Next week’s night sky:
Named for a now-defunct constellation called the Mural Quadrant, the annual Quadrantids meteor shower runs from December 30 to January 12. This shower’s most intense period, when 50 to 100 meteors per hour can occur, lasts only about 6 hours surrounding the peak, which is predicted to occur on Sunday, January 3 at 10:00 GMT (or 5 a.m. Eastern time).
Ripples in Space-time
There’s something a ittle off about our theory of the universe. Almost everything fits, but there’s a fly in the cosmic ointment, a particle of sand in the infinite sandwich. Some scientists think the culprit might be gravity—and that subtle ripples in the fabric of space-time could help us find the missing piece.
Gravitational waves are ripples in the fabric of space-time itself; since 2015, humanity has been able to pick up these ripples using the LIGO observatories. Whenever two massively heavy objects collide elsewhere in the universe, they create a ripple that travels across space, carrying the signature of whatever made it—perhaps two black holes or two neutron stars colliding.
Scientists argue that if such waves hit a supermassive black hole or cluster of galaxies on their way to Earth, the signature of the ripple would change. If there were a difference in gravity compared to Einstein’s theory, the evidence would be embedded in that signature.
For example, one theory for the missing piece of the universe is the existence of an extra particle. Such a particle would, among other effects, generate a kind of background or “medium” around large objects. If a traveling gravitational wave hit a supermassive black hole, it would generate waves that would get mixed up with the gravitational wave itself. Depending on what it encountered, the gravitational wave signature could carry an “echo,” or show up scrambled.
The increased numbers make it more likely that one or more waves will have traveled through a massive object, and that scientists will be able to analyze them for clues to the missing components.
A new supercluster
By analyzing the data from the eROSITA Final Equatorial Depth Survey (eFEDS), an international team of astronomers has detected a new supercluster.
The supercluster consists of a chain of eight galaxy clusters at a redshift of 0.36. The observations show that the northernmost clusters of this structure are going through an off-axis major merger activity. Optical and X-ray data suggest that it is a triple merging system with a double merger and a pre-merger.
The cluster designated eFEDS J093513.3+004746, residing at the northern part of the supercluster, is the most massive and luminous one of the eight. It is also one of the most massive and luminous clusters in the entire eFEDS field. Its mass was calculated to be 580 trillion solar masses.
The least massive clusters of this supercluster, eFEDS J093546.4-000115 and eFEDS J093543.9-000334, have masses of around 130 trillion solar masses. The masses of the remaining five clusters are estimated to be between 140 and 250 trillion solar masses.
Furthermore, the data revealed the existence of two radio relics in the north and southeast region of the northernmost clusters and an elongated radio halo, which also supports the ongoing merger activity scenario.
Do you have any cool astronomy research news from this week? Share it in the comments below!