Detection of Methyl Alcohol in Sagittarius

Ball, John A.; Gottlieb, C. A.; Lilley, A. E.; Radford, H. E.

doi:10.1086/180654

Cited by 175 publications

(122 citation statements)

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“…The detection of acetaldehyde was first reported toward Sgr B2 (Ball et al 1971) and the molecule has been observed in cold dark clouds and translucent clouds (Turner et al 1999). Interestingly, Chengalur & Kanekar (2003) observed that CH 3 CHO is more widespread toward the Galactic center than most other complex organic molecules.…”

Section: B18 Ch 3 Chomentioning

confidence: 94%

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Molecules atz= 0.89

Müller

Beelen

Guèlin

et al. 2011

A&A

163

284

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We present the results of a 7 mm spectral survey of molecular absorption lines originating in the disk of a z = 0.89 spiral galaxy located in front of the quasar PKS 1830−211. Our survey was performed with the Australia Telescope Compact Array and covers the frequency interval 30-50 GHz, corresponding to the rest-frame frequency interval 57-94 GHz. A total of 28 different species, plus 8 isotopic variants, were detected toward the south-west absorption region, located about 2 kpc from the center of the z = 0.89 galaxy, which therefore has the largest number of detected molecular species of any extragalactic object so far. The results of our rotation diagram analysis show that the rotation temperatures are close to the cosmic microwave background temperature of 5.14 K that we expect to measure at z = 0.89, whereas the kinetic temperature is one order of magnitude higher, indicating that the gas is subthermally excited. The molecular fractional abundances are found to be in-between those in typical Galactic diffuse and translucent clouds, and clearly deviate from those observed in the dark cloud TMC 1 or in the Galactic center giant molecular cloud Sgr B2. The isotopic ratios of carbon, nitrogen, oxygen, and silicon deviate significantly from the solar values, which can be linked to the young age of the z = 0.89 galaxy and a release of nucleosynthesis products dominated by massive stars. Toward the north-east absorption region, where the extinction and column density of gas is roughly one order of magnitude lower than toward the SW absorption region, only a handful of molecules are detected. Their relative abundances are comparable to those in Galactic diffuse clouds. We also report the discovery of several new absorption components, with velocities spanning between −300 and +170 km s −1 . Finally, the line centroids of several species (e.g., CH 3 OH, NH 3 ) are found to be significantly offset from the average velocity. If caused by a variation in the proton-to-electron mass ratio μ with redshift, these offsets yield an upper limit | Δμ μ | < 4×10 −6 , which takes into account the kinematical noise produced by the velocity dispersion measured from a large number of molecular species.

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Section: B18 Ch 3 Chomentioning

confidence: 94%

“…Interstellar methanol was first detected toward Sgr B2 and Sgr A by Ball et al (1970) and is widely observed toward star forming Notes. For species with hyperfine structure, the relative intensities were fixed, and the given uncertainty corresponds to that in the total integrated intensity.…”

Section: B8 Ch 3 Ohmentioning

confidence: 99%

Molecules atz= 0.89

Müller

Beelen

Guèlin

et al. 2011

A&A

163

284

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“…methanol (CH 3 OH; Ball et al 1970;Gottlieb et al 1979), methyl formate (HCOOCH 3 ; Churchwell & Winnewisser 1975;Favre et al 2014), acetaldehyde (CH 3 CHO; Fourikis et al 1974;Matthews et al 1985), acetic acid (CH 3 COOH; Mehringer et al 1997;Remijan et al 2003) and acetamide (CH 3 CONH 2 ; Hollis et al 2006; Halfen et al 2011). On the other hand, fewer molecules Sulfur-containing molecules can be important in the chemical evolution of hot cores.…”

Section: Introductionmentioning

confidence: 99%

Laboratory microwave, millimeter wave and far-infrared spectra of dimethyl sulfide

Jabri

Van

Nguyen

et al. 2016

A&A

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Context. Dimethyl sulfide, CH 3 SCH 3 (DMS), is a nonrigid, sulfur-containing molecule whose astronomical detection is considered to be possible in the interstellar medium. Very accurate spectroscopic constants were obtained by a laboratory analysis of rotational microwave and millimeter wave spectra, as well as rotation-torsional far-infrared (FIR) spectra, which can be used to predict transition frequencies for a detection in interstellar sources. Aims. This work aims at the experimental study and theoretical analysis of the ground torsional state and ground torsional band ν 15 of DMS in a large spectral range for astrophysical use. Methods. The microwave spectrum was measured in the frequency range 2−40 GHz using two Molecular Beam Fourier Transform MicroWave (MB-FTMW) spectrometers in Aachen, Germany. The millimeter spectrum was recorded in the 50−110 GHz range. The FIR spectrum was measured for the first time at high resolution using the FT spectrometer and the newly built cryogenic cell at the French synchrotron SOLEIL. Results. DMS has two equivalent methyl internal rotors with a barrier height of about 730 cm −1 . We performed a fit, using the XIAM and BELGI-C s -2Tops codes, that contained the new measurements and previous transitions reported in the literature for the ground torsional state ν t = 0 (including the four torsional species AA, AE, EA and EE) and for the ground torsional band ν 15 = 1 ← 0 (including only the AA species). In the microwave region, we analyzed 584 transitions with J ≤ 30 of the ground torsional state ν t = 0 and 18 transitions with J ≤ 5 of the first excited torsional state ν t = 1. In the FIR range, 578 transitions belonging to the torsional band ν 15 = 1 ← 0 with J ≤ 27 were assigned. Totally, 1180 transitions were included in a global fit with 21 accurately determined parameters. These parameters can be used to produce a reliable line-list for an astrophysical detection of DMS.

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“…Among the most exciting species discovered, one may consider the first aldehyde H 2 CO (Snyder et al 1969), the first alcohol CH 3 OH (Ball et al 1970), the first conjugated molecule HC 3 N (Turner 1971), the first acid HCOOH (Zuckerman et al 1971) and the first alkyl cyanide CH 3 CN (Solomon et al 1971). It is also the time when formamide NH 2 CHO, the simplest model of the peptide bond was identified in Sgr B2 (Rubin et al 1971).…”

Section: Introductionmentioning

confidence: 99%

A new weapon for the interstellar complex organic molecule hunt: the minimum energy principle

Lattelais¹,

Pauzat²,

Ellinger³

et al. 2010

A&A

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Context. The hunt for the interstellar complex organic molecules (COMs) supposed to be the building blocks of the molecules at the origin of life is a challenging but very expensive task. It starts with laboratory experiments, associated with theoretical calculations, that give the line frequencies and strengths of the relevant molecules to be identified and finishes with observations at the telescopes. Aims. The present study aims to suggest possible guidelines to optimize this hunt. Levering on the minimum energy principle (MEP) presented in a previous study, we discuss the link between thermodynamic stability and detectability of a number of structures in the important families of amides, sugars and aminonitriles. Methods. The question of the relative stability of these different species is addressed by means of quantum density functional theory simulations. The hybrid B3LYP formalism was used throughout. All 72 molecules part of this survey were treated on an equal footing. Each structure, fully optimized, was verified to be a stationary point by vibrational analysis. Results. A comprehensive screening of 72 isomers of CH 3 NO, C 2 H 5 NO, C 3 H 7 NO, C 2 H 4 O 2 , C 3 H 6 O 3 and C 2 H 4 N 2 chemical formula has been carried out. We found that formamide, acetamide and propanamide (the first two identified in the Inter-Stellar Medium) are the most stable compounds in their families demonstrating at the same time that the peptide bond >N-C=O at the origin of life is the most stable bond that can be formed. Dihydroxyacetone, whose detection awaits for confirmation, is far from being the most stable isomer of its family while aminoacetonitrile, that has been recently identified, is effectively the most stable species. Conclusions. The MEP appears to be a useful tool for optimizing the hunt for new species by identifying the potentially more abundant isomers of a given chemical formula.

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Detection of Methyl Alcohol in Sagittarius

Cited by 175 publications

References 0 publications

Molecules atz= 0.89

Molecules atz= 0.89

Laboratory microwave, millimeter wave and far-infrared spectra of dimethyl sulfide

A new weapon for the interstellar complex organic molecule hunt: the minimum energy principle

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