| Epoch | J2000 |
|---|---|
| Ra | [1][2] |
| Dec | [2] |
| Constellation name | Boötes |
| Z | 0.461687 ± 0.000049[3] |
| H radial v | 138,410 ± 15 km/s[3] |
| Gal v | 138,528 ± 15 km/s[3] |
| Dist ly | 2,047.1 ± 143.3 Mpc (Comoving)[3] 4.910 Gly (Light-travel)[3] |
| Appmag v | 20.80[4][2] |
| Appmag b | 22.34[4][2] |
| Mag j | 15.193 ± 0.196[5][2] |
| Mag h | 14.811 ± 0.223[5][2] |
| Mag k | 13.637 ± 0.183[5][2] |
| Size | 113.93 by 95.70 kpc (371,590 by 312,130 ly) (diameter; 25.0 B-mag arcsec−2)[3][a] 226.28 by 226.28 kpc (738,030 by 738,030 ly) (diameter; "total" magnitude)[3][a] |
| Size v | 0.157 arcminute[5] |
3C 295 is a narrow-line radio galaxy located in the constellation of Boötes. With a redshift of approximately 0.46,[3] it is approximately 2.05 Gpc from Earth.[3] At time of the discovery of its redshift in 1960, this was the most remote object known.[8]
History
The number in its name corresponds with it being the 295th object in the Third Cambridge Catalogue of Radio Sources (which are ordered by right ascension). This is also where the prefix 3C came from.
The radio galaxy itself is a fairly normal small radio galaxy although unusually its hotspots are readily detected in optical and X-ray emission.[9] The X-ray emission from the source is dominated by thermal emission from a rich cluster of galaxies. In optical images about 100 galaxies can be seen. 3C 295's cluster has enough material to create another 1,000 galaxies or more, making it one of the most massive objects in the known Universe. However, X-ray data showed that there is not enough mass to hold 3C 295 together gravitationally, which suggests the presence of dark matter.[10]
Notes
- ^ The quoted diameter in this infobox was based on NED's provided scale "Virgo + GA + Shapley" of 9.925 kpc/arcsec multiplied with given angular diameters.
References
- ^ Laurent-Muehleisen, S. A.; Kollgaard, R. I.; Ryan, P. J.; Feigelson, E. D.; Brinkmann, W.; Siebert, J. (1997). "Radio-loud active galaxies in the northern ROSAT All-Sky Survey. I. Radio identifications". Astronomy and Astrophysics Supplement Series. 122 (2): 235. arXiv:astro-ph/9607058. Bibcode:1997A&AS..122..235L. doi:10.1051/aas:1997331
- ^ "3C 295"
- ^
- ^ Véron-Cetty, M. -P. & Véron, P. (2010). "A catalogue of quasars and active nuclei: 13th edition". Astronomy and Astrophysics. 518: A10. Bibcode:2010A&A...518A..10V. doi:10.1051/0004-6361/201014188
- ^ Skrutskie, M. F. et al. (2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163. Bibcode:2006AJ....131.1163S. doi:10.1086/498708
- ^ Van Dokkum, Pieter G. & Van Der Marel, Roeland P. (2007). "The Star Formation Epoch of the Most Massive Early-Type Galaxies". The Astrophysical Journal. 655 (1): 30. arXiv:astro-ph/0609587. Bibcode:2007ApJ...655...30V. doi:10.1086/509633
- ^ "3C 295". XJET: X-Ray Emission from Extragalactic Radio Jets. 2004-07-16. Retrieved 2010-04-06.
- ^ Table 1 in Daniel Stern & Hyron Spinrad (1999). "Search Techniques for Distant Galaxies". Publications of the Astronomical Society of the Pacific. 111 (766): 1475–1502. arXiv:astro-ph/9912082. Bibcode:1999PASP..111.1475S. doi:10.1086/316471. S2CID 17540092
- ^ Hardcastle, M. J (2001). "An optical inverse-Compton hotspot in 3C 196?". Astronomy & Astrophysics. 373 (3): 881–885. arXiv:astro-ph/0105228. Bibcode:2001A&A...373..881H. doi:10.1051/0004-6361:20010687. S2CID 384935
- ^ "3C 295: X-rays From A Giant Galaxy". 25 November 1999. Retrieved 2007-04-20.
External links
- www.jb.man.ac.uk/atlas/ (J. P. Leahy)