The molecular emissions and the infall motion in the high-mass young stellar object G8.68−0.37
Abstract
We present a multi-wavelength observational study towards the high-mass young stellar object G8.68−0.37. A single massive gas-and-dust core is observed in the (sub)millimetre continuum and molecular line emissions. We fitted the spectral energy distribution (SED) from the dust continuum emission. The best-fitting SED suggests the presence of two components with temperature of T_d = 20 and 120 K, respectively. The core has a total mass of up to 1.5 × 10^3 M_⊙ and a bolometric luminosity of 2.3 × 10^4 L_⊙. Both the mass and luminosity are dominated by the cold component (T_d= 20 K). The molecular lines of C^(18)O, C^(34)S, DCN and thermally excited CH_(3)OH are detected in this core. Prominent infall signatures are observed in the ^(12)CO (1 − 0) and (2 − 1). We estimated an infall velocity of 0.45 km s^(−1) and a mass infall rate of 7 × 10^(−4) M_⊙ yr^(−1). From the molecular lines, we have found a high DCN-to-HCN abundance ratio of 0.07. The overabundant DCN may originate from a significant deuteration in the previous cold pre-protostellar phase. And the DCN should now be rapidly sublimated from the grain mantles to maintain the overabundance in the gas phase.
Additional Information
© 2012 The Authors. Monthly Notices of the Royal Astronomical Society. © 2012 RAS. Accepted 2012 February 2. Received 2012 February 1; in original form 2010 December 22. We are grateful to the SMA observers and the SMA data archive. We would thank the anonymous reviewer for the detailed, thoughtful comments and suggestions helping us to largely improve the presentation and interpretation. This work is supported by the NSFC grant nos 10733033, 10873019 and 10973003, and the NKBRP grant nos 2009CB24901 and 2012CB821800, and the Doctoral Candidate Innovation Research Support Program (Kjdb 201001-1) from Science & Technology Review.Attached Files
Published - Ren2012p18449Mon_Not_R_Astron_Soc.pdf
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Additional details
- Eprint ID
- 31889
- Resolver ID
- CaltechAUTHORS:20120613-103500187
- 10733033
- National Natural Science Foundation of China
- 10873019
- National Natural Science Foundation of China
- 10973003
- National Natural Science Foundation of China
- 2009CB24901
- National Key Basic Research Program of China
- 2012CB821800
- National Key Basic Research Program of China
- Kjdb 201001-1
- Doctoral Candidate lnnovation Research Support Program
- Created
-
2012-06-14Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field