Hard X-Ray Emission from the M87 AGN Detected with NuSTAR


M87 hosts a 3-6 billion solar mass black hole with a remarkable relativistic jet that has been regularly monitored in radio to TeV bands. However, hard X-ray emission. greater than or similar to 10 keV, which would be expected to primarily come from the jet or the accretion flow, had never been detected from its unresolved X-ray core. We report NuSTAR detection up to 40 keV from the the central regions of M87. Together with simultaneous Chandra observations, we have constrained the dominant hard X-ray emission to be from its unresolved X-ray core, presumably in its quiescent state. The core spectrum is well fitted by a power law with photon index Gamma = 2.11(-0.11)(+0.15) . The measured flux density at 40 keV is consistent with a jet origin, although emission from the advection-dominated accretion flow cannot be completely ruled out. The detected hard X-ray emission is significantly lower than that predicted by synchrotron self-Compton models introduced to explain emission above a GeV.

accretion, accretion disks, black hole physics, galaxies: elliptical and lenticular, cD, galaxies: individual (M87), galaxies: nuclei, X-rays: galaxies, SUPERMASSIVE BLACK-HOLE, JET, ACCRETION, HST-1, Astronomy & Astrophysics
Wong, K., Nemmen, R., Irwin, J., Lin, D. (2017): Hard X-Ray Emission from the M87 AGN Detected with NuSTAR. The Astrophysical Journal Letters, 849(1). DOI: 10.3847/2041-8213/aa92c2