Astronomers Spot Giant Nebula around Distant Quasar

Astronomers Spot Giant Nebula around Distant Quasar.

Astronomers using ESO’s Very Large Telescope in Chile have discovered an enormous cloud of gas around an extremely distant quasar called 4C 10.29.

This MUSE image shows a huge cloud of gas around the distant quasar 4C 10.29. Image credit: Arrigoni Battaia et al / ESO.

Quasars are the luminous centers of active galaxies, which are kept active by material falling onto the central supermassive black hole.

4C 10.29 (also known as SDSS J102009.99+104002.7) and its surrounding cloud are at a redshift larger than 3, meaning that they are seen as they were only about 2 billion years after the Big Bang.

The cloud of gas surrounding the quasar is known to astronomers as an Enormous Lyman-Alpha Nebula (ELAN).

These types of nebula are massive structures of gas which formed in the early Universe, and they can help astronomers to learn how angular momentum — which explains the observed rotation of more recent galaxies — was created in the Universe.

Thanks to the Multi Unit Spectroscopic Explorer (MUSE) instrument on the Very Large Telescope, it is now possible to observe these rare giant nebulae in greater detail than ever before.

This particular ELAN has a diameter of about 970,000 light-years, and MUSE’s spectral imaging capabilities have allowed a research team led by ESO astronomer Fabrizio Arrigoni Battaia to measure the signature of inspiraling motions within the nebula — for the first time ever.

“This ELAN is associated with an additional four previously unknown embedded sources: two Lyman-alpha emitters and two faint active galactic nuclei (one type-1 and one type-2 quasar),” Dr. Arrigoni Battaia and colleagues said.

“By mapping at high significance, the line-of-sight velocity in the entirety of the observed structure, we unveiled a large-scale coherent rotation-like pattern spanning 300 km/s with a velocity dispersion of 270 km/s, which we interpret as a signature of the inspiraling accretion of substructures within the quasar’s host halo.”

The team’s findings are published in the Monthly Notices of the Royal Astronomical Society ( arXiv.org preprint ).