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Title: THE DISK IMAGING SURVEY OF CHEMISTRY WITH SMA. I. TAURUS PROTOPLANETARY DISK DATA

Journal Article · · Astrophysical Journal
; ; ; ; ;  [1]; ;  [2];  [3]
  1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
  2. Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States)
  3. Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)

Chemistry plays an important role in the structure and evolution of protoplanetary disks, with implications for the composition of comets and planets. This is the first of a series of papers based on data from DISCS, a Submillimeter Array survey of the chemical composition of protoplanetary disks. The six Taurus sources in the program (DM Tau, AA Tau, LkCa 15, GM Aur, CQ Tau, and MWC 480) range in stellar spectral type from M1 to A4 and offer an opportunity to test the effects of stellar luminosity on the disk chemistry. The disks were observed in 10 different lines at {approx}3'' resolution and an rms of {approx}100 mJy beam{sup -1} at {approx}0.5 km s{sup -1}. The four brightest lines are CO 2-1, HCO{sup +} 3-2, CN 2{sub 33/4/2} - 1{sub 22/3/1}, and HCN 3-2, and these are detected toward all sources (except for HCN toward CQ Tau). The weaker lines of CN 2{sub 22}-1{sub 11}, DCO{sup +} 3-2, N{sub 2}H{sup +} 3-2, H{sub 2}CO 3{sub 03}-2{sub 02}, and 4{sub 14}-3{sub 13} are detected toward two to three disks each, and DCN 3-2 only toward LkCa 15. CH{sub 3}OH 4{sub 21}-3{sub 1} {sub 2} and c-C{sub 3}H{sub 2} are not detected. There is no obvious difference between the T Tauri and Herbig Ae sources with regard to CN and HCN intensities. In contrast, DCO{sup +}, DCN, N{sub 2}H{sup +}, and H{sub 2}CO are detected only toward the T Tauri stars, suggesting that the disks around Herbig Ae stars lack cold regions for long enough timescales to allow for efficient deuterium chemistry, CO freeze-out, and grain chemistry.

OSTI ID:
21460127
Journal Information:
Astrophysical Journal, Vol. 720, Issue 1; Other Information: DOI: 10.1088/0004-637X/720/1/480; ISSN 0004-637X
Country of Publication:
United States
Language:
English