scholarly journals Carbon-chain Chemistry versus Complex-organic-molecule Chemistry in Envelopes around Three Low-mass Young Stellar Objects in the Perseus Region

2021 ◽  
Vol 910 (2) ◽  
pp. 141
Author(s):  
Kotomi Taniguchi ◽  
Liton Majumdar ◽  
Shigehisa Takakuwa ◽  
Masao Saito ◽  
Dariusz C. Lis ◽  
...  
2008 ◽  
Vol 4 (S251) ◽  
pp. 105-110 ◽  
Author(s):  
Sandrine Bottinelli ◽  
Adwin C. A. Boogert ◽  
Ewine F. van Dishoeck ◽  
Martha Beckwith ◽  
Jordy Bouwman ◽  
...  

AbstractNH3 and CH3OH are key molecules in the chemical networks leading to the formation of complex N- and O-bearing organic molecules. However, despite a number of recent studies, there is still a lot to learn about their abundances in the solid state and how they relate to those of other N/O-bearing organic molecules or to NH3 and CH3OH abundances in the gas phase. This is particularly true in the case of low-mass young stellar objects (YSOs), for which only the recent advent of the Spitzer Space Telescope has allowed high sensitivity observations of the ices in their enveloppes. We present a combined study of Spitzer data (obtained within the Legacy program “From Molecular Cores to Planet-Forming Disks”, c2d) and laboratory spectra, leading to the detections of NH3 and CH3OH in the ices of low-mass protostars. We investigate correlations with other ice features and conclude with prospects on further studies linking these two precursors of complex organic molecules with their gas-phase products.


1997 ◽  
Vol 182 ◽  
pp. 391-405 ◽  
Author(s):  
Lee Hartmann

Outflows from low-mass young stellar objects are thought to draw upon the energy released by accretion onto T Tauri stars. I briefly summarize the evidence for this accretion and outline present estimates of mass accretion rates. Young stars show a very large range of accretion rates, and this has important implications for both mass ejection and for the structure of stellar magnetospheres which may truncate T Tauri disks.


2012 ◽  
Vol 58 ◽  
pp. 349-352
Author(s):  
M. Bertin ◽  
X. Michaut ◽  
M. Lattelais ◽  
H. Mokrane ◽  
F. Pauzat ◽  
...  

1995 ◽  
pp. 117-120
Author(s):  
K. F. Schuster ◽  
A. P. G. Russell ◽  
A. I. Harris

2019 ◽  
Vol 629 ◽  
pp. A28 ◽  
Author(s):  
Natalia Inostroza ◽  
Diego Mardones ◽  
Jose Cernicharo ◽  
Hans Zinnecker ◽  
Jixing Ge ◽  
...  

We present a detailed simulation of a dust grain covered by a decamer of (CH3OH)10-ice-mantle, bombarded by an OH− closed-shell molecule with kinetic energies from 10–22 eV. The chemical pathways are studied through Born-Oppenheimer (ab initio) molecular dynamics. The simulations show that methanol ice-mantles can be a key generator of complex organic molecules (COMs). We report the formation of COMs such as methylene glycol (CH2(OH)2) and the OCH2OH radical, which have not been detected yet in the interstellar medium (ISM). We discuss the chemical formation of new species through the reaction of CH3OH with the hydroxyl projectile. The dependence of the outcome on the kinetic energy of the projectile and the implications for the observation and detection of these molecules might explain why the methoxy radical (CH3  ⋅ ) has been observed in a wider range of astrophysical environments than the hydroxymethyl (CH2OH ⋅) isomer. Because of the projectile kinetic energies required for these reactions to occur, we suggest that these processes are likely relevant in the production of COMs in photodissociation and shock regions produced by high-velocity jets and outflows from young stellar objects.


2000 ◽  
Vol 197 ◽  
pp. 61-70
Author(s):  
Nagayoshi Ohashi

We have carried out interferometric observations of pre-protostellar and protostellar envelopes in Taurus. Protostellar envelopes are dense gaseous condensations with young stellar objects or protostars, while pre-protostellar envelopes are those without any known young stellar objects. Five pre-protostellar envelopes have been observed in CCS JN=32–21, showing flattened and clumpy structures of the envelopes. The observed CCS spectra show moderately narrow line widths, ~0.1 to ~0.35 km s–1. One pre-protostellar envelope, L1544, shows a remarkable velocity pattern, which can be explained in terms of infall and rotation. Our C18O J=1–0 observations of 8 protostellar envelopes show that they have also flattened structures like pre-protostellar envelopes but no clumpy structures. Four out the eight envelopes show velocity patterns that can be explained by motions of infall (and rotation). Physical properties of pre-protostellar and protostellar envelopes are discussed in detail.


1998 ◽  
Vol 502 (1) ◽  
pp. 315-336 ◽  
Author(s):  
Michiel R. Hogerheijde ◽  
Ewine F. van Dishoeck ◽  
Geoffrey A. Blake ◽  
Huib Jan van Langevelde

2003 ◽  
Vol 55 (3) ◽  
pp. 653-681 ◽  
Author(s):  
Kensuke Imanishi ◽  
Hiroshi Nakajima ◽  
Masahiro Tsujimoto ◽  
Katsuji Koyama ◽  
Yohko Tsuboi

2019 ◽  
Author(s):  
Debora Scuderi ◽  
Ariel F. Perez-Mellor ◽  
Joël Lemaire ◽  
Suvasthika Indrajith ◽  
Jean-Xavier Bardaud ◽  
...  

<p>In the present study, we have shown for the first time how glycine can be synthesized under prebiotic-like conditions using an Infra-Red laser to trigger the reaction. In particular, we observed that in the low-density conditions it can be obtained from simple ion-molecule reactions of acetic acid and protonated hydroxylamine. This reaction, studied years ago in more dense conditions [<i>J. Am. Chem. Soc.</i> <b>2007</b>, <i>129</i>, 9910-9917R], was the center of a controversy, since accurate quantum chemistry calculations have shown that it is not barrierless [<i>Astrophys. J.</i> <b>2012</b>, <i>748</i>, 99] such that a source of energy is needed. In space, and more in general in prebiotic conditions (interstellar medium, comets, asteroids) temperature is very low but the photon density can be important. Here we propose a way of synthesizing such complex organic molecule in a very low-pressure environment (about 10<sup>-3</sup> mbar). This way of forming complex organic molecule is of relevance also beyond the prebiotic interest of finding a scenario which was at the origin of the synthesis of such molecules. In fact our work proposes a new way of assisting reactions using IR radiation. Only few cases were found in which IR can trigger complex reactions (i.e. not simple dissociations) while there is a clear interest of using such low-energy radiation. This study will be at the basis of new researches devoted to find other reactions which can be assisted by IR laser.</p>


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