Astronomers observe lone distant galaxy that seems to have consumed all of its former companions

Over 13 billion years in the past, the primary galaxies within the universe shaped. They have been elliptical, with intermediate black holes (IMBHs) at their facilities surrounded by a halo of stars, gasoline, and mud. Over time, these galaxies developed by flattening out into disks with a big bulge within the center. They have been then drawn collectively by mutual gravitational attraction to kind galaxy clusters, large collections that comprise the large-scale cosmic construction. This power of attraction additionally led to mergers, the place galaxies and their central black holes got here collectively to create bigger spiral galaxies with central supermassive black holes (SMBHs).

This means of mergers and assimilation (and their function in galactic evolution) continues to be a thriller to astronomers right this moment since a lot of it came about throughout the early universe, which continues to be very troublesome to look at with current telescopes. Utilizing knowledge from NASA’s Chandra X-ray Observatory and the Worldwide Gemini Observatory, a world staff of astronomers noticed a lone distant galaxy that seems to have consumed all of its former companions. Their findings, which lately appeared in The Astrophysical Journal, recommend galaxies within the early universe grew sooner than beforehand thought.

The analysis staff was led by Valentina Missaglia, a postdoctoral astrophysicist on the College of Turin. She was joined by colleagues from the Nationwide Nuclear Physics Institute (INFN), the Astrophysical Observatory of Turin, The College of Texas Rio Grande Valley, the Max Planck Institute for Astronomy (MPIA), the Brazil Ministry of Science, Expertise, Innovation, and Communication (MCTIC), the Instituto Nacional de Pesquisas Espaciais (INPE), the Harvard & Smithsonian Middle for Astrophysics, Institute of Theoretical and Experimental Astronomy (IATE), and the Nationwide Institute of Astrophysics (INAF).

The staff reported the surprising discovery of a solo galaxy (3C 297) about 9.2 billion light-years away. In addition they famous that it contained a quasar at its heart and highly effective jets (shiny within the radio spectrum) emanating from its poles. The setting of this galaxy seems to have a number of key options of a galaxy cluster; nonetheless, the galaxy seems to be alone. As Missaglia mentioned in a Harvard-Chandra press launch, “It appears that evidently we’ve a galaxy cluster that’s lacking nearly all of its galaxies,” she mentioned. “We anticipated to see no less than a dozen galaxies in regards to the measurement of the Milky Approach, but we see just one.”

Missaglia and her colleagues famous three options related to galaxy clusters primarily based on the Chandra knowledge. First, the X-ray knowledge revealed that 3C 297 is surrounded by massive portions of high-temperature gasoline (tens of tens of millions of levels)—one thing not often seen exterior of galaxy clusters. Second, the relativistic jet streaming from its SMBH created a shiny X-ray supply about 140,000 light-years away, which implied it had pushed by means of gasoline surrounding the galaxy. Third, one of many radio jets appeared bent, indicating it was interacting with its environment.

This final discovering was beforehand noticed primarily based on knowledge collected by the Karl G. Jansky Very Giant Array (VLA). However when the staff consulted their knowledge from the Gemini Observatory, they observed that not one of the 19 galaxies that appeared near 3C 297 have been really on the identical distance. Stated co-author Juan Madrid, an assistant professor on the College of Texas Rio Grande Valley:

“The query is, what occurred to all of those galaxies? We expect the gravitational pull of the one massive galaxy mixed with interactions between the galaxies was too sturdy, they usually merged with the massive galaxy. For these galaxies, apparently, resistance was futile.”

Whereas the authors can’t rule out the potential for dwarf galaxies positioned round 3C 297, their presence would nonetheless not clarify why no bigger galaxies are close by. As well as, they anticipate that 3C 297 will spend a number of billion years by itself earlier than it good points any massive galactic companions (like M87 and the Virgo Cluster). Whereas it isn’t clear how 3C 297 ended up by itself in a cluster-like setting, the staff theorizes that it could possibly be a “fossil group”—the tip stage of a galaxy merging with a number of others.

Whereas many different fossil teams have been detected earlier than, at 9.2 billion light-years distant, this one is essentially the most distant ever seen. The earlier report holders for fossil teams have been 4.9 and seven.9 billion light-years away (respectively). “It might be difficult to clarify how the universe can create this method solely 4.6 billion years after the Massive Bang,” mentioned co-author Mischa Schirmer of the MPIA. “This does not break our concepts of cosmology, but it surely begins to push the boundaries on how shortly each galaxies and galaxy clusters will need to have shaped.”