Astronomy:Blue Nugget
Blue Nugget (also called BN) galaxies are a type of distant galaxy that only existed in the early universe. Blue nugget galaxies are small and compact but high mass galaxies undergoing mass bursts of star formation which result in the formation of many large, bright blue stars. As their stellar population evolves and ages, blue nugget galaxies transition into red nugget galaxies.[1]
The "Blue" derives from their blue coloration and "Nugget" derives from their small size.[2]
Evolution
Studies that use high-resolution cosmological simulations show that galaxies located at high-redshifts will tend to undergo a phase of gas compaction. This will usually trigger a phase of compact star formation forming a blue nugget. The process of compaction begins when the gas in a galaxy experiences a drastic lost in angular momentum often caused by wet galaxy mergers, counter-rotating cold streams of gas or violent instability in the galactic disk.
Then there will be a phase where star formation is suddenly quenched leading to the blue nugget transitioning into a red nugget (RN). This quenching is “inside-out” beginning at the center of the galaxy.[3][4] Blue nuggets that are transitioning into a red nugget are called “Green nuggets”.[5] Then from there, they will start to gradually grow and transform into the early-type galaxies, often elliptical, of the modern day Universe through the accretion of satellite galaxies.[6]
Examples
Examples of Blue Nugget galaxies can be found below:
- KIDS J122456+005048[7]
- KiDSJ224546−295559 -post blue nugget[8]
- KiDSJ234804-302855 -post blue nugget[8]
- KiDS J023929−321129 -post blue nugget[8]
- KiDSJ230226−335637 -post blue nugget[8]
- KIDS J232940-340922 -post blue nugget[7]
References
- ↑ Kohler, Susanna (2020-12-09). "Nugget Galaxies Cross in the Sky" (in en-US). https://aasnova.org/2020/12/09/nugget-galaxies-cross-in-the-sky/.
- ↑ "Astronomers Solve the Mystery of Small Galaxies with Monster Black Holes" (in en). 2019-07-26. https://www.space.com/small-galaxies-monster-black-holes-mystery-solved.html.
- ↑ Lapiner, Sharon; Dekel, Avishai; Freundlich, Jonathan; Ginzburg, Omri; Jiang, Fangzhou; Kretschmer, Michael; Tacchella, Sandro; Ceverino, Daniel et al. (2023-05-02). "Wet compaction to a blue nugget: a critical phase in galaxy evolution" (in en). Monthly Notices of the Royal Astronomical Society 522 (3). doi:10.1093/mnra. ISSN 0035-8711. https://academic.oup.com/mnras/article/522/3/4515/7146211.
- ↑ Kohler, Susanna (2020-12-09). "Nugget Galaxies Cross in the Sky" (in en-US). https://aasnova.org/2020/12/09/nugget-galaxies-cross-in-the-sky/.
- ↑ Kannappan, Sheila J. (August 2020). "Compaction in Action: Blue, Green, and Red Nuggets at Redshift Zero" (in en). NSF Award 20 (2007351): 7351. https://ui.adsabs.harvard.edu/abs/2020nsf....2007351K/abstract.
- ↑ Carr, D.; Kannappan, S.; Palumbo, M.; Norris, M.; Eckert, K.; Frazer, E.; Norman, D.; Cleaves, N. (January 2020). "Compaction in Action: Tracing the Formation and Evolution of Blue and Red Nuggets at Redshift Zero in the RESOLVE Survey" (in en). American Astronomical Society Meeting Abstracts #235 235: 207.38. https://ui.adsabs.harvard.edu/abs/2020AAS...23520738C/abstract.
- ↑ 7.0 7.1 Napolitano, N. R.; Li, R.; Spiniello, C.; Tortora, C.; Sergeyev, A.; D’Ago, G.; Guo, X.; Xie, L. et al. (December 2020). "Discovery of Two Einstein Crosses from Massive Post-blue Nugget Galaxies at z > 1 in KiDS*" (in en). The Astrophysical Journal Letters 904 (2): L31. doi:10.3847/2041-8213/abc95b. ISSN 2041-8205.
- ↑ 8.0 8.1 8.2 8.3 Li, Rui; Napolitano, Nicola R.; Xie, Linghua; Li, Ran; Guo, Xiaotong; Sergeyev, Alexey; Tortora, Crescenzo; Spiniello, Chiara et al. (October 2024). "Multiband Analysis of Strong Gravitationally Lensed Post-blue Nugget Candidates from the Kilo-degree Survey" (in en). The Astrophysical Journal 973 (2): 145. doi:10.3847/1538-4357/ad684c. ISSN 0004-637X. https://ui.adsabs.harvard.edu/abs/2024ApJ...973..145L/abstract.
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