Hot gas density distributions can be fitted to the X-ray emission and ?absorption observations of the Milky Way to determine the mass and ?metallicity, mainly within 50 kpc. We have now included optical depth ?effects in the critical O VII and O VIII lines and find the same ?result from three different data sets. An extended spherical hot halo ?is the main mass component, containing about 3-4E10 Msun within 250 ?kpc, significantly lower than the mass of missing baryons, about ?1.7E11 Msun. The hot halo is rotating at 180 +/- 40 km/s within 50 ?kpc, the density declines as r^-3/2, and the metallicity is about half ?solar. Adding a disk component improves the fit but it is a minor ?contributor to the total mass. The missing baryons most likely lie ?beyond the virial radius, probably 2-3 R200. In nearby external ?galaxies, we detect a SZ signal when stacking the nearest dozen spiral ?galaxies with L ~ L*. This signal suggests a gas mass of about 5E10 ?Msun within R200, similar to that found around the Milky Way.

BIO

EDUCATION
Ph.D. in Astronomy and Astrophysics, Univ. of ?California, Santa Cruz (Lick Observatory), 1977
B.S. in Physics ?and Astronomy, State University of New York at Stony Brook, 1973.

EMPLOYMENT SINCE Ph.D.
09/2010-present H.D. Curtis Professor and ?Chair of Astronomy, University of Michigan
09/1995-08/2010 ?Professor, University of Michigan
09/1989-08/1995 Associate ?Professor, University of Michigan
09/1984-08/1989 Associate ?Scientist and Scientist, National Radio Astronomy ?Observatory
09/1979-09/1984 Postdoctoral Research Scientist and ?Research Assistant Professor, NYU
09/1977-08/1979 Columbia ?University, Postdoctoral Research Associate

RESEARCH INTERESTS
Interests: the gaseous component of the ?Universe; high-energy astrophysics
Observing Participation (past ?5 years): space-based missions HST, FUSE, GALEX, Chandra, ?XMM,
Suzaku, Spitzer, and Herschel. Ground-based radio facilities ?(VLA, GBT) and optical facilities (MDM,
Magellan)