Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 안덕근 | * |
dc.date.accessioned | 2022-06-02T16:31:09Z | - |
dc.date.available | 2022-06-02T16:31:09Z | - |
dc.date.issued | 2022 | * |
dc.identifier.issn | 0004-637X | * |
dc.identifier.other | OAK-31433 | * |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/261227 | - |
dc.description.abstract | To study the demographics of interstellar ices in the Central Molecular Zone (CMZ) of the Milky Way, we obtain near-infrared spectra of 109 red point sources using NASA IRTF/SpeX at Maunakea. We select the sample from near-and mid-infrared photometry, including 12 objects in the previous paper of this series, to ensure that these sources trace a large amount of absorption through clouds in each line of sight. We find that most of the sample (100 objects) show CO band-head absorption at 2.3 μm, tagging them as red (super-) giants. Despite the photospheric signature, however, a fraction of the sample with L-band spectra (9/82 = 0.11) exhibit large H2O ice column densities (N > 2 × 1018 cm-2), and six of them also reveal CH3OH ice absorption. As one of such objects is identified as a young stellar object (YSO) in our previous work, these ice-rich sight lines are likely associated with background stars in projection to an extended envelope of a YSO or a dense cloud core. The low frequency of such objects in the early stage of stellar evolution implies a low star-formation rate (â‰20.02 M yr-1), reinforcing the previous claim on the suppressed star-formation activity in the CMZ. Our data also indicate that the strong "shoulder"CO2 ice absorption at 15.4 μm observed in YSO candidates in the previous paper arises from CH3OH-rich ice grains having a large CO2 concentration [N(CO2)/N(CH3OH) ≈ 1/3]. © 2022. The Author(s). Published by the American Astronomical Society. | * |
dc.language | English | * |
dc.publisher | Institute of Physics | * |
dc.title | Massive Young Stellar Objects in the Galactic Center. II. Seeing Through the Ice-rich Envelopes | * |
dc.type | Article | * |
dc.relation.issue | 1 | * |
dc.relation.volume | 930 | * |
dc.relation.index | SCIE | * |
dc.relation.index | SCOPUS | * |
dc.relation.journaltitle | Astrophysical Journal | * |
dc.identifier.doi | 10.3847/1538-4357/ac5d51 | * |
dc.identifier.wosid | WOS:000788783900001 | * |
dc.identifier.scopusid | 2-s2.0-85129921403 | * |
dc.author.google | Jang D. | * |
dc.author.google | An D. | * |
dc.author.google | Sellgren K. | * |
dc.author.google | Ramírez S.V. | * |
dc.author.google | Boogert A.C.A. | * |
dc.author.google | Schultheis M. | * |
dc.contributor.scopusid | 안덕근(8661118800) | * |
dc.date.modifydate | 20240130115827 | * |