Binary black hole mergers in gaseous environments: 'Binary Bondi' and 'binary Bondi-Hoyle-Lyttleton' accretion

Journal Article · Thu Apr 15 04:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.084008· OSTI ID:21431047

Farris, Brian D; Liu, Yuk Tung; Shapiro, Stuart L ^[1]

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1. Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

Merging supermassive black hole-black hole binaries produced in galaxy mergers are promising sources of detectable gravitational waves. If such a merger takes place in a gaseous environment, there is a possibility of a simultaneous detection of electromagnetic and gravitational radiation, as the stirring, shock heating, and accretion of the gas may produce variability and enhancements in the electromagnetic flux. Such a simultaneous detection can provide a wealth of opportunities to study gravitational physics, accretion physics, and cosmology. We investigate this scenario by performing fully general-relativistic, hydrodynamic simulations of merging, equal-mass, nonspinning black hole-black hole binaries embedded in gas clouds. We evolve the metric using the Baumgarte-Shapiro-Shibata-Nakamura formulation with standard moving puncture gauge conditions and handle the hydrodynamics via a high-resolution shock-capturing scheme. We consider both 'binary Bondi accretion' in which the binary is at rest relative to the ambient gas cloud, as well as 'binary Bondi-Hoyle-Lyttleton accretion' in which the binary moves relative to the gas cloud. The gas cloud is assumed to be homogeneous far from the binary and governed by a {Gamma}-law equation of state. We vary {Gamma} between 4/3 and 5/3. For each simulation, we compute the gas flow and accretion rate and estimate the electromagnetic luminosity due to bremsstrahlung and synchrotron emission. We find evidence for significant enhancements in both the accretion rate and luminosity over values for a single black hole of the same mass as the binary. We estimate that this luminosity enhancement should be detectable by the Large Synoptic Survey Telescope for a 10{sup 6}M{sub {center_dot}}binary in a hot gas cloud of density n{approx}10 cm{sup -3} and temperature T{approx}10{sup 6} K at z=1, reaching a maximum of L{approx}3x10{sup 43} erg s{sup -1}, with the emission peaking in the visible band, and lasting for {approx}1 hour.

• OSTI ID: 21431047
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 8 Vol. 81; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCELERATORS
BLACK HOLES
BREMSSTRAHLUNG
COSMOLOGY
CYCLIC ACCELERATORS
DENSITY
ELECTROMAGNETIC RADIATION
EMISSION
ENERGY RANGE
EQUATIONS
EQUATIONS OF STATE
FLUID FLOW
FLUID MECHANICS
GALAXIES
GAS FLOW
GRAVITATIONAL RADIATION
GRAVITATIONAL WAVE DETECTORS
HEATING
HYDRODYNAMICS
LUMINOSITY
MASS
MEASURING INSTRUMENTS
MECHANICS
METRICS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PLASMA HEATING
RADIATION DETECTORS
RADIATIONS
RELATIVISTIC RANGE
RESOLUTION
SHOCK HEATING
SIMULATION
SYNCHROTRONS