In 1963, Caltech researcher Maarten Schmidt had a eureka moment. He was looking at the spectrum of a mysterious object named 3C 273, a source that had been found and cataloged with then-novel radio ...

GREENBELT, Md. — An ongoing X-ray survey undertaken by NASA’s Swift spacecraft is revealing differences between nearby active galaxies and those located about halfway across the universe.

This week’s image from the Hubble Space Telescope shows a pair of interacting galaxies, collectively known as Arp 282. The bottom galaxy, NGC 169, is a type of highly active galaxy known as a Seyfert ...

Astronomers have performed very long baseline interferometry (VLBI) observations of a gamma-ray loud blazar known as TXS ...

Investigating the history of our cosmos with a large sample of distant ‘active’ galaxies observed by ESA’s XMM-Newton, a team of astronomers found there might be more to the early expansion of the ...

The vastness of space allows for a huge variety of structures to pop up all over the place. Even things we think of as one-and-done objects—like galaxies—come in quite a few shapes and sizes. Follow ...

Astronomers from the California Institute of Technology (Caltech) and elsewhere have observed an ultraluminous X-ray source known as NGC 925 ULX-3 using NASA's Swift and NuSTAR spacecraft, as well as ...

After starting science operations in February, Japan-led XRISM (X-ray Imaging and Spectroscopy Mission) studied the monster black hole at the center of galaxy NGC 4151. After starting science ...

Supermassive black holes at the hearts of active galaxies may be churning out a lot of the universe’s high-energy neutrinos. “I would say that they can be the major contributor,” says astronomer ...