X-ray Deep: Studying the Universe in X-rays

Research Scientists

Dr. Ann Hornschemeier

ann.hornschemeier AT nasa.gov

Dr. Ann Hornschemeier Dr. Ann E. Hornschemeier specializes in studies of X-ray emission from X-ray binary populations, both in the local universe and at cosmologically interesting distances (z > 0.1). This work is carried out using surveys by space-based X-ray, UV, and infrared observatories as well as ground-based telescopes. She chairs the NuSTAR Starburst and Local Group science working group, carrying out observations on seven nearby galaxies, involving coordinated observations with Chandra, XMM-Newton and Swift, and a team of approximately ten scientists both at NASA GSFC and universities. Dr. Hornschemeier is also the Chief Scientist for the Physics of the Cosmos (PCOS) program, which is the high energy astrophysics and cosmology program at NASA and is also heavily involved in future missions as a research scientist at NASA, including co-chairing a science panel for the ESA Athena mission due for launch in 2028. Dr. Hornschemeier's CV is available HERE.

Dr. Andy Ptak

andrew.ptak AT nasa.gov

Dr. Andy Ptak Dr. Andy Ptak got his PhD in Physics from the University of Maryland, College Park in 1997, working at NASA/GSFC with Pete Serlemitsos and Rich Mushotzky on X-ray observations of starburst galaxies and low-luminosity active galactic nuclei. His current interests are in the X-ray properties of starburst galaxies, particularly hot gas and ultra-luminous X-ray sources (ULXs), and in active galactic nuclei. He also has a strong interest in astrophysics software development, having written an automated analysis program for Chandra and XMM-Newton data that produced one of the first serendipitous source catalogs for Chandra and XMM-Newton (www.xassist.org). He is a member of the LSST galaxy and astrostatistics science teams. He is currently a member of the NuSTAR starburst and ULX teams, and is working on strategies for future strategic and explorer X-ray missions. Prior to coming to GSFC he worked as a post-doc under Prof. Richard Griffiths at Carnegie-Mellon University (1997-2001) and as a research scientist at the Johns Hopkins University (2001-2010).

Dr. Antara Basu-Zych

antara.r.basu-zych AT nasa.gov
Web page: http://astroantara.wordpress.com/

Dr. Antara Basu-Zych Dr. Antara Basu-Zych (CV) received her Ph.D. in astronomy from Columbia University in Jan. 2009, having worked with Dr. David Schiminovich on Lyman break analogs (LBAs). These low-redshift (z < 0.3) analogs of distant Lyman break galaxies offer a more-detailed view into galaxy evolution in the early Universe. She began working at Goddard Space Flight Center (GSFC) as a NASA Postdoctoral Program (NPP) fellow, and has since continued at GSFC as a research scientist under the CRESST/UMBC program, with Dr. Ann Hornschemeier. Her current work is on X-ray and UV studies of star formation in galaxies using Chandra and SWIFT/UVOT data. Antara is interested in studying galaxy evolution and star formation, observing actively star-forming galaxies to study their stellar (and X-ray binary) populations and addressing the question(s): what triggers (and quenches) star formation activity in galaxies? She has experience with a wide range of multi-wavelength data, spanning from radio (VLA and GBT) to X-ray (Chandra), and including Spitzer Infrared, OSIRIS (Keck) NIR Integral Field Spectroscopy, SDSS optical, and GALEX UV data.

Dr. Panayiotis Tzanavaris

panayiotis.tzanavaris-1 AT nasa.gov

Dr. Panayiotis Tzanavaris Dr. Panayiotis Tzanavaris has studied the intergalactic medium with quasar absorption lines, astrophysical constraints on the variation of fundamental constants, and the X-ray luminosity function of normal galaxies. He has extensive expertise in techniques and analysis from different wavelength regions, including radio, optical, UV and X-ray. He is currently working on a multiwavelength (UV, optical, X-ray, IR) project to characterize star-formation activity and evolution of Hickson Compact Groups of galaxies. He has been awarded a NASA Post-doctoral Fellowship to work at NASA Goddard Space Flight Center on the evolution of normal galaxies in the X-rays (starting in September 2009). He received his masters degree from the University of London and his Ph.D. from the University of Cambridge.

Dr. Mihoko Yukita

mihoko.yukita AT nasa.gov

Dr. Mihoko Yukita Dr. Mihoko Yukita began her career in astrophysics at the Chandra X-ray Center in Cambridge, MA where she assisted observers through the Chandra Director's Office. She moved to the University of Alabama in Huntsville where she received her Ph.D in physics working with the X-ray Astronomy group at Marshall Space Flight Center. She then studied diffuse X-ray emission from the central regions of nearby galaxies as a post-doctoral fellow at the University of Alabama in Tuscaloosa. Currently, she holds a post-doctoral position at Johns Hopkins University as a member of the NuSTAR starburst galaxy science group. Her research concerns the multi-wavelength study of stellar feedback in individual star-forming regions in nearby galaxies to assess the energy and momentum balance on local scales and to investigate how host galaxy structure and evolution are affected by feedback.

Dr. Vallia Antoniou

vantoniou AT cfa.harvard.edu

Dr. Vallia Antoniou Dr. Vallia Antoniou got her PhD from the University of Crete, Greece in 2008, having worked at SAO with Andreas Zezas and Despina Hatzidimitriou. From there, she moved to Iowa State University first as a postdoctoral research associate working with Massimo Marengo and then (2010-2013) as an affiliate Assistant Professor. In 2013 she returned at SAO as a postdoctoral fellow working with Jeremy Drake and Andreas Zezas. Currently, she is the Project Scientist of a Chandra X-ray Visionary Project overseeing all technical and scientific aspects, including source detection and characterization. Her main research is focused on the multi-wavelength (X-ray, optical, IR) study of X-ray binary populations in nearby star-forming galaxies with the aim to understand and constrain the parameters that affect their formation and evolution (such as the age and metallicity of the stellar populations, and the star formation properties of their galactic environment). She is a member of the following science working groups: NuSTAR's "Starburst Galaxies and Local Group Galaxies", Spitzer's "SAGE-Spec" and Athena's "SWG3-Observatory". Vallia Antoniou's CV can be found HERE.

Dr. Neven Vulic

neven.vulic AT nasa.gov

Dr. Neven Vulic Dr. Neven Vulic received his PhD in astronomy from The University of Western Ontario in June 2016, working with Prof. Pauline Barmby and Prof. Sarah C. Gallagher on X-ray populations in nearby galaxies. Combining expertise in X-ray and optical wavelengths he investigated the X-ray binary populations associated with star clusters. He is currently a CRESST/UMCP postdoctoral associate at NASA/GSFC. Using data from NuSTAR, he is studying the spectral properties of X-ray binary populations in nearby galaxies to characterize their accretion states and compact object types. By exploiting multiwavelength data, Neven is interested in explaining the properties associated with formation and evolution of X-ray binaries in different environments.

Former Group Members

Dr. Leigh Jenkins

Dr. Leigh Jenkins Dr. Leigh Jenkins was a postdoctoral research scientist in the X-ray Laboratory at NASA/GSFC. She received her Ph.D. in Astronomy from the University of Leicester in the UK in 2005, and a Master of Science degree in Astrophysics from University College London in 2001. Leigh's current research interests involve a wide variety of phenomena in extragalactic astronomy at many wavelengths. These include X-ray binaries/ultraluminous X-ray sources in nearby star-forming galaxies, the X-ray properties of starburst galaxies, as well as the nature of nuclear X-ray activity in local barred and unbarred galaxies. She has also conducted a study of the near-infrared properties of thousands of galaxies in the Coma cluster. Leigh is currently working on the X-ray SINGS survey, which will characterize the X-ray emission from a diverse sample of &mt; 50 nearby galaxies, and relate this to galaxy properties measured at ultraviolet, infrared and optical wavelengths. Currently, Dr. Jenkins works as a Commissioning Editor at IOP Publishing.

Dr. Bret Lehmer

Dr. Bret Lehmer Dr. Bret Lehmer was an Einstein Postdoctoral Fellow, working at Johns Hopkins University and Goddard Space Flight Center since 2009. He received undergraduate degrees in Physics and Astronomy from the University of Iowa and completed his PhD in Astronomy and Astrophysics from Penn State University in 2007. From 2007-2009 he worked at Durham University for the United Kingdom's Science and Technology Facilities Council as a Research Fellow. His main research utilizes deep X-ray observations with the Chandra Observatory to study populations of distant galaxies and supermassive black holes. Currently, Dr. Lehmer is an Assistant Professor at University of Arkansas.

Dr. Barb Mattson

Dr. Barb Mattson Dr. Barb Mattson completed her Ph.D. in astronomy at the University of Maryland. Her Ph.D. thesis research concentrated on X-ray spectral analysis of Seyfert galaxies, with a particular eye on how the results could be interpreted (or not) in the context of the standard AGN model. She has worked at Goddard Space Flight Center for 10 years, starting as a graduate student, pausing to work as a support scientist for several NASA missions, including Swift, Integral and Constellation-X, and finally doing dual duty as a contractor and grad student to finish her Ph.D. Currently, Dr. Mattson works at Goddard Space Flight Center as the Acting Education and Public Outreach (E/PO) Lead for NASA's Physics of the Cosmos and Cosmic Origins Programs, Acting E/PO Lead for the High Energy Science Archive Research Center (HEASARC), and E/PO Lead for the Suzaku and Astro-H missions at GSFC.

Dr. Malachi Tatum

Dr. Malachi Tatum Malachi Tatum earned his Ph.D. at the University of Maryland, Baltimore County in November 2013, having worked with Jane Turner on the importance of the Compton-thick, X-ray reprocessor in active galactic nuclei (AGN). This work included modeling selected Seyfert galaxies using a Compton-thick, accretion disk wind and understanding the spectral properties of a hard X-ray-selected sample in context of reflection-dominated and absorption-dominated models. Malachi joined the Astrophysics Science Division at Goddard Space Flight Center as a NASA Postdoctoral Program (NPP) fellow in November 2013 under the supervision of Andy Ptak. He is focused on using the hard X-ray bandpass as a proxy for understanding the underlying powerlaw continuum of active galactic nuclei and exploring how Compton-thick absorption in the X-ray band affects the energy budget of these systems, both offering insight into understanding the link between black hole mass and the galactic bulge properties. He also has interest in the connection between starbursts and active galactic nuclei.

Dr. Daniel Wik

Dr. Daniel Wik Dr. Daniel Wik received his Ph.D. in astronomy from the University of Virginia in Dec. 2010, working on the physical and cosmological implications of inverse Compton (IC) processes in galaxy clusters with Dr. Craig Sarazin, which made use of data from hydrodynamical simulations and from the Suzaku, Swift, and XMM-Newton observatories. At GSFC as an NPP fellow, he got involved with the hard X-ray NuSTAR mission, including the ground calibration effort of NuSTAR's optics and target planning for the galaxy cluster and starburst galaxy science working groups. In between failing to find IC emission in galaxy clusters, Dan studies the hard X-ray emission from binary populations in nearby galaxies such as M31, M82, and NGC 253 (where he couldn't help but also search for an IC signal, which he unsurprisingly failed to find, yet again). His work on galaxies and clusters of galaxies with NuSTAR led him to develop the nuskybgd background tool and analysis software to decompose the emission of diffuse and/or mildly confused point sources.