Astronomers at the Indian Institute of Astrophysics (IIA), an autonomous institute of the Department of Science and Technology, have recently detected iron Lines in X-rays from a well-known binary black hole system in the radio galaxy 4C+37.11 750. This is the first time that X-rays have been detected in a binary system.
The system is located 750 million light years away from the Earth. Discovered in 2004, this system contains two supermassive black holes (SMBHs) located just 23 light years apart. The proximity of these SMBHs makes 4C+37.11 a unique and important case for studying the dynamics and interactions in such extreme environments.
Astronomers have detected iron emissions from the binary Active Galactic Nucleus system 4C+37.11 using data from the Chandra Space Telescope. They found that this emission comes from the accretion disk and the ionized plasma around the two supermassive black holes in the system.
Santanu Mondal, a Ramanujam Fellow at the Indian Institute of Astrophysics and lead author of the paper said, “We decided to look at 4C+37.11, which is one such fascinating and unique astrophysical object. It is one of the few confirmed binary active galactic nuclei (bAGN) located about 750 million light years away from the Earth and is a very well-studied system of its kind. The proximity of these two SMBHs makes 4C+37.11 a rare and valuable case for studying the dynamics and interactions in such extreme environments.”
Mousumi Das of IIA, a co-author of the study, said, “Although Fe K emission lines have been detected from many nearby SMBHs, they have never been detected in this SMBH binary system. Such a spectral line can reveal facts about the merging of SMBHs, which is even known to produce gravitational waves at their final moments at the merger.”
“We studied 4C+37.11 using archival data from Chandra and discovered two Fe K lines for the first time. Through modeling, we could infer that this line emission originates from the combined effects of the accretion disk around the supermassive black holes and the collisionally ionized plasma surrounding them”, said Mondal. The team also determined the total mass of the binary SMBHs to be 15 billion times that of the Sun, rotating with a moderate or low spin of less than 0.8.”
“Our study shows that detecting the Fe K line emissions from binary supermassive black holes is important for estimating the individual black hole masses and their spins, as well as exploring the emission regions and the behavior of matter around them and radiation in extreme conditions,” said Mousumi Das.
Journal Reference:
- Santanu Mondal, Mousumi Das, Khatun Rubinur et al. Detection of the Fe K lines from the binary AGN in 4C+37.11. Astronomy & Astrophysics. DOI: 10.1051/0004-6361/202450616
