2007MNRAS.382..733R


C.D.S. - SIMBAD4 rel 1.7 - 2020.01.21CET17:58:50

2007MNRAS.382..733R - Mon. Not. R. Astron. Soc., 382, 733-742 (2007/December-1)

Desorption from interstellar ices.

ROBERTS J.F., RAWLINGS J.M.C., VITI S. and WILLIAMS D.A.

Abstract (from CDS):

The desorption of molecular species from ice mantles back into the gas phase in molecular clouds results from a variety of very poorly understood processes. We have investigated three mechanisms: desorption resulting from H2 formation on grains, direct cosmic ray heating and cosmic ray-induced photodesorption. Whilst qualitative differences exist between these processes (essentially deriving from the assumptions concerning the species selectivity of the desorption and the assumed threshold adsorption energies, Et), all the three processes are found to be potentially very significant in dark cloud conditions. It is therefore important that all three mechanisms should be considered in studies of molecular clouds in which freeze-out and desorption are believed to be important.

Employing a chemical model of a typical static molecular core and using likely estimates for the quantum yields of the three processes, we find that desorption by H2 formation probably dominates over the other two mechanisms. However, the physics of the desorption processes and the nature of the dust grains and ice mantles are very poorly constrained. We therefore conclude that the best approach is to set empirical constraints on the desorption, based on observed molecular depletions - rather than try to establish the desorption efficiencies from purely theoretical considerations. Applying this method to one such object (L1689B) yields upper limits to the desorption efficiencies that are consistent with our understanding of these mechanisms.


Abstract Copyright: 2007 The Authors. Journal compilation © 2007 RAS

Journal keyword(s): astrochemistry - molecular processes - stars: formation - ISM: abundances - dust, extinction - ISM: molecules

Simbad objects: 11

goto Full paper

goto View the reference in ADS

Number of rows : 11

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 TMC-1 CP Cld 04 41 34.97 +25 38 53.2           ~ 34 1
2 TMC-1 MoC 04 41 45.9 +25 41 27           ~ 1333 0
3 LDN 1544 DNe 05 04 16.6 +25 10 48           ~ 661 0
4 NAME [BM89] L1544 cor 05 04 22.5 +25 11 36           ~ 434 1
5 LDN 183 MoC 15 54 12.2 -02 49 42           ~ 675 1
6 NAME Ophiuchus D MoC 16 28 29.2 -24 18 25           ~ 102 0
7 LDN 1709A DNe 16 30 50.7 -23 41 03           ~ 24 0
8 LDN 1689B DNe 16 34 42.1 -24 36 11           ~ 131 0
9 LDN 310 DNe 18 07 12 -18 21.6           ~ 10 0
10 LDN 429 DNe 18 16 44 -08 18.9           ~ 31 0
11 LDN 328 DNe 18 17 00 -18 01.9           ~ 46 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2007MNRAS.382..733R and select 'bookmark this link' or equivalent in the popup menu


2020.01.21-17:58:50

© Université de Strasbourg/CNRS

    • Contact