Five years ago, gravitational waves were not yet discovered by mankind.
Now, the observations are flowing at an astonishing speed. In the first six months of last year, LIGO-maiden cooperation averaged 1.5 Gravitational wave Events per week.
From April 1 to October 1, 2019, the upgraded LIGO and maiden interferometers detected 39 new gravitational wave events: from massive collisions between neutron stars or from the shock wave over time. Black holes. In all, the Gravitational-Wave Transient Catalog 2 (GWTC-2) now boasts 50 such events.
This gave us the most complete census of black holes in our toolkit, representing a series of black holes never discovered before, and can reveal the unplugged depths before the evolution and the afterlife of binary stars.
“Gravitational-wave astronomy is revolutionary – revealing to us the hidden lives of black holes and neutron stars.” Said astronomer Christopher Berry Member, LGO Scientific Combination (LSC) at Northwestern University.
“In just five years, we did not know that binary black holes have more than 40 catalogs. The third observation run led to more discoveries than ever before. Combining these with previous discoveries paints a beautiful picture of the rich diversity of the universe.”
You may have already heard of some new discoveries made from the observation race.
GW 190412 (named for the date of discovery of gravitational wave events) The first black hole with an unmatched mass between two black holes collided; All other previously discovered black hole collisions involved more or less equal-mass binary.
GW190425 is thought to be from a collision between two neutron stars, the second of which was discovered (the first in August 2017).
GW 190521 finally confirmed the existence of a ‘middleweight’ class of black holes, between galaxies and supermassive behemoths.
GW 190814 was the first collision involving an object in a ‘mass gap’ between neutron stars and black holes.
“So far, the third observation race of Lego and the Virgin has caused many surprises.” Said astronomer Maya Fishback Northwestern University, L.Sc.
“After the second observation run, I thought we would see the full spectrum of binary black holes, but the landscape of black holes is much richer and more diverse than I thought. I’m excited to see what future observations will teach us.”
That’s not all the new data hole has to offer. The other two events, GW 190426_152155 and GW 190924_021846, are unusually distinct. Yes, those names are too long: when we find more and more events, the date will not be enough to identify them, so the new naming convention will include time in UTC.
“One of our new discoveries, GW190426_152155, may have merged a black hole with six solar masses into a neutron star. Unfortunately the signal is dim, so we are not entirely sure.” Said astronomer Sergui Ossokine Of the Albert Einstein Institute in Potsdam, Germany.
“GW 190924_021846 Of course, this is from the fusion of two of the lightest black holes we’ve ever seen. One has six solar masses, the other nine suns.
The new populations of black holes and neutron star mergers are described in four print papers.
The first paper Lists 39 new events. The second paper Reconstructs the mass and spin distribution of the 47 fusion events found in the GWTC-2 catalog, and estimates the rate of black hole and neutron star collisions. Third paper Looks hard for gamma-ray bursts associated with merger events (none found). And Fourth Paper Evaluates data contrary to the forecasts of General relativity; Spoiler maintains complete general relativity.
Overall, the new collection of merger events is not a way to learn about collisions. It provides a way to study black holes directly, as they do not emit any detectable radiation – which is notoriously difficult to investigate.
Thanks to gravitational waves, we know more about these objects than we did a year ago. It goes from here to snowball.
“The merging of the black hole and the neutron star binary is a unique laboratory.” Berry said.
“We can use them to study both gravity – so far Einstein’s general relativity has succeeded in all experiments – and the astronomy of how giant stars live.