2019A&A...623A.124C


C.D.S. - SIMBAD4 rel 1.7 - 2020.05.26CEST23:19:00

2019A&A...623A.124C - Astronomy and Astrophysics, volume 623A, 124-124 (2019/3-1)

Upper limits on CH3OH in the HD 163296 protoplanetary disk. Evidence for a low gas-phase CH3OH-to-H2CO ratio.

CARNEY M.T., HOGERHEIJDE M.R., GUZMAN V.V., WALSH C., OBERG K.I., FAYOLLE E.C., CLEEVES L.I., CARPENTER J.M. and QI C.

Abstract (from CDS):


Context. Methanol (CH3OH) is at the root of organic ice chemistry in protoplanetary disks. Its connection to prebiotic chemistry and its role in the chemical environment of the disk midplane make it an important target for disk chemistry studies. However, its weak emission has made detections difficult. To date, gas-phase CH3OH is detected in only one Class II disk, TW Hya.
Aims. We aim to constrain the methanol content of the HD 163296 protoplanetary disk.
Methods. We used the Atacama Large Millimeter/submillimeter Array (ALMA) to search for a total of four CH3OH emission lines in bands six and seven toward the disk around the young Herbig Ae star HD 163296. The disk-averaged column density of methanol and its related species formaldehyde (H2CO) were estimated assuming optically thin emission in local thermodynamic equilibrium. We compared these results to the gas-phase column densities of the TW Hya disk.
Results. No targeted methanol lines were detected with Keplerian masking in the image plane nor with matched filter analysis in the uv plane individually nor after line stacking. The 3σ disk-integrated intensity upper limits are <51mJy.km/s for the band six lines and <26mJy.km/s for the band seven lines. The band seven lines provide the strictest 3σ upper limit on disk-averaged column density with Navg<5.0x1011cm–2. The methanol-to-formaldehyde ratio is CH3OH/H2CO<0.24 in the HD 163296 disk compared to a ratio of 1.27 in the TW Hya disk.
Conclusions. The HD 163296 protoplanetary disk is less abundant in methanol with respect to formaldehyde compared to the disk around TW Hya. Differences in the stellar irradiation in this Herbig Ae disk as compared to that of a disk around a T Tauri star likely influence the gaseous methanol and formaldehyde content. Possible reasons for the lower HD 163296 methanol-to-formaldehyde ratio include: a higher than expected gas-phase formation of H2CO in the HD 163296 disk, uncertainties in the grain surface formation efficiency of CH3OH and H2CO, and differences in the disk structure and/or CH3OH and H2CO desorption processes that drive the release of the molecules from ice mantles back into the gas phase. These results provide observational evidence that the gas-phase chemical complexity found in disks may be strongly influenced by the spectral type of the host star.

Abstract Copyright: © ESO 2019

Journal keyword(s): astrochemistry - protoplanetary disks - submillimeter: stars

Status at CDS:  

Simbad objects: 8

goto Full paper

goto View the reference in ADS

Number of rows : 8

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 V* V883 Ori Or* 05 38 18.0974260202 -07 02 25.963144400   14.80       F:I: 104 0
2 V* TW Hya TT* 11 01 51.9054298616 -34 42 17.031550898   11.94 10.50 10.626 9.18 K6Ve 1510 1
3 QSO B1730-130 QSO 17 33 02.70578476 -13 04 49.5481484   18 18.5 18.78 17.39 ~ 976 1
4 ICRF J174211.6-151729 QSO 17 42 11.6628530 -15 17 29.158662           ~ 16 1
5 PSR J1745-2900 Psr 17 45 40.1640 -29 00 29.818           ~ 215 0
6 4C 09.57 BLL 17 51 32.81857318 +09 39 00.7284829   17.46 16.78 15.57   ~ 808 1
7 HD 163296 Ae* 17 56 21.2882188601 -21 57 21.872343282 7.00 6.93 6.85 6.86 6.67 A1Vep 784 0
8 QSO B1921-293 BLL 19 24 51.05595514 -29 14 30.1210524   18.71 18.21 15.07   ~ 683 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2019A&A...623A.124C and select 'bookmark this link' or equivalent in the popup menu


2020.05.26-23:19:00

© Université de Strasbourg/CNRS

    • Contact