False-colour cut g+r from the Corvus A Megacamera image. The blue region of recent star formation is clearly visible on the eastern side of the galaxy, but there is also a redder population of stars. Credit: Jones et al., 2024.
Astronomers report the discovery of a new galaxy in the constellation Corvus. The newly discovered galaxy, named Corvus A, is relatively low-mass, gas-rich, and isolated. The discovery was presented in a research paper published July 3 on the server ahead of print arXiv.
One of the projects that has discovered many nearby low-mass galaxy candidates is the Semi-Automatic Machine Learning Search for Semi-Resolved Galaxies (SEAMLESS). The project relies on masking the high surface brightness emission from bright stars and galaxies and then filtering the images at different scales in order to identify faint and extended sources.
Corvus A was first identified in the legacy Dark Energy Spectroscopic Instrument (DESI) imaging surveys. Recently, a team of astronomers led by Michael G. Jones of the University of Arizona in Tucson has conducted follow-up observations of this object using instruments such as the Magellan Clay telescope or the Karl G. Jansky Very Large Array (VLA), of which allowed them to confirm the low-mass galaxy status for Corvus A.
“Corvus A is a newly discovered low-mass galaxy identified during the initial phase of the SEAMLESS project,” the researchers write.
The observations revealed that the stellar body of Corvus A has an irregular structure and its light is dominated by a region of young blue stars on its eastern side. Therefore, astronomers pointed out that its blue, thick and irregular appearance is reminiscent of Leo P – a small irregular star-forming galaxy in the constellation Leo, one of the least massive in the Local Group as its stellar mass is estimated to be about 560,000 solar masses.
According to the paper, Corvus A, with a half-light radius of 834 light years, is only a few times more massive than Leo P and contains many young stars with an age of no more than 200 million years. The study found that Corvus A is a gas-rich galaxy without regions of ionized interstellar atomic hydrogen – so-called H II regions.
The distance from Corvus A was measured to be about 11.3 million light years. It also turns out that there are no other galaxies within approximately 3.3 million light-years of Corvus A, making it an extremely isolated galaxy.
The astronomers noted that Corvus A’s proximity makes it an excellent target for follow-up higher-resolution observations at radio and optical wavelengths, which could shed more light on the kinematics of this newly discovered low-mass galaxy. .
“With higher spectral and spatial resolution data (e.g. from MeerKAT or additional VLA configurations) it should be possible to separate the expansion from warm and cold neutral media, and distinguish contributions from turbulence and rotation , at which point it may be possible to fit a kinematic model and determine a rotation rate if the slope is not too small,” the authors of the paper conclude.
More information:
Michael G. Jones et al, Corvus A: A low-mass, isolated galaxy at 3.5 Mpc, arXiv (2024). DOI: 10.48550/arxiv.2407.03393
Magazine Information:
arXiv
© 2024 Science X Network
citation: A new low-mass galaxy discovered (2024, July 15) Retrieved July 15, 2024 from https://phys.org/news/2024-07-mass-galaxy.html
This document is subject to copyright. Except for any fair agreement for study or private research purposes, no part may be reproduced without written permission. The content is provided for informational purposes only.