2008A&A...491..821S


Query : 2008A&A...491..821S

2008A&A...491..821S - Astronomy and Astrophysics, volume 491, 821-827 (2008/12-1)

Chemistry in disks. II. Poor molecular content of the AB Aurigae disk.

SCHREYER K., GUILLOTEAU S., SEMENOV D., BACMANN A., CHAPILLON E., DUTREY A., GUETH F., HENNING T., HERSANT F., LAUNHARDT R., PETY J. and PIETU V.

Abstract (from CDS):

We study the molecular content and chemistry of a circumstellar disk surrounding the Herbig Ae star AB Aur at (sub-)millimeter wavelengths. Our aim is to reconstruct the chemical history and composition of the AB Aur disk and to compare it with disks around low-mass, cooler T Tauri stars. We observe the AB Aur disk with the IRAM Plateau de Bure Interferometer in the C- and D-configurations in rotational lines of CS, HCN, C2H, CH3OH, HCO+, and CO isotopes. Using an iterative minimization technique, observed columns densities and abundances are derived. These values are further compared with results of an advanced chemical model that is based on a steady-state flared disk structure with a vertical temperature gradient, and gas-grain chemical network with surface reactions. We firmly detect HCO+ in the 1-0 transition, tentatively detect HCN, and do not detect CS, C2H, and CH3OH. The observed HCO+ and 13CO column densities as well as the upper limits to the column densities of HCN, CS, C2H, and CH3OH are in good agreement with modeling results and those from previous studies. The AB Aur disk possesses more CO, but is less abundant in other molecular species compared to the DM Tau disk. This is primarily caused by intense UV irradiation from the central Herbig A0 star, which results in a hotter disk where CO freeze out does not occur and thus surface formation of complex CO-bearing molecules might be inhibited.

Abstract Copyright:

Journal keyword(s): stars: circumstellar matter - stars: planetary systems: protoplanetary disks - stars: individual: AB Aurigae - radio lines: stars

Simbad objects: 12

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Number of rows : 12
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 3C 84 Sy2 03 19 48.1599902040 +41 30 42.108850836   13.10 12.48 11.09   ~ 3766 3
2 V* T Tau TT* 04 21 59.4319873992 +19 32 06.432393336   11.22 10.12 9.80   K0IV/Ve 1364 1
3 V* DM Tau Or* 04 33 48.7336763736 +18 10 09.973460280 14.30 14.82 14.00     M2Ve 579 0
4 EM* LkCa 15 Or* 04 39 17.7911622816 +22 21 03.390090984   13.01 12.03 11.61   K5:Ve 612 1
5 RAFGL 618 pA* 04 42 53.6242032600 +36 06 53.400902220   16.32   12.59   C-rich 981 0
6 V* AB Aur Ae* 04 55 45.8458932216 +30 33 04.292077032 7.20 7.16 7.05 6.96 6.70 A0Ve 992 2
7 HD 31648 Ae* 04 58 46.2655706952 +29 50 36.987625680 7.84 7.78 7.62 7.76 7.43 A5Vep 458 0
8 * bet Pic PM* 05 47 17.0876901 -51 03 59.441135 4.13 4.03 3.86 3.74 3.58 A6V 1781 1
9 3C 345 QSO 16 42 58.8102993888 +39 48 37.002763188   16.81 16.59 16.84   ~ 1615 2
10 * alf Lyr dS* 18 36 56.33635 +38 47 01.2802 0.03 0.03 0.03 0.07 0.10 A0Va 2591 0
11 EM* MWC 349 ** 20 32 45.499080 +40 39 36.74124   15.88 13.15 12.13   Bep 752 0
12 * alf PsA ** 22 57 39.04625 -29 37 20.0533 1.31 1.25 1.16 1.11 1.09 A4V 1179 3

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2022.05.21-23:39:16

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