Hard X-ray view of the past activity of Sgr A in a natural Compton mirror

By M. Revnivtsev, E. Churazov, S. Sazonov, R. Sunyaev, A. Lutovinov, M. Gilfanov, A. Vikhlinin, P. Shtykovsky, M. Iki, Moscow and 7 more. 2004

144 citations recorded by the source corpus.

We report the association of the recently discovered hard X-ray source IGR J17475−2822 with the giant molecular cloud Sgr B2 in the Galactic Center region. The broad band (3-200 keV) spectrum of the source constructed from data of different observatories strongly supports the idea that the X-ray emission of Sgr B2 is Compton scattered and reprocessed radiation emitted in the past by the Sgr Asource. We conclude that 300-400 years ago Sgr Awas a low luminosity (L ≈ 1.5 × 10 39 erg s −1 at 2-200 keV) AGN with a characteristic hard X-ray spectrum (photon index Γ ≈ 1. 8). We estimate the mass and iron abundance of the Sgr B2 scattering gas at 2 × 10 6 M� (r/10 pc) 2 and 1.9 solar, respectively (where r is the radius of

Subfields: Astronomy and Astrophysics, Radiation

View Paper: https://www.semanticscholar.org/paper/0c3ef9fb867d6b8df81a3133d55c2ba68f24b1a2

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In Astronomy and Astrophysics

1. D. M. Alexander
2. P. Hopkins
3. R. Hickox
4. Kevin Schawinski
5. L. Hernquist
6. R. Genzel
7. T. Alexander
8. D. Thomas

In Radiation

1. U. Leicester
2. D. M. Alexander
3. J. Vink
4. R. Hickox

Citations in the corpus

• INTEGRAL/IBIS all-sky survey in hard X-rays (2007, methodology): “This source was originally reported by Revnivtsev et al. (2004c) and erroneously associated with the X-ray burster AX J17456−2901.”
• The Masses and Spins of Neutron Stars and Stellar-Mass Black Holes (2014, unknown): “[233]).”
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics, and Formation (2006, background): “It is therefore possible that the past event of AGN activity of Sgr A* 300–400 year ago (Revnivtsev et al. 2004) was linked with the passage of IRS 13E at its periapsis.”
• Observational Signatures of Particle Acceleration in Supernova Remnants (2012, background): “The surveys of the central 100 pc have also discovered that several massive molecular clouds in the GC display intense Fe Kα 6.4 keV line emission (Koyama et al., 1996, 2007) and non-thermal continuum (Sunyaev et al., 1993; Revnivtsev et al., 2004; Bélanger et al., 2006).”
• GIANT GAMMA-RAY BUBBLES FROM FERMI-LAT: ACTIVE GALACTIC NUCLEUS ACTIVITY OR BIPOLAR GALACTIC WIND? (2010, unknown): “The luminosity is ∼1.5×1039 erg s−1 in 2 − 200 keV with a power law spectrum dN/dE ∝ E−γ with γ=1.8±0.2 (Ponti et al. 2010; Revnivtsev et al. 2004; Nobukawa et al. 2008).”
• DISCOVERY OF A SUPERLUMINAL Fe K ECHO AT THE GALACTIC CENTER: THE GLORIOUS PAST OF Sgr A* PRESERVED BY MOLECULAR CLOUDS (2010, background): “On the other hand, the detection of hard X-ray emission up to 100 keV from Sgr B2 obtained with the Integral observatory by Revnivtsev et al. (2004) supports the reflection nebula interpretation.”
• A CORRELATION BETWEEN STAR FORMATION RATE AND AVERAGE BLACK HOLE ACCRETION IN STAR-FORMING GALAXIES (2013, background): “There is also observational evidence in the X-ray Fe Kα echoes from the quiescent SMBH in the center of the Milky Way, suggesting it might have been a low-luminosity AGN a few hundred years ago (e.g. Revnivtsev et al. 2004; Ponti et al. 2010; Nobukawa et al. 2011).”
• Active galactic nuclei flicker: an observational estimate of the duration of black hole growth phases of ∼105 yr (2015, background): “X-ray light echoes in the Galactic Center show moderate-luminosity flares in the last few centuries (Revnivtsev et al. 2004; Ponti et al. 2010), though these were likely too short and not sufficiently luminous to generate narrow lines across the Milky Way.”
• The 511 keV emission from positron annihilation in the Galaxy (2010, background): “18) which has been interpreted as the delayed reflexion of (a much stronger) past emission from Sgr A∗ (e.g. Markevitch et al., 1993, Koyama et al., 2006, Murakami et al., 2000, Revnivtsev et al., 2004).”
• GALAXY ZOO: THE FUNDAMENTALLY DIFFERENT CO-EVOLUTION OF SUPERMASSIVE BLACK HOLES AND THEIR EARLY- AND LATE-TYPE HOST GALAXIES (2010, methodology): “Suzaku observations by Nobukawa et al. (2008) detect a Kα luminosity consistent with Sgr A∗ having been at 1038−39 ergs−1 a mere 300 yrs ago, while Revnivtsev et al. (2004) used INTEGRAL data to argue that Sgr A∗ was at a 2–200 keV luminosity of L ∼ 1.5× 1039 ergs−1 just 300 to 400 years ago.”