Tidal Disruptor Event J150052 Was Caused by Rapidly Rotating Intermediate-Mass Black Hole, Study Finds

Using NASA’s Chandra and ESA’s XMM-Newton space telescopes, astronomers from Radboud University in the Netherlands and elsewhere made X-ray observations of a tidal disturbance event designated 3XMM J150052.0+015452, or J150052 for short. The results show that J150052 was triggered by a rapidly rotating intermediate-mass black hole. The discovery was detailed in an article published November 30 on arXiv.org.

Tidal Disturbance Events (TDE) are astronomical phenomena that occur when a star passes close enough to a supermassive black hole and is pulled apart by tidal forces from the black hole, causing the disturbance process. This tidal-disturbed stellar debris begins to rain down on the black hole, and radiation emerges from the innermost region of the accretionary debris, which is an indicator of the presence of a TDE.

For astronomers and astrophysicists, TDEs are potentially important probes of strong gravity and accretion physics, providing answers about the formation and evolution of supermassive black holes.

J150052 was first detected in 2005 as an X-ray source, during XMM-Newton and Chandra observations of the foreground group of galaxies NGC 5813 at a redshift of 0.0064. Its position coincides with the center of the galaxy SDSS J150052.07+015453.8 at a redshift of 0.145.

Follow-up observations of this source revealed it to be a slowly decaying TDE, experiencing a decade-long decay. Some studies have suggested that the black hole responsible for J150052 has a mass of around 100,000 solar masses, making it an intermediate-mass black hole (IMBH).

Now, a team of astronomers led by Zheng Cao of Radboud presents the results of their study confirming the IMBH hypothesis.

“In this paper, we present and analyze all publicly available XMMNewton and Chandra data from the J150052 tidal disturbance event since 2008, obtained during its decade-long decay. We fit the X-ray spectra with the thin-disk model (Wen et al. 2020, 2021), thereby constraining the mass and spin of the black hole to higher precision than before,” the researchers wrote.

The mass of the black hole for J150052 has been measured at around 200,000 solar masses. The black hole’s dimensionless spin parameter has been calculated to be at least 0.97. Therefore, the researchers concluded that J150052 is a fast-turning, and possibly near-extreme, IMBH.

Mass and spin measurements indicate that J150052 did not form near its current mass. Therefore, the authors of the paper assume that the black hole must have accreted to its current mass in episodes where the angular momentum vectors of spin and accreted material were aligned.

Additionally, spectral analyzes of J150052 suggest that it undergoes a transition during its decay, quenching the corona as the rate of mass accretion decreases from super-Eddington levels to Eddington levels. The study also revealed that the crown of J150052 was optically thick and warm.

Summarizing the results, the researchers noted that their findings demonstrate the potential of using X-ray spectra from TDEs to find IMBHs and measure their masses and spins.

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