On methyl formate, methane, and deuterated ammonia in Orion A

Elldér, J.; Friberg, Per; Hjalmarson, Å.; Höglund, B.; Johansson, Lars; Olofsson, H.; Rydbeck, G.; Rydbeck, O. E. H.; Guèlin, M.; Irvine, W. M.

doi:10.1086/183410

Cited by 44 publications

(25 citation statements)

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“…This species has been found in the interstellar medium 1,2 and in the coma of the Hale-Bopp comet. 3 It has been suggested that it may be a key compound in the formation of glycine (NH 2 CH 2 COOH) in the interstellar medium.…”

Section: ■ Introductionmentioning

confidence: 91%

Dimers of the Higher-Energy Conformer of Formic Acid: Experimental Observation

et al. 2012

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We report on the first experimental observation of formic acid dimers composed of two molecules of the higher-energy cis conformer. The cis−cis formic acid dimers are prepared in an argon matrix by selective vibrational excitation of the ground state trans conformer (deuterated form HCOOD) combined with thermal annealing of the matrix at about 30 K. Five cis−cis formic acid dimers are predicted by ab initio calculations (interaction energies from −16.9 to −27.2 kJ mol −1 ), and these structures are used for the assignment of the experimental spectra. Selective vibrational excitation of the obtained cis−cis dimers leads to the formation of several trans−cis dimers, which supports the proposed assignments.

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Section: ■ Introductionmentioning

confidence: 91%

Dimers of the Higher-Energy Conformer of Formic Acid: Experimental Observation

et al. 2012

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“…Two other species worth mentioning are the two isomers of glycolaldehyde, methyl formate (CH 3 OCHO) and acetic acid (CH 3 COOH). The former is relatively common in high-mass star forming regions (e.g., Brown et al 1975;Ellder et al 1980;Blake et al 1987;MacDonald et al 1996;Gibb et al 2000;Bisschop et al 2007) and has also been detected toward low-mass protostars (e.g., Cazaux et al 2003;Bottinelli et al 2004a;Jør-gensen et al 2005a;Sakai et al 2006) and even prestellar cores (e.g. Öberg et al 2010;Bacmann et al 2012), while acetic acid is less abundant (Mehringer et al 1997;Remijan et al 2002) and tentatively detected toward low-mass protostars (Cazaux et al 2003;Shiao et al 2010).…”

Section: Glycolaldehyde Ethylene Glycol and Acetic Acidmentioning

confidence: 98%

The ALMA Protostellar Interferometric Line Survey (PILS)

Jørgensen

Wiel

Coutens

et al. 2016

A&A

380

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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“…Methyl formate (HCOOCH 3 ) is a relatively abundant molecule in interstellar hot cores and corinos (Ellder et al 1980;Blake et al 1987;Millar et al 1997;Hatchell et al 1998;Nummelin et al 2000;Cazaux et al 2003;Bottinelli et al 2004aBottinelli et al , 2004b. In fact, its spectrum is so rich that it is known informally as an interstellar weed.…”

Section: Introductionmentioning

confidence: 99%

The Millimeter‐ and Submillimeter‐Wave Spectrum of¹³C₁‐Methyl Formate (H¹³COOCH₃) in the Ground State

Maeda

Medvedev

Lucia

et al. 2008

ASTROPHYS J SUPPL S

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A large number of rotational transitions of 13 C 1 -methyl formate in its ground A and E torsional substates were measured in the 110Y380 GHz region with the Fast Scan Submillimeter Spectroscopic Technique (FASSST). Besides strong a-type transitions, many b-type transitions through rotational quantum numbers J 00 ¼ 59 and K 00 a ¼ 16 were newly measured, and some forbidden c-and x-type transitions in the E substate were also assigned. The new lines were analyzed together with previous submillimeter-wave data using an effective rotational-torsional Hamiltonian method designated ''ERHAM'' developed for a molecule with one or two internal rotors. In total, over 4900 transitions of 13 C 1 -methyl formate were analyzed. Systematic deviations due to perturbations were found in Q-branch transitions at high J, and higher order Coriolis-type interaction terms were included to fit the data better. A standard deviation of 86 kHz was obtained by varying 33 parameters. In addition to 13 C 1 -methyl formate, the normal isotopologue was studied anew and some high-K a transitions were newly assigned. The previous data of the normal species in the ground state were reanalyzed with the ERHAM method together with new transitions measured in the present study. The same deviations in Q-branch transitions, not observed in previous studies, were also found in the normal species. Using spectroscopic parameters obtained in this study, predictions have been made for many strong lines of 13 C 1 -methyl formate through 620 GHz in frequency not analyzed in the fit.

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On methyl formate, methane, and deuterated ammonia in Orion A

Cited by 44 publications

References 0 publications

Dimers of the Higher-Energy Conformer of Formic Acid: Experimental Observation

Dimers of the Higher-Energy Conformer of Formic Acid: Experimental Observation

The ALMA Protostellar Interferometric Line Survey (PILS)

The Millimeter‐ and Submillimeter‐Wave Spectrum of¹³C₁‐Methyl Formate (H¹³COOCH₃) in the Ground State

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On methyl formate, methane, and deuterated ammonia in Orion A

Cited by 44 publications

References 0 publications

Dimers of the Higher-Energy Conformer of Formic Acid: Experimental Observation

Dimers of the Higher-Energy Conformer of Formic Acid: Experimental Observation

The ALMA Protostellar Interferometric Line Survey (PILS)

The Millimeter‐ and Submillimeter‐Wave Spectrum of13C1‐Methyl Formate (H13COOCH3) in the Ground State

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The Millimeter‐ and Submillimeter‐Wave Spectrum of¹³C₁‐Methyl Formate (H¹³COOCH₃) in the Ground State