Acetic Acid in the Hot Cores of Sagitarrius B2(N) and W51

Remijan, Anthony J.; Snyder, L. E.; Liu, Sheng-Yuan; Mehringer, David M.; Kuan, Yi‐Jehng

doi:10.1086/341627

Cited by 90 publications

(88 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Acetic acid has been observed to be between 1/10 to 1/100 less abundant than methyl formate (Mehringer et al 1997;Remijan et al 2002Remijan et al , 2003Cazaux et al 2003), whereas the abundance of ethanol has been found to be between 0.3 and 3 times that of dimethyl ether (Millar et al 1988;Ikeda et al 2001;Nummelin et al 1998a;White et al 2003). The contradiction with the MEP comes from the relative stabilities of these isomers.…”

Section: Discussion and Concluding Remarksmentioning

confidence: 99%

Differential adsorption of complex organic molecules isomers at interstellar ice surfaces

Lattelais

Bertin

Mokrane

et al. 2011

A&A

View full text Add to dashboard Cite

Context. Over 20 of the ∼150 different species detected in the interstellar and circumstellar media have also been identified in icy environments. For most of the species observed so far in the interstellar medium (ISM), the most abundant isomer of a given generic chemical formula is the most stable one (minimum energy principle -MEP) with few exceptions such as, for example, CH 3 COOH/HCOOCH 3 and CH 3 CH 2 OH/CH 3 OCH 3 , whose formation is thought to occur on the icy mantles of interstellar grains. Aims. We investigate whether differences found in the compositions of molecular ices and the surrounding gas phase could originate from differences between the adsorption of one isomer from that of another at the ice surface. Methods. We performed a coherent and concerted theoretical/experimental study of the adsorption energies of the four molecules mentioned above, i.e. acetic acid (AA)/methyl formate (MF) and ethanol (EtOH)/dimethyl ether (DME) on the surface of water ice at low temperature. The question was first addressed theoretically at LCT using solid state periodic density functional theory (DFT) to represent the organized solid support. The experimental determination of the ice/molecule interaction energies was then carried out independently by two teams at LPMAA and LERMA/LAMAp using temperature programmed desorption (TPD) under an ultra-high vacuum (UHV) between 70 and 160 K. Results. For each pair of isomers, theory and experiments both agree that the most stable isomer (AA or EtOH) interacts more efficiently with the water ice than the higher energy isomer (MF or DME). This differential adsorption can be clearly seen in the different desorption temperatures of the isomers. It is not related to their intrinsic stability but instead to both AA and EtOH producing more and stronger hydrogen bonds with the ice surface. Conclusions. We show that hydrogen bonding may play an important role in the release of organic species from grains and propose that, depending on the environment, differential adsorption should not be rejected as a possible way of interpreting MEP exceptions.

show abstract

Section: Discussion and Concluding Remarksmentioning

confidence: 99%

Differential adsorption of complex organic molecules isomers at interstellar ice surfaces

Lattelais

Bertin

Mokrane

et al. 2011

A&A

View full text Add to dashboard Cite

show abstract

“…The chemistry of the W51e2 region has been investigated by several groups. For example, Zhang et al (1998) has done CH 3 CN and CS (3-2) observations, Remijan et al (2004Remijan et al ( , 2002 investigated CH 3 CN and CH 3 COOH, Liu et al (2001) looked for HCOOH in this source and Kuan et al (2004) searched for several molecules of potential prebiotic importance. The hydrogen column density 3.6 × 10 23 cm −2 (Ikeda et al 2001) is based on C 18 O data from Schloerb et al (1987).…”

Section: Source Selectionmentioning

confidence: 99%

Trans-ethyl methyl ether in space

Fuchs

Fuchs²,

Giesen³

et al. 2005

A&A

View full text Add to dashboard Cite

An extensive search for the complex molecule trans-ethyl methyl ether towards several hot core regions has been performed. Using the IRAM 30 m telescope and the SEST 15 m we looked at several frequencies where trans-ethyl methyl ether has strong transitions, as well as lines which are particularly sensitive to the physical conditions in which the molecule can be found. We included G34.26, NGC 6334(I), Orion KL, and W51e2 which have previously been proven to have a rich chemistry of complex molecules. Our observations cannot confirm the tentative Orion KL detection made by Charnley et al. (2001) within their stated column density limits, but we confirm the existence of the trans-ethyl methyl ether towards W51e2 with a column density of 2 × 10 14 cm −2 . The dimethyl ether/methanol ratio of 0.6 as well as the newly found ethyl methyl ether/ethanol ratio of 0.13 indicate relative high abundances of ethers toward W51e2. Furthermore, the observation of ethyl methyl ether also confirms the importance of ethanol as a grain mantle constituent. We present new upper limits of around 8 × 10 13 cm −2 for the column densities of the molecule toward Orion KL, G34.26, NGC 6334(I) and estimate the column density towards SgrB2(N) to be of the same order. The W51e2 observations are discussed in more detail.

show abstract

“…We present observations searching for PN and PO toward two massive starforming regions: the W51 e1/e2 and the W3(OH) complexes (with luminosities of 1.5 × 10 6 and 1.0 × 10 5 L e , respectively). The W51 star-forming region, located at a distance of 5.1 kpc (Xu et al 2009) in the Sagittarius arm of our Galaxy, harbors two compact radio sources (Scott 1978) known as e1 and e2, which are associated with hot molecular cores with a rich chemistry (Zhang & Ho 1997;Zhang et al 1998;Ikeda et al 2001;Liu et al 2001;Remijan et al 2002;Demyk et al 2008;Kalenskii & Johansson 2010;Lykke et al 2015). The W3(OH) complex, located at 2.04 kpc (Hachisuka et al 2006), harbors two massive objects separated by 6″: the UC H II region W3(OH) (Wilner et al 1995) and the chemically rich W3(H 2 O) hot molecular core (Wyrowski et al 1999;Zapata et al 2011;Qin et al 2015).…”

Section: Introductionmentioning

confidence: 99%

The First Detections of the Key Prebiotic Molecule Po in Star-Forming Regions

Rivilla

Fontani

Beltrán

et al. 2016

ApJ

110

135

View full text Add to dashboard Cite

Phosphorus is a crucial element in biochemistry, in particular the P−O bond, which is key in the formation of the backbone of deoxyribonucleic acid. So far, PO has only been detected toward the envelope of evolved stars, but never toward star-forming regions. We report the first detection of PO toward two massive star-forming regions, W51 e1/e2 and W3(OH), using data from the IRAM 30 m telescope. PN has also been detected toward the two regions. The abundance ratio PO/PN is 1.8 and 3 for W51 and W3(OH), respectively. Our chemical model indicates that the two molecules are chemically related and are formed via gas-phase ion-molecule and neutralneutral reactions during cold collapse. The molecules freeze out onto grains at the end of the collapse and desorb during the warm-up phase once the temperature reaches ∼35 K. Similar abundances of the two species are expected during a period of ∼5 × 10 4 yr at the early stages of the warm-up phase, when the temperature is in the range 35-90 K. The observed molecular abundances of 10 −10 are predicted by the model if a relatively high initial abundance of 5 × 10 −9 of depleted phosphorus is assumed.

show abstract

Acetic Acid in the Hot Cores of Sagitarrius B2(N) and W51

Cited by 90 publications

References 36 publications

Differential adsorption of complex organic molecules isomers at interstellar ice surfaces

Differential adsorption of complex organic molecules isomers at interstellar ice surfaces

Trans-ethyl methyl ether in space

The First Detections of the Key Prebiotic Molecule Po in Star-Forming Regions

Contact Info

Product

Resources

About