Boötes Dwarf Galaxy
SDSS image of Boo I
Observation data (J2000 epoch)
ConstellationBoötes
Right ascension14h 00m 06s[1]
Declination+14° 30′ 00″ ± 15″[1]
Distance197 ± 18 kly (60 ± 6 kpc)[1]
Apparent magnitude (V)13.1[a]
Characteristics
TypedSph[1]
Apparent size (V)26.0′ ± 1.4′[1]
Other designations
Boo dSph, Boötes Satellite, Boötes Dwarf Spheroidal Galaxy, Boötes dSph galaxy,[2] PGC 4713553

The Boötes Dwarf Galaxy (Boo I dSph) is a galaxy discovered in 2006, which appears faint, with a luminosity of 100,000 L☉ and an absolute magnitude of –5.8. It lies about 197,000 light-years (60.4 kiloparsecs) away in the constellation Boötes. This dwarf spheroidal galaxy appears to be tidally disrupted[1] by the Milky Way Galaxy, which it orbits, and has two stellar tails that cross over to form a cross. Tidally disrupted galaxies usually only form one tail. The galaxy appears to be significantly elongated, with an ellipticity of ε = 0.68 ± 0.15.[3]

Like many of the ultrafaint dwarf spheroidals, the entire galaxy appears fainter than the Rigel system (absolute magnitude –7.84).[4] Even so, it is one of the more luminous UFDs.[5] It is metal-poor, like other UFDs, with a mean metallicity of −2.34.[5]

The stellar population of Boötes I is mostly very old stars. The two populations have essentially the same age, 13.4 billion and 13.3 billion years, respectively, with most of the stars being of the latter population.[6]

Notes

  1. ^ Apparent magnitude = Absolute magnitude + Distance modulus = –5.8[1] + 18.9[1] = 13.1

References

  1. 1 2 3 4 5 6 7 8 Belokurov, V.; Zucker, D. B.; Evans, N. W.; Wilkinson, M. I.; et al. (2006). "A Faint New Milky Way Satellite in Bootes". The Astrophysical Journal. 647 (2): L111–L114. arXiv:astro-ph/0604355. Bibcode:2006ApJ...647L.111B. doi:10.1086/507324. S2CID 15348323.
  2. ↑ "NAME Bootes Dwarf Spheroidal Galaxy". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-12-20.
  3. ↑ Longeard, Nicolas; Jablonka, Pascale; Arentsen, Anke; Thomas, Guillaume F.; Aguado, David S.; Carlberg, Raymond G.; Lucchesi, Romain; Malhan, Khyati; Martin, Nicolas; McConnachie, Alan W.; Navarro, Julio F.; Sánchez-Janssen, Rubén; Sestito, Federico; Starkenburg, Else; Yuan, Zhen (2022). "The Pristine dwarf galaxy survey – IV. Probing the outskirts of the dwarf galaxy Boötes I". Monthly Notices of the Royal Astronomical Society. 516 (2): 2348–2362. arXiv:2107.10849. Bibcode:2022MNRAS.516.2348L. doi:10.1093/mnras/stac1827.
  4. ↑ Shultz, M.; Wade, G. A.; Petit, V.; Grunhut, J.; Neiner, C.; Hanes, D.; MiMeS Collaboration (2014). "An observational evaluation of magnetic confinement in the winds of BA supergiants". Monthly Notices of the Royal Astronomical Society. 438 (2): 1114. arXiv:1311.5116. Bibcode:2014MNRAS.438.1114S. doi:10.1093/mnras/stt2260.
  5. 1 2 Jenkins, Sydney A.; Li, Ting S.; Pace, Andrew B.; Ji, Alexander P.; Koposov, Sergey E.; Mutlu-Pakdil, Burçin (2021). "Very Large Telescope Spectroscopy of Ultra-faint Dwarf Galaxies. I. Boötes I, Leo IV, and Leo V". The Astrophysical Journal. 920 (2): 92. arXiv:2101.00013. Bibcode:2021ApJ...920...92J. doi:10.3847/1538-4357/ac1353. S2CID 230433692.
  6. ↑ Brown, Thomas M.; Tumlinson, Jason; Geha, Marla; Simon, Joshua D.; Vargas, Luis C.; Vandenberg, Don A.; Kirby, Evan N.; Kalirai, Jason S.; Avila, Roberto J.; Gennaro, Mario; Ferguson, Henry C.; Muñoz, Ricardo R.; Guhathakurta, Puragra; Renzini, Alvio (2014). "The Quenching of the Ultra-Faint Dwarf Galaxies in the Reionization Era". The Astrophysical Journal. 796 (2): 91. arXiv:1410.0681. Bibcode:2014ApJ...796...91B. doi:10.1088/0004-637X/796/2/91. S2CID 10097277.


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