MOLECULAR AND IONIZED HYDROGEN IN 30 DORADUS. I. IMAGING OBSERVATIONS

Journal Article · Fri Jul 10 04:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/807/2/117· OSTI ID:22522186

Yeh, Sherry C. C. ^[1]; Seaquist, Ernest R.; Matzner, Christopher D. ^[2]

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1. Subaru Telescope, National Astronomical Observatory of Japan, 650 North A’ohoku Place, Hilo, HI 96720 (United States)
2. Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada)

We present the first fully calibrated H{sub 2} 1–0 S(1) image of the entire 30 Doradus nebula. The observations were conducted using the NOAO Extremely Wide-field Infrared Imager (NEWFIRM) on the CTIO 4 m Blanco Telescope. Together with a NEWFIRM Brγ image of 30 Doradus, our data reveal the morphologies of the warm molecular gas and ionized gas in 30 Doradus. The brightest H{sub 2}-emitting area, which extends from the northeast to the southwest of R136, is a photodissociation region (PDR) viewed face-on, while many clumps and pillar features located at the outer shells of 30 Doradus are PDRs viewed edge-on. Based on the morphologies of H{sub 2}, Brγ, CO, and 8 μm emission, the H{sub 2} to Brγ line ratio, and Cloudy models, we find that the H{sub 2} emission is formed inside the PDRs of 30 Doradus, 2–3 pc to the ionization front of the H ii region, in a relatively low-density environment <10{sup 4} cm{sup −3}. Comparisons with Brγ, 8 μm, and CO emission indicate that H{sub 2} emission is due to fluorescence, and provide no evidence for shock excited emission of this line.

• OSTI ID: 22522186
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 807; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CARBON MONOXIDE
COMPARATIVE EVALUATIONS
DENSITY
DISSOCIATION
EMISSION
FLUORESCENCE
HYDROGEN
IMAGES
MAGELLANIC CLOUDS
MOLECULES
MORPHOLOGY
NEBULAE
PHOTOLYSIS
PHOTONS
TELESCOPES