With two new gravitational-wave candidates on May 27, there are now 101 such likely astrophysical events in O4, the fourth observing run of the gravitational-wave detectors @LIGO, Virgo, KAGRA, and GEO600.
The researchers still need to investigate the signal candidates in more detail before characterizing and publishing them in scientific papers.
Fingers crossed that there will be 200 gravitational-wave events at the end of O4 (in February 2025).
Wow! The universe seems quite active right now: The gravitational-wave detectors have observed three possible binary black hole mergers in the past three days.
This Orrery (by Zoheyr Doctor) illustrates the diverse black hole binaries and neutron star black–hole binaries from our O3b run. More massive binaries are shown as orbiting more slowly
Neutron stars typically have about 40 % more mass than our Sun with a diameter of only about 20 kilometres. This image shows a neutron star next to Hannover, a site of the @mpi_grav.
Researchers from the permanent independent research group “Continuous Gravitational Waves” use these very waves to search for otherwise invisible neutron stars.
“Hopes of Big Bang Discoveries Ride on a Future Spacecraft” article in @QuantaMagazine on @LISA and how this ESA mission will be a new probe of primordial processes.
:blobwizard: Gravitational waves reveal “mystery object” merging with a neutron star | @arstechnica
「 “The idea of a gap between neutron-star and black-hole masses, an idea that has been around for a quarter of a century, was driven by such electromagnetic observations. GW230529 is an exciting discovery because it hints at this ‘mass gap’ being less empty than astronomers previously thought 」
When a neutron star meets an unusual black hole: Shortly after the start of the fourth observing run, the @LIGO/Virgo/KAGRA collaborations detected a remarkable gravitational-wave signal.
Our press release from Friday evening (local time) on the first publication from the fourth observing run of the international gravitational-wave detector network.
This visualisation shows the merger of a mass-gap black hole (dark grey) with a neutron star (orange) similar to GW230529 observed by @LIGO. The colours show the neutron stars' increasing density from dark orange to white. The emitted gravitational waves are shown in light blue.
Animation: I. Markin, T. Dietrich, H. Pfeiffer, A. Buonanno / @unipotsdam / @mpi_grav
🚨 Mysterious object in the gap – Shortly after the start of the fourth observing run, the @LIGO-Virgo-KAGRA collaborations detected a remarkable gravitational-wave signal. 😲
It's from the merger of a neutron star with an unknown compact object, most likely an unusually light-weight black hole falling into the “lower mass gap” between the heaviest neutron stars and the lightest black holes.
The @LIGO- and Virgo detectors are preparing for the start of the second half of the fourth observation run (April 10). The first measurement data is already being collected, which looks promising. 👍
This diagram shows (over the last 48 hours) the distance from which they can detect the merger of two neutron stars via gravitational waves. 🌟🌀🌟
We have compiled further information on the current state of gravitational-wave astronomy, many links to other sites, and pointers to helpful apps you might like:
🚨 Gravitational-wave detector network restarts fourth observing run ⚫🌀⚫
Next week, the @LIGO and Virgo detectors will resume their observing campaigns, which promise to collect more than 200 gravitational-wave events by the end of this current observing run (O4) in early 2025. @mpi_grav scientist have made key contributions to the detectors and the analysis of the data they provide.
Angela Borchers Pascual is a PhD student in the @maxplanckgesellschaft independent research group “Binary Merger Observations and Numerical Relativity”. She is working on understanding the imprint of gravitational kicks in the gravitational-wave signals emitted by merging black hole binaries.
Eight years ago, lecture theater 222 in the Kelvin Building, University of Glasgow was full to bursting with people waiting for an announcement by @LIGO about 'the event' ...
Dr. Elisa Maggio is a postdoctoral researcher in the “Astrophysical and Cosmological Relativity” department. She works on tests of gravity in the strong field regime with gravitational-wave observations and on tests of the nature of black holes.