Herschel spectroscopy of massive young stellar objects in the Magellanic Clouds

被引：12

作者：

Oliveira, J. M. ^{[1
]}

van Loon, J. Th. ^{[1
]}

Sewilo, M. ^{[2
,3
,4
]}

Lee, M. -Y. ^{[5
,6
]}

Lebouteiller, V. ^{[7
]}

Chen, C. -H. R. ^{[6
]}

Cormier, D. ^{[7
]}

Filipovic, M. D. ^{[8
]}

Carlson, L. R.

Indebetouw, R. ^{[9
,10
]}

Madden, S. ^{[7
]}

Meixner, M. ^{[11
,12
]}

Sargent, B. ^{[12
]}

Fukui, Y. ^{[13
]}

机构：

[1] Keele Univ, Sch Chem & Phys Sci, Lennard Jones Labs, Keele ST5 5BG, Staffs, England

[2] NASA, Goddard Space Flight Ctr, CRESST II, Greenbelt, MD 20771 USA

[3] NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA

[4] Univ Maryland, Dept Astron, College Pk, MD 20742 USA

[5] Korea Astron & Space Sci Inst, 776 Daedeokdae Ro, Daejeon 34055, South Korea

[6] Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany

[7] CEA Saclay, CEA, Lab AIM, Serv Astrophys, Bat 709, F-91191 Gif Sur Yvette, France

[8] Western Sydney Univ, Locked Bag 1797, Penrith, NSW 2751, Australia

[9] Univ Virginia, Dept Astron, POB 400325, Charlottesville, VA 22904 USA

[10] Natl Radio Astron Observ, 520 Edgemont Rd, Charlottesville, VA 22903 USA

[11] Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA

[12] Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA

[13] Nagoya Univ, Dept Phys, Chikusa Ku, Nagoya, Aichi 4648602, Japan

来源：

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | 2019年 / 490卷 / 03期

关键词：

stars: formation; stars: protostars; ISM: clouds; Magellanic Clouds; POINT-SOURCE CLASSIFICATION; SPITZER LEGACY PROGRAM; INTEGRAL FIELD SPECTROSCOPY; INFRARED SPECTRAL ATLAS; LIFE-CYCLE; COMPACT SOURCES; STAR-FORMATION; ICE CHEMISTRY; WATER MASERS; ESO-VLT;

D O I：

10.1093/mnras/stz2810

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present Herschel Space Observatory Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver Fourier Transform Spectrometer (SPIRE FTS) spectroscopy of a sample of 20 massive Young Stellar Objects (YSOs) in the Large and Small Magellanic Clouds (LMC and SMC). We analyse the brightest far-infrared (far-IR) emission lines, that diagnose the conditions of the heated gas in the YSO envelope and pinpoint their physical origin. We compare the properties of massive Magellanic and Galactic YSOs. We find that [O I] and [C II] emission, that originates from the photo-dissociation region associated with the YSOs, is enhanced with respect to the dust continuum in the Magellanic sample. Furthermore the photoelectric heating efficiency is systematically higher for Magellanic YSOs, consistent with reduced grain charge in low metallicity environments. The observed CO emission is likely due to multiple shock components. The gas temperatures, derived from the analysis of CO rotational diagrams, are similar to Galactic estimates. This suggests a common origin to the observed CO excitation, from low-luminosity to massive YSOs, both in the Galaxy and the Magellanic Clouds. Bright far-IR line emission provides a mechanism to cool the YSO environment. We find that, even though [O I], CO, and [C II] are the main line coolants, there is an indication that CO becomes less important at low metallicity, especially for the SMC sources. This is consistent with a reduction in CO abundance in environments where the dust is warmer due to reduced ultraviolet-shielding. Weak H2O and OH emission is detected, consistent with a modest role in the energy balance of wider massive YSO environments.

引用

页码：3909 / 3935

页数：27