New fossil galaxy discovery could answer important questions about the history of the universe.
An ultra-faint dwarf galaxy, thought to be a “fossil” of one of the first ever galaxies, has been discovered by galactic archeologists at the University of Surrey in the UK.
The fossil was uncovered via a systematic visual search of legacy survey images using the Mayall 4-meter telescope, led by Dr. David Martinez Delgado. It could teach astrophysicists about how galaxies form and confirm their understanding of cosmology and dark matter.
Dr. Michelle Collins, an astronomer at the University of Surrey and lead author of the paper announcing this discovery said:
“We have found a new, extremely faint galaxy whose stars formed very early in the history of the Universe. This discovery marks the first time a galaxy this faint has been found around Andromeda using an astronomical survey that wasn’t specifically designed for the task.”
Named ‘Pegasus V,’ the dwarf galaxy is located on the outskirts of the Andromeda galaxy and appears as just a few sparse stars hidden in the sky.
The discovery was made in collaboration with NSF NOIRLab and the International Gemini Observatory.
Emily Charles, a PhD student at the University of Surrey who was also involved in the study said:
“The trouble with these extremely faint galaxies is that they have very few of the bright stars which we typically use to identify them and measure their distances. Gemini’s large 8.1-meter mirror allowed us to find faint, old stars which enabled and allowed us to both to measure the distance to Pegasus V and to determine that its stellar population is extremely old.”
More astronomical facilities are looking into researching faint galaxies in the near future.
For more on this discovery, see Unusual Fossil Galaxy Discovered on Outskirts of Andromeda.
Reference: “Pegasus V — a newly discovered ultra-faint dwarf galaxy on the outskirts of Andromeda” by Michelle L. M. Collins, Emily J. E. Charles, David Martínez-Delgado, Matteo Monelli, Noushin Karim, Giuseppe Donatiello, Erik J. Tollerud, Walter Boschin, 27 July 2022, Monthly Notices of the Royal Astronomical Society.