Ethyl alcohol and sugar in comet C/2014 Q2 (Lovejoy)

Biver, Nicolás; Bockelée‐Morvan, Dominique; Moreno, R.; Crovisier, J.; Colom, P.; Lis, D. C.; Sandqvist, Aage; Boissier, J.; Despois, D.; Milam, Stefanie N.

doi:10.1126/sciadv.1500863

Cited by 141 publications

(169 citation statements)

References 33 publications

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“…The CO2 ice-rich zone seen in this work can help explain CO2-rich comets ( Comets are rich in many complex organics; and the recent measurements for 67P/Churyumov-Gerasimenko with the Rosetta mission are revealing even more complexity than suggested by earlier observations (Capaccioni et al 2015;Goesmann et al 2015;Le Roy et al 2015). Molecules as large as ethanol and glycolaldehyde have also been recently detected for comet Lovejoy (Biver et al 2015), so chemical complexity seems to be characteristic to comets. The detected abundances are fractions of a per cent relative to water, however relative to methanol the abundances are as high as few per cent.…”

Section: Comparison With Cometscontrasting

confidence: 40%

Cometary ices in forming protoplanetary disc midplanes

Drozdovskaya¹,

Walsh²,

Dishoeck³

et al. 2016

Mon. Not. R. Astron. Soc.

101

137

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Low-mass protostars are the extrasolar analogues of the natal Solar System. Sophisticated physicochemical models are used to simulate the formation of two protoplanetary discs from the initial prestellar phase, one dominated by viscous spreading and the other by pure infall. The results show that the volatile prestellar fingerprint is modified by the chemistry en route into the disc. This holds relatively independent of initial abundances and chemical parameters: physical conditions are more important. The amount of CO 2 increases via the grain-surface reaction of OH with CO, which is enhanced by photodissociation of H 2 O ice. Complex organic molecules are produced during transport through the envelope at the expense of CH 3 OH ice. Their abundances can be comparable to that of methanol ice (few % of water ice) at large disc radii (R > 30 AU). Current Class II disc models may be underestimating the complex organic content. Planet population synthesis models may underestimate the amount of CO 2 and overestimate CH 3 OH ices in planetesimals by disregarding chemical processing between the cloud and disc phases. The overall C/O and C/N ratios differ between the gas and solid phases. The two ice ratios show little variation beyond the inner 10 AU and both are nearly solar in the case of pure infall, but both are sub-solar when viscous spreading dominates. Chemistry in the protostellar envelope en route to the protoplanetary disc sets the initial volatile and prebiotically-significant content of icy planetesimals and cometary bodies. Comets are thus potentially reflecting the provenances of the midplane ices in the Solar Nebula.

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Section: Comparison With Cometscontrasting

confidence: 40%

Cometary ices in forming protoplanetary disc midplanes

Drozdovskaya¹,

Walsh²,

Dishoeck³

et al. 2016

Mon. Not. R. Astron. Soc.

101

137

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“…Organic molecules are commonly observed in many different astronomical sources (Herbst & van Dishoeck 2009) and the fact that many of the known interstellar organics are also present in protoplanetary disks and in comets (e.g. Öberg et al 2015;Walsh et al 2016;Cochran et al 2015;Biver et al 2015;Altwegg et al 2016) supports the view that interstellar clouds could plausibly be the first formation sites for the prebiotic molecules that may have been delivered to the early Earth by comets (e.g. Mumma & Charnley 2011).…”

Section: Introductionmentioning

confidence: 69%

Deep K-band Observations of TMC-1 with the Green Bank Telescope: Detection of HC₇O, Nondetection of HC₁₁N, and a Search for New Organic Molecules

Cordiner

Charnley²,

Kisiel

et al. 2017

ApJ

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The 100 m Robert C. Byrd Green Bank Telescope K-band (KFPA) receiver was used to perform a highsensitivity search for rotational emission lines from complex organic molecules in the cold interstellar medium towards TMC-1 (cyanopolyyne peak), focussing on the identification of new carbon-chain-bearing species as well as molecules of possible prebiotic relevance. We report a detection of the carbon-chain oxide species HC 7 O and derive a column density of (7.8 ± 0.9) × 10 11 cm −2 . This species is theorized to form as a result of associative electron detachment reactions between oxygen atoms and C 7 H − , and/or reaction of C 6 H 2 + with CO (followed by dissociative electron recombination). Upper limits are given for the related HC 6 O, C 6 O and C 7 O molecules. In addition, we obtained the first detections of emission from individual 13 C isotopologues of HC 7 N, and derive abundance ratios HC 7 N/HCCC 13 CCCCN = 110 ± 16 and HC 7 N/HCCCC 13 CCCN = 96 ± 11, indicative of significant 13 C depletion in this species relative to the local interstellar elemental 12 C/ 13 C ratio of 60-70. The observed spectral region covered two transitions of HC 11 N, but emission from this species was not detected, and the corresponding column density upper limit is 7.4 × 10 10 cm −2 (at 95% confidence). This is significantly lower than the value of 2.8 × 10 11 cm −2 previously claimed by Bell et al. (1997) and confirms the recent non-detection of HC 11 N in TMC-1 by Loomis et al. (2016). Upper limits were also obtained for the column densities of malononitrile and the nitrogen heterocycles quinoline, isoquinoline and pyrimidine.

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“…Since its first detection toward the Galactic Center (Hollis et al 2000; see also Hollis et al 2001;Hollis et al 2004;Halfen et al 2006;Requena-Torres et al 2008) it has been detected in a number of other places in the ISM, both associated with formation of stars of high (Beltrán et al 2009;Calcutt et al 2014), intermediate (Fuente et al 2014) and low mass (Jørgensen et al 2012;Coutens et al 2015;Taquet et al 2015). Recently, glycolaldehyde has also been detected in comet C/2014 Q2 (Lovejoy) (Biver et al 2015). Ethylene glycol is closely related to glycolaldehyde being its reduced alcohol version.…”

Section: Glycolaldehyde Ethylene Glycol and Acetic Acidmentioning

confidence: 99%

The ALMA Protostellar Interferometric Line Survey (PILS)

Jørgensen

Wiel

Coutens

et al. 2016

A&A

372

582

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Context. The inner regions of the envelopes surrounding young protostars are characterised by a complex chemistry, with prebiotic molecules present on the scales where protoplanetary disks eventually may form. The Atacama Large Millimeter/submillimeter Array (ALMA) provides an unprecedented view of these regions zooming in on Solar System scales of nearby protostars and mapping the emission from rare species. Aims. The goal is to introduce a systematic survey, "Protostellar Interferometric Line Survey (PILS)", of the chemical complexity of one of the nearby astrochemical templates, the Class 0 protostellar binary IRAS 16293−2422, using ALMA, to understand the origin of the complex molecules formed in its vicinity. In addition to presenting the overall survey, the analysis in this paper focuses on new results for the prebiotic molecule glycolaldehyde, its isomers and rarer isotopologues and other related molecules.Methods. An unbiased spectral survey of IRAS 16293−2422 covering the full frequency range from 329 to 363 GHz (0.8 mm) has been obtained with ALMA, in addition to a few targeted observations at 3.0 and 1.3 mm. The data consist of full maps of the protostellar binary system with an angular resolution of 0.5 (60 AU diameter), a spectral resolution of 0.2 km s −1 and a sensitivity of 4-5 mJy beam −1 km s −1 -approximately two orders of magnitude better than any previous studies. Results. More than 10,000 features are detected toward one component in the protostellar binary, corresponding to an average line density of approximately one line per 3 km s −1 . Glycolaldehyde, its isomers, methyl formate and acetic acid, and its reduced alcohol, ethylene glycol, are clearly detected and their emission well-modeled with an excitation temperature of 300 K. For ethylene glycol both lowest state conformers, aGg and gGg , are detected, the latter for the first time in the ISM. The abundance of glycolaldehyde is comparable to or slightly larger than that of ethylene glycol. In comparison to the Galactic Center these two species are over-abundant relative to methanol, possibly an indication of formation of the species at low temperatures in CO-rich ices during the infall of the material toward the central protostar. Both 13 C and deuterated isotopologues of glycolaldehyde are detected, also for the first time ever in the ISM. For the deuterated species a D/H ratio of ≈5% is found with no differences between the deuteration in the different functional groups of glycolaldehyde, in contrast to previous estimates for methanol and recent suggestions of significant equilibration between water and -OH functional groups at high temperatures. Measurements of the 13 C-species lead to a 12 C: 13 C ratio of ≈30, lower than the typical ISM value. This low ratio may reflect an enhancement of 13 CO in the ice due to either ion-molecule reactions in the gas before freeze-out or differences in the temperatures where 12 CO and 13 CO ices sublimate. Conclusions. The results reinforce the importance of low temperature grain surfac...

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Ethyl alcohol and sugar in comet C/2014 Q2 (Lovejoy)

Abstract: First detections of ethyl alcohol and glycolaldehyde in a comet provide new constraints on solar system chemical complexity.

Cited by 141 publications

References 33 publications

Cometary ices in forming protoplanetary disc midplanes

Cometary ices in forming protoplanetary disc midplanes

Deep K-band Observations of TMC-1 with the Green Bank Telescope: Detection of HC₇O, Nondetection of HC₁₁N, and a Search for New Organic Molecules

The ALMA Protostellar Interferometric Line Survey (PILS)

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Ethyl alcohol and sugar in comet C/2014 Q2 (Lovejoy)

Abstract: First detections of ethyl alcohol and glycolaldehyde in a comet provide new constraints on solar system chemical complexity.

Cited by 141 publications

References 33 publications

Cometary ices in forming protoplanetary disc midplanes

Cometary ices in forming protoplanetary disc midplanes

Deep K-band Observations of TMC-1 with the Green Bank Telescope: Detection of HC7O, Nondetection of HC11N, and a Search for New Organic Molecules

The ALMA Protostellar Interferometric Line Survey (PILS)

Contact Info

Product

Resources

About

Deep K-band Observations of TMC-1 with the Green Bank Telescope: Detection of HC₇O, Nondetection of HC₁₁N, and a Search for New Organic Molecules