HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details.

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XL-Calibur Image Gallery: Science

All figures shown here are from the GX301-2 observations made by the X-Calibur flight in December 2018, one of the two targets studied during the flight. These figures appear in Abarr, Q et al., ApJ, 891, 70 (2020).


X-Calibur constraints on the linear polarization of GX301-2 at 15–35 keV in the plane of the normalized Stokes parameters (with 1σ statistical error bars):
  • black filled circle: entire data set
  • red square: the main pulse (phase 0.8–1.14)
  • green triangle: secondary pulse (phase (0.14–0.8)
Polarization fractions are shown for illustrative purposes as:
  • center: Q = U = 0 (0%)
  • red circle: 30%
  • black circle: 100%


Q (filled circles) and U (open circles) parameters for the background-subtracted on source (red) and off source (black) as a function of time.

GX301-2 detection rates at apastron flare as seen by X-Calibur
GX301-2 detection rates around the apastron flare as seen by X-Calibur, Swift BAT, NICER, and Swift XRT.

Movies

Still frame from presentation on X-ray Polarimetry of Microquasers with IXPE and XL-Calibur
Principal Investigator Henric Krawcyznski discusses plans and modeled data to explain how polarimetry observations of known black holes will provide new insights on extreme condition physics (33 min; 640 x 360 MP4 (53.4 MB); YouTube).