Original prediction by Einstein’s Theory of General Relativity, Black holesThese are the most extreme objects known in the Universe.
These objects are formed when stars at the end of their lives cycle blow off their outer layers and become so powerfully gravitationally that nothing (not even Light) can escape from their surfaces.
These are of particular interest to astronomers because they permit them to observe the laws and consequences of physics in extreme situations. Periodically, these gravitational giants will consume stars and other objects within their immediate vicinity, releasing enormous amounts of light as well as radiation.
Astronomers observed one such event in October 2018 while observing a nova. Black holeA galaxy 665 millions light-years away from Earth.
Astronomers have seen events similar to this before. However, another team from the Harvard & Smithsonian Center for AstrophysicsThey discovered something new when they looked at the same black hole three more years later.
They explained this in a Recent studiesThe black hole was shining brightly because it was ejecting leftover material from the star at twice the speed of light. The findings could offer new insights into how black hole growth and feeding over time.
The team was commanded by Yvette CendesA research associate with CfA, Dr., was joined by an international team comprising researchers from all over the globe. Commonwealth Scientific and Industrial Research Organisation(CSIRO), Center for Interdisciplinary Exploration and Research in Astrophysics(CIERA), Space Telescope Science Institute(STScI), Columbia Astrophysics LaboratoryThe Flatiron Institute’s Center for Computational AstrophysicsUC Berkeley, Radboud University, and York University in Toronto.
Their findings were recently described in a paper published in the Astrophysical Journal.
The team stated that they observed the outburst as they were reviewing data about tidal disruptions (TDEs), which occurred in the last few years.
These happen when stars pass too closely to black holes. They are then pulled apart in multiple passes. This process is known as “spaghetification” due to the way that stars are ripped into strings.
The TDE was observed at Ohio State University in 2018 as part of the Observatory. All-Sky Automated Survey of Supernovae (ASAS-SN).
Kurz thereafter, an international group examined AT2018hyz using the ultraviolet and visible wavelengths. All-Sky Automated Survey of SupernovaeThe Fred Lawrence Whipple ObservatoryThe, and UV-Optical Telescope(UVOT). Neil Gehrels Swift Observatory.
This team was led Sebastian GomezCo-author of the paper is, who is a postdoctoral fellow at Space Telescope Science Institute. According to him, the TDE was not remarkable at the time.
Cendes and her fellow colleagues examined it once more using radio data from New Mexico’s Very Large Array (VLA). They were shocked to discover that the black hole had miraculously reanimated. Cendes explained this in a CfA Press release:
“This caught us completely by surprise – no one has ever seen anything like this before.
We applied to Director’s Discretionary Timing on multiple telescopes. This happens when something is so surprising that you can’t wait until the normal cycle for proposals to telescopes to view it. All of the applications were quickly accepted.”
The team conducted further observations of AT2018hyz using multiple telescopes at different wavelengths. The team also conducted radio observations with the VLA. Atacama Large Millimeter-submillimeter Array(ALMA) Observatory Chile, MeerKATSouth Africa is home to the Australian Telescope Compact arrayAustralia
These were combined together with X-ray, Gamma and Gamma radiation data obtained from space-based Chandra X-Ray Observatory(respectively) and the Neil Gehrels Swift Observatory
According to Edo BergerThe most striking radio observations of TDE by Professor of Astronomy, Harvard University and the CfA was made by.
“We have been studying TDEs in radio telescopes over the past ten years and we often find them shining in radio waves while they emit material, as the star is being consumed by the black holes.
At2018hyz, however, was radio silent for the first three year and it is now dramatically lit up to be one of most radio-luminous TDEs we have ever seen.”
The black hole was ejecting the residual material from star at relativistic speeds (a fraction the speed of light), according to the team.
This is the first time that astronomers have seen such a phenomenon. The team is unsure of the reason why the outflow was delayed several years.
TDEs emit light when they happen because spaghettified material from the stars becomes elongated around a black hole, heating up and creating a flash that can be seen by astronomers millions of light-years distant.
Some cases will see spaghettified material being thrown back in space. Astronomers refer to this as black holes being “messy eaters”. However, outflow emissions typically develop quickly after a TDE happens and not years later.
Cendes stated that it’s almost as if the black holes suddenly burped out some of the stellar material it ate many years ago.
What’s more, these “burps” were extremely energetic, with ejected material reaching speeds of up to 50 percent the speed of light – about five times what astronomers have observed with other TDEs. Berger stated:
“This is the first instance of such a long delay in the feeding and outflow. The next step will be to investigate whether this occurs more frequently.
Astronomers will be able to use these observations and other similar events to help them better understand the feeding behavior black holes. This will allow astronomers to gain insight into the growth and evolution of black holes over time and their role as part of galactic evolution.
This article was first published by Universe Today. Please read the Original article.
