Tony Sohn

Astronomer and Scientist in Baltimore, Maryland

Tony Sohn

Astronomer and Scientist in Baltimore, Maryland

I am a Support Scientist working at the Space Telescope Science Institute (STScI). I mainly work on measuring "proper motions" (astronomical term for sideways motions across the sky) of stellar systems in the Local Group to improve our understanding on how galaxies form and evolve in the Universe. The motions I try to measure are so tiny that the resolving power of the Hubble Space Telescope (HST) is essential. My recent works have focused on the following topics:

The First Proper Motion Measurement of M31

Proper Motion of Leo I: Constraining the Milky Way Mass

Proper Motions along the Sagittarius and Orphan Streams: Constraining the Milky Parameters and Dark Halo Shape

The Nature of Dark Matter: Halo Cusps or Cores from dSph Internal Proper Motion Dynamics

Proper Motions of Distant Milky Way Halo Stars

Some of my works have been presented in the media including a live televised NASA press conference and a Scientific American article.

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About the Background Image: This background image of the Eagle Nebula (M16) was taken by myself at the Cerro Tololo Interamerican Observatory (CTIO) using the Mosaic II CCD camera in 3 narrow-band filters (Hα, OIII, and SII).

  • Work
    • Space Telescope Science Inst.
  • Education
    • Ph.D., University of Virginia