effects of the accretion/ejection activity on the disk evolution in terms of mass reservoir, grain growth, disk stability, and chemical composition ? Protostellar disks physical and chemical structure may be affected by several processes -high (accretion) luminosity may push snowlines outwards -accretion streamers channeling material from the large scale envelope to the disk -disk winds removing mass and angular momentum from the disk Protostellar disks is the chemical composition of young protostellar disks inherited by the forming planets ?
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets What are the effects of the accretion/ejection activity on the disk evolution in terms of mass reservoir, grain growth, disk stability, and chemical composition ? Protostellar disks physical and chemical structure may be affected by several processes -high (accretion) luminosity may push snowlines outwards -accretion streamers channeling material from the large scale envelope to the disk -disk winds removing mass and angular momentum from the disk Protostellar disks
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets Accretion luminosity may push snowines outwards Adapted from Tobin et al. 2023
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets Protostellar disks are warm molecular emission resolved vertically in edge-on disk allow a direct estimate of the snowline position van’t Hoff et al. 2020 Podio et al. 2020 In Class I disk the molecular snowlines are located further than in Class II disks, e.g.: RCO ~ 100 au in IRAS04302 and RCO ~ 20 au in TW Hya H2CO CO Talk by R. Le Gal
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets Protostellar disks are warm Class 0 disk HH 212: Lee et al. 2022 The radial and vertical stratification of molecular emission in then disk of HH 212: CH3OH (Tevp~100 K) probe a more extended region (out to R~40 au, and z~50 au) than NH2CHO (Tevp ~ 230 K) (extends out to R~30 au, and z~35 au) CH3OH NH2CHO Ceccarelli et al. PPVII
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets Protostellar outbursting disks Tobin et al. Nature 2023 Lee, Jeong-Eun et al. Nature2019
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets implications on the disk evolution in terms of final mass budget and chemical composition Increasing observational evidences that: - disks do not form in isolated spherical collapsing cores - episodic and non axisymmetric accretion onto the disk (accretion streamers) Accretion streamers Pineda et al. 2023, PPVII See also Lucy Evans et al. 2025 POSTER Talk by M. T. Valdivia Mena
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets Accretion streamer & disk chemistry The reaction CH3+ + HD is exothermic D2CO and HDCO may form in gasphase at T< 50 - 70 K H2CO HDCO abstraction reactions on grains favour the formation of DCO/D2CO high abundance of D2CO (wrt HDCO & H2CO) on grains and release in the accretion shock Bergman et al. 2011 Hidaka et al. 2009 Taquet et al. 2012 Aikawa et al. 2012 Podio et al. 2024 The super deuteration (D2CO/HDCO ~30%-70%) in IRS63 disk is due to grain chemistry the accretion shock reveals the chemistry of ices in the disk set at the prestellar stage or in the disk midplane Roueff et al. 2007, 2013, Roberts & Millar 2007 CHD2+ CH3D2+ CHD2 D2CO
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets Winds remove mass and angular momentum ~0.02” / 8 AU ~ 250 AU SiO 5-4 Lee+ Science 2017a SiO 8-7 Lee+ Nature 2017b De Simone et al. 2024 Nazari et al. 2024 IRAS4A2 L1448 HH 212
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets A collimated SiO jet originating from fractions of au (Lee et al. 2017) the Disk-wind probed by SO2 from 0.1-40 au disk region (Tabone et al. 2017) and the rotating outflow cavities (Codella et al. 2014) Rlaunch ~ 0.1 - 40 au ~ 250 AU SiO 8-7 Rlaunch ~ 0.05 - 0.3 au Lee et al. 2017 Tabone et al. 2017 Lee et al. 2018 Ohashi & FAUST 2022 Codella et al. 2014 HH 212 Orion d = 450 pc VLA 1623-2417 Ophiucus A d = 131 pc Winds remove mass and angular momentum
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets implications on the disk evolution in terms of dust growths & dust mixing and chemical composition Disk winds can also extract large grains from the inner disk. These may be transported in the envelope by the wind and later fall back in the outer disk (ASH-FALL) Tsukamoto, Machida et al. 2021 Winds transport of dust grains from disks to envelopes ? Models of transport can justify >100 grains at typical Class 0/I mass loss rates Giacalone et al. 2019 μm
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets larger grains Lower , hence larger grains, are associated with larger mass accretion rates β Cacciapuoti et al. 2024 larger mass loss rate of the jet/outflow Galametz et al. 2019 dust emissivity index β: a proxy of the grain size in the envelope (70-700 au) Winds transport of dust grains from disks to envelopes ? Podio et al. 2021
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets The ash fall scenario may explain - Dust mixing in disk —> may explain similarity of chondrules (outer SS) and CAI (inner SS) (e.g. Hellmann+23) - Replenishment of the outer disk with large grains as solution for meter-barrier (e.g. Weidenschilling+1977) JWST first evidence of lifting of grains >10 in a Class II YSO, with much weaker μm · M Protostellar chimneys ? Duchene et al. 2023 0.4 M☉ young star in Taurus 2MASS J04202144+2813491 Sabatini & FAUST, subSabatini & FAUST 2024 ALMA first evidence of large grains (beta <1) along the outflow cavity walls of protostellar sources Talks by G. Sabatini
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets is the chemical composition of young protostellar disks inherited by the forming planets ? Linking the chemistry of disks & SS fossils Lippi et al. 2021 iCOMs abundance ratios Deuteration
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets Testing the “inheritance”: iCOMs abundance ratios iCOMs abundance ratios in Class 0 (104 yr) and I (105 yr) protostars and in comets Drozdovskaya+ 2019 (IRAS 16293) Bianchi+ 2019 Mercimek+ 2022 Class 0: ALMA-PILS IRAS 16293 (Jorgensen et al. 2016) Comets: 67P/C-G (Rubin et al. 2019) Class 0 Class IComets Class 0: Jorgensen et al. 2016, 2018, Manigand et al. 2020, Belloche et al. 2020, Yang et al. 2021; Class I: Bergner et al. 2019, Bianchi et al. 2020, Comets: Le Roy et al. 2015 ? ? Class 0: Taquet+ 2015, Lopez-Sepulcre+ 2017, Jaber+ 2014, Jorgensen et al. 2016, 2018, Codella+ 2018; Class I: Oberg et al. 2014, Graninger et al. 2016, Bergner et al. 2019, Comets: Le Roy et al. 2015
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets HD 100546 Class II CH3OH/H2CO in disks vary with radial distance CH3OH/H2CO in DISKS HOT CORINOS DISK-AVERAGED DISKS COMETS (Lippi et al. 2021) HD 100546 CH3OH/H2CO in COMETS Testing the “inheritance”: [CH3OH/H2CO] Booth et al. 2021, 2023 Podio et al. 2020a, Garufi et al. 2021 Class II DISKS Walsh+ 2016, Carney+ 2017, 2019, Booth+ 2021 HOT-CORINOS Taquet+ 2015, Jørgensen+ 2018, Persson+ 2018, Manigand+ 2020 COMETS Biver+ 2015, Rubin+ 2019 Lippi et al. 2021, 2024 CH3OH/H2CO in comets CH3OH/H2CO in comets vary with heliocentric distance 67P C-G may not be representative of cometary chemistry Lippi et al. 2024 mm obs: Biver et al. NIR obs: Lippi et al. 2021 Rosina: Rubin et al.
Towards New Frontiers: the astrochemical journey from young stellar nurseries to exoplanets CH3OH/H2CO: disks versus comets inner disks abundance ratios in agreement with protostellar and cometary values Class 0 hot corinos Inner disk region disk-averaged 67P/C-G Rh<1 Rh>1 Hyperbolic Long P Jupiter family disks averaged values may be biased by the low CH3OH abundance in the outer disk comet 67P/C-G may not be representative of the cometary population Lippi et al. 2024 POSTER by L. Evans