X-ray Studies of Galaxy Clusters, Galaxies and Diffuse Background

Position Overview

The NASA Postdoctoral Program (NPP) offers unique research opportunities to highly‑talented scientists to engage in ongoing NASA research projects at a NASA Center, NASA Headquarters, or a NASA‑affiliated research institute. These one‑to‑three year fellowships are competitive and designed to advance NASA’s missions in space science, Earth science, aeronautics, space operations, exploration systems, and astrobiology.

We study the distribution of galaxy clusters as a function of mass and redshift to probe large‑scale structure and constrain cosmological models. This work involves detailed observational and theoretical studies of the X‑ray emitting intergalactic medium across mass scales from galaxies to superclusters, including shock fronts, dynamic phenomena, and cluster non‑thermal components. Techniques use X‑ray, optical, Sunyaev‑Zeldovich, and radio data, with primary X‑ray data from Chandra, XMM‑Newton, Swift, Suzaku, and NuSTAR.

Leveraging our expertise in building mirrors and micro‑calorimeter detectors for Hitomi, XRISM, and Athena, we analyze high‑resolution spectra (e.g., Perseus) and conduct high‑resolution MHD simulations to compare with observations and aid future X‑ray missions.

An ongoing program concentrates on analyzing Chandra, XMM‑Newton, and NuSTAR AGN data. Research covers broad topics such as fitting broadband spectra (0.6 keV to > 30 keV) of broad‑line active galaxies and BL Lac objects, searching for correlated temporal/spectral variations, and determining the nature of X‑ray emission from Seyfert IIs and LINERs. Extensive correlative studies involve infrared satellite and Hubble Space Telescope observations.

The HEAO‑1 and ROSAT all‑sky databases enable study of high‑latitude and unresolved X‑ray background emission. The absolute intensity measures the accretion history of the Universe; spatial fluctuations in the HEAO‑1 background probe nearby cosmological structures; temporal fluctuations in the ROSAT background trace heliospheric charge‑exchange emission. We explore these topics by correlating databases with Chandra and XMM‑Newton observations, participate in new mission designs, and investigate cross‑calibration between observatories, as well as instrumental and observational effects affecting background measurements.

Goddard Space Flight Center
Greenbelt, Maryland

Astrophysics

Maxim Markevitch (Maxim.Markevitch)
Andy Ptak (andrew.ptak)
Francesca Civano (francesca.m.civano)

Applications with citizens from Designated Countries will not be accepted at this time, unless they are Legal Permanent Residents of the United States. A complete list of Designated Countries can be found at: https://(Use the "Apply for this Job" box below)..

• U.S. Citizens;
• U.S. Lawful Permanent Residents (LPR);
• Foreign Nationals eligible for an Exchange Visitor J‑1 visa status;
• Applicants for LPR, asylees, or refugees in the U.S. at the time of application with
  1) a valid EAD card and
  2) I‑485 or I‑589 forms in pending status.

• Degree:
  Doctoral Degree.