2014A&A...563A..33W


Query : 2014A&A...563A..33W

2014A&A...563A..33W - Astronomy and Astrophysics, volume 563A, 33-33 (2014/3-1)

Complex organic molecules in protoplanetary disks.

WALSH C., MILLAR T.J., NOMURA H., HERBST E., WIDICUS WEAVER S., AIKAWA Y., LAAS J.C. and VASYUNIN A.I.

Abstract (from CDS):

Protoplanetary disks are vital objects in star and planet formation, possessing all the material, gas and dust, which may form a planetary system orbiting the new star. Small, simple molecules have traditionally been detected in protoplanetary disks; however, in the ALMA era, we expect the molecular inventory of protoplanetary disks to significantly increase. We investigate the synthesis of complex organic molecules (COMs) in protoplanetary disks to put constraints on the achievable chemical complexity and to predict species and transitions which may be observable with ALMA. We have coupled a 2D steady-state physical model of a protoplanetary disk around a typical T Tauri star with a large gas-grain chemical network including COMs. We compare the resulting column densities with those derived from observations and perform ray-tracing calculations to predict line spectra. We compare the synthesised line intensities with current observations and determine those COMs which may be observable in nearby objects. We also compare the predicted grain-surface abundances with those derived from cometary comae observations. We find COMs are efficiently formed in the disk midplane via grain-surface chemical reactions, reaching peak grain-surface fractional abundances ∼10–6-10–4 that of the H nuclei number density. COMs formed on grain surfaces are returned to the gas phase via non-thermal desorption; however, gas-phase species reach lower fractional abundances than their grain-surface equivalents, ∼10–12-10–7. Including the irradiation of grain mantle material helps build further complexity in the ice through the replenishment of grain-surface radicals which take part in further grain-surface reactions. There is reasonable agreement with several line transitions of H2CO observed towards T Tauri star-disk systems. There is poor agreement with HC3N lines observed towards LkCa 15 and GO Tau and we discuss possible explanations for these discrepancies. The synthesised line intensities for CH3OH are consistent with upper limits determined towards all sources. Our models suggest CH3OH should be readily observable in nearby protoplanetary disks with ALMA; however, detection of more complex species may prove challenging, even with ALMA ``Full Science'' capabilities. Our grain-surface abundances are consistent with those derived from cometary comae observations providing additional evidence for the hypothesis that comets (and other planetesimals) formed via the coagulation of icy grains in the Sun's natal disk.

Abstract Copyright:

Journal keyword(s): protoplanetary disks - astrochemistry - ISM: molecules - stars: formation

Simbad objects: 21

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Number of rows : 21
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 V* GG Tau Or* 04 32 30.3506925552 +17 31 40.494063144 14.84 14.78 13.40 11.54   M0e+M2.0e 692 1
2 V* DM Tau Or* 04 33 48.7336763736 +18 10 09.973460280 14.30 14.82 14.00     M2Ve 579 0
3 V* AA Tau Or* 04 34 55.4201902392 +24 28 53.033624580 13.14 13.34 12.20     K5Ve 679 0
4 V* GM Tau Or* 04 38 21.3383367240 +26 09 13.775325624     17.577   15.04 M6.5 104 0
5 EM* LkCa 15 Or* 04 39 17.7911622816 +22 21 03.390090984   13.01 12.03 11.61   K5:Ve 612 1
6 NAME Taurus Complex SFR 04 41.0 +25 52           ~ 3926 0
7 V* GO Tau Or* 04 43 03.0761840904 +25 20 18.706850340   16.2 14.40     M2.3 174 0
8 V* GM Aur Or* 04 55 10.9815576936 +30 21 59.373771876 14.59 13.351 12.242 11.798   K3Ve 616 0
9 HOPS 68 Y*O 05 35 24.2999 -05 08 30.686           ~ 55 0
10 NAME ORI MOL CLOUD MoC 05 56 -01.8           ~ 955 1
11 V* TW Hya TT* 11 01 51.9053285064 -34 42 17.033218380   11.94 10.50 10.626 9.18 K6Ve 1736 1
12 HD 100546 Be* 11 33 25.4408872296 -70 11 41.241297948   6.71 6.30   6.64 A0VaekB8_lB 717 1
13 THA 15-12 Or* 15 56 09.2066646912 -37 56 06.126118692   13.12 11.93 11.45   M0e 338 0
14 HD 142527 Ae* 15 56 41.8882637904 -42 19 23.248281828   9.04 8.34     F6III 560 1
15 V* V866 Sco Or* 16 11 31.345632 -18 38 25.96200   13.98 12.63 12.81   K0e+K5e 261 0
16 IRAS 16293-2422 cor 16 32 22.56 -24 28 31.8           ~ 1158 1
17 EM* AS 209 Or* 16 49 15.3034917000 -14 22 08.643317664   12.62 11.28     K4Ve 303 0
18 NAME Galactic Center reg 17 45 39.60213 -29 00 22.0000           ~ 12914 0
19 NAME Sgr B2 (North) Rad 17 47 20.2 -28 22 21           ~ 598 1
20 HD 163296 Ae* 17 56 21.2881851168 -21 57 21.871819008 7.00 6.93 6.85 6.86 6.67 A1Vep 953 0
21 HD 319139 SB* 18 14 10.4818675368 -32 47 34.516836060   11.47 10.68   9.11 K5+K7 328 0

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2022.05.28-21:36:20

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