Welcome!


see also the obligatory mountain picture
(credit: H.-W. Rix)

I am an Assistant Professor and Canada Research Chair in Galactic Astrophysics in the Astronomy and Astrophysics Department at the University of Toronto. Before this, I was a Bahcall fellow and Long-term member at the Institute for Advanced Study in Princeton. My research is currently mostly focused on understanding the dynamical structure, formation, and evolution of the Milky Way, but I work on a variety of problems in astrophysics.

I served as the Science Working Group Chair for the APOGEE survey, which used high-resolution, high signal-to-noise infrared spectroscopy to investigate the structure of the bulge and disk regions of the Milky Way, as well as many other topics in stellar and galactic astrophysics. Currently, I am a member of the follow-up APOGEE-2 survey, which is extending APOGEE's coverage of the Milky Way to larger distances and to the Southern hemisphere.

I am the main developer of galpy, a well-tested, well-documented python library for galactic dynamics. For more information on other code with general usefulness, see the code section of this website or my GitHub profile. I strongly believe that scientific software should be freely available and open source; all of the code used for many of my papers is available online (search for the [code] links on my publications page)

Recent highlights

  • I appear in a short video that provides an inside view of the Institute for Advanced Study:


  • First measurement of the Sun's motion using disk stars beyond the immediate Solar neighborhood. This measurement strongly demonstrates that the Sun's motion with respect to the circular velocity is 25 km/s, about twice as large as it was thought to be before based on local observations. The difference is due to a streaming motion of the entire solar neighborhood that is at least partly due to the Galactic bar at the center of the Milky Way.
    (figure from: Astrophys. J. 800, 83 (2015) [link])





  • I was deeply involved in a series of papers in which my collaborators and I employed the APOGEE data to perform the first detailed measurements of the chemical structure of the entire Milky Way disk. Bovy et al. (2014; link) developed a novel, highly efficient method for finding red-clump stars in high-resolution spectroscopic surveys such as APOGEE. Nidever, Bovy, et al. (2014; link) used this APOGEE red-clump sample to study the elemental abundances [Fe/H] and [α/Fe] over a large part of the Milky Way's disk, finding a remarkable uniformity over the disk of the abundances of old stars. This implies that the early history was very similar in all parts of the disk. In Hayden, Holtzman, Bovy et al. (2014; link) and Hayden, Bovy, Holtzman et al. (2015; link) we extended this study to the entire disk using brighter giants and also investigate the full metallicity distribution function. The latter has a strong change in skew between the inner and outer disk, a tell-tale sign that radial redistribution of angular momentum has been significant over the history of the Milky Way. This result got some press: [Daily Mail][astronomy.com][discovery.com]
  • First dynamical measurement of the surface density profile of the Milky Way's disk, directly measuring the Milky Way disk's scale length and breaking the disk–halo degeneracy in the inner Milky Way
    (figure from: Astrophys. J. 779, 115 (2013) [link])





  • First measurement of the Milky Way's circular velocity and rotation curve from stellar kinematics covering a large part of the Galactic disk from the first year of APOGEE data. These data show that Vc = 218 ± 6 km s-1, the most precise measurement of the circular velocity ever [link]
  • Discovered that the Milky Way disk's vertical structure is very different from what was previously thought: By separating disk populations by their chemical signatures, we have shown that there is a continuous range of disk thicknesses present. Most of the stellar mass is in the thinnest components, with a smaller amount of mass in the thicker components (see figure below). This is in contrast with the previous picture where the vertical structure was characterized by a "thin" and a "thick" component,
    (figure from: Astrophys. J. 751, 131 (2012) [link])




  • Direct observation of the inside-out growth of the Milky Way's disk
    (paper: Astrophys. J. in press, (2012) [link])




  • Developed the XDQSO technique used to discover more than 100,000 quasars as part of SDSS-III's BOSS; this sample includes the largest homogeneously selected sample of quasars with redshift ≥ 2.2 [link]
  • Showed that data from Moni Bidin et al. (2012) imply a local dark matter density near the Sun of 0.3 ± 0.1 GeV cm-3, in contrast with previous claims. Press: [New Scientist] [Universe Today] [The Guardian] [La Libération]
    (paper: Astrophys. J. submitted, (2012) [link])




contact info

email: bovy [at] astro.utoronto.ca

address:
Department of Astronomy and Astrophysics
University of Toronto
50 St. George Street
Toronto, ON M5S 3H4