Astronomers Spot a Rare Galaxy Shutting Down Star Formation

[Mercury]

Astronomers Spot a Rare Galaxy Shutting Down Star Formation

A distant galaxy has been caught in the act of shutting down.

by Lisa Grossman

Link: Science News

[bystander]

Galaxy Survives Black Hole’s Feast – For Now
NASA | USRA | SOFIA | 2020 Nov 27

Illustration of the galaxy called CQ4479. ~ Credits: NASA/Daniel Rutter

---

The hungriest of black holes are thought to gobble up so much surrounding material they put an end to the life of their host galaxy. This feasting process is so intense that it creates a highly energetic object called a quasar – one of the brightest objects in the universe – as the spinning matter is sucked into the black hole’s belly. Now, researchers have found a galaxy that is surviving the black hole’s ravenous forces by continuing to birth new stars – about 100 Sun-sized stars a year.

The discovery from NASA’s telescope on an airplane, the Stratospheric Observatory for Infrared Astronomy, can help explain how massive galaxies came to be, even though the universe today is dominated by galaxies that no longer form stars. ...

SOFIA, a joint project of NASA and the German Aerospace Center, DLR, studied an extremely distant galaxy, located more than 5.25 billion light years away called CQ4479. At its core is a special type of quasar that was recently discovered by Kirkpatrick called a “cold quasar.” In this kind of quasar, the active black hole is still feasting on material from its host galaxy, but the quasar’s intense energy has not ravaged all of the cold gas, so stars can keep forming and the galaxy lives on. This is the first time researchers have a detailed look at a cold quasar, directly measuring the black hole’s growth, star birth rate, and how much cold gas remains to fuel the galaxy. ...

Astronomers Find Puzzling 'Cold Quasar' Forming
New Stars in Spite of Active Galactic Nucleuss
University of Kansas | 2020 Nov 27

Dying of the Light: An X-Ray Fading Cold Quasar at z ~ 0.405 ~ Kevin C. Cooke et al

• Astrophysical Journal 903(2):106 (2020 Nov 10) DOI: 10.3847/1538-4357/abb94a
• arXiv.org > astro-ph > arXiv:2009.08465 > 17 Sep 2020 (v1), 04 Jan 2021 (v2)

[Ann]

Cold quasar CQ4479. Photo: SDSS.

---

I love this image of cold quasar CQ4479. The quasar is the intensely blue object in the SDSS image (no wonder I love it). It is the quasar activity and not the star formation that makes the object look blue, unless I'm very much mistaken. The vast distance between us and the quasar has redshifted a good deal of the ultraviolet light emitted by the quasar into the visible blue part of the spectrum.

The red object next to the quasar another galaxy. It could be interacting with CQ4479, or it could be unrelated.

Ann