ESO: Brilliant Galaxy Returns to the Shadows

[bystander]

Starving Black Hole Returns Brilliant Galaxy to the Shadows
ESO Science Release | CARS | 2016 Sep 15

AGN Mrk 1018 -- Credit: ESO/CARS

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The mystery of a rare change in the behaviour of a supermassive black hole at the centre of a distant galaxy has been solved by an international team of astronomers using ESO’s Very Large Telescope along with the NASA/ESA Hubble Space Telescope and NASA’s Chandra X-ray Observatory. It seems that the black hole has fallen on hard times and is no longer being fed enough fuel to make its surroundings shine.

Many galaxies are found to have an extremely bright core powered by a supermassive black hole. These cores make “active galaxies” some of the brightest objects in the Universe. They are thought to shine so brightly because hot material is glowing fiercely as it falls into the black hole, a process known as accretion. This brilliant light can vary hugely between different active galaxies, so astronomers classify them into several types based on the properties of the light they emit [1].

Some of these galaxies have been observed to change dramatically over the course of only 10 years; a blink of an eye in astronomical terms. However, the active galaxy in this new study, Markarian 1018 stands out by having changed type a second time, reverting back to its initial classification within the last five years. A handful of galaxies have been observed to make this full-cycle change, but never before has one been studied in such detail.

The discovery of Markarian 1018’s fickle nature was a chance by-product of the Close AGN Reference Survey (CARS), a collaborative project between ESO and other organisations to gather information on 40 nearby galaxies with active cores. Routine observations of Markarian 1018 with the Multi-Unit Spectroscopic Explorer (MUSE) installed on ESO’s Very Large Telescope (VLT) revealed the surprising change in the light output of the galaxy. ...

The Close AGN Reference Survey (CARS)

• Mrk 1018 returns to the shadows after 30 years as a Seyfert 1 - R. E. McElroy et al
  • Astronomy & Astrophysics 593:L8 (2016 Sep) DOI: 10.1051/0004-6361/201629102 (pdf)
  • arXiv.org > astro-ph > arXiv:1609.04423 > 14 Sep 2016
  What is causing Mrk 1018’s return to the shadows after 30 years? - B. Husemann et al
  • Astronomy & Astrophysics 593:L9 (2016 Sep) DOI: 10.1051/0004-6361/201629245 (pdf)
  • arXiv.org > astro-ph > arXiv:1609.04425 > 14 Sep 2016

[bystander]

Markarian 1018: Starvation Diet for Black Hole Dims Brilliant Galaxy
NASA | MSFC | SAO | Chandra X-ray Observatory | 2016 Nov 09

[img3="Credit: X-ray: NASA/CXC/Univ Sydney/McElroy et al, Optical: ESO/CARS Survey"]http://chandra.si.edu/photo/2016/mrk1018/mrk1018.jpg[/img3][hr][/hr]

Astronomers may have solved the mystery of the peculiar volatile behavior of a supermassive black hole at the center of a galaxy. Combined data from NASA's Chandra X-ray Observatory and other observatories suggest that the black hole is no longer being fed enough fuel to make its surroundings shine brightly. ...

After discovering the AGN's fickle nature during a survey project using ESO's Very Large Telescope (VLT), astronomers requested and received time to observe it with both NASA's Chandra X-ray Observatory and Hubble Space Telescope. The accompanying graphic shows the AGN in optical light from the VLT (left) with a Chandra image of the galaxy's central region in X-rays showing the point source for the AGN (right). ...