Black holes

Scenarios after the kilonova (Image NRAO/AUI/NSF: D. Berry)

An article published in the journal “Nature” describes a research on the consequences of the merger between two neutron stars observed in the emission of both electromagnetic and gravitational waves. A team of researchers led by Kunal Mooley of the US National Radio Astronomy Observatory (NRAO) used the Very Large Array (VLA) together with the Australia Telescope Compact Array and the Giant Metrewave Radio Telescope in India for three months from the beginning of September to detect the radio waves emitted by the event at the origin of the gravitational waves recorded on August 17, 2017 in the event labeled as GW170817.

Cygni V404 during its outburst (Image Andrew Beardmore (Univ. of Leicester) and NASA/Swift)

An article published in the journal “Science” describes a precise measurement of the magnetic field of the corona of the black hole V404 Cygni. A team of researchers used the data collected in 2015 during a violent outburst of energy connected to the emission of jets from the black hole detected at many wavelengths using various space and ground-based telescopes. The result of this measurement was very surprising, being about 400 times lower than previous estimates.

The Quasar J1342+0928 (Image courtesy Mpia / Venemans et al.)

Two articles, one published in the journal “Nature” and one published in the “Astrophysical Journal Letters”, describe different aspects of a research that led to the discovery of the oldest known supermassive black hole. According to an estimate it formed about 690 million years after the Big Bang and it’s difficult to explain how it reached 800 million times the Sun’s mass. Labeled as Ulas J134208.10+092838.61 or more simply as J1342+0928, it may have formed during the so-called reionization period.

The protostars detected by ALMA (Image ALMA (ESO/NAOJ/NRAO), Yusef-Zadeh et al.; B. Saxton (NRAO/AUI/NSF))

An article published in the “Astrophysical Journal Letters” describes the discovery of protostars near the center of the Milky Way, near the supermassive black hole known as Sagittarius A* (or Sgr A*). A team of astronomers made this discovery using the ALMA radio telescope, a surprising result because the conditions in that area were considered too hostile due to the gravitational tides caused by Sgr A* and the intense electromagnetic emissions from the heated gas and dust ring around it.