Pisces Dwarf Explained
| Pisces Dwarf |
| Epoch: | J2000 |
| Type: | dIrr/dSph[1] |
| Dist Ly: | 2.51 ± 0.08 Mly (769 ± 25 kpc) |
| Z: | -287 ± 0 km/s |
| Appmag V: | 14.2 |
| Size V: | 2′ × 2′ |
| Constellation Name: | Pisces |
| Names: | Pisces I, Psc I, LGS 3, PGC 3792, LEDA 3792 |
The Pisces Dwarf, also known as Pisces I, is an irregular dwarf galaxy that is part of the Local Group. The galaxy, taking its name from the constellation Pisces where it appears, is suspected of being a satellite galaxy of the Triangulum Galaxy (M33). It displays a blueshift, as it is approaching the Milky Way at 287 km/s. It may be transition-type galaxy, somewhere between dwarf spheroidal and dwarf irregular. Alternatively, it may be a rare, but statistically acceptable, version of one of the two types.[2]
History
It was discovered by Valentina Karachentseva in 1976.[3] [4]
Star formation history
Apparently, the star formation rate in the Pisces Dwarf has been declining for the past 10 billion years. Most of the galaxy's stars were formed in its early years, about 8 billion years ago. The study has also shown that there has been no significant star formation for the past 100 million years. Hence, most of the stars that populate this galaxy are old, metal-rich stars aged about 2.5 billion years. However, there are small clusters of young, hot, blue stars on the outer areas of the galaxy.[5]
Notes and References
- Web site: NASA/IPAC Extragalactic Database . Results for Pisces Dwarf . 2007-03-15 .
- McConnachie, A. W. . Irwin, M. J. . Ferguson, A. M. N. . Ibata, R. A. . Lewis, G. F. . Tanvir, N. . Distances and metallicities for 17 Local Group galaxies . . 2005 . 356 . 4 . 979–997 . 2005MNRAS.356..979M . 10.1111/j.1365-2966.2004.08514.x . free . astro-ph/0410489 .
- Karachentseva, V. E. . Some characteristics of isolated pairs composed of a normal galaxy and DDO-dwarf . Soobshch. Spets. Astrofiz. Obs. . 18 . 1976 . 18 . 42–51 . 1976SoSAO..18...42K .
- 10.1088/0004-637X/730/1/14. 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. 2011. 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. 1101.5762 . 2011ApJ...730...14H . 118411768.
- Miller, B. W., Dolphin, A. E., Lee, M. G., Kim, S. C., Hodge, P. . The Star Formation History of LGS3 . The Astrophysical Journal . 562 . 2 . 713–726 . 10.1086/323853 . astro-ph/0108408 . 2001ApJ...562..713M . 2001 . 119089499 .
