COMPARISON OF THE DIFFUSE H{alpha} AND FUV CONTINUUM BACKGROUNDS: ON THE ORIGINS OF THE DIFFUSE H{alpha} BACKGROUND

Journal Article · Tue Dec 20 04:00:00 EST 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/743/2/188· OSTI ID:22004432

Seon, Kwang-Il; Kim, Il-Joong; Shinn, Jong-Ho; Han, Wonyong ^[1]; Witt, Adolf ^[2]; Edelstein, Jerry ^[3]; Min, Kyoung-Wook ^[4]

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1. Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)
2. Ritter Astrophysical Research Center, University of Toledo, Toledo, OH 43606 (United States)
3. Space Sciences Laboratory, University of California, Berkeley, CA 94702 (United States)
4. Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)

We compare the diffuse H{alpha} map of our Galaxy with the FUV (1370-1710 A) continuum map. The H{alpha} intensity correlates well with the FUV intensity. The H{alpha}/FUV intensity ratio increases in general with the H{alpha} intensity and the FUV hardness ratio (1370-1520 A to 1560-1710 A), implying that late OB stars may be the main source of the H{alpha} recombination line at high latitudes. The variation of the H{alpha} intensity as a function of the Galactic latitude is also very similar to that of the FUV intensity. The results likely suggest that not only the original radiation sources of the H{alpha} and FUV backgrounds but also the radiative transfer mechanisms responsible for the diffuse backgrounds are largely common. Therefore, we propose a scenario wherein the H{alpha} background at high latitudes is mostly composed of two components, H{alpha} photons produced by in situ recombination at the ionized regions around late OB stars and dust-scattered light of the H{alpha} photons originating from late OB stars.

• OSTI ID: 22004432
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 743; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DUSTS
GALAXIES
RADIATION SOURCES
RECOMBINATION
STARS
ULTRAVIOLET RADIATION