Bright X-ray flares from Sgr A*

Abstract

We address a question whether the observed light curves of X-ray flares originating deep in galactic cores can give us independent constraints on the mass of the central supermassive black hole. To this end we study four brightest flares that have been recorded from Sagittarius A*. They all exhibit an asymmetric shape consistent with a combination of two intrinsically separate peaks that occur at a certain time-delay with respect to each other, and are characterized by their mutual flux ratio and the profile of raising/declining parts. Such asymmetric shapes arise naturally in the scenario of a temporary flash from a source orbiting near a super- massive black hole, at radius of only 10-20 gravitational radii. An interplay of relativistic effects is responsible for the modulation of the observed light curves: Doppler boosting, gravitational redshift, light focusing, and light-travel time delays. We find the flare properties to be in agreement with the simulations (our ray-tracing code sim5lib). The inferred mass for each of the flares comes out in agreement with previous estimates based on orbits of stars; the latter have been observed at radii and over time-scales two orders of magnitude larger than those typical for the X-ray flares, so the two methods are genuinely different. We test the reliability of the method by applying it to another object, namely, the Seyfert I galaxy RE J1034+396.

MNRAS in press; 12 pages; 9 figures; 3 tables Accepted 2017 September 4. Received 2017 September 4; in original form 2017 May 22; minor changes applied

References in corpus (57)

• Monitoring stellar orbits around the Massive Black Hole in the Galactic Center
• Closest Star Seen Orbiting the Supermassive Black Hole at the Centre of the Milky Way
• The Proper Motion of Sgr A*: II. The Mass of Sgr A*
• Chandra X-ray Spectroscopic Imaging of Sgr A* and the Central Parsec of the Galaxy
• Lense-Thirring Precession and QPOs in Low Mass X-Ray Binaries
• The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole: A Paradox of Youth
• Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre
• Rapid X-ray flaring from the direction of the supermassive black hole at the Galactic Centre
• kHz Quasi Periodic Oscillations in Low Mass X-ray Binaries as Probes of General Relativity in the Strong Field Regime
• Radiative Models of Sgr A* from GRMHD Simulations
• An Improved Distance and Mass Estimate for Sgr A* from a Multistar Orbit Analysis
• Variable Infrared Emission from the Supermassive Black Hole at the Center of the Milky Way
• Imaging Optically-Thin Hot Spots Near the Black Hole Horizon of Sgr A* at Radio and Near-Infrared Wavelengths
• The Nature of the 10 Kilosecond X-ray Flare in Sgr A*
• Spectral evolution of magnetic flares and time lags in accreting black hole sources
• XMM-Newton observation of the brightest X-ray flare detected so far from SgrA*
• A Fast New Public Code for Computing Photon Orbits in a Kerr Spacetime
• A Bayesian test for periodic signals in red noise
• Testing Properties of the Galactic Center Black Hole Using Stellar Orbits
• Evidence for X-ray synchrotron emission from simultaneous mid-IR to X-ray observations of a strong Sgr A* flare
• A Combined Optical and X-ray Study of Unobscured Type 1 AGN. I. Optical Spectra and SED Modeling
• Polarimetry of near-infrared flares from Sagittarius A*
• Imaging Bright Spots in the Accretion Flow Near the Black Hole Horizon of Sgr A*
• Stellar Orbits Near Sagittarius A*
• On The Nature of the Variable Infrared Emission from Sgr A*
• First Simultaneous NIR/X-ray Detection of a Flare from SgrA*
• Chandra-HETGS Observations of the Brightest Flare Seen from Sgr A*
• A Multi-Wavelength Study of Sgr A*: The Role of Near-IR Flares in Production of X-ray, Soft $\gamma$-ray and Sub-millimeter Emission
• Observational appearance of inefficient accretion flows and jets in 3D GRMHD simulations: Application to Sgr~A*
• A Constant Spectral Index for Sagittarius A* During Infrared/X-ray Intensity Variations
• A Magnetohydrodynamic Model for the Formation of Episodic Jets
• X-ray hiccups from SgrA* observed by XMM-Newton. The second brightest flare and three moderate flares caught in half a day
• Vortices In Circumstellar Disks
• A polarised infrared flare from Sagittarius A* and the signatures of orbiting plasma hotspots
• Coupled jet-disk model for Sgr A*: explaining the flat-spectrum radio core with GRMHD simulations of jets
• Simultaneous Multi-Wavelength Observations of Sgr A* during 2007 April 1-11
• The variability of accretion onto Schwarzschild black holes from turbulent magnetized discs
• Near-infrared polarimetry setting constraints on the orbiting spot model for Sgr A* flares
• RE J1034+396: The origin of the soft X-ray excess and QPO
• Light Curves from an MHD Simulation of a Black Hole Accretion Disk
• Polarized NIR and X-ray Flares from SgrA*
• The Rotation Measure and 3.5mm Polarization of Sgr A*
• K-band polarimetry of an Sgr A* flare with a clear sub-flare structure
• Near infrared flares of Sagittarius A*: Importance of near infrared polarimetry
• Detection of a QPO in 5 XMM-Newton observations of RE J1034+396
• The X-ray Flux Distribution of Sagittarius A* as Seen by Chandra
• On the orientation of the Sagittarius A* system
• Weighing the cusp at the Galactic Centre
• Quasi-Periodic Flares from Star-Accretion Disc Collisions
• Searching for the trigger of the AGN QPO: 8 years of RE J1034+396
• Interpreting the High Frequency QPO Power Spectra of Accreting Black Holes
• Star Formation in the vicinity of Nuclear Black Holes: Young Stellar Objects close to Sgr A*
• The host galaxy of a narrow-line Seyfert 1 galaxy RE J1034+396 with X-ray quasi-periodic oscillations
• The model constraints from the observed trends for the quasi-periodic oscillation in RE J1034+396
• Predictions for Fourier-resolved X-ray spectroscopy from the model of magnetic flare avalanches above an accretion disc with hot ionized skin
• Near-infrared polarimetry as a tool for testing properties of accreting super-massive black holes
• Near-infrared Polarimetry of flares from Sgr A* with Subaru/CIAO

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