Pisces Dwarf
| Pisces Dwarf | |
|---|---|
| Hubble Space Telescope image of the Pisces Dwarf | |
| Observation data (J2000 epoch) | |
| Constellation | Pisces |
| Right ascension | 01h 03m 55.0s[1] |
| Declination | +21° 53′ 06″[1] |
| Redshift | -287 ± 0 km/s [1] |
| Distance | 2.51 ± 0.08 Mly (769 ± 25 kpc)[2] |
| Apparent magnitude (V) | 14.2[1] |
| Characteristics | |
| Type | dIrr/dSph[1] |
| Apparent size (V) | 2′ ×ばつ 2′[1] |
| Other designations | |
| Pisces I, Psc I, LGS 3,[1] PGC 3792,[1] LEDA 3792 | |
The Pisces Dwarf, also known as Pisces I (Psc I) or LGS3,[1] is an irregular dwarf galaxy and suspected satellite galaxy of the Triangulum Galaxy (M33), located within the Pisces constellation.[2] [3] Discovered by astronomer Valentina Karachentseva in 1976,[3] it is approaching the Milky Way at 287 km/s, evident by its blueshift, and may be a galaxy currently transitioning between a dwarf spheroidal and dwarf irregular galaxy;[4] alternatively, it may be a rare unique version of one of the two types.[2]
Structure
[edit ]The Pisces Dwarf has a very irregular shape, and is composed primarily of moderately aged and young stars, as given by its metallicity of [Fe/H]=−2.10 ± 0.22.[2] Its star formation has declined, with its peak starburst period suspected to be an estimated 8 billion years ago,[5] and a significant lack of new star formation within the past 100 million years.[2] [6] It is suspected to be a potential transition galaxy, currently transitioning from a dwarf irregular to a dwarf spheroidal galaxy.[3] [6] [7]
Gallery
[edit ]-
Cropped Hubble image of part of Pisces I
References
[edit ]- ^ a b c d e f g h i "NASA/IPAC Extragalactic Database". Results for Pisces Dwarf. Retrieved 2007年03月15日.
- ^ a b c d e McConnachie, A. W.; Irwin, M. J.; Ferguson, A. M. N.; Ibata, R. A.; Lewis, G. F.; Tanvir, N. (2005). "Distances and metallicities for 17 Local Group galaxies". Monthly Notices of the Royal Astronomical Society . 356 (4): 979–997. arXiv:astro-ph/0410489 . Bibcode:2005MNRAS.356..979M. doi:10.1111/j.1365-2966.2004.08514.x .
- ^ a b c "Dwarf Galaxies in Pisces - NASA Science". 2016年08月11日. Retrieved 2026年04月21日.
- ^ Garofalo, Alessia; Tantalo, Maria; Cusano, Felice; Clementini, Gisella; Calura, Francesco; Muraveva, Tatiana; Paris, Diego; Speziali, Roberto (2021年07月01日). "Born in a Pair (?): Pisces II and Pegasus III*". The Astrophysical Journal. 916 (1): 10. arXiv:2105.11488 . Bibcode:2021ApJ...916...10G. doi:10.3847/1538-4357/ac0253 . ISSN 0004-637X.
- ^ Karachentseva, V. E. (1976). "Some characteristics of isolated pairs composed of a normal galaxy and DDO-dwarf". Soobshch. Spets. Astrofiz. Obs. 18 (18): 42–51. Bibcode:1976SoSAO..18...42K.
- ^ a b Miller, B. W., Dolphin, A. E., Lee, M. G., Kim, S. C., Hodge, P. (2001). "The Star Formation History of LGS3". The Astrophysical Journal. 562 (2): 713–726. arXiv:astro-ph/0108408 . Bibcode:2001ApJ...562..713M. doi:10.1086/323853. S2CID 119089499.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Hidalgo, Sebastian L.; Aparicio, Antonio; Skillman, Evan; Monelli, Matteo; Gallart, Carme; Cole, Andrew; Dolphin, Andrew; Weisz, Daniel; Bernard, Edouard J.; Cassisi, Santi; Mayer, Lucio; Stetson, Peter; Tolstoy, Eline; Ferguson, Henry (2011). "The Acs Lcid Project. V. The Star Formation History of the Dwarf Galaxy Lgs-3: Clues to Cosmic Reionization and Feedback". The Astrophysical Journal. 730 (1): 14. arXiv:1101.5762 . Bibcode:2011ApJ...730...14H. doi:10.1088/0004-637X/730/1/14. S2CID 118411768.
External links
[edit ]- Wikimedia Commons logo Media related to Pisces Dwarf at Wikimedia Commons
