DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Gravitational interactions of stars with supermassive black hole binaries – II. Hypervelocity stars

Journal Article · · Monthly Notices of the Royal Astronomical Society
 [1]; ORCiD logo [2];  [3];  [1]
  1. Univ. of California, Berkeley, CA (United States)
  2. Univ. of California, Berkeley, CA (United States); Columbia Univ., New York, NY (United States). Columbia Astrophysics Lab.
  3. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Supermassive black holes (SMBHs) in galactic nuclei can eject hypervelocity stars (HVSs). Using restricted three-body integrations, we study the properties of stars ejected by circular, binary SMBHs as a function of their mass ratios q = M2/M1 and separations a, focusing on the stellar velocity and angular distributions. We find that the ejection probability is an increasing function of q and a, and that the mean ejected velocity scales with q and a similar to previous work but with modified scaling constants. Binary SMBHs tend to eject their fastest stars towards the binary orbital plane. We calculate the ejection rates as the binary SMBHs inspiral, and find that they eject stars with velocities v > 1000 km s-1 at rates of ~ 4 × 10-2 - 2 × 10-1 yr-1 for q = 1 (~ 10-4 - 10-3 yr-1 for q = 0.01) over their lifetimes, and can emit a burst of HVSs with v > 3000 km s-1 as they coalesce. We integrate the stellar distributions over the binary SMBH inspiral and compare them to those produced by the ‘Hills mechanism’ (in which a single SMBH ejects a star after tidally separating a binary star system), and find that N ~ 100 HVS velocity samples with v∞ ≳ 200 km s-1 are needed to confidently distinguish between a binary and single SMBH origin.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Univ. of California, Oakland, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC); USDOE
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
1481794
Alternate ID(s):
OSTI ID: 1543973
Journal Information:
Monthly Notices of the Royal Astronomical Society, Vol. 482, Issue 2; ISSN 0035-8711
Publisher:
Royal Astronomical SocietyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 12 works
Citation information provided by
Web of Science

References (83)

Interaction of Massive Black Hole Binaries with Their Stellar Environment. II. Loss Cone Depletion and Binary Orbital Decay journal May 2007
Binary black holes and tori in AGN: I. Ejection of stars and merging of the binary journal October 2001
Revised Rates of Stellar Disruption in Galactic Nuclei journal January 2004
Statistical Dynamics of Solar-like Binaries journal January 1998
Ejection of hypervelocity binary stars by a black hole of intermediate mass orbiting Sgr A journal January 2009
REBOUND: an open-source multi-purpose N -body code for collisional dynamics journal January 2012
The distribution and consumption rate of stars around a massive, collapsed object journal January 1977
Revisiting hypervelocity stars after Gaia DR2 journal June 2018
Evolution of massive binary black holes journal April 2002
Gaia and the Galactic Center Origin of Hypervelocity Stars journal October 2018
Hypervelocity Binary Stars: Smoking Gun of Massive Binary Black Holes journal August 2007
Predicting the hypervelocity star population in Gaia journal March 2018
Stellar Binaries Incident on Supermassive Black Hole Binaries: Implications for Double Tidal Disruption Events, Calcium-rich Transients, and Hypervelocity Stars journal August 2018
The Fastest Unbound Stars in the Universe journal June 2015
Hyper-velocity and tidal stars from binaries disrupted by a massive Galactic black hole journal February 1988
Hypervelocity Stars journal August 2015
Double Tidal Disruptions in Galactic Nuclei journal May 2015
Probing the Shape of the Galactic Halo with Hypervelocity Stars journal November 2005
A Cluster of Black Holes at the Galactic Center journal December 2000
Rates of tidal disruption of stars by massive central black holes journal October 1999
Rates of stellar tidal disruption as probes of the supermassive black hole mass function journal November 2015
Tracing intermediate-mass black holes in the Galactic Centre journal February 2008
Tidal disruption events from supermassive black hole binaries journal November 2016
Runaway and Hypervelocity Stars in the Galactic Halo: Binary Rejuvenation and Triple Disruption journal May 2009
HE 0437-5439: An Unbound Hypervelocity Main-Sequence B-Type Star journal November 2005
Ejection of hypervelocity stars from the Galactic Centre by intermediate-mass black holes journal October 2006
Hypervelocity stars and the environment of Sgr A journal July 2007
The dynamical evolution of massive black hole binaries I. Hardening in a fixed stellar background journal July 1996
ias15: a fast, adaptive, high-order integrator for gravitational dynamics, accurate to machine precision over a billion orbits journal November 2014
Where Are the Old‐Population Hypervelocity Stars? journal July 2007
Tidal disruption by extreme mass ratio binaries and application to ASASSN-15lh journal November 2017
Hypervelocity stars from the Andromeda galaxy journal May 2008
Discovery of an Unbound Hypervelocity Star in the Milky Way Halo journal February 2005
The fate of close encounters between binary stars and binary supermassive black holes journal January 2018
Gravitational interactions of stars with supermassive black hole binaries – I. Tidal disruption events journal April 2018
Three-body encounters in the Galactic Centre: the origin of the hypervelocity star SDSS J090745.0+024507 journal October 2005
Effects of Massive Central Black Holes on Dense Stellar Systems journal September 1976
Tidal breakup of triple stars in the Galactic Centre journal January 2018
Ejection of Hypervelocity Stars by the (Binary) Black Hole in the Galactic Center journal December 2003
Interaction of Massive Black Hole Binaries with Their Stellar Environment. I. Ejection of Hypervelocity Stars journal November 2006
Ejection of High‐Velocity Stars from the Galactic Center by an Inspiraling Intermediate‐Mass Black Hole journal December 2006
The Velocity Distribution of Hypervelocity Stars journal October 2014
A hypervelocity star from the Large Magellanic Cloud journal March 2007
The stellar distribution around a black hole - Numerical integration of the Fokker-Planck equation journal December 1978
Hypervelocity Stars: From the Galactic Center to the Halo journal June 2008
Production of hypervelocity stars through encounters with stellar-mass black holes in the Galactic Centre journal January 2008
Hypervelocity Stars: Predicting the Spectrum of Ejection Velocities journal December 2006
A New Look at the Binary Characteristics of Massive Stars journal November 2007
Stellar disruption by a supermassive black hole: is the light curve really proportional to t −5/3 ? journal January 2009
The fine line between total and partial tidal disruption events journal April 2017
Interaction of Massive Black Hole Binaries with Their Stellar Environment. III. Scattering of Bound Stars journal October 2008
A Dipole on the sky: Predictions for Hypervelocity Stars from the Large Magellanic Cloud journal June 2016
Proper Motions and Trajectories for 16 Extreme Runaway and Hypervelocity Stars journal April 2015
Hydrodynamical Simulations to Determine the Feeding rate of Black Holes by the Tidal Disruption of Stars: the Importance of the Impact Parameter and Stellar Structure journal March 2013
THE M -σ AND M - L RELATIONS IN GALACTIC BULGES, AND DETERMINATIONS OF THEIR INTRINSIC SCATTER journal May 2009
PREDICTED SPACE MOTIONS FOR HYPERVELOCITY AND RUNAWAY STARS: PROPER MOTIONS AND RADIAL VELOCITIES FOR THE GAIA Era journal September 2014
Gravitational Radiation and the Motion of Two Point Masses journal November 1964
Revisiting hypervelocity stars after Gaia DR2 text January 2018
Binary black holes and tori in AGN: II. Can stellar winds constitute a dusty torus? journal November 2002
Evolution of massive binary black holes journal April 2003
Gravitational radiation and the motion of two point masses text January 1964
Tracing Intermediate-Mass Black Holes in the Galactic Centre journal September 2007
Hypervelocity Stars from the Andromeda Galaxy text January 2007
Interaction of massive black hole binaries with their stellar environment: III. Scattering of bound stars text January 2007
Tracing intermediate-mass black holes in the Galactic Centre text January 2007
Stellar disruption by a supermassive black hole: is the light curve really proportional to $t^{-5/3}$? text January 2008
Ejection of hypervelocity binary stars by a black hole of intermediate mass orbiting Sgr A* text January 2008
The M-sigma and M-L Relations in Galactic Bulges and Determinations of their Intrinsic Scatter text January 2009
Hydrodynamical Simulations to Determine the Feeding Rate of Black Holes by the Tidal Disruption of Stars: The Importance of the Impact Parameter and Stellar Structure text January 2012
IAS15: A fast, adaptive, high-order integrator for gravitational dynamics, accurate to machine precision over a billion orbits text January 2014
Double tidal disruptions in galactic nuclei text January 2015
Tidal disruption events from supermassive black hole binaries text January 2016
Tidal disruption by extreme mass ratio binaries and application to ASASSN-15lh text January 2017
Tidal breakup of triple stars in the Galactic Centre text January 2018
A Cluster of Black Holes at the Galactic Center text January 2000
Binary black holes and tori in AGN I. Ejection of stars and merging of the binary text January 2001
Revised Rates of Stellar Disruption in Galactic Nuclei text January 2003
Three-body encounters in the Galactic centre: the origin of the hypervelocity star SDSS J090745.0+024507 text January 2005
Ejection of high-velocity stars from the Galactic Center by an inspiraling Intermediate-Mass Black Hole text January 2005
Interaction of massive black hole binaries with their stellar environment: I. Ejection of hypervelocity stars text January 2006
Interaction of massive black hole binaries with their stellar environment: II. Loss-cone depletion and binary orbital decay text January 2006
A hypervelocity star from the Large Magellanic Cloud text January 2006
The dynamical evolution of massive black hole binaries - I. Hardening in a fixed stellar background text January 1996

Cited By (5)

Evolution of supermassive black hole binaries and tidal disruption rates in non-spherical galactic nuclei journal January 2019
Hypervelocity Stars from a Supermassive Black Hole–Intermediate-mass Black Hole Binary journal June 2019
A Hidden Friend for the Galactic Center Black Hole, Sgr A* journal December 2019
Hypervelocity Stars from a Supermassive Black Hole-Intermediate-mass Black Hole binary text January 2018
Evolution of supermassive black hole binaries and tidal disruption rates in nonspherical galactic nuclei text January 2019

Figures / Tables (17)