Leo II (dwarf galaxy)

Leo II
Leo II
Observation data (J2000 epoch)
Constellation	Leo
Right ascension	11h 13m 29.2s
Declination	+22° 09′ 17″
Redshift	0.000264 (79 ± 1 km/s)
Distance	690 ± 70 kly (210 ± 20 kpc)
Apparent magnitude (V)	12.6
Characteristics
Type	E0 pec
Apparent size (V)	12.0 x 11.0 arcmin
Other designations
	PGC 34176, DDO 93

Leo II (or Leo B) is a dwarf spheroidal galaxy about 690,000 light-years away in the constellation Leo. It is one of 24 known satellite galaxies of the Milky Way.^[4] Leo II is thought to have a core radius of 178 ± 13 pc and a tidal radius of 632 ± 32 pc.^[5] It was discovered in 1950 by Robert George Harrington and Albert George Wilson, from the Mount Wilson and Palomar Observatories in California.

Recent Findings

In 2007 a team of 15 scientists observed Leo II through the 8.2 meter Subaru optical-infrared telescope in Mauna Kea, Hawaii. Over 2 nights, 90 minutes of exposures were taken and 82,252 stars were detected down to a visible magnitude of 26. They found that Leo II consists largely of metal-poor older stars, a sign that it has survived the galactic cannibalism under which massive galaxies (e.g., the Milky Way) consume smaller galaxies to attain their extensive size.^[6]

Observation at ESO estimates Leo II's mass to be (2.7 ± 0.5)×10⁷ M_⊙.^[7]

References

^ ^a ^b ^c ^d ^e ^f "NASA/IPAC Extragalactic Database". Results for Leo B. Retrieved 2006-11-18.
^ I. D. Karachentsev; V. E. Karachentseva; W. K. Hutchmeier; D. I. Makarov (2004). "A Catalog of Neighboring Galaxies". Astronomical Journal. 127 (4): 2031–2068. Bibcode:2004AJ....127.2031K. doi:10.1086/382905.
^ Karachentsev, I. D.; Kashibadze, O. G. (2006). "Masses of the local group and of the M81 group estimated from distortions in the local velocity field". Astrophysics. 49 (1): 3–18. Bibcode:2006Ap.....49....3K. doi:10.1007/s10511-006-0002-6. S2CID 120973010.arXiv:0708.1853
^ Tollerud, E.; et al. (Nov 2008). "Hundreds of Milky Way Satellites? Luminosity Bias in the Satellite Luminosity Function". Astrophysical Journal. 688 (1): 277–289. arXiv:0806.4381. Bibcode:2008ApJ...688..277T. doi:10.1086/592102. S2CID 15468628.
^ Coleman, M.; et al. (Nov 2007). "A Wide-Field View of Leo II: A Structural Analysis Using the Sloan Digital Sky Survey". Astronomical Journal. 134 (5): 1938–1951. arXiv:0708.1853. Bibcode:2007AJ....134.1938C. doi:10.1086/522229. S2CID 14819170.
^ "Leo II: An Old Dwarf Galaxy with Juvenescent Heart". National Astronomical Observatory of Japan. 28 Nov 2007. Retrieved 25 Nov 2008.
^ Andreas Koch; et al. (August 2007). "Stellar Kinematics in the Remote Leo II Dwarf Spheroidal Galaxy—Another Brick in the Wall". Astronomical Journal. 134 (2): 566–578. arXiv:0704.3437. Bibcode:2007AJ....134..566K. doi:10.1086/519380. S2CID 15079314.

Harrington R. G.; Wilson A. G. (1950). "Two New Stellar Systems in Leo". Publications of the Astronomical Society of the Pacific. 62 (365): 118–120. Bibcode:1950PASP...62..118H. doi:10.1086/126249.

External links

Media related to Leo II (dwarf galaxy) at Wikimedia Commons

This elliptical galaxy article is a stub. You can help Wikipedia by expanding it.

Zdroj:https://en.wikipedia.org?pojem=Leo_II_(dwarf_galaxy)
Text je dostupný za podmienok Creative Commons Attribution/Share-Alike License 3.0 Unported; prípadne za ďalších podmienok. Podrobnejšie informácie nájdete na stránke Podmienky použitia.

[ned-1] ^ ^a ^b ^c ^d ^e ^f "NASA/IPAC Extragalactic Database". Results for Leo B. Retrieved 2006-11-18.

[kara04-2] I. D. Karachentsev; V. E. Karachentseva; W. K. Hutchmeier; D. I. Makarov (2004). "A Catalog of Neighboring Galaxies". Astronomical Journal. 127 (4): 2031–2068. Bibcode:2004AJ....127.2031K. doi:10.1086/382905.

[kara06-3] Karachentsev, I. D.; Kashibadze, O. G. (2006). "Masses of the local group and of the M81 group estimated from distortions in the local velocity field". Astrophysics. 49 (1): 3–18. Bibcode:2006Ap.....49....3K. doi:10.1007/s10511-006-0002-6. S2CID 120973010.arXiv:0708.1853

[toll08-4] Tollerud, E.; et al. (Nov 2008). "Hundreds of Milky Way Satellites? Luminosity Bias in the Satellite Luminosity Function". Astrophysical Journal. 688 (1): 277–289. arXiv:0806.4381. Bibcode:2008ApJ...688..277T. doi:10.1086/592102. S2CID 15468628.

[5] Coleman, M.; et al. (Nov 2007). "A Wide-Field View of Leo II: A Structural Analysis Using the Sloan Digital Sky Survey". Astronomical Journal. 134 (5): 1938–1951. arXiv:0708.1853. Bibcode:2007AJ....134.1938C. doi:10.1086/522229. S2CID 14819170.

[pr07nov28-6] "Leo II: An Old Dwarf Galaxy with Juvenescent Heart". National Astronomical Observatory of Japan. 28 Nov 2007. Retrieved 25 Nov 2008.

[brick-7] Andreas Koch; et al. (August 2007). "Stellar Kinematics in the Remote Leo II Dwarf Spheroidal Galaxy—Another Brick in the Wall". Astronomical Journal. 134 (2): 566–578. arXiv:0704.3437. Bibcode:2007AJ....134..566K. doi:10.1086/519380. S2CID 15079314.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

Recent Findings

See also

References

External links