X-ray Line Diagnostics of Hot Accretion Flows around Black Holes

Abstract

We compute X-ray emission lines from thermal plasma in hot accretion flows. We show that line profiles are strong probes of the gas dynamics, and we present line-ratio diagnostics which are sensitive to the distribution of mass with temperature in the flow. We show how these can be used to constrain the run of density with radius, and the size of the hot region. We also present diagnostics which are primarily sensitive to the importance of recombination versus collisional ionization, and which could help discriminate ADAFs from photoionization-dominated accretion disk coronae. We apply our results to the Galactic center source Sagittarius A* and to the nucleus of M87. We find that the brightest predicted lines are within the detection capability of current $X$-ray instruments.

16 pages, 1 table, 9 figures, accepted to ApJ

References in corpus (4)

• Convection-Dominated Accretion Flows
• Self-Similar Accretion Flows with Convection
• The Cooling Flow to Accretion Flow Transition
• HST-FOS Observations of M87: Ly-a Emission from the Active Galactic Nucleus

Cited by in corpus (14)

• Hot Accretion Flows Around Black Holes
• Chandra X-ray Spectroscopic Imaging of Sgr A* and the Central Parsec of the Galaxy
• Dissecting X-ray-emitting Gas around the Center of our Galaxy
• Testing Radiatively-Inefficient Accretion Flow Theory: an XMM-Newton Observation of NGC 3998
• The Quiescent X-ray Spectrum of Accreting Black Holes
• NuSTAR Hard X-ray View of Low-luminosity Active Galactic Nuclei: High-energy Cutoff and Truncated Thin Disk
• Chandra Observations of the Dwarf Nova WX Hyi in Quiescence
• Hot Accretion onto White Dwarfs in Quiescent Dwarf Novae
• Reprocessed emission line profiles from dense clouds in geometrically thick accretion engines
• Thermal X-ray iron line emission from the advection dominated accretion flow in the galactic binary GX 339-4
• Blob ejection from advection-dominated accretion flow: observational consequences
• X-Ray Lines from Hot Flows around White Dwarfs. Application to SS Cygni
• The dependence of the viscosity-parameter on the disk scale height profile
• On the thermal line emission from the outflows in ultraluminous X-ray sources