A supermassive black hole (SMBH) occupies the center of a galaxy. With masses ranging from one million to 10 billion solar masses, some SMBHs are in the bright phase known as the active galactic nucleus (AGN).
The AGN will eventually run out of power, as there is a maximum mass limit for SMBH. Scientists have long pondered when that will be the case.
Kohei Ichikawa of Tohoku University and his research group may have accidentally discovered AGN at the end of its life after capturing the AGN signal from the galaxy Arp 187.
By observing radio images of the galaxy using two astronomical observatories, the Atacama Large Millimeter/submillimeter Array (ALMA) and Atacama’s Very Large Array (VLA), they found the cloud petals, a key symbol of AGN.
However, they noticed that there was no signal from the nucleus. This indicates that the AGN activity may have been silent.
From further analysis of multi-wavelength data They found that all small AGN indicators were quiet. while the big indicator is bright This is because AGN has only been suspended within the last 3,000 years.
When the AGN dies, the properties of the smaller AGN fade due to the other photons. will shut down as well But large ionized gas regions are still visible. This is because photons take about 3000 years to reach the edge of the region. Observing past AGN activity is called reflected light.
“We used NASA NuSTAR’s X-ray satellite, which is the best tool to observe current AGN activity,” Ichikawa said. So we were able to discover that the nucleus was dead.”
The results indicate that AGN shutdown occurs within 3000 years and that the nucleus has dimmed more than 1,000 times over the past 3000 years.
Ichikawa, a co-author of the paper for the 238 Meeting of the American Astronomical Society, said they will continue to investigate dying AGNs. this We will also be observing high spatial resolution to monitor gas inflow and outflow. This might explain how the AGN activity shutdown happens.
Study explores extremely bright infrared galaxies. WISEJ0909+0002
Kohei Ishikawa et al. Accidental Discovery of the Dying Milky Way Nucleus in Arp 187 Conference: 238th Congress of the American Astronomical Society.
Provided by Tohoku University
reference: Discovery of a dying supermassive black hole with a 3,000-year-long reflection (2021, June 8). Retrieved 8 June 2021 from https://phys.org/news/2021-06-discovery. -dying-supermassive-black-hole.html
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