Pre-biotic Chemistry in the ISM: from Cold Cores to Galactic Center Clouds

Pre-biotic Chemistry in the ISM: from Cold Cores to Galactic Center Clouds Izaskun Jimenez-Serra (STFC Ernest Rutherford Fellow) Shaoshan Zeng (QMUL), David Quenard (QMUL), Paola Caselli (MPE), Serena Viti (UCL), Anton Vasyunin (MPE), Victor Rivilla (Arcetri), Rafael Martin-Domenech (CAB), Leonardo Testi (ESO), Jesus-Martin-Pintado (CAB), Sergio Martin (ESO), Miguel Requena-Torres (JU), Denise Riquelme (MPIfR), Nuria Marcelino (ICMM), Nicolas Billot (IRAM), Charlotte Vastel (IRAP), Bertrand Lefloch (IPAG), Rafael Bachiller (OAN), Rebeca Aladro (Chalmers)

Star Formation in our Galaxy Star formation deeply embedded in molecular clouds A v >100 mag è only accessible at λ = mm/sub-mm & far-ir

The Formation of a Solar-type System

The Formation of a Solar-type System Caselli & Ceccarelli (2012) n & T different physical conditions and processes at every stage è different types of chemistry è different levels of chemical complexity

From the ISM to the Origin of Life Caselli & Ceccarelli (2012)

Molecules in Space Almost 200 molecules have been detected in space From CDMS catalog (https://www.astro.uni-koeln.de/cdms)

Molecules in Space Almost 200 molecules have been detected in space SgrB2(N) & SgrB2(M) Tmb (K) IRAM 30m NOEMA Rest Frequency (Mz) Belloche+2013 Observe molecular rotational transitions at mm/sub-mm λ s JCMT 8 ALMA SMA

Complex Organic Molecules (COMs) in Space COMs are carbon-based compounds with >6 atoms (erbst & van Dishoeck 2009) From CDMS catalog (https://www.astro.uni-koeln.de/cdms)

Complex Organic Molecules (COMs) in Space COMs are carbon-based compounds with >6 atoms (erbst & van Dishoeck 2009)

Pre-biotic COMs in Space Prebiotic COMs: species believed to be involved in the processes leading to the origin of life Formamide (N 2 CO) Glycolaldehyde (C 2 OCO) Amino Acetonitrile (N 2 C 2 CN)

Pre-biotic COMs in Space Prebiotic COMs: species believed to be involved in the processes leading to the origin of life Formamide (N 2 CO) Glycolaldehyde (C 2 OCO) Amino Acetonitrile (N 2 C 2 CN) Phosphorus Monoxide (PO)

First detections of COMs in the ISM Ø Star forming regions: ot Cores and ot Corinos (ollis+2000,2004; Beltran+2009; Belloche+2016; Jorgensen+2012; Lykke+2017) Ø Galactic Center GMCs (SgrB2) (Martin-Pintado+2001;Requena-Torres+2006,2008) Glycolaldehyde (C 2 OCO) T B (K) δ (J2000) Beltran+2009 α (J2000) ν (Gz) Amino Acetonitrile ( 2 NC 2 CN)

First detections of COMs in the ISM Ø Star forming regions: ot Cores and ot Corinos (ollis+2000,2004; Beltran+2009; Belloche+2016; Jorgensen+2012; Lykke+2017) Ø Galactic Center GMCs (SgrB2) (Martin-Pintado+2001;Requena-Torres+2006,2008) δ (J2000) Beltran+2009 COM chemistry triggered by α (J2000) T B (K) proto-stellar heating (T gas /T dust > 100 K) ν (Gz) Glycolaldehyde (C 2 OCO) Amino Acetonitrile ( 2 NC 2 CN)

COM formation in hot sources COMs formed mainly via: 1. ydrogenation ( addition; Charnley et al. 1997, 2001) 2. Radical-radical surface reactions (efficient at T>30 K; Garrod et al. 2008) (Burke & Brown 2010)

COMs ubiquitous in the ISM Ø Star forming regions: ot Cores and ot Corinos (ollis+2000,2004; Beltran+2009; Belloche+2016; Jorgensen+2012; Lykke+2017) Ø Galactic Center GMCs (SgrB2) (Martin-Pintado+2001;Requena-Torres+2006,2008) Ø Molecular Outflows (Arce+2008; Codella+2015,2017) Ø Photon-Dominated Regions (Guzman+2013; Cuadrado et al. 2017) Ø Dark Clouds Cores and Pre-stellar Cores (Marcelino+2007; Oberg+2010; Bacmann+2012; Cernicharo+2012; Vastel+2014)

COM formation in cold sources (T=10 K) Radical-radical surface formation inefficient at T<30 K New mechanisms proposed: 1. Gas phase formation (Vasyunin & erbst 2013; Balucani+2015; Vasyunin+2017) 2. Non-canonical explosions (Rawlings et al. 2013) 3. Cosmic-ray induced radical diffusion (Reboussin et al. 2014) 4. Impulsive spot heating on grains (Ivlev et al. 2015) 5. Formation after atom addition/abstraction on grains (Chuang et al. 2016) Av=3 Av=10 time (years) time (years)

Pre-stellar cores: Precursors of Solar-type systems L1544 (Taurus) Pre-stellar cores: Cold and dense cores on the verge of gravitational collapse (no star inside yet) Keto & Caselli 2008 Caselli+2002 Δδ (arcsec) Δδ (arcsec)

Caselli+2002 Δδ (arcsec) L1544 as a testbed Water vapour in L1544 (Caselli+2012) Δδ (arcsec) Caselli+2012

Caselli+2002 Δδ (arcsec) L1544 as a testbed Water vapour in L1544 (Caselli+2012) COMs released alongside water (C 3 O, 2 CCO, COO, C 3 CO) (Vastel+2014) Δδ (arcsec) C 3 O-ring at r~4000 AU C 3 O peak (0,0 ) Bizzocchi et al. 2014 Intermediate density shell interesting chemistry appears

IRAM 30m Detection of large COMs in L1544 C3OCO, C3OC3, C3CO, c-c32o, C2CCN, C3NC, CCNC, CCCO (0,0) Jimenez-Serra et al. (2016)

IRAM 30m Detection of large COMs in L1544 C3OCO, C3OC3, C3CO, c-c32o, C2CCN, C3NC, CCNC, CCCO C3O peak Jimenez-Serra et al. (2016)

COM abundance profile in L1544 Jimenez-Serra et al. (2016) C 3 O, C 3 CO: >6-10 x more abundant at r~4000 AU C 3 OC 3, C 3 OCO and N-bearing COMs: ( ~2-3 x more abundant at r~4000 AU

COM abundance profile in L1544 Jimenez-Serra et al. (2016) Important non-detections: X [Glycine] < 10-10 X [N 2 CO] < 10-12 (Lopez-Sepulcre+2014) X [C 3 NCO] < 10-12 (Cernicharo+2016)

O-bearing COM chemical modelling in L1544 4000 AU Vasyunin et al. (2017) UV photodissociation of COMs n( 2 )<10 4 cm -3 Strong depletion onto grains n( 2 )>10 6 cm -3 Moderate Av + No severe depletion (CO) n( 2 )~10 4 cm -3

O-bearing COM chemical modelling in L1544 4000 AU Vasyunin et al. (2017) Catastrophic depletion of CO è CO snow-line in pre-stellar cores Strong depletion onto grains Moderate Av + No severe depletion (CO) UV photodissociation of COMs n( 2 )<10 4 cm -3 n( 2 )>10 6 cm -3 n( 2 )~10 4 cm -3

Small-scale structure of the C3O peak C3O shows inward motions (gas accretion?) Gas dynamics need to be considered Punanova+17, subm.

Modelling the chemistry of N-bearing COMs Glycine (N 2 C 2 COO) Methylamine N 2 C 3 Glycolaldehyde OC 2 CO ydroxylamine N 2 O Cyanamide N 2 CN Methyl Formate COOC 3 Acetamide N 2 COC 3 Aminoacetonitrile N 2 C 2 CN Acetic Acid C 3 COO Formamide N 2 CO N-methyl Formamide N-C 3 NCO Isocyanic Acid (+isomers) NCO/CNO/OCN Methyl Isocyanate C 3 NCO Requires understanding of the chemistry of the precursors of glycine and of any COM-related species.

Modelling the chemistry of N-bearing COMs David Quenard Methylamine N 2 C 3 Glycolaldehyde OC 2 CO ydroxylamine N 2 O Glycine (N 2 C 2 COO) Cyanamide N 2 CN Methyl Formate COOC 3 Acetamide N 2 COC 3 Aminoacetonitrile N 2 C 2 CN Acetic Acid C 3 COO Formamide N 2 CO N-methyl Formamide N-C 3 NCO Isocyanic Acid (+isomers) NCO/CNO/OCN Methyl Isocyanate C 3 NCO Requires understanding of the chemistry of the precursors of glycine and of any COM-related species.

Modelling the chemistry of N-bearing COMs David Quenard Methylamine N 2 C 3 Glycolaldehyde OC 2 CO ydroxylamine N 2 O Glycine (N 2 C 2 COO) Cyanamide N 2 CN Methyl Formate COOC 3 Acetamide N 2 COC 3 Aminoacetonitrile N 2 C 2 CN Acetic Acid C 3 COO Formamide N 2 CO N-methyl Formamide N-C 3 NCO Isocyanic Acid (+isomers) NCO/CNO/OCN Methyl Isocyanate C 3 NCO Mar=n- Domenech+(2017) Ligterink et al. (2017) Requires understanding of the chemistry of the precursors of glycine and of any COM-related species.

Modelling of N 2 CO, C 3 NCO, NCO (& isomers) UCL_CEM (Viti et al. 2004; oldship et al. 2017; Quenard et al. subm.) https://uclchem.github.io/ Astronomical sources considered in the modelling: L1544 IRAS16293 B Cold Core T=10 K n( 2 )~10 5-10 6 cm -3 Cold envelope T=20 K n( 2 )~10 6 cm -3 ot corino T=250 K n( 2 )~10 8 cm -3

L1544 (core center + C 3 O peak) N 2 CO is produced by a combination of gas-phase and dust-grain processes T=10 K N 2 CO formed mainly by gas phase reaction N 2 + 2 CO -> N 2 CO + at cold T (better match obtained with E a ~25 K, slightly higher than that of Skouteris+2017) C3O peak (T=10 K) X(N 2 CO)~7x10-13 X(C 3 NCO)~6x10-12 (Jimenez-Serra+2016)

X(N 2 CO)~6x10-10 -2x10-9 X(C 3 NCO)~2x10-10 (Coutens+2016; Martin-Domenech+2017; Ligterink+2017) IRAS16293-2422 (cold envelope + hot corino) Cold envelope (T=20 K) gas-phase dominates hydrogenation unlikely (Noble+2015; Fedoseev+15) T=110 K X(N 2 CO)~3x10-12 (Lopez-Sepulcre+2014) T=20 K ot corino (T=250 K) Radical-radical diffusion dominates

X(N 2 CO)~6x10-10 -2x10-9 X(C 3 NCO)~2x10-10 (Coutens+2016; Martin-Domenech+2017; Ligterink+2017) IRAS16293-2422 (cold envelope + hot corino) Cold envelope (T=20 K) gas-phase dominates hydrogenation unlikely (Noble+2015; Fedoseev+15) X(N 2 CO)~3x10-12 T=110 K (Lopez-Sepulcre+2014) Formamide forms both in the gas-phase and/ or on grains depending on the physical conditions T=20 K ot corino (T=250 K) Radical-radical diffusion dominates

Search for pre-biotic species Advantages: Tgas<10 K low level of line confusion! Narrow linewidths <0.5 kms-1 little line blending L1544 Easier line identification. Not limited by sensitivity any longer Searches with ALMA and SKA!!!

Formamide with SKA1 TW ydrae ALMA GASS + LIME N 2 CO @ 15.4 Gz Abundance (wrt 2 ) 10-6 N 2 CO 10-8 10-10 10-12 10-14 10-16 UCL_CEM TW ya @ 1 arcsec (~50 AU) SKA-MID Band 5 (Phase 1) Quenard et al., in prep. 10-18 10 0 10 1 10 2 10 3 Radius (AU)

Formamide with SKA2 TW ydrae ALMA GASS + LIME N 2 CO @ 15.4 Gz 10-6 N 2 CO 10-8 Abundance (wrt 2 ) 10-10 10-12 10-14 10-16 UCL_CEM TW ya @ 40 mas (~2 AU) SKA-MID Band 5 (Phase 2) 10-18 10 0 10 1 10 2 10 3 Radius (AU) Quenard et al., in prep.

T mb (K) Simulations of Glycine in L1544 Jimenez-Serra et al. (2014) T(K), log[n (cm -3 )] χ(mol) Derived 2 O vapour profile (Caselli+2012) Glycine abundance in ices ~0.01% wrt 2 O (Munoz-Caro+2002; Bernstein+2002). Radius (AU) Intensities > 10 mk!!! L1544 (T=10K) Brightest lines appear at ν < 85 Gz ALMA Band 2

Chemical complexity in the Galactic Center Shaoshan Zeng Central Molecular Zone (central 100 pc) hosts 80% of dense gas in the MW (star-forming + quiescent GMCs)

Chemical complexity in the Galactic Center Battersby et al. (2016) G+0.2-0.03 G+0.76-0.05 G-0.02-0.07 Martin-Pintado et al. (2001); Requena-Torres et al. (2006,2008)

Requena-Torres et al. (2006,2008) Chemical complexity in the Galactic Center Battersby et al. (2016) G+0.2-0.03 G+0.76-0.05 G-0.02-0.07 The quiescent GMCs in the Galactic Center: main reservoir of COMs in the Galaxy

Chemical complexity in the Galactic Center G0693-0.03 Quiescent GMC -> no sign of star-formation activity q n( 2 )~4x10 4 cm -3 q T dust <20 K q T gas >100 K q Richest quiescent GMC in COMs (Requena-Torres et al. 2008)

G+0.693-0.33 G0693-0.03 3mm survey 2mm survey 93 species detected 50% of them are COMs

O-O O C=O -C=O <8.6E-10 3.1E-10. 2 C=O 8.8E-9 6.5E-8 C 3 O 2.1E-9 <3.4E-9 O C 3 O 4.5E-7 1.1E-6 COO 2.7E-9 3.7E-9 2 CO 2 O O-bearing COMs in G+0.693-0.33 COO C C COOC 3 4.5E-8 7.8E-8 3 COOC C C 3 OC 3 C 3 OC 3 2.7E-8 5.6E-8 C 3 COO <1.6E-9 <8.0E-10 CCOO O. C=C=O 2 C=C=O 7E-9 1.6E-8 2 C 2 =CO <4.5E-9 <1.8E-8 C 3 C=O 1.4E-8 3.0E-8 2 O C 3 C 2 O 3.1E-8 6.0E-8 OC 2 C 2 O 9.0E-9 2.8E-8 C C-C C-C-C 3 2 C 2 OC=O 6.8E-9 1.8E-8 2 O=C-C=O OCCO C-C 2 4 O 3.0E-9 5.6E-9 C. C C-C=O <5.7E-10 <3.6E-9 C C-C=O 9.0E-10 2.3E-9 2 C 2 =C-C=O 4.5E-10 2.3E-9 2 C 3 C 2 C=O 2.3E-9 4.4E-9 2 C 3 C 2 C 2 O <7.2E-9 <1.2E-8 Zeng et al., in prep. O-N N=C=O 9.6E-8 1.3E-7 O NCO N 2 CO 3.4E-9 6.7E-10 N 2 CO N 2 C 2 O COON 2 O-O-N C COCON 2 C 2 OCON 2 C 3 OCON 2 <1.2E-10 <4.3E-8 N=C=C=O 2 N 2 C=C=O 2 N 2 C 2 C=O 2 N 2 C 2 C 2 O <1.1E-9 <1.0E-8 C(O)C N <9.0E-10 <2.3E-9 N 2 C(O)C 3 3.6E-9 3.4E-9 N C-C=C=O 4.5E-10 <1.0E-9

N-O-O C C-C C 3 OCON 2 C COON 2 <8.08E-10 2 C-C-C C-C-C-C C-C-C-C-C COOC 2 N 2 N-O N N-N -N=C 3.81E-9 NC=N <3.53E-10 CO CO CNO 3.22E-10 ONC <7.71E-12 N 2 C=N 8.65E-10 O N OCN 4.87E-10 O C N N NCO -C N 6.74E-9 2 C=N 1.04E-9 C 2 N 1.37E-9 O C 2 N 2 N 2 C 2 O N 2 CO N 2 CO 9.06E-10 NCO C 3 N 2 3.29E-9 NCO 8.86E-8 C 3 N C C C N 2 C 2 C 2 O <2.2E-10 2 N 2 C 2 C=O N 2 C(O)C 3 4 3 C-C N 6.64E-7 C 3 C=N C 3 C 2 N -CO-C N <9.71E-11.. -C-C N 3.22E-11. 2 C-C N 4.65E-9 O CCN C 3 C 2 N 2 2 C=C=N <2.38E-9 C 2 C=N C 3 C=N C-C 2 4 N <2.87E-10 C 2 C=N 2 <1.17E-9 C 3 CN 2 C 3 NCO 1.4E-9 C 3 CNO <3.87E-11 C 3 OCN <1.22E-10 2 -C N-CO C C C O C C-C N 8.65E-10 -C C-C N 1.5E-8 -NC-C C 5.85E-11 -C C-NC 1.54E-9 C-C-C N C 2 =C-C N 1.81E-9 C 3 CC N C 3 C 2 C N 1.40E-9 C 3 C 2 CN C 3 C 2 CN C 3 C 2 C 2 N C 3 C 2 C 2 N 2 N-bearing COMs in G+0.693-0.33 N C-C=C=O <4.24E-10 C C.. -C C-C-C N <4.44E-11 2 C=C=C-C N <1.06E-10 C 4 N. 2 C=C=C-C N 8.86E-10 3 C-C C-C N 5.59E-10 C 3 C 3 =N C 3 C 3 =N C 3 C 3 2 N C 3 C 3 2 N 2 C C C 3 C 2 C=N C 3 C 2 2 C=N C 3 C 2 3 C=N C 3 C 2 4 C=N Zeng et al., in prep. C 5 N -C C-C C-C N 6.13E-9 C -C 7 N 3.45E-10 -C 9 N <2.93E-11

Conclusions Ø COMs are ubiquitous in the ISM. Large COMs even detected in PSCs and quiescent GC GMCs. Ø COM abundance profile predicted by chemical modelling -> Outer, intermediate-av shells in PSCs represent the main O-bearing COM reservoir. Ø Chemistry of N 2 CO, C 3 NCO, NCO in PSCs and hot corinos can be reproduced considering both gas-phase chemistry and dust grains. Ø Quiescent GC GMCs richest COM repository in the MW. Survival of COMs under extreme conditions.

Modelling of N 2 CO, C 3 NCO, NCO (& isomers) L1544 -> N 2 CO gas-phase formation (N 2 + 2 CO -> N 2 CO + ) requires a small activation barrier of 25 K (Quenard et al., subm.)

Chemical differentiation in L1544 Spezzano et al. (2017)

Where does CO depletion occur? Caselli et al. (1999) DEC Offset (arscsec) Integrated Intensity (km s -1 ) RA Offset (arscsec) RA Offset (arscsec) Low-Av shell: MAIN RESERVOIR of COMs IN PRE-STELLAR CORES

Modelling of N 2 CO, C 3 NCO, NCO (& isomers) UCL_CEM (Viti et al. 2004; oldship et al. 2017; Quenard et al. subm.) https://uclchem.github.io/ Gas-phase + Dust Grain chemical code (310 species; 3097 # of reactions) a) Thermal desorption (Viti et al. 2004; Collings et al. 2004) b) Non-thermal desorption (direct UV, CR-induced UV, direct CR, 2 form.) New treatment of grain surface chemistry (Quenard et al. in prep.): 1. Diffusion (asegawa et al. 1992) 2. Chemical reactive desorption (Minissale et al. 2016) 3. Reaction-diffusion competition (Garrod & Pauli 2011; Ruaud et al. 2015)