Nustar view of the central region of the Perseus cluster

Abstract

Located at the center of the Perseus cluster, 3C 84 is an extremely bright and nearby radio galaxy. Because of the strong diffuse thermal emission from the cluster in X-rays, the detailed properties and the origin of a power-law component from the central active galactic nucleus (AGN) remains unclear in the source. We report here the first NuSTAR observations of 3C 84. The source was observed for 24.2 and 32 ks on February 01 and 04, 2018, respectively. NuSTAR observations spectrally decompose the power-law AGN component above 10 keV. The power-law component dominates the spectrum above 20 keV with a photon index $\sim$1.9 and an energy flux F${}_{20-30keV}$ = 1.0 $\times$10${}^{-11}$ erg cm${}^{-2}$ s${}^{-1}$, corresponding to an isotropic luminosity, $L_{20-30keV}$ = 7.4$\times$10${}^{42}$ erg s${}^{-1}$. We discuss possible emitting sites for the power-law component. The expected thermal emission from the accretion disk is not hot enough to account for the hard X-rays detected from the source. Similar X-ray and $\gamma$-ray photon indices and long-term flux variations, the absence of cutoff energy in the hard X-ray spectrum of the source, correlated hard X-ray flux and hardness ratio variations, and the similarity of optical-X-ray slope to blazar rather than Seyfert galaxies supports the hard X-ray power-law component originating from the jet.

arXiv commentaccepted for publication in ApJ Letters

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Cited by in corpus (9)

• Comprehensive Broadband X-ray and Multiwavelength Study of Active Galactic Nuclei in Local 57 Ultra/luminous Infrared Galaxies Observed with NuSTAR and/or Swift/BAT
• Hard X-Ray to Radio Multiwavelength SED Analysis of Local U/LIRGs in GOALS Sample with Self-consistent AGN Model Including Polar-dust Component
• NuSTAR hard X-ray spectra of radio galaxies
• Unsupervised Machine Learning for the Classification of Astrophysical X-ray Sources
• Origin of the UV to X-ray emission of radio galaxy NGC 1275 explored by analyzing its variability
• Multiwavelength monitoring of NGC 1275 over a decade: Evidence of a shift in synchrotron peak frequency and long-term multi-band flux increase
• The NuSTAR View of Perseus: the ICM and a Peculiar Hard Excess
• Detection of Compton scattering in the jet of 3C 84
• The X-ray coronae in NuSTAR bright active galactic nuclei