Squeezars: Tidally powered stars orbiting a massive black hole

Abstract

We propose that there exists a class of transient sources, "squeezars", which are stars caught in highly eccentric orbits around a massive (m<10^8 Mo) black hole (MBH), whose atypically high luminosity (up to a significant fraction of their Eddington luminosity) is powered by tidal interactions with the MBH. Their existence follows from the presence of a mass sink, the MBH, in the galactic center, which drives a flow of stars into nearly radial orbits to replace those it has destroyed. We consider two limits for the stellar response to tidal heating: surface heating with radiative cooling ("hot squeezars") and bulk heating with adiabatic expansion ("cold squeezars"), and calculate the evolution of the squeezar orbit, size, luminosity and effective temperature. The squeezar formation rate is only ~0.05 that of tidal disruption flares, but squeezar lifetimes are many orders of magnitude longer, and so future observations of squeezars in nearby galaxies can probe the tidal process that feeds MBHs and the effects of extreme tides on stars. The mean number of squeezars orbiting the Galactic MBH is estimated at 0.1-1.

ApJ Lett. accepted. 4 pp. 1 fig

References in corpus (6)

• Closest Star Seen Orbiting the Supermassive Black Hole at the Centre of the Milky Way
• The Accelerations of Stars Orbiting the Milky Way's Central Black Hole
• Tidal spin-up of stars in dense stellar cusps around massive black holes
• Orbital inspiral into a massive black hole in a galactic center
• Adaptive Optics Near-Infrared Spectroscopy of the Sgr A* Cluster
• Tidal scattering of stars on supermassive black holes in galactic centers

Cited by in corpus (44)

• SINFONI in the Galactic Center: young stars and IR flares in the central light month
• The Stellar Cusp Around the Supermassive Black Hole in the Galactic Center
• A Disk of Young Stars at the Galactic Center as Determined by Individual Stellar Orbits
• Stellar Processes Near the Massive Black Hole in the Galactic Center
• Massive perturber-driven interactions of stars with a massive black hole
• The effect of mass-segregation on gravitational wave sources near massive black holes
• Resonant relaxation near a massive black hole: the stellar distribution and gravitational wave sources
• The orbital statistics of stellar inspiral and relaxation near a massive black hole: characterizing gravitational wave sources
• Stellar Dynamics and Stellar Phenomena Near A Massive Black Hole
• The Tidal Disruption of Giant Stars and Their Contribution to the Flaring Supermassive Black Hole Population
• Twelve years of spectroscopic monitoring in the Galactic Center: the closest look at S-stars near the black hole
• An Overabundance of Black Hole X-Ray Binaries in the Galactic Center from Tidal Captures
• Steady state relativistic stellar dynamics around a massive black hole
• The Disruption of Stellar Clusters Containing Massive Black Holes near the Galactic Center
• Stellar Tidal Disruption Events in General Relativity
• Ultraluminous X-ray Sources as Intermediate Mass Black Holes Fed by Tidally Captured Stars
• S62 and S4711: Indications of a population of faint fast moving stars inside the S2 orbit -- S4711 on a 7.6 year orbit around Sgr~A*
• Spoon-Feeding Giant Stars to Supermassive Black Holes: Episodic Mass Transfer from Evolving Stars and Their Contribution to the Quiescent Activity of Galactic Nuclei
• Tidal Disruption of a Star By a Black Hole : Observational Signature
• Tidal break-up of binary stars at the Galactic center and its consequences
• Orbital capture of stars by a massive black hole via exchanges with compact remnants
• Turbovelocity Stars: Kicks Resulting From the Tidal Disruption of Solitary Stars
• Orbital inspiral into a massive black hole in a galactic center
• Tidal Capture of Stars by Intermediate-Mass Black Holes
• Models of Ultraluminous X-Ray Sources with Intermediate-Mass Black Holes
• High Precision Stellar Radial Velocities in the Galactic Center
• The ultra-luminous X-ray source in M82: an intermediate mass black hole with a giant companion
• Disruption of a Red Giant Star by a Supermassive Black Hole and the Case of PS1-10jh
• In-situ extreme mass ratio inspirals via sub-parsec formation and migration of stars in thin, gravitationally unstable AGN discs
• Spectroscopic Detection of a Cusp of Late-type Stars around the Central Black Hole in the Milky Way
• The Process of Stellar Tidal Disruption by Supermassive Black Holes. The first pericenter passage
• Constraining the dark cusp in the Galactic Center by long-period binaries
• Accumulated Tidal Heating of Stars Over Multiple Pericenter Passages Near SgrA*
• Radial Velocities of Stars in the Galactic Center
• Stellar dynamics and tidal disruption events in galactic nuclei
• Tidal disruptions of separated binaries in galactic nuclei
• The secular evolution of discrete quasi-Keplerian systems. II. Application to a multi-mass axisymmetric disc around a supermassive black hole
• Lobe Overflow as the Likely Cause of Pericenter Outburst in an SMBH Orbiter
• Stellar Relaxation Processes Near the Galactic Massive Black Hole
• Influence of the black hole spin on the chaotic particle dynamics within a dipolar halo
• The S stars' zone of avoidance in the Galactic center
• Model Atmospheres for Irradiated Giant Stars: Implications for the Galactic Center
• The former companion of the hyper-velocity star S5-HVS1
• Star formation in the central 0.5 pc of the Milky Way