AKARI near-infrared spectroscopy: Detection of H2O and CO 2 ICES toward young stellar objects in the Large Magellanic Cloud

Takashi Shimonishi; Takashi Onaka; Daisuke Kato; Itsuki Sakon; Yoshifusa Ita; Akiko Kawamura; Hidehiro Kaneda

doi:10.1086/592948

AKARI near-infrared spectroscopy: Detection of H₂O and CO ₂ ICES toward young stellar objects in the Large Magellanic Cloud

Takashi Shimonishi, Takashi Onaka, Daisuke Kato, Itsuki Sakon, Yoshifusa Ita, Akiko Kawamura, Hidehiro Kaneda

Creative Interdisciplinary Research Division

Research output: Contribution to journal › Article › peer-review

41 Citations (Scopus)

Abstract

We present the first results of AKARI Infrared Camera near-infrared spectroscopic survey of the Large Magellanic Cloud (LMC). We detected absorption features of the H2O ice 3.05 μm and the CO₂ ice 4.27 μm stretching mode toward seven massive young stellar objects (YSOs). These 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.

Original language	English
Pages (from-to)	L99-L102
Journal	Astrophysical Journal
Volume	686
Issue number	2 PART 2
DOIs	https://doi.org/10.1086/592948
Publication status	Published - 2008

Keywords

Abundances
Circumstellar matter
Dust
Extinction
ISM
Magellanic clouds
Molecules
Pre-main-sequence
Stars

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1086/592948

Cite this

@article{c301cbb941af4acf97e8324c0ce27a47,

title = "AKARI near-infrared spectroscopy: Detection of H2O and CO 2 ICES toward young stellar objects in the Large Magellanic Cloud",

abstract = "We present the first results of AKARI Infrared Camera near-infrared spectroscopic survey of the Large Magellanic Cloud (LMC). We detected absorption features of the H2O ice 3.05 μm and the CO2 ice 4.27 μm stretching mode toward seven massive young stellar objects (YSOs). These 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.",

keywords = "Abundances, Circumstellar matter, Dust, Extinction, ISM, Magellanic clouds, Molecules, Pre-main-sequence, Stars",

author = "Takashi Shimonishi and Takashi Onaka and Daisuke Kato and Itsuki Sakon and Yoshifusa Ita and Akiko Kawamura and Hidehiro Kaneda",

year = "2008",

doi = "10.1086/592948",

language = "English",

volume = "686",

pages = "L99--L102",

journal = "Astrophysical Journal",

issn = "0004-637X",

number = "2 PART 2",

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TY - JOUR

T1 - AKARI near-infrared spectroscopy

T2 - Detection of H2O and CO 2 ICES toward young stellar objects in the Large Magellanic Cloud

AU - Shimonishi, Takashi

AU - Onaka, Takashi

AU - Kato, Daisuke

AU - Sakon, Itsuki

AU - Ita, Yoshifusa

AU - Kawamura, Akiko

AU - Kaneda, Hidehiro

PY - 2008

Y1 - 2008

N2 - We present the first results of AKARI Infrared Camera near-infrared spectroscopic survey of the Large Magellanic Cloud (LMC). We detected absorption features of the H2O ice 3.05 μm and the CO2 ice 4.27 μm stretching mode toward seven massive young stellar objects (YSOs). These 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.

AB - We present the first results of AKARI Infrared Camera near-infrared spectroscopic survey of the Large Magellanic Cloud (LMC). We detected absorption features of the H2O ice 3.05 μm and the CO2 ice 4.27 μm stretching mode toward seven massive young stellar objects (YSOs). These 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.

KW - Abundances

KW - Circumstellar matter

KW - Dust

KW - Extinction

KW - ISM

KW - Magellanic clouds

KW - Molecules

KW - Pre-main-sequence

KW - Stars

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JO - Astrophysical Journal

JF - Astrophysical Journal

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