Detection of glycolaldehyde toward the solar-type protostar NGC 1333 IRAS2A

Abstract

Glycolaldehyde is a key molecule in the formation of biologically relevant molecules such as ribose. We report its detection with the Plateau de Bure interferometer towards the Class 0 young stellar object NGC 1333 IRAS2A, which is only the second solartype protostar for which this prebiotic molecule is detected. Local thermodynamic equilibrium analyses of glycolaldehyde, ethylene glycol (the reduced alcohol of glycolaldehyde) and methyl formate (the most abundant isomer of glycolaldehyde) were carried out. The relative abundance of ethylene glycol to glycolaldehyde is found to be ∼5 -higher than in the Class 0 source IRAS 16293-2422 (∼1), but comparable to the lower limits derived in comets (≥ 3-6). The different ethylene glycol-to-glycolaldehyde ratios in the two protostars could be related to different CH 3 OH:CO compositions of the icy grain mantles. In particular, a more efficient hydrogenation on the grains in NGC 1333 IRAS2A would favor the formation of both methanol and ethylene glycol. In conclusion, it is possible that, like NGC 1333 IRAS2A, other low-mass protostars show high ethylene glycol-to-glycolaldehyde abundance ratios. The cometary ratios could consequently be inherited from earlier stages of star formation, if the young Sun experienced conditions similar to NGC 1333 IRAS2A.

Formation of Glycerol through Hydrogenation of CO Ice under Prestellar Core Conditions

“…Many of the basic chemical compounds required for the emergence of life consist of chains of carbon atoms with repeatable functional groups, such as (un)saturated fatty acids, simple sugars, and sugar alcohols. The two latter classes deserve special attention, as their smallest members, glycolaldehyde (HOCH 2 CHO) and ethylene glycol (HOCH 2 CH 2 OH), have been successfully observed in the gas phase toward our Galactic center (Hollis et al 2000(Hollis et al , 2002, in solar-mass protostars (Jørgensen et al 2012(Jørgensen et al , 2016Coutens et al 2015;Taquet et al 2015;Rivilla et al 2017), and in cometary ices (Biver et al 2014;Goesmann et al 2015;Le Roy et al 2015). It is possible that the mechanism responsible for the formation of glycolaldehyde and ethylene glycol also holds the potential to form the next larger members in these series, glyceraldehyde and glycerol.…”

Tentative detection of ethylene glycol toward W51/e2 and G34.3+0.2

“…But since Coutens et al (2015) report a value of around five for a low-mass protostar, and both we and Brouillet et al (2015), report lower limits of >6-16 for highmass sources, then a (CH 2 OH) 2 /CH 2 OHCHO ratio greater than three can be expected to be observed in other sources as well.…”

“…) and NGC 1333 IRAS 2A (Maury et al 2014;Coutens et al 2015) as well as toward the intermediate-mass protostar NGC 7129 FIRS2 (Fuente et al 2014). CH 2 OHCHO has been detected toward Sgr B2(N) (Hollis et al 2000(Hollis et al , 2001(Hollis et al , 2004Halfen et al 2006;Requena-Torres et al 2008), the high-mass hot molecular core G31.41+0.31 (Beltrán et al 2009), in IRAS 16293-2422 by Jørgensen et al (2012) and recently also in NGC 7129 FIRS2 (Fuente et al 2014), NGC 1333 IRAS 2A (Coutens et al 2015;Taquet et al 2015) and NGC 1333 IRAS 4A (Taquet et al 2015). HCOOCH 3 is the most abundant isomer of CH 2 OHCHO, and it has previously been observed in numerous hot cores and corinos (e.g., Blake et al 1987;Bisschop et al 2007;Demyk et al 2008;Favre et al 2014Favre et al , 2011.…”

Deep, Broadband Spectral Line Surveys of Molecule-rich Interstellar Clouds

“…Intensive studies have focused on this low-mass star-forming region (Blake et al 1995;Gregersen et al 1997;Bachiller et al 1998;Stark et al 1999;Knee & Sandell 2000;Bottinelli et al 2004Bottinelli et al , 2007Jørgensen et al 2004Jørgensen et al , 2005aJørgensen et al , 2005bJørgensen et al , 2007Maret et al 2004Maret et al , 2005Wakelam et al 2005;Parise et al 2006;Plume et al 2007;Choi et al 2010;Sakai et al 2012Sakai et al , 2006Coutens et al 2013Coutens et al , 2015Lyo et al 2014;Taquet et al 2015;De Simone et al 2017). Numerous COMs, such as CH 3 CN, CH 3 OH, CH 2 DOH, 13 CH 3 OH, trans-HCOOH, HCOOCH 3 , CH 3 OCH 3 , C 2 H 5 OH, C 2 H 5 CN, and CH 2 OCHO, were detected in the IRAS 2 and IRAS 4A regions in this cloud (Blake et al 1995;Bachiller et al 1998;Bottinelli et al 2004Bottinelli et al , 2007Jørgensen et al 2004Jørgensen et al , 2005aJørgensen et al , 2005bJørgensen et al , 2007Maret et al 2005;Parise et al 2006;Sakai et al 2012;Coutens et al 2015;Taquet et al 2015;De Simone et al 2017). (CH 2 OH) 2 was also detected in IRAS 2 (Coutens et al 2...…”