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Title: Searching for High-energy, Horizon-scale Emissions from Galactic Black Hole Transients during Quiescence

Abstract

We search for the gamma-ray counterparts of stellar-mass black holes using the long-term Fermi archive to investigate the electrostatic acceleration of electrons and positrons in the vicinity of the event horizon. We achieve this by applying the pulsar outer-gap model to their magnetospheres. When a black hole transient (BHT) is in a low-hard or quiescent state, the radiatively inefficient accretion flow cannot emit enough MeV photons that are required to sustain the force-free magnetosphere in the polar funnel via two-photon collisions. In this charge-starved gap region, an electric field arises along the magnetic field lines to accelerate electrons and positrons into ultra-relativistic energies. These relativistic leptons emit copious Gamma-rays via the curvature and inverse-Compton (IC) processes. It is found that these gamma-ray emissions exhibit a flaring activity when the plasma accretion rate typically stays between 0.01% and 0.005% of the Eddington value for rapidly rotating, stellar-mass black holes. By analyzing the detection limit determined from archival Fermi /Large Area Telescope data, we find that the 7-year averaged duty cycle of such flaring activities should be less than 5% and 10% for XTE J1118+480 and 1A 0620-00, respectively, and that the detection limit is comparable to the theoretical prediction for V404more » Cyg. It is predicted that the gap emission can be discriminated from the jet emission if we investigate the high-energy spectral behavior or observe nearby BHTs during deep quiescence simultaneously in infrared wavelength and very-high energies.« less

Authors:
; ; ; ;  [1]; ;  [2];  [3]
  1. Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China)
  2. Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)
  3. School of Physics and Astronomy, Sun Yat-Sen University, Zhuhai 519082 (China)
Publication Date:
OSTI Identifier:
22663285
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 845; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCELERATION; BLACK HOLES; DETECTION; ELECTRIC FIELDS; ELECTRONS; ELECTROSTATICS; EMISSION; GAMMA RADIATION; MAGNETIC FIELDS; MASS; MEV RANGE; PHOTON COLLISIONS; PHOTONS; PLASMA; POSITRONS; PULSARS; RELATIVISTIC RANGE; STARS; TELESCOPES; WAVELENGTHS

Citation Formats

Lin, L. C.-C., Pu, Hung-Yi, Hirotani, Kouichi, Matsushita, Satoki, Inoue, Makoto, Kong, Albert K. H, Chang, Hsiang-Kuang, and Tam, Pak-Hin T., E-mail: lupin@asiaa.sinica.edu.tw, E-mail: hpu@perimeterinstitute.ca, E-mail: hirotani@tiara.sinica.edu.tw. Searching for High-energy, Horizon-scale Emissions from Galactic Black Hole Transients during Quiescence. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA7E7F.
Lin, L. C.-C., Pu, Hung-Yi, Hirotani, Kouichi, Matsushita, Satoki, Inoue, Makoto, Kong, Albert K. H, Chang, Hsiang-Kuang, & Tam, Pak-Hin T., E-mail: lupin@asiaa.sinica.edu.tw, E-mail: hpu@perimeterinstitute.ca, E-mail: hirotani@tiara.sinica.edu.tw. Searching for High-energy, Horizon-scale Emissions from Galactic Black Hole Transients during Quiescence. United States. doi:10.3847/1538-4357/AA7E7F.
Lin, L. C.-C., Pu, Hung-Yi, Hirotani, Kouichi, Matsushita, Satoki, Inoue, Makoto, Kong, Albert K. H, Chang, Hsiang-Kuang, and Tam, Pak-Hin T., E-mail: lupin@asiaa.sinica.edu.tw, E-mail: hpu@perimeterinstitute.ca, E-mail: hirotani@tiara.sinica.edu.tw. Thu . "Searching for High-energy, Horizon-scale Emissions from Galactic Black Hole Transients during Quiescence". United States. doi:10.3847/1538-4357/AA7E7F.
@article{osti_22663285,
title = {Searching for High-energy, Horizon-scale Emissions from Galactic Black Hole Transients during Quiescence},
author = {Lin, L. C.-C. and Pu, Hung-Yi and Hirotani, Kouichi and Matsushita, Satoki and Inoue, Makoto and Kong, Albert K. H and Chang, Hsiang-Kuang and Tam, Pak-Hin T., E-mail: lupin@asiaa.sinica.edu.tw, E-mail: hpu@perimeterinstitute.ca, E-mail: hirotani@tiara.sinica.edu.tw},
abstractNote = {We search for the gamma-ray counterparts of stellar-mass black holes using the long-term Fermi archive to investigate the electrostatic acceleration of electrons and positrons in the vicinity of the event horizon. We achieve this by applying the pulsar outer-gap model to their magnetospheres. When a black hole transient (BHT) is in a low-hard or quiescent state, the radiatively inefficient accretion flow cannot emit enough MeV photons that are required to sustain the force-free magnetosphere in the polar funnel via two-photon collisions. In this charge-starved gap region, an electric field arises along the magnetic field lines to accelerate electrons and positrons into ultra-relativistic energies. These relativistic leptons emit copious Gamma-rays via the curvature and inverse-Compton (IC) processes. It is found that these gamma-ray emissions exhibit a flaring activity when the plasma accretion rate typically stays between 0.01% and 0.005% of the Eddington value for rapidly rotating, stellar-mass black holes. By analyzing the detection limit determined from archival Fermi /Large Area Telescope data, we find that the 7-year averaged duty cycle of such flaring activities should be less than 5% and 10% for XTE J1118+480 and 1A 0620-00, respectively, and that the detection limit is comparable to the theoretical prediction for V404 Cyg. It is predicted that the gap emission can be discriminated from the jet emission if we investigate the high-energy spectral behavior or observe nearby BHTs during deep quiescence simultaneously in infrared wavelength and very-high energies.},
doi = {10.3847/1538-4357/AA7E7F},
journal = {Astrophysical Journal},
number = 1,
volume = 845,
place = {United States},
year = {Thu Aug 10 00:00:00 EDT 2017},
month = {Thu Aug 10 00:00:00 EDT 2017}
}