THE EVOLUTION OF MASSIVE YOUNG STELLAR OBJECTS IN THE LARGE MAGELLANIC CLOUD. II. THERMAL PROCESSING OF CIRCUMSTELLAR ICES

AbstractWe present the first results of the AKARI Infrared Camera near-infrared spectroscopic survey of the Large Magellanic Cloud (LMC). The circumstellar material of young stellar objects (YSOs) are affected by galactic environments such as a metallicity or radiation field. Ices control the chemical balance of circumstellar environments of embedded YSOs. We detected absorption features of the H2O ice 3.05 μm and the CO2 ice 4.27 μm stretching mode toward seven massive YSOs in the LMC. This is the first detection of the 4.27 μm CO2 ice feature toward extragalactic YSOs. The present samples are for the first time spectroscopically confirmed to be YSOs. We used a curve-of-growth method to evaluate the column densities of the ices and derived the CO2/H2O ratio to be 0.45±0.17. This is clearly higher than that seen in Galactic massive YSOs (0.17±0.03). We suggest that the strong ultraviolet radiation field and/or the high dust temperature in the LMC may be responsible for the observed high CO2 ice abundance.

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Identifying young stellar objects in nine Large Magellanic Cloud star-forming regions

Astronomy and Astrophysics ◽

10.1051/0004-6361/201118627 ◽

2012 ◽

Vol 542 ◽

pp. A66 ◽

Cited By ~ 34

Author(s):

L. R. Carlson ◽

M. Sewiło ◽

M. Meixner ◽

K. A. Romita ◽

B. Lawton

Keyword(s):

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Young Stellar Objects ◽

Stellar Objects ◽

Star Forming ◽

Star Forming Regions

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YOUNG STELLAR OBJECTS IN THE LARGE MAGELLANIC CLOUD STAR-FORMING REGION N206

The Astrophysical Journal ◽

10.1088/0004-637x/721/1/357 ◽

2010 ◽

Vol 721 (1) ◽

pp. 357-368 ◽

Cited By ~ 10

Author(s):

Krista Alexandra Romita ◽

Lynn Redding Carlson ◽

M. Meixner ◽

M. Sewiło ◽

B. Whitney ◽

...

Keyword(s):

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Young Stellar Objects ◽

Stellar Objects ◽

Star Forming

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Characterising the Protostellar Population of the Magellanic Clouds with VLT/SINFONI

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316008449 ◽

2015 ◽

Vol 11 (S315) ◽

Author(s):

Jacob Ward ◽

Joana Oliveira ◽

Jacco van Loon ◽

Marta Sewilo

Keyword(s):

Star Formation ◽

Milky Way ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Magellanic Clouds ◽

Emission Lines ◽

Young Stellar Objects ◽

Small Magellanic Cloud ◽

Stellar Objects ◽

Accretion Rates

AbstractAt distances of ~50 kpc and ~60 kpc for the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) respectively the Magellanic Clouds present us with a unique opportunity to study star formation in environments outside our own galaxy. Through Spitzer and Herschel photometry and spectroscopy, samples of Young Stellar Objects (YSOs) have been selected and spectroscpically confirmed in the Magellanic Clouds. Here we present some of the key results of our SINFONI K-band observations towards massive YSOs in the Magellanic Clouds. We resolve a number of Spitzer sources into multiple, previously unresolved, components and our analysis of emission lines suggest higher accretion rates and different disc properties compared with massive YSOs in the Milky Way.

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Formation of high-mass stars in an isolated environment in the Large Magellanic Cloud

Publications of the Astronomical Society of Japan ◽

10.1093/pasj/psz011 ◽

2019 ◽

Vol 71 (2) ◽

Cited By ~ 3

Author(s):

Ryohei Harada ◽

Toshikazu Onishi ◽

Kazuki Tokuda ◽

Sarolta Zahorecz ◽

Annie Hughes ◽

...

Keyword(s):

Star Formation ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Young Stellar Objects ◽

High Mass ◽

Mass Star ◽

Giant Molecular Clouds ◽

Stellar Objects ◽

Stellar Cluster ◽

The Galaxy

Abstract The aim of this study is to characterize the distribution and basic properties of the natal gas associated with high-mass young stellar objects (YSOs) in isolated environments in the Large Magellanic Cloud. High-mass stars usually form in giant molecular clouds (GMCs) as part of a young stellar cluster, but some OB stars are observed far from GMCs. By examining the spatial coincidence between the high-mass YSOs and 12CO (J = 1–0) emission detected by NANTEN and Mopra observations, we selected ten high-mass YSOs that are located away from any of the NANTEN clouds but are detected by the Mopra pointed observations. The ALMA observations revealed that a compact molecular cloud whose mass is a few thousand solar masses or smaller is associated with the high-mass YSOs, which indicates that these compact clouds are the sites of high-mass star formation. The high density and high temperature throughout the clouds are explained by the severe photodissociation of CO due to the lower metallicity than in the Galaxy. The star formation efficiency ranges from several to as high as ∼40%, indicating efficient star formation in these environments. The enhanced turbulence may be a cause of the efficient star formation therein, as judged from the gas velocity information and the association with the lower density gas.

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