Bulletin de la Société Royale des Sciences de Liège Bulletin de la Société Royale des Sciences de Liège -  Volume 80 - Année 2011 

Single-Star HII Regions as a Probe of Massive Star SEDs

Jordan Zastrow

Department of Astronomy, 500 Church Street, University of Michigan, Ann Arbor, MI, 48109, USA

M.S. Oey

Department of Astronomy, 500 Church Street, University of Michigan, Ann Arbor, MI, 48109, USA

E.W. Pellegrini

Department of Astronomy, 500 Church Street, University of Michigan, Ann Arbor, MI, 48109, USA

Abstract

We critically examine stellar atmosphere models by exploiting the strong dependence of HII region optical spectra on the SED of the ionizing source. To accomplish this, we compare spatially resolved, longslit observations of LMC single-star HII regions to photoionization simulations based on observed nebular and stellar properties. We select stellar atmosphere models from the CoStar (Schaerer & de Koter, 1997), TLUSTY (Lanz & Hubeny, 2003), WM-basic (Pauldrach et al. 2001) and Smith et. al. (2002) grids to define the ionizing source in our simulations. Gas density fluctuations are necessary to simultaneously fit the emission from high and low excitation ions. We evaluate the atmospheres relative to each other and overall, find atmosphere models using the WM-basic code have the best agreement with our observations.

Pour citer cet article

Jordan Zastrow, M.S. Oey & E.W. Pellegrini, «Single-Star HII Regions as a Probe of Massive Star SEDs», Bulletin de la Société Royale des Sciences de Liège [En ligne], Volume 80 - Année 2011, 450 - 454 URL : http://popups.ulg.be/0037-9565/index.php?id=2959.