Two objects, a cosmic gas cloud and a supermassive black hole, are simultaneously separated by 100 light years and united by something spectacular – a distinct heartbeat.
An international team of researchers discovered what they describe as a ‘gamma-ray heartbeat’ from a cosmic gas cloud that is accidentally synchronized with a massive black hole. They are still not exactly sure how that happened.
The discovery is detailed in a study published Monday in the journal Nature, and offers new clues that may prove useful in improving our understanding of how cosmic rays are produced in the universe.
“Like water in the crossing above the turn of a bath” – About 15,000 light-years away from Earth in the Milky Way galaxy, a black hole orbits a giant star in a micro-quasar system called SS 433. A quasar is a very bright, active galactic nucleus with a supermassive black hole in the center . SS 433 appears as a scaled-down version of a quasar.
The star is round 30 times more massive then the Sun, and the black hole is around 10 to 20 solar masses.
The two objects orbit each other over a period of 13 days, because the black hole matter of the giant star rises.
“This material collects on a discretionary disk before it falls into the black hole, like water shrinking above the drain of a bath,” explains co-author Jian Li, a fellow at the German Electron Synchrotron (DESY). “However, part of that case does not fall under the turn, but shoots out at high speed into two narrow jets in opposite directions above and below the rotating action disk.”
The action disk does not lie precisely in the plane of the star’s orbit and its associated black hole, making it swing like a spinning top. As a result, the two flowing jets spiral their way into space instead of radiating out in two straight lines.
The jets’ progress, like wobbling, has a period of about 162 days. Excitingly, about 100 light-years away from SS 433, astronomers discovered a gamma ray, like electromagnetic radiation, signaling a cosmic gas cloud with the same period of time. This gas cloud is known as Fermi J1913 + 0515.
Scientists believe that the black hole somehow powers the gamma-ray emission through the cloud, because they both follow the same rhythm – but how and why this is possible has yet to be confirmed.
“Finding such an untimely connection via timing, about 100 light-years away from the microquasar, not even along the direction of the jets is as unexpected as it is amazing,” Li said. “But how the black hole can support the heartbeat of the gas cloud is unclear to us.”
Further observations are needed to determine the main cause behind this improbably synchronized duo, but scientists have so far one theory: They believe that the nuclei of the hydrogen atoms produced at the end of the jets of the black hole the gamma ray cause emission.
“SS 433 remains observant about all frequencies and theorists alike,” Li said. “And it is sure to provide a test bed for our ideas on cosmic ray production and propagation at microquasars for years to come.”
Abstract: Microquasars, the local sibling of extragalactic quasars, are binary systems that include a compact object and a companion star. By accepting business from their companion, microquasars launch powerful winds and jets, and affect the interstellar environment around them. Steady gamma-ray emission is expected to rise from its central objects, or from interactions between its outflow and the surrounding medium. The latest prediction was recently confirmed with the detection of SS 433 at high (TeV) energies1. In this report, we analyze more than ten years of gigaelectronvolt gamma-ray data from the Fermi Gamma-ray Space Telescope on this source. Detailed control of the data reveals emissions near SS 433, co-spatially with a gas magnification, and hints of emissions possibly connected to a terminal lobe of one of the jets. Both gamma-ray measurements are relatively far from the central binary, and the former shows evidence of a periodic variation on the previous period of SS 433, and links it to the microquasar. This result challenges obvious interpretations and is unexpected from previously published theoretical models. It offers us the opportunity to discover the particle transport of SS 433 and to investigate the structure of the magnetic field in its surroundings.
