Galaxies

Blogs about galaxies, singles ones on in clusters

Artist's concept of galaxies merging near a quasar (Image MPIA using material from the NASA/ESA Hubble Space Telescope)

An article published in the journal “Nature” describes the discovery of four galaxies that are very ancient, so much that they formed less than a billion years after the Big Bang. A very high stellar formation rate was observed within them. A team of astronomers led by Roberto Decarli of the Max Planck Institute for Astronomy discovered by chance these four galaxies, noting that they were close to as many quasars.

A comparison between supermassive black holes in a normal galaxy and in one involved in a galaxy merger (Image National Astronomical Observatory of Japan)

An article published in the journal “Monthly Notices of the Royal Astronomical Society” describes the effects that a merger between two galaxies can have on a supermassive black hole at the center of a galaxy involved in that process. A team of researchers led by Claudio Ricci used especially NASA’s NuSTAR space telescope to study how in the last stages of galactic merger gas and dust fall towards a black hole enshrouding it and generating an active galactic nucleus.

X-ray image of the hot gas in the Perseus galaxy cluster (Image NASA's Goddard Space Flight Center/Stephen Walker et al.)

An article published in the journal “Monthly Notices of the Royal Astronomical Society” describes the discovery of a large wave of hot gas in the Perseus galaxy cluster that extends for about 200,000 light years. A team of astronomers led by Dr. Stephen Walker of NASA’s Goddard Space Flight Center combined observations with NASA’s Chandra X-ray Observatory and others at radio frequencies with computer simulations to study it.

The galaxy NGC 5917 (Image ESA/Hubble & NASA)

An image captured by the Hubble Space Telescope of the galaxy NGC 5917 just published shows it on its own. This could be considered normal but this is a special case because it’s a galaxy known mainly for its interaction with a neighbor known as MCG-01-39-003. Those are interacting galaxies, an expression used when there are galaxies that affect each other with their mutual gravity. NGC 5917 and MCG-01-39-003 could end up merging.

The galaxy NGC 7250 and the star TYC 3203-450-1 (Image ESA/Hubble & NASA)

An image captured by the Hubble Space Telescope portrays the irregular galaxy NGC 7250, along with the star TYC 3203-450-1, which is much closer and thus from the Earth looks much brighter than a whole galaxy. That star’s presence makes studying the galaxy more difficult because its light interferes with NGC 7250’s dimmer light, polluting the observations of an object that’s interesting because of its peculiar characteristics.