2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
A new candidate event with the number S190408an has appeared in the gravitational wave registration database. This happened less than 10 days after the start of the new observation phase of the American LIGO antennas. At the moment, no burst of electromagnetic radiation from the same direction has been recorded - this means that the most likely source of the gravitational wave is the merging of black holes.
A new session of searching for gravitational waves on a pair of American LIGO installations and the European Virgo antenna began on April 1. The observatories resumed their work after modernization, which took 19 months. The sensitivity of the equipment after it increased significantly, as did the volume of the Universe, in which gravitational telescopes can "hear" the merging of black holes. Preliminary optimistic estimates indicated that a registration rate of one event per week could be expected.
And these estimates have practically been confirmed: the new event was recorded at 18:18:02 GMT (21:18:02 Moscow time) on April 8, just 8 days after the start of the new observation period. The signal source was in the region of the constellation Lizard, but the accuracy and number of gravitational antennas are still not enough to determine the direction with small errors: the localization area with 90% accuracy occupies an area of 387 square degrees in the sky. The source is 4.7 billion light years away with an error of about 1.1 billion light years.
At the moment there is no information about the size and mass of black holes, but judging by the sufficiently large distance and reliable detection, as evidenced by the high signal-to-noise ratio (43), these were rather massive objects, with masses of about 30 solar masses.
Immediately after receiving data on the event, "conventional" electromagnetic telescopes and particle detectors began to scan the area from which the signal came to find traces of a burst that could have occurred if gravitational waves were generated by the merger of neutron stars. In total, more than 10 instruments were included in the observations, including the space X-ray and gamma telescopes Fermi, Integral, Swift, the IceCube neutrino telescope, the Russian network of MASTER telescopes and many others. However, no electromagnetic signal was detected.
The head of the MASTER project, Vladimir Lipunov, told N + 1 that his colleagues managed to fix optical transients, but they most likely have nothing to do with the gravitational-wave event.
LIGO antennas allowed for the first time in history to record gravitational waves, which was announced in 2016, and in 2017 the Nobel Prize in Physics was awarded. More details about the registration of gravitational waves can be found in the materials "On the crest of the metric tensor", "Sharpener for a quantum pencil" and "Thinner than a proton".
