May 20, 2024

Galactic Belly Flop: Mysterious “Blue Blobs” Reveal a New Kind of Star System

The outstanding systems– which astronomers state appear through a telescope as “blue blobs” and have to do with the size of small dwarf galaxies– lie within the fairly close-by Virgo galaxy cluster. The five systems are separated from any possible moms and dad galaxies by over 300,000 light years in many cases, making it challenging to determine their origins.
The astronomers found the new systems after another research group, led by the Netherlands Institute for Radio Astronomys Elizabeth Adams, compiled a brochure of nearby gas clouds, providing a list of potential sites of brand-new galaxies. When that catalog was released, several research study groups, including one led by UArizona associate astronomy teacher David Sand, started trying to find stars that might be associated with those gas clouds.
The gas clouds were believed to be associated with our own galaxy, and most of them probably are, but when the first collection of stars, called SECCO1, was found, astronomers recognized that it was not near the Milky Way at all, but rather in the Virgo cluster, which is much farther away but still really close-by in the scale of the universe.
SECCO1 was one of the extremely uncommon “blue blobs,” said Michael Jones, a postdoctoral fellow in the UArizona Steward Observatory and lead author of a research study that describes the brand-new excellent systems. Jones presented the findings, which Sand co-authored, throughout the 240th American Astronomical Society meeting in Pasadena, California, Wednesday.
” Its a lesson in the unanticipated,” Jones said. “When youre trying to find things, youre not necessarily going to find the thing youre looking for, however you may find something else very interesting.”
The group got their observations from the Hubble Space Telescope, the Very Large Array telescope in New Mexico and the Very Large Telescope in Chile. Research study co-author Michele Bellazzini, with the Istituto Nazionale di Astrofisica in Italy, led the analysis of the information from Very Large Telescope and has sent a companion paper focusing on that data.

” When a galaxy stubborn belly flops into a cluster that has lots of hot gas, then its gas gets forced out behind it. Thats the mechanism that we think were seeing here to create these items.”

University of Arizona astronomers have determined a brand-new class of star system. “In fact, there need to be some molecular gas since they are still forming stars. The existence of mainly young stars and little gas signals that these systems must have lost their gas just recently.”
” Stars that are born red are lower mass and for that reason live longer than blue stars, which burn quick and die young, so old red stars are typically the last ones left living,” Jones said. “And theyre dead because they do not have any more gas with which to form new stars.

Together, the team found out that many of the stars in each system are very blue and extremely young and that they contain extremely little atomic hydrogen gas. This is considerable since star development starts with atomic hydrogen gas, which ultimately progresses into thick clouds of molecular hydrogen gas prior to forming into stars.
” We observed that most of the systems do not have atomic gas, however that does not indicate there isnt molecular gas,” Jones stated. “In fact, there should be some molecular gas because they are still forming stars. The presence of primarily young stars and little gas signals that these systems must have lost their gas recently.”
The mix of blue stars and lack of gas was unanticipated, as was an absence of older stars in the systems. Many galaxies have older stars, which astronomers describe as being “dead and red.”
” Stars that are born red are lower mass and for that reason live longer than blue stars, which burn quickly and pass away young, so old red stars are generally the last ones left living,” Jones stated. “And theyre dead due to the fact that they dont have anymore gas with which to form brand-new stars. These blue stars resemble a sanctuary in the desert, basically.”
The truth that the brand-new outstanding systems are abundant in metals tips at how they might have formed.
” To astronomers, metals are any component much heavier than helium,” Jones said. “This informs us that these stellar systems formed from gas that was stripped from a huge galaxy, since how metals are developed is by numerous repeated episodes of star development, and you just truly get that in a big galaxy.”
There are two primary methods gas can be removed from a galaxy. The first is tidal removing, which occurs when 2 huge galaxies go by each other and gravitationally tear away gas and stars.
The other is whats called ram pressure removing.
” This is like if you tummy flop into a swimming pool,” Jones said. “When a galaxy stubborn belly flops into a cluster that is complete of hot gas, then its gas gets displaced behind it. Thats the system that we believe were seeing here to develop these items.”
The group chooses the ram pressure removing description due to the fact that in order for the blue blobs to have ended up being as separated as they are, they need to have been moving very quickly, and the speed of tidal removing is low compared to ram pressure removing.
Astronomers expect that a person day these systems will eventually divide off into individual clusters of stars and expanded throughout the larger galaxy cluster.
What researchers have found out feeds into the larger “story of recycling of gas and stars in deep space,” Sand said. “We believe that this belly-flopping process alters a great deal of spiral nebula into elliptical galaxies on some level, so finding out more about the basic procedure teaches us more about galaxy formation.”
Recommendation: “Young, blue, and separated excellent systems in the Virgo Cluster. II. A brand-new class of stellar system” by Michael G. Jones, David J. Sand, Michele Bellazzini, Kristine Spekkens, Ananthan Karunakaran, Elizabeth A. K. Adams, Giuseppina Battaglia, Giacomo Beccari, Paul Bennet, John M. Cannon, Giovanni Cresci, Denija Crnojevic, Nelson Caldwell, Jackson Fuson, Puragra Guhathakurta, Martha P. Haynes, John L. Inoue, Laura Magrini, Ricardo R. Munoz, Burcin Mutlu-Pakdil, Anil Seth, Jay Strader, Elisa Toloba and Dennis Zaritsky, 3 May 2022, Astrophysics > > Astrophysics of Galaxies.arXiv:2205.01695.

University of Arizona astronomers have determined a new class of star system. The collection of mainly young blue stars are seen here using the Hubble Space Telescope Advanced Camera for Surveys. Credit: Michael Jones
When galaxies collide with hot gas in a procedure that might be compared to doing a stubborn belly flop in a swimming pool, the excellent structures are believed to be developed.
University of Arizona astronomers have recognized five examples of a new class of stellar system. Theyre not rather galaxies and only exist in seclusion.
The new outstanding systems include just young, blue stars, which are dispersed in an irregular pattern and appear to exist in surprising seclusion from any potential parent galaxy.