| Revision as of 01:57, 16 January 2024 editBD2412 (talk | contribs)Autopatrolled, IP block exemptions, Administrators2,454,452 editsm →top: clean up spacing around commas and other punctuation fixes, replaced: , → ,Tag: AWB← Previous edit | Revision as of 14:53, 26 January 2024 edit undoDrbogdan (talk | contribs)Autopatrolled, Extended confirmed users, Pending changes reviewers, Rollbackers90,412 edits add => <ref name="NYT-20240126">{{cite news |last=Overbye |first=Dennis |authorlink=Dennis Overbye|title=What Do You Call a Galaxy Without Stars? - To dark matter and dark energy, add dark galaxies — collections of stars so sparse and faint that they are all but invisible. |url=https://www.nytimes.com/2024/01/26/science/space/dark-galaxy-stars.html |date=26 January 2024 |work=The New York Times |url-status=live |archiveurl=https://archive.ph/6Nbb0 |archivedate=26 January 2024 }}</ref>Tag: RevertedNext edit → | ||
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| ], a low surface brightness ], by ].]] | ], a low surface brightness ], by ].]] | ||
| ] is located over 110 million light-years away in the constellation of ].<ref>{{cite web|title=Hiding in the night sky|url=http://www.spacetelescope.org/images/potw1614a/|access-date=4 April 2016}}</ref>]] | ] is located over 110 million light-years away in the constellation of ].<ref>{{cite web|title=Hiding in the night sky|url=http://www.spacetelescope.org/images/potw1614a/|access-date=4 April 2016}}</ref>]] | ||
| A '''low-surface-brightness galaxy''', or '''LSB galaxy''', is a diffuse ] with a ] that, when viewed from ], is at least one magnitude lower than the ambient night sky. | A '''low-surface-brightness galaxy''', or '''LSB galaxy''', or ''']''',<ref name="NYT-20240126">{{cite news |last=Overbye |first=Dennis |authorlink=Dennis Overbye|title=What Do You Call a Galaxy Without Stars? - To dark matter and dark energy, add dark galaxies — collections of stars so sparse and faint that they are all but invisible. |url=https://www.nytimes.com/2024/01/26/science/space/dark-galaxy-stars.html |date=26 January 2024 |work=] |url-status=live |archiveurl=https://archive.ph/6Nbb0 |archivedate=26 January 2024 }}</ref> is a diffuse ] with a ] that, when viewed from ], is at least one magnitude lower than the ambient night sky. | ||
| Most LSBs are ], and most of their ]ic matter is in the form of neutral gaseous hydrogen, rather than stars. They appear to have over 95% of their mass as non-]ic ]. There appears to be little supernova (SN) activity in these galaxies,{{Citation needed|date=July 2007}} although LSB galaxy IC 217 hosted 2014cl.<ref name=LSB_1>{{cite journal| title=A search for Low Surface Brightness galaxies in the near-infrared I. Selection of the sample| author1=D. Monnier Ragaigne| author2=W. van Driel| author3=S.E. Schneider| author4= T.H. Jarrett| author5=C. Balkowski| journal=Astronomy and Astrophysics| volume=405| pages=99–109| date=July 2003| doi=10.1051/0004-6361:20030585|arxiv=astro-ph/0304380 | bibcode=2003A&A...405...99M| doi-access=free}}</ref><ref name=CBET2014cl>{{cite journal| title=Supernova 2014cl in IC 217| author1=L. Gonzalez| author2=M. Hamuy| author3=R. Antezana| journal=Central Bureau Electronic Telegrams| date=August 2014| volume=3950| page=1| bibcode=2014CBET.3950....1G| url=https://ui.adsabs.harvard.edu/abs/2014CBET.3950....1G}}</ref> | Most LSBs are ], and most of their ]ic matter is in the form of neutral gaseous hydrogen, rather than stars. They appear to have over 95% of their mass as non-]ic ]. There appears to be little supernova (SN) activity in these galaxies,{{Citation needed|date=July 2007}} although LSB galaxy IC 217 hosted 2014cl.<ref name=LSB_1>{{cite journal| title=A search for Low Surface Brightness galaxies in the near-infrared I. Selection of the sample| author1=D. Monnier Ragaigne| author2=W. van Driel| author3=S.E. Schneider| author4= T.H. Jarrett| author5=C. Balkowski| journal=Astronomy and Astrophysics| volume=405| pages=99–109| date=July 2003| doi=10.1051/0004-6361:20030585|arxiv=astro-ph/0304380 | bibcode=2003A&A...405...99M| doi-access=free}}</ref><ref name=CBET2014cl>{{cite journal| title=Supernova 2014cl in IC 217| author1=L. Gonzalez| author2=M. Hamuy| author3=R. Antezana| journal=Central Bureau Electronic Telegrams| date=August 2014| volume=3950| page=1| bibcode=2014CBET.3950....1G| url=https://ui.adsabs.harvard.edu/abs/2014CBET.3950....1G}}</ref> | ||
Revision as of 14:53, 26 January 2024
Galaxy which is less bright than the ambient night sky
A low-surface-brightness galaxy, or LSB galaxy, or Dark galaxy, is a diffuse galaxy with a surface brightness that, when viewed from Earth, is at least one magnitude lower than the ambient night sky.
Most LSBs are dwarf galaxies, and most of their baryonic matter is in the form of neutral gaseous hydrogen, rather than stars. They appear to have over 95% of their mass as non-baryonic dark matter. There appears to be little supernova (SN) activity in these galaxies, although LSB galaxy IC 217 hosted 2014cl.
Rotation curve measurements indicate an extremely high mass-to-light ratio, meaning that stars and luminous gas contribute only very little to the overall mass balance of an LSB. The centers of LSBs show no large overdensities in stars, unlike e.g. the bulges of normal spiral galaxies. Therefore, they seem to be dark-matter-dominated even in their centers, which makes them excellent laboratories for the study of dark matter.
In comparison to the high-surface-brightness galaxies, LSBs are mainly isolated field galaxies, found in regions devoid of other galaxies. In their past, they had fewer tidal interactions or mergers with other galaxies, which could have triggered enhanced star formation. This is an explanation for the small stellar content.
LSB galaxies were theorized to exist in 1976 by Mike Disney.
Giant low-surface-brightness galaxies
Giant low surface brightness (GLSB) galaxies are among the most massive known spiral galaxies in the Universe. They have very faint stellar disks that are very rich in neutral hydrogen but low in star formation and thus low in surface brightness. Such galaxies often have bright bulges that can host low luminosity active galactic nuclei. GLSB galaxies are usually isolated systems that rarely interact with other galaxies. The first LSB galaxy verified to exist was Malin 1, discovered in 1986. As such, it was also the first giant LSB galaxy identified. At the time of its discovery, it was the largest spiral galaxy known (by scale-length measurement).
UGC 1382 was previously thought to be an elliptical galaxy, but low-brightness spiral arms were later detected. UGC 1382 is much closer to Earth than Malin 1.
Examples
- Andromeda V
- Pegasus Dwarf Spheroidal Galaxy
- IC 10
- NGC 45
- Eridanus II
- Malin 1
- Malin 2
- Phoenix Dwarf
- Sagittarius Dwarf Irregular Galaxy (SagDIG)
- Sextans A
- Sextans B
- Wolf–Lundmark–Melotte galaxy (WLM)
- UGC 477
See also
References
- "Hiding in the night sky". Retrieved 4 April 2016.
- Overbye, Dennis (26 January 2024). "What Do You Call a Galaxy Without Stars? - To dark matter and dark energy, add dark galaxies — collections of stars so sparse and faint that they are all but invisible". The New York Times. Archived from the original on 26 January 2024.
- D. Monnier Ragaigne; W. van Driel; S.E. Schneider; T.H. Jarrett; C. Balkowski (July 2003). "A search for Low Surface Brightness galaxies in the near-infrared I. Selection of the sample". Astronomy and Astrophysics. 405: 99–109. arXiv:astro-ph/0304380. Bibcode:2003A&A...405...99M. doi:10.1051/0004-6361:20030585.
- L. Gonzalez; M. Hamuy; R. Antezana (August 2014). "Supernova 2014cl in IC 217". Central Bureau Electronic Telegrams. 3950: 1. Bibcode:2014CBET.3950....1G.
- ^ Mousumi Das (March 2013). "Giant Low Surface Brightness Galaxies: Evolution in Isolation". Journal of Astrophysics and Astronomy. 34 (1): 19–31. arXiv:1310.6495. Bibcode:2013JApA...34...19D. doi:10.1007/s12036-013-9166-8. S2CID 118546432.
- ^ Scientific American, "The Ghostliest Galaxies", GD Bothun, Vol. 276, No. 2, February 1997, pp.40-45, Bibcode:1997SciAm.276b..40B
- Ken Crosswell, "Malin 1: A Bizarre Galaxy Gets Slightly Less So", 22 January 2007
- "Surprise: Small elliptical galaxy actually a giant disk". 11 July 2016. Retrieved 12 July 2016.
- K. O'Neil, The HI Content and Extent of Low Surface Brightness Galaxies - Could LSB Galaxies be Responsible for Damped Ly-alpha Absorption?. For publication in Extragalactic Gas at Low Redshift, by Mulchaey, et al., eds (2001).
- S.D. Rosenbaum and D.J. Bomans, The environment of Low Surface Brightness Galaxies. Astronomy & Astrophysics Letters, 422, 5-8 (2004).
- A.J. Barth, A normal stellar disk in the galaxy Malin 1. Astronomical Journal 133, 1085-1091 (2007).
