Predicting Neutral-Cloud Absorption Line Profiles in Galactic Winds
Abstract
We present theoretical predictions for NaI lines produced in cool clouds entrained in galactic winds (GWs), calculated for hydrogen column densities and temperatures appropriate to cool clouds above starburst galaxies. We focus on lines that are observed in the outflows from starburst galaxies because we wish to constrain GWs, which are important to a variety of astrophysical phenomena and possibly to the formation of large-scale cosmological structure. NaI lines in the spectra of starburst galaxies can be used to extract properties of cool gas entrained in the GWs. Our group has developed a semi-analytical model of large-scale GWs to calculate the acceleration of the hot-gas component of these winds, and in addition, to calculate the acceleration of cool clouds within the wind (see poster by E. Cheng). The work presented here uses the physical parameters of clouds, derived from these models, in conjunction with the stellar population modeling software Starburst99 and the photoionization code Cloudy. Together, these allow us to predict the NaI line shapes expected to occur in cool clouds entrained in GWs, and specifically, line shapes for the prototypical starburst galaxy M82. In the future, comparing these line shapes with observations will help us understand and constrain the physical mechanisms that drive such large-scale winds.
This work was supported by the National Science Foundation grant AST-1109218.- Publication:
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American Astronomical Society Meeting Abstracts #220
- Pub Date:
- May 2012
- Bibcode:
- 2012AAS...22043404W