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Research Professor
Department of Astronomy, University of Washington



My research interests include the evolution of galaxies as determined through stellar populations and X-ray source populations analysis. I did my undergraduate work in physics at  Middlebury College with  Professor Frank Winkler I received my Ph. D. from the University of Washington in 2002, working with Paul Hodge.  Some highlights from that era are here.

Over the years, I have played a large role in the implementation of several large surveys, including the ACS Nearby Galaxy Survey Treasury  (ANGST).  This project measured the star formation history of nearly all known galaxies outside the Local Group but nearby enough to measure resolved stellar photometry with HST (~4 Mpc).  We have constructed a sophisticated data reduction pipeline to measure stellar photometry from Hubble Space Telescope images. Above is an example of some of our data: a mosaic of the nearby disk galaxy NGC 253 and a close-up of a small portion of the image to show the detail we can see with HST.  We clearly see the individual stars of a galaxy 4 Mpc away.

I was also heavily involved in a very large Chandra X-ray telescope program performing a high-resolution survey of the  galaxy M33 (ChASeM33) as well as a large XMM-Newton program performing a wide-field survey of the galaxy M31 (XMM M31).

I am now playing a large role in other very large surveys, such as the Panchromatic Hubble Andromeda Treasury survey (PHAT). This is a 828 orbit HST program to map the northern half of M31 in six colors from the near ultroviolet to the near infrared. This survey received HST data for 4 years, and completed observations in the summer of 2013. Current survey coverage can be seen here.

I am also leading a large XMM-Newton Survey of M33, which is a wide-field, soft-sensitive follow-up to ChASeM33. This 800 ks program covers the full extent of the M33 optical disk, and has nearly a thousand detected sources. All of the data are currently in hand, and are being analyzed.

My personal interests include alpine skiing, rock and mountain climbing, backpacking, and guitar, but most of my free time is spent helping to parent my daughter, Brooke, who was born September 8, 2006, and my son Cole, who was born November 30, 2009.


 Benjamin Williams  (
Phone : 206 543 9849
FAX : 206 685 0403

Astronomy Dept.
University of Washington
Box 351580
Seattle WA 98195-1580

3910 15th Ave NE 
Seattle WA 98195-1580