Galaxies

Blogs about galaxies, singles ones on in clusters

Mosaic of candidate active galactic nuclei in dwarf galaxie

An article to be published in “The Astrophysical Journal” reports the discovery of about 2,500 new candidate active galactic nuclei in dwarf galaxies and about 300 new candidate intermediate-mass black holes. A team of researchers examined observations conducted with the Dark Energy Spectroscopic Instrument (DESI) on the Nicholas U. Mayall 4-meter Telescope in Arizona to find all these possible black holes.

The Einstein ring around galaxy NGC 6505 (Image ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre, G. Anselmi, T. Li / CC BY-SA 3.0 IGO)

An article published in the journal “Astronomy & Astrophysics” reports the identification of a practically perfect so-called Einstein ring around the galaxy NGC 6505. A team of researchers Conor led by O’Riordan of the Max Planck Institute for Astrophysics in Munich, Germany, examined observations conducted with the Euclid space telescope to study the image of a much more distant galaxy distorted by the gravitational lens created by NGC 6505. This effect allows to study NGC 6505 as well because its mass creates that gravitational lens, so its effects allow to analyze it.

The galaxy LEDA 131342

An article published in “The Astrophysical Journal Letters” reports a study of the galaxy LEDA 131342 that identified nine concentric rings composed of stars that make it look like a sort of cosmic bullseye. A team of researchers used the Hubble Space Telescope and the Keck Observatory in Hawaii to identify these rings that form a truly extraordinary configuration considering that so far, galaxies with only two or three rings were known. The cause of this unique conformation is a dwarf galaxy that, according to calculations, about 50 million years ago passed through LEDA 131342 drastically changing its original shape.

Perseus and Centaurus galaxy clusters

An article published in the journal Nature Astronomy reports the results of a study of seven galaxy clusters which contain various supermassive black holes that offers evidence that outbursts generated at these black holes help cool the gas they feed on. A team of researchers used observations with multiple instruments to examine seven galaxy clusters. Outbursts in the form of jets from the supermassive black holes in those clusters cool the gas by forming thin filaments. Some of that gas will eventually flow back toward those black holes, triggering more outbursts in a mechanism in which the black holes “cook” their own meals.

The Andromeda Galaxy

A new image of the Andromeda Galaxy has been created by combining images captured by the Hubble Space Telescope from about 600 separate fields of view. It took two observing programs over a total of more than a decade and a thousand Hubble orbits to achieve this result. The new mosaic includes more than two hundred million individual stars in the Andromeda Galaxy, a minority made up of the stars that are more massive and bright than the Sun. Hubble’s observations provide a wealth of information about these stars that helps us better understand Andromeda’s history.