Starburst Galaxies

Starburst Galaxies - NGC 7714 from the Kennicutt spectral...

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Starburst Galaxies Some galaxies, or their nuclei, show evidence of a recent and transient increase in SFR by as much as a factor of 50. Symptoms of this may be large Balmer-line luminosity and equivalent width high L(IR)/L B rapid gas consumption timescale M(gas)/SFR unusually strong radio continuum emission The burst may be galaxy-wide or confined to a small region about the nucleus (few hundred parsec scales). Many (but by no means all) are associated with interacting or merging galaxies. Starbursts are strongly represented in flux-limited samples of UV-bright galaxies (the Markarian catalog) or IR-bright systems. Their optical spectra resembly those of H II regions, with a blue stellar continuum and strong line emission, as seen in the integrated spectrum of the prototype
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Unformatted text preview: NGC 7714 from the Kennicutt spectral atlas: The role of reddening and obscuration in starbursts is complex, and makes detailed interpretation of their continuum and emission-line properties complicated. Calzetti et al. (1994 ApJ 429, 582) derived an effective reddening law, including effects of scattering and the mix of stars and dust, which changes systematically depending on the metallicity of the system and the far-IR fraction. There is evidence that the reddening of the gas and stars is systematically different, perhaps due to dust associated specifically with the gas emission regions, and there is different weighting of gas along the line of sight for different lines, reflecting density and reddening structure....
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This note was uploaded on 11/10/2011 for the course AST AST1002 taught by Professor Emilyhoward during the Fall '10 term at Broward College.

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Starburst Galaxies - NGC 7714 from the Kennicutt spectral...

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