Ho co es in he ou e Galaxy: impac o me allici y on he
o ma ion o complex o ganic molecules
Youxin Wang (MPI R)
Collabo a o s: A naud Belloche (MPI R), Robin Ga od (UVA)
ESO, Ga ching
11 Ma ch, 2025
`@IRAM
@IRAM
●Compac (< 0.1 pc)
● High densi y (> 106 cm-3)
●High gas/dus empe a u e (150-250 K)
● Rich spec um, wi h many lines o COMs
C edi s: Co mac Pu cell 1
Ho co es in high-mass s a - o ming egions
●Compac (< 0.1 pc)
● High densi y (> 106 cm-3)
●High gas/dus empe a u e (150-250 K)
● Rich spec um, wi h many lines o COMs
C edi s: Co mac Pu cell 1
Ho co es in high-mass s a - o ming egions
excellen a ge s o s udy he chemical composi ion o he ma e ial in ol ed in he
o ma ion o s a s and plane s
2
Simila chemical composi ion in he inne Galaxy
(Jø gensen+2020)
Sg B2(N2): Galac ic cen e
IRAS 16293-2433B: Sola neighbo hood
(Luck & Lambe 2011) (Gianne i+2017)
3
gas- o-dus mass a io
Low me allici y in he ou e Galaxy
Me allici y Gas- o-dus a io
(Luck & Lambe 2011) (Gianne i+2017)
3
gas- o-dus mass a io
Low me allici y in he ou e Galaxy
Me allici y Gas- o-dus a io
Does me allici y ha e an impac on he p e alence o COMs
in s a - o ming egions o ou Galaxy?
4
Low me allici y in he ou e Galaxy
P edic ions o as ochemical model MAGICKAL (Ga od+2022)
(R. Ga od p i . comm.)
(X/CH3OH)lowZ low me allici y
(X/CH3OH)basic no mal en i .
wha e e he wa m-up model imescale:
molecules wi h educed abundance a low Z
molecules ~ insensi i e o Z
R =
4
Low me allici y in he ou e Galaxy
P edic ions o as ochemical model MAGICKAL (Ga od+2022)
(R. Ga od p i . comm.)
(X/CH3OH)lowZ low me allici y
(X/CH3OH)basic no mal en i .
wha e e he wa m-up model imescale:
molecules wi h educed abundance a low Z
molecules ~ insensi i e o Z
R =
⇒ use ou e -Galaxy ho co es o es
chemical model
Obse a ions
●Only one ho co e known in he ou e Galaxy (Shimonishi+21)
5
Sea ch o ho co es in he ou e Galaxy
LTE syn he ic spec a wi h Weeds, spec oscopic p edic ions om CDMS/LSD/JPL
> Line wid h & Veloci y o se > Tempe a u e & Column densi y
> Emission size
8
LTE modelling o he COM emission
CH3OH
CH3OH
LTE syn he ic spec a wi h Weeds, spec oscopic p edic ions om CDMS/LSD/JPL
> Line wid h & Veloci y o se > Tempe a u e & Column densi y
> Emission size
8
LTE modelling o he COM emission
T o = 175.4 ± 2.1 K
N = (2.1 ± 0.1)x 1018 cm-2
CH3OH
Compac (< 0.1 pc) High gas empe a u e Rich spec um
9
G135.27: second ho co e in he ou e Galaxy
T o = 175.4 ± 2.1 K
N = (2.1 ± 0.1)x 1018 cm-2
10
Bipola ou low
12CO 13CO
11
Sg B2(N2): Galac ic cen e
G31.41: inne Galaxy
IRAS16293B: sola neighbo hood
Compa ison wi h as ochemical models
11
Sg B2(N2): Galac ic cen e
G31.41: inne Galaxy
IRAS16293B: sola neighbo hood
Compa ison wi h as ochemical models
⇒ App oxima e ag eemen be ween he as ochemical models and he COM
abundances ( ela i e o CH3OH) o G135.27 ela i e o he h ee inne Galaxy
sou ces (Sg B2(N2), G31.41, and IRAS16293B)
12
Compa ison wi h ho co es in he Milky Way
- simila chemical composi ion
be ween G31.41 and G135.27,
bu G135.27 has lowe COMs
abundance
- COM abundances in G135.27
is be ween hose o G31.41 and
WB89-789
- much poo e co ela ion wi h
Sg B2(N2) and IRAS16293B
Summa y
● NOEMA de ec ion a second ho co e in he ou e Galaxy
● associa ed wi h bipola ou low
●12 COMs a e de ec ed
● App oxima e ag eemen wi h p edic ions o as ochemical model
● COM abundances in G135.27 (Dgc = 13.1 kpc) in be ween G31.41 (Dgc = 5 kpc) and
WB89-789 (Dgc = 17 kpc)
Summa y
● NOEMA de ec ion a second ho co e in he ou e Galaxy
● associa ed wi h bipola ou low
●12 COMs a e de ec ed
● App oxima e ag eemen wi h p edic ions o as ochemical model
● COM abundances in G135.27 (Dgc = 13.1 kpc) in be ween G31.41 (Dgc = 5 kpc) and
WB89-789 (Dgc = 17 kpc)
Ou look: wo addi ional candida es obse ed wi h NOEMA
Thanks o you a en ion!
@ IRAM
