The Gemini Northern Telescope reveals the oldest traces of galaxies.
A very faint dwarf galaxy has been discovered at the outer edge of the Andromeda galaxy thanks to the keen eye of an amateur astronomer examining archival data processed by NSF’s NOIRLab Science and Data Center. A dwarf galaxy – Pegasus V – has been revealed to contain very few heavier elements and may be one of the first fossil galaxies in fFollow-up observations by professional astronomers using the Gemini International Observatory, a program of NSF NOIRLab.
An unusually faint dwarf galaxy has been discovered at the edge of the Andromeda Galaxy with the help of several NSF’s NOIRLab facilities. The galaxy, called Pegasus V, was first discovered as part of a systematic search for Andromeda dwarfs coordinated by David Martinez-Delgado of the Instituto de Astrofísica de Andalucía, Spain, when amateur astronomer Giuseppe Donatello discovered strange “spots” in the data at[{” attribute=””>DESI صورة استطلاعات التصوير القديمة.” width=”777″ height=”396″ srcset=”” sizes=”” ezimgfmt=”rs rscb1 src ng ngcb1 srcset” loading=”eager” importance=”high”/>
تم التقاط الصورة بكاميرا الطاقة المظلمة المصنّعة من وزارة الطاقة الأمريكية على تلسكوب Víctor M. Blanco الذي يبلغ ارتفاعه 4 أمتار في مرصد Cerro Tololo Inter-American (CTIO). تمت معالجة البيانات من خلال خط أنابيب المجتمع الذي يديره مركز علوم المجتمع والبيانات (CSDC) التابع لـ NOIRLab.
The fainter stars in Pegasus V have been detected in a more in-depth follow-up by astronomers using the larger Gemini North Telescope, the 8.1 meter telescope with the GMOS instrument, which confirms that it is a very faint dwarf galaxy on the periphery of the Andromeda Galaxy. Gemini North in Hawaii is half of the Gemini International Observatory.
Observations with Gemini indicate that the galaxy appears to be very deficient in heavier elements compared to similar dwarf galaxies, meaning it is very old and possibly one of the first fossilized galaxies in the universe.
“We found a very faint galaxy whose stars formed very early in the history of the universe,” comments Michelle Collins, an astronomer at the University of Surrey, UK and lead author of the paper announcing the discovery. “This discovery is the first time that a dimly lit galaxy has been found in the vicinity of the Andromeda galaxy using an astronomical survey not specifically designed for this task.”
A very faint dwarf galaxy has been discovered in the outer periphery of the Andromeda Galaxy thanks to the keen eye of an amateur astronomer who examined archival data from the US Department of Energy’s Dark Energy Camera on the Víctor M. Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory (CTIO) and processed by the Community and Data Science Center (CSDC). Follow-up by professional astronomers using the Gemini International Observatory has revealed that the dwarf galaxy – Pegasus V – contains very few heavier elements and is likely a fossil from the first galaxy. The three facilities involved are NSF’s NOIRLab program. Credit: Gemini International Observatory/NOIRLab/NSF/AURA, Recognition: Image Processing: TA Chancellor (University of Alaska Anchorage/NSF’s NOIRLab), M. Zamani (NSF’s NOIRLab) and D. de Martin (NSF’s NOIRLab)
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Dim galaxies were among the first fossilized galaxies to form, and the remnants of these galaxies contain clues to the formation of the first stars. While astronomers speculate that the universe is full of fainter galaxies like Pegasus V,[2] They haven’t figured out what their theory predicts. If the number of faint galaxies is really less than expected, this means there are serious problems for astronomers in understanding cosmology and dark matter.
Therefore, finding examples of these faint galaxies is an important, but also challenging, endeavor. Part of the challenge is that these faint galaxies are very difficult to see, appearing only as a few scattered stars hidden in the big pictures of the sky.
“The problem with these very faint galaxies is that they contain so few bright stars that we usually use them to identify and measure their distance,” explains Emily Charles, a PhD student at the University of Surrey who was also involved in the study. . “The 8.1-meter Gemini mirror allowed us to find a faint old star, allowing us to measure the distance to Pegasus V and determine that the number of stars there is very old.”
The strong concentration of ancient stars the team found in Pegasus V suggests that the object may be the first galactic fossil. When compared to other fainter galaxies around Andromeda, Pegasus V appears old and less mineralized, indicating that its star formation actually stopped very early.
“We hope that further studies of the chemical properties of Pegasus V will provide clues about the early period of star formation in the universe,” Collins concluded. “These tiny fossil galaxies from the early universe can help us understand how galaxies form, and whether our understanding of dark matter is correct.”
“The publicly available Gemini North telescope provides a wide range of capabilities for community astronomers,” said Martin Steele, Gemini Program Officer at the National Science Foundation. “In this regard, Gemini is supporting this international team to confirm the existence of a dwarf galaxy, physically link it to the Andromeda galaxy, and identify the mineral-deficient nature of its advanced star cluster.”
An upcoming astronomical facility is set to shed light on more of the fainter galaxies. Pegasus V witnessed a time in the history of the universe known as reionization, and other objects dating from this period will soon be observed. NASA’s James Webb Space Telescope. Astronomers also hope to find other fainter galaxies in the future using the Vera C. Rubin Observatory, a program of NSF NOIRLab. The Rubin Observatory will conduct an unprecedented ten-year optical sky survey called the Legacy of Space and Time (LSST) survey.
Notes
- An ancient DESI imaging survey was carried out to identify the targets of the dark energy spectroscopic instrumentation (DESI) process. The survey includes a unique combination of three projects that have monitored a third of the night sky: the Inherited Dark Energy Camera Survey (DECaLS), observed by the Dark Energy Camera (DECam) created by the Department of Energy at the Víctor M. Blanco 4-meter telescope at Cerro Tololo Pan-American Observatory (CTIO) in Chile; Mayall z-band Legacy Survey (MzLS), by camera Mosaic3 on the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory (KPNO); Beijing-Arizona Sky Survey (BASS) with 90 Prime Cameras on a 2.3 meter Bock Telescope, owned and operated by the University of Arizona and located at KPNO. CTIO and KPNO are NSF NOIRLab affiliate programs.
- Pegasus V is so named because it is the fifth dwarf galaxy to be discovered in the constellation Pegasus. The distance between Pegasus V and the Andromeda galaxy in the sky is about 18.5 degrees.
further information
The research is presented in a paper entitled “Pegasus V – a newly discovered ultra-light dwarf galaxy on the outskirts of Andromeda” to emerge in Monthly Notices of the Royal Astronomical Society.
Reference: “Pegasus V – newly discovered ultra-light dwarf galaxy on the outskirts of Andromeda” By Michelle LM Collins, Emily JE Charles, David Martinez-Delgado, Matteo Monelli, Nuchin Creme, Giuseppe Donatello, Eric J. Tollerud and Walter Buchen, Agreed , Monthly Notices of the Royal Astronomical Society.
arXiv: 2204.09068
The team consisted of Michel LM Collins (Department of Physics, University of Surrey, UK), Emily GE Charles (Department of Physics, University of Surrey, UK), David Martinez-Delgado (Instituto Astrophysica of Andalusia, Spain), Matteo Monelli (Instituto).de Astrofísica de Canarias (IAC) and Universidad de La Laguna, Spain), Noushin Karim (Department of Physics, University of Surrey, UK), Giuseppe Donatiello (UAI – Unione Astrophyli Italiani, Italy), Erik J. Tollerud ( Institute of Space Telescope Science , USA), Walter Boschin (Instituto de Astrofísica de Canarias (IAC), Universidad de La Laguna, Fundación G. Galilei – INAF (Telescopio Nazionale Galileo), Spain).
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