Astronomers using NASA’s Chandra X-ray Observatory, ESA’s XMM-Newton and other telescopes have found evidence for a massive stellar disruption (over 3 solar masses) in the X-ray spectrum of ASASSN-14li, a tidal disruption event that occurred in a galaxy approximately 290 million light-years away. Their results appear in the Astrophysical Journal Letters.
Tidal disruption events are observed as multiwavelength flares when a star is disrupted by a massive black hole.
The tidal disruption flare ASASSN-14li was discovered on November 11, 2014 by the All-sky Automated Survey for Supernovae (ASASSN).
The event occurred in the center of PGC 43234, a galaxy located approximately 290 million light-years away.
At the time of the discovery it was the closest tidal disruption to Earth discovered in about a decade.
Because of this proximity, ASASSN-14li has provided an extraordinary level of detail about the destroyed star.
Dr. Brenna Mockler, an astronomer at Carnegie Observatories and the University of California, Los Angeles, and colleagues applied new theoretical models to make improved estimates, compared to previous work, of the amount of nitrogen and carbon around the black hole in the center of PGC 43234.
“These X-ray telescopes can be used as forensic tools in space,” Dr. Mockler said.
“The relative amount of nitrogen to carbon that we found points to material from the interior of a doomed star weighing about three times the mass of the Sun.”
The star in ASASSN-14li is therefore one of the most massive — and perhaps the most massive — that astronomers have seen ripped apart by a black hole to date.
“ASASSN-14li is exciting because one of the hardest things with tidal disruptions is being able to measure the mass of the unlucky star, as we have done here,” said Dr. Enrico Ramirez-Ruiz, an astronomer at the University of California, Santa Cruz.
“Observing the destruction of a massive star by a supermassive black hole is spellbinding because…
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