scholarly journals AKARI Near-Infrared Spectroscopy: Detection of H 2 O and CO 2 Ices toward Young Stellar Objects in the Large Magellanic Cloud

2008 ◽  
Vol 686 (2) ◽  
pp. L99-L102 ◽  
Author(s):  
Takashi Shimonishi ◽  
Takashi Onaka ◽  
Daisuke Kato ◽  
Itsuki Sakon ◽  
Yoshifusa Ita ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Young Stellar Objects ◽  
Stellar Objects

scholarly journals AKARI near-infrared spectroscopy: Detection of H2O and CO2 ices toward young stellar objects in the Large Magellanic Cloud

2008 ◽  
Vol 4 (S256) ◽  
pp. 233-238
Author(s):  
Takashi Shimonishi ◽  
Takashi Onaka ◽  
Daisuke Kato ◽  
Itsuki Sakon ◽  
Yoshifusa Ita ◽  
...  
Keyword(s):  
Radiation Field ◽  
Near Infrared ◽  
Infrared Camera ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Young Stellar Objects ◽  
Stellar Objects ◽  
Chemical Balance ◽  
Circumstellar Material ◽  
Growth Method

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.

scholarly journals Medium-resolution near-infrared spectroscopy of massive young stellar objects

2017 ◽  
Vol 472 (3) ◽  
pp. 3624-3636 ◽  
Author(s):  
R. Pomohaci ◽  
R. D. Oudmaijer ◽  
S. L. Lumsden ◽  
M. G. Hoare ◽  
I. Mendigutía
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Young Stellar Objects ◽  
Stellar Objects ◽  
Medium Resolution

scholarly journals Infrared spectroscopy in the C–H stretching region towards embedded high-mass young stellar objects in the Large Magellanic Cloud

2015 ◽  
Vol 11 (A29A) ◽  
Author(s):  
Takashi Shimonishi ◽  
Emmanuel Dartois ◽  
Takashi Onaka ◽  
François Boulanger
Keyword(s):  
Infrared Spectroscopy ◽  
Absorption Band ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Young Stellar Objects ◽  
High Mass ◽  
Stellar Objects ◽  
Spectroscopic Observations ◽  
Spectral Bands ◽  
Low Metallicity

AbstractWe report the results of infrared spectroscopic observations of embedded high-mass young stellar objects in the Large Magellanic Cloud. The CH3OH ice absorption band as well as the 3.47 μm absorption band are detected toward the embedded sources in the LMC. The properties of these spectral bands in the low metallicity environment are investigated based on comparisons with Galactic embedded sources.

Near-infrared spectroscopy of young stellar objects

1994 ◽  
Vol 425 ◽  
pp. 231 ◽  
Author(s):  
D. M. Kelly ◽  
G. H. Rieke ◽  
B. Campbell
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Young Stellar Objects ◽  
Stellar Objects

scholarly journals VLT/X-shooter spectroscopy of massive young stellar objects in the 30 Doradus region of the Large Magellanic Cloud

2020 ◽  
Vol 636 ◽  
pp. A54 ◽  
Author(s):  
M. L. van Gelder ◽  
L. Kaper ◽  
J. Japelj ◽  
M. C. Ramírez-Tannus ◽  
L. E. Ellerbroek ◽  
...  
Keyword(s):  
Near Infrared ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Young Stellar Objects ◽  
Clear Correlation ◽  
Infrared Excess ◽  
Stellar Objects ◽  
Very Large Telescope ◽  
Circumstellar Extinction ◽  
30 Doradus

The process of massive star (M ≥ 8 M⊙) formation is still poorly understood. Observations of massive young stellar objects (MYSOs) are challenging due to their rarity, short formation timescale, large distances, and high circumstellar extinction. Here, we present the results of a spectroscopic analysis of a population of MYSOs in the Large Magellanic Cloud. We took advantage of the spectral resolution and wavelength coverage of X-shooter (300−2500 nm), which is mounted on the European Southern Observatory Very Large Telescope, to detect characteristic spectral features in a dozen MYSO candidates near 30 Doradus, the largest starburst region in the Local Group hosting the most massive stars known. The X-shooter spectra are strongly contaminated by nebular emission. We used a scaling method to subtract the nebular contamination from our objects. We detect Hα, β, [O I] 630.0 nm, Ca II, infrared triplet [Fe II] 1643.5 nm, fluorescent Fe II 1687.8 nm, H2 2121.8 nm, Brγ, and CO bandhead emission in the spectra of multiple candidates. This leads to the spectroscopic confirmation of ten candidates as bona fide MYSOs. We compared our observations with photometric observations from the literature and find all MYSOs to have a strong near-infrared excess. We computed lower limits to the brightness and luminosity of the MYSO candidates, confirming the near-infrared excess and the massive nature of the objects. No clear correlation is seen between the Brγ luminosity and metallicity. Combining our sample with other LMC samples results in a combined detection rate of disk features, such as fluorescent Fe II and CO bandheads, which is consistent with the Galactic rate (40%). Most of our MYSOs show outflow features.

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