DSpace
 

RRI Digital Repository >
04. Astronomy and Astrophysics >
Research Papers (A&A) >

Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/4455

Title: Roles of radiation and ram pressure in driving galactic winds
Authors: Sharma, Mahavir
Nath, Biman B.
Keywords: galaxies: evolution
galaxies: starburst
intergalactic medium
Issue Date: May-2012
Publisher: American Astronomical Society
Citation: Astrophysical Journal,2012, Vol. 750, p1
Abstract: We study gaseous outflows from disk galaxies driven by the combined effects of ram pressure on cold gas clouds and radiation pressure on dust grains. Taking into account the gravity due to disk, bulge, and dark matter halo, and assuming continuous star formation in the disk, we show that radiation or ram pressure alone is not sufficient to drive escaping winds from disk galaxies and that both processes contribute. We show that in the parameter space of star formation rate (SFR) and rotation speed of galaxies the wind speed in galaxies with rotation speeds vc <= 200 km s-1 and SFR <= 100 M sun yr-1 has a larger contribution from ram pressure, and that in high-mass galaxies with large SFR radiation from the disk has a greater role in driving galactic winds. The ratio of wind speed to circular speed can be approximated as {v_w / v_c} \sim 10^{0.7} \, [SFR/ 50 \, {M_{\odot } \,yr^{-1}}] ^{0.4} \ [{v_c/ 120\, km\,s^{-1}}]^ {-1.25}. We show that this conclusion is borne out by observations of galactic winds at low and high redshift and also of circumgalactic gas. We also estimate the mass loading factors under the combined effect of ram and radiation pressure, and show that the ratio of mass-loss rate to SFR scales roughly as v -1 c Σ g -1, where Σ g is the gas column density in the disk.
Description: Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations)
URI: http://hdl.handle.net/2289/4455
ISSN: 0004-6256
1538-3881 (Online)
Alternative Location: http://adsabs.harvard.edu/abs/2012ApJ...750...55S
http://arxiv.org/abs/1112.3447
http://dx.doi.org/10.1088/0004-637X/750/1/55
Copyright: 2012 The American Astronomical Society
Appears in Collections:Research Papers (A&A)

Files in This Item:

File Description SizeFormat
2012_Apj_V750_p55.pdfRestricted Access370.05 kBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

    RRI Library DSpace