Predictions for reverberating spectral line from a newly formed black hole accretion disk: case of tidal disruption flares

Abstract

Tidal Disruption Events (TDEs) can be perfect probes of dormant SMBHs in normal galaxies. During the rising phase, the accretion luminosity can increase by orders of magnitude in several weeks and the emergent ionizing radiation illuminates the fresh accretion flow. In this paper, we simulated the evolution of the expected spectral line profile of iron due to such a flare by using a ray-tracing code with effects of general relativity (GR) taken into account. We found that the time-dependent profile changes significantly with black hole spin, inclination angle with respect to the black-hole equatorial plane, and the expansion velocity of the ionization front. At low values of spin, a "loop" feature appears in the line profile vs. time plot when the inclination is no less than $30^{\circ }$ and the expansion velocity $v_{\exp }$ is no less than half speed of light, due to a shadow in the emission of the truncated disk. In the light curve two peaks occur depending on the inclination angle. At large $v_{\exp }$, a shallow "nose" feature may develop ahead of the loop, its duration depends on the expansion velocity and the inclination angle. We explore the entire interval of black hole spin parameter ranging from extreme prograde to extreme retrograde rotation, $-1<a<1$. In the prograde case, a low-energy tail appears to be more pronounced in the evolving centroid energy of the line. Our results demonstrate the importance to search for X-ray spectral lines in the early phase of TDE flares in order to constrain black hole mass and spin, as well as properties of the innermost accretion flow.

arXiv comment12 pages, including 8 figures, accepted for publication in ApJ

References in corpus (39)

• Improved Reflection Models of Black-Hole Accretion Disks: Treating the Angular Distribution of X-rays
• Discovery of the Onset of Rapid Accretion by a Dormant Massive Black Hole
• Broad iron lines in Active Galactic Nuclei
• A light bending model for the X-ray temporal and spectral properties of accreting black holes
• Optical Flares from the Tidal Disruption of Stars by Massive Black Holes
• An ultraviolet-optical flare from the tidal disruption of a helium-rich stellar core
• The Birth of a Relativistic Outflow in the Unusual γ-ray Transient Swift J164449.3+573451
• Swift J2058.4+0516: Discovery of a Possible Second Relativistic Tidal Disruption Flare?
• An extremely luminous panchromatic outburst from the nucleus of a distant galaxy
• A long hard look at MCG-6-30-15 with XMM-Newton
• A rapidly spinning supermassive black hole at the centre of NGC 1365
• An extended scheme for fitting X-ray data with accretion disk spectra in the strong gravity regime
• UV/Optical Detections of Candidate Tidal Disruption Events by GALEX and CFHTLS
• Large-Amplitude X-ray Outbursts from Galactic Nuclei: A Systematic Survey Using ROSAT Archival Data
• Iron fluorescence from within the innermost stable orbit of black hole accretion disks
• Broad iron L-line and X-ray reverberation in 1H0707-495
• Luminous Thermal Flares from Quiescent Supermassive Black Holes
• Ultraviolet Detection of the Tidal Disruption of a Star by a Supermassive Black Hole
• X-ray iron line reverberation from black hole accretion disks
• A Huge Drop in X-ray Luminosity of the Non-Active Galaxy RXJ1242.6-1119A, and First Post-Flare Spectrum - Testing the Tidal Disruption Scenario
• A tidal disruption-like X-ray flare from the quiescent galaxy SDSS J120136.02+300305.5
• NuSTAR Spectroscopy of GRS 1915+105: Disk Reflection, Spin, and Connections to Jets
• Extreme Coronal Line Emitters: Tidal Disruption of Stars by Massive Black Holes in Galactic Nuclei?
• Evolution of Accretion Disks in Tidal Disruption Events
• A Tidal Disruption Flare in Abell 1689 from an Archival X-ray Survey of Galaxy Clusters
• Effects of Kerr Spacetime on Spectral Features from X-Ray Illuminated Accretion Discs
• Tidal effects on small bodies by massive black holes
• Spectroscopic Signatures of the Tidal Disruption of Stars by Massive Black Holes
• Sgr A* flares: tidal disruption of asteroids and planets?
• Discovery of Fe K-alpha X-ray reverberation around the black holes in MCG-5-23-16 and NGC 7314
• An XMM-Newton observation of Ark 120: the X-ray spectrum of a `bare' Seyfert 1 nucleus
• Ripple effects & oscillations in the broad FeKa line as a probe of massive black hole mergers
• Iron line reverberation mapping with Constellation-X
• Role of emission angular directionality in spin determination of accreting black holes with broad iron line
• Kinetic theory of equilibrium axisymmetric collisionless plasmas in off-equatorial tori around compact objects
• Stellar dynamics in a galactic centre surrounded by a massive accretion disc. I. Newtonian description
• A cloud model of active galactic nuclei: the iron K-alpha line diagnostics
• The structure and X-ray radiation spectra of illuminated accretion disks in AGN. III. Modeling fractional variability
• Black hole accretion rings revealed by future X-ray spectroscopy

Cited by in corpus (7)

• Observatory science with eXTP
• On the formation of a quasi-stationary twisted disc after a tidal disruption event
• How to Test the Two-Families Scenario
• The Profiles of Fe Kα Line From the Inhomogeneous Accretion Flow
• Tidal disruption events as a site of an evolving relativistic spectral~line
• Probing the Bardeen-Petterson effect in tidal disruption events with spectral line reverberation mapping
• Lense-Thirring effect on accretion flow from counter-rotating tori