ESA-AURA Astronomer

Since joining STScI in 2011, Dr Andrew J. Fox has served in a number of functional roles. He is currently the User Support block lead in the Cosmic Origins Spectrograph (COS) instrument team, where he oversees the work to support COS users as they prepare their observations. He is also the chair of the Telescope Time Review Board (TTRB), which reviews changes to accepted Hubble Space Telescope (HST) programs. Previously, he served as the review coordinator for HST Director’s Discretionary proposals.

Dr Fox’s research is concerned with understanding the diffuse gas that exists in and around galaxies, particularly in the Milky Way and Local Group. This interstellar and circumgalactic gas plays vital roles in the evolution of galaxies, and Dr Fox uses ultraviolet, optical, and radio observations to characterize its properties, origin, and fate. He has led multiple HST observing programs as principal investigator, including a spectroscopic program on the gas near the Galactic Center that led to discoveries recognized with the 2016 AURA Science Award. He has first-authored over 20 refereed articles on this subject in journals such as the Astrophysical Journal, Astronomy and Astrophysics, and the Monthly Notices of the Royal Astronomical Society. He recently co-authored an article in Annual Reviews of Astronomy and Astrophysics on the Magellanic Stream and edited a contributed volume of invited reviews on Gas Accretion onto Galaxies.

Before joining STScI, Dr Fox obtained his undergraduate degree at University College London in England and his PhD at the University of Wisconsin-Madison, where he completed a thesis on the origins of highly ionized gas in high-velocity clouds. He then held a Marie Curie postdoctoral fellowship at the Institut d’Astrophysique de Paris (IAP) in France, followed by an ESO Fellowship at the European Southern Observatory in Chile, where he supported the UVES spectrograph on the Very Large Telescope (VLT). As part of his ESO Fellowship he spent a year working on research at the Institute of Astronomy in Cambridge, England. He values the international aspect of modern astronomy and enjoys sharing his passion for astronomy with the general public.


PhD in Astronomy, University of Wisconsin-Madison
MSc in Astronomy, University of Wisconsin-Madison
MScI in Astrophysics, University College London


Science Interests:

  • Dr Fox leads international teams of researchers devoted to studying the gas in the Milky Way halo. This effort is focused on several key structures, including the giant Fermi Bubbles that straddle the Galactic Center and the Magellanic Stream, an extended tail of material stripped off the Magellanic Clouds. Dr Fox’s research group were the first to study the Fermi Bubbles in ultraviolet absorption; this program has led to new results on the kinematics and chemical composition of the gas in the Galactic Center and has opened a new window to the Galactic Center environment. Dr Fox’s research group has provided new constraints on the chemical composition of the Magellanic Stream and confirmed the dual origin hypothesis, in which both the Small and Large Magellanic Clouds both contributed to its material. They have also established new estimates for the total mass and mass flow rate of the Stream, which include the substantial amount of mass hidden in ionized gas.


Research Topics: Local Group Galaxies; Galaxy Formation and Evolution; Interstellar Medium


Professional Websites:

Professional Website


ORCID ID: 0000-0003-0724-4115

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