DEUTERIUM FRACTIONATION AS AN EVOLUTIONARY PROBE IN THE INFRARED DARK CLOUD G28.34+0.06

Journal Article · Sat Apr 10 04:00:00 EDT 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/713/1/L50; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21305049

Chen, H -R ^[1]; Liu, S -Y; Su, Y -N ^[2]

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1. Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu, Taiwan (China)
2. Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan (China)

We have observed the J = 3 - 2 transition of N{sub 2}H{sup +} and N{sub 2}D{sup +} to investigate the trend of deuterium fractionation with evolutionary stage in three selected regions in the infrared dark cloud (IRDC) G28.34+0.06 with the Submillimeter Telescope and the Submillimeter Array. A comprehensible enhancement of roughly 3 orders of magnitude in deuterium fractionation over the local interstellar D/H ratio is observed in all sources. In particular, our sample of massive star-forming cores in G28.34+0.06 shows a moderate decreasing trend over a factor of 3 in the N(N{sub 2}D{sup +})/N(N{sub 2}H{sup +}) ratio with evolutionary stage, a behavior resembling that previously found in low-mass protostellar cores. This suggests a possible extension for the use of the N(N{sub 2}D{sup +})/N(N{sub 2}H{sup +}) ratio as an evolutionary tracer to high-mass protostellar candidates. In the most evolved core, MM1, the N{sub 2}H{sup +}(3-2) emission appears to avoid the warm region traced by dust continuum emission and emission of {sup 13}CO sublimated from grain mantles, indicating an instant release of gas-phase CO. The majority of the N{sub 2}H{sup +} and N{sub 2}D{sup +} emission is associated with extended structures larger than 8'' ({approx}0.2 pc)

• OSTI ID: 21305049
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 713; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
ABUNDANCE
CARBON MONOXIDE
DEUTERIUM
DUSTS
FRACTIONATION
MASS
STARS
TELESCOPES