Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-10-13
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
10 pages, 8 figures, accepted to ApJ 10/11/10
Scientific paper
The fate of ionizing radiation is vital for understanding cosmic ionization, energy budgets in the interstellar and intergalactic medium, and star formation rate indicators. The low observed escape fractions of ionizing radiation have not been adequately explained, and there is evidence that some starbursts have high escape fractions. We examine the spectral energy distributions of a sample of local star-forming galaxies, containing thirteen local starburst galaxies and ten of their ordinary star-forming counterparts, to determine if there exist significant differences in the fate of ionizing radiation in these galaxies. We find that the galaxy-to-galaxy variations in the SEDs is much larger than any systematic differences between starbursts and non-starbursts. For example, we find no significant differences in the total absorption of ionizing radiation by dust, traced by the 24um, 70um, and 160um MIPS bands of the Spitzer Space Telescope, although the dust in starburst galaxies appears to be hotter than that of non-starburst galaxies. We also observe no excess ultraviolet flux in the GALEX bands that could indicate a high escape fraction of ionizing photons in starburst galaxies. The small H-alpha fractions of the diffuse, warm ionized medium in starburst galaxies are apparently due to temporarily boosted H-alpha luminosity within the star-forming regions themselves, with an independent, constant WIM luminosity. This independence of the WIM and starburst luminosities contrasts with WIM behavior in non-starburst galaxies and underscores our poor understanding of radiation transfer in both ordinary and starburst galaxies.
de Mello Duilia F.
Hanish Daniel J.
Lee Jae-Chul
Oey Sally M.
Rigby Jane R.
No associations
LandOfFree
A Multiwavelength Study on the Fate of Ionizing Radiation in Local Starbursts does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Multiwavelength Study on the Fate of Ionizing Radiation in Local Starbursts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Multiwavelength Study on the Fate of Ionizing Radiation in Local Starbursts will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-227179