C.D.S. - SIMBAD4 rel 1.7 - 2021.01.18CET20:20:04

2015A&A...579A..82R - Astronomy and Astrophysics, volume 579A, 82-82 (2015/7-1)

Chemistry in protoplanetary disks: the gas-phase CO/H2 ratio and the carbon reservoir.


Abstract (from CDS):

The gas mass of protoplanetary disks and the gas-to-dust ratio are two key elements driving the evolution of these disks and the formation of planetary system. We explore to what extent CO (or its isotopologues) can be used as a tracer of gas mass. We use a detailed gas-grain chemical model and study the evolution of the disk composition, starting from a dense prestellar core composition. We explore a range of disk temperature profiles, cosmic-ray ionization rates, and disk ages for a disk model representative of T Tauri stars. At the high densities that prevail in disks, we find that because of fast reactions on grain surfaces, CO can be converted to less volatile forms (principally s-CO2, and to a lesser extent s-CH4) instead of being evaporated over a wide range of temperature. The canonical gas-phase abundance of 10–4 is only reached above about 30-35K. The dominant carbon bearing entity depends on the temperature structure and age of the disk. The chemical evolution of CO is also sensitive to the cosmic-ray ionization rate. Larger gas phase CO abundances are found in younger disks. Initial conditions, such as parent cloud age and density, have a limited impact. This study reveals that CO gas-phase abundance is heavily dependent on grain surface processes, which remain very incompletely understood so far. The strong dependence on dust temperature profile makes CO a poor tracer of the gas-phase content of disks.

Abstract Copyright:

Journal keyword(s): astrochemistry - protoplanetary disks - molecular processes

Simbad objects: 6

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Number of rows : 6

N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
1 V* BP Tau Or* 04 19 15.8342975037 +29 06 26.929456808   13.13 12.12 11.89   K5/7Ve 611 0
2 V* DM Tau Or* 04 33 48.7335659850 +18 10 09.974471722 14.30 14.82 14.00     M2Ve 529 0
3 V* RW Aur TT* 05 07 49.5662483 +30 24 05.177426   10.86 9.60 9.95   K1/5e+K5e 726 0
4 HD 36112 Ae* 05 30 27.5286772598 +25 19 57.082162439   8.57 8.27     A8Ve 376 0
5 V* CQ Tau Ae* 05 35 58.4671238887 +24 44 54.086375712 11.290 10.780 10.000   8.33 F5IVe 264 0
6 V* TW Hya TT* 11 01 51.9054298616 -34 42 17.031550898   11.94 10.50 10.626 9.18 K6Ve 1586 1

    Equat.    Gal    SGal    Ecl

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