A binary system of black holes in an active galaxy about 4 billion light-years away was seen to light up dramatically when one of the black holes burst through the accretion disk of the other, briefly creating a double quasar.
A quasar is an extremely active nucleus of a distant galaxy. This activity is the product of a supermassive black hole hungrily absorbing matter, so much matter in fact that it can’t handle it all – instead, a lot of material is indiscriminately spit out in a magnetically collimated jet rather than falling outside the black hole’s boundaries. event horizon like the rest of the thing. When we see such a stream of charged particles (moving at nearly the speed of light) head on, the quasar looks particularly bright. We call it a blazar.
Galaxy OJ 287 at a distance of about 4 billion light years away, is one of the closest examples of a blazar. In fact, it is bright enough to be seen with large amateur telescopes, and there are observations of OJ 287 from the late 1800s. Observations like these suggest that every 12 years OJ 287 appears to brighten. In 2014, he received his Ph.D. student Pauli Pihajoki from the University of Turku in Finland suggested that this brightening was due to the presence of a second, less massive black hole orbiting and interacting with the primary black hole. If it did exist, the second black hole’s orbit around the primary would be protracted, meaning it would only approach the primary every 12 years.
In addition to the general brightening of the system, Pihajoki reasoned that this interaction should also lead to the smaller black hole stealing some matter from the large accretion disk of material around the primary black hole and briefly creating its own smaller quasar jet. time. Pihajoki also roughly predicted when this would happen. So in November 2021 NASA A satellite for the exploration of transiting exoplanets (TESS) has been temporarily withdrawn exoplanet– hunting duties to investigate OJ 287. TESS joined NASA‘with Quick and Fermi gamma radiation telescopes, as well as a number of ground-based observatories, but it was TESS in particular that made the critical observations.
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On November 12, 2021, TESS detected OJ 287 brightening by about two magnitudes for about 12 hours, as it released as much energy in this short burst as 100 average galaxies would release in the same time. This eruption was attributed to a jet from a second black hole; observations from other telescopes also supported this result, especially Fermi detection of a significant gamma ray burst.
“We can now say that wen has ‘seen’ an orbiting black hole for the first time, in the same way that we can say that TESS has seen planets orbiting other stars” said Mauri Valtonen from the University of Turku, who led the observation, va declaration.
It also allowed the masses to observe black holes to confirm. The primordial black hole – aka the main source of energy in OJ 287 – has a whopping 18.35 billion solar mass, while the secondary is not light, with 150 million solar masses. Compared, A* scorerwhich is the black hole at the center of ours Milky way galaxyit has a mass of only 4.1 million solar masses.
Short quantity time during which the eruption was active explains why neither it nor eruptions from other binary black hole systems have yet been discovered. Knowing when and where to look to see such a flare is crucial, and there could be many other binary black holes experiencing similar flares that we don’t know about. However, these black hole binaries may soon have nowhere to hide.
“A smaller black hole may soon reveal its existence in other ways as it is expected to emit nano-Hertz gravitational wavesAchamveedu Gopakumar of the Tata Institute of Fundamental Research in India, who participated in the observations, said in a statement. “The gravitational waves of OJ 287 should be detectable in the coming years using maturing pulsar timing fields.”
Pulsar Timing Fields work by constantly orbiting a network of pulsars in deep space. Pulsars spins neutron stars which send out radio jets like cosmic beacons. We can measure how fast they are spinning by counting how often we see their radio jets spinning in our direction. Some pulsars can spin hundreds of times per second, causing them to appear to pulsate in radio waves as their jets flash repeatedly at us.
Remarkably, pulsars keep time very well, with their pulsation periods being unerringly precise. However, if gravitational waves passed by, they would distort it space between us and the pulsar, which would affect our perspective on the timing of these pulses.
Binary black holes are also important for the growth of supermassive black holes. Recent results presented at the 244th meeting of the American Astronomical Society this June in Wisconsin showed that merging supermassive black holes is an important secondary factor in their enormous growth, releasing ripples as they spiral closer in the merging process. gravitational waves. Although these gravitational waves are too low in frequency LIGOlaser Interferometer Gravitational-wave Observatory to detect, a proposed space detector called LISA, Laser Interferometer Space Antenna, would be able to detect their coalescence as they merge in large cosmic crashes.
The results of the observation of OJ 287 were published on June 11 in The Astrophysical Journal.