Black holes

Brightest quasar in the early universe discovered

An article published in the journal “Astrophysical Journal Letters” reports the discovery of the brightest quasar in the early universe. A team of researchers used observations of the Hubble Space Telescope and some ground-based telescopes to identify the galaxy cataloged as J043947.08+163415.7 at a distance of about 12.8 billion light years from the Earth. The supermassive black hole at its center is surrounded by a lot of materials that emit the huge amount of light that allows it to be identified even at that enormous distance, but only thanks to a gravitational lensing effect. That activity dates back almost a billion years after the Big Bang.

A catalog of gravitational wave detections includes 4 new events

Two articles published on the arXiv server show a catalog of gravitational wave events detected by the LIGO and Virgo collaborations and the inferred properties concerning the black hole pairs discovered in the mergers. So far, 7 events were announced but the analysis of the data led to the discovery of 4 more events of which one was detected by Virgo as well. Of the 11 now known, there’s the one that became famous because it was generated by two neutron stars that led to a kilonova while the other 10 were generated by black hole pairs.

The quasar 3C 273 (Image ESA/Hubble & NASA)

An article published in the journal “Nature” describes the first detailed observation of the environment surrounding a supermassive black hole outside the Milky Way. A team of astronomers led by Professor Hagai Netzer of the Tel Aviv University used the GRAVITY instrument installed on ESO’s VLTI to examine the first quasar discovered, known as 3C 273, uncovering gas clouds that move quickly around the black hole that powers that quasar and forms its heart.

The brightest known galaxy is devouring its neighbors

An article published in the journal “Science” describes a study of the galaxy W2246-0526, the brightest known. A team of researchers used the ALMA radio telescope to examine it by uncovering streams of materials as they are stripped from three smaller galaxies orbiting it. In one case a “tidal tail” is generated, a large stram of materials that connects W2246-0526 with one of its satellites. According to an article published in “The Astrophysical Journal” the supermassive black hole at its center has a mass that’s about 4 billion times the Sun’s.

Galaxy mergers reveal pairs of supermassive black holes

An article published in the journal “Nature” describes the discovery of five pairs of supermassive black holes in galaxies in the final stages of mergers. A team of researchers coordinated by the University of Maryland used data gathered at the Keck Observatory in Hawaii and in over twenty years by the Hubbble space telescope to find out these cases among hundreds of galaxies selected from those with strong X-ray emissions detected by the Swift space telescope.