| Markarian 501 | |
|---|---|
 Sloan Digital Sky Survey image of Mrk 501 | |
| Observation data (J2000 epoch) | |
| Constellation | Hercules |
| Right ascension | 16h 53m 52.21s[1] |
| Declination | 39° 45′ 37.6″[1] |
| Redshift | 9915±25 km/s or 0.033640 Z |
| Distance | 456 Mly (140 Mpc; 4.32x1024 m) |
| Group or cluster | zw1707.6+4045 |
| Characteristics | |
| Type | S0 [2] |
| Size | ~210,000 ly (64 kpc) (estimated)[3][2][a] |
| Apparent size (V) | 94.86" × 71.1" [2] |
| Notable features | brightest object in very-high-energy gamma rays |
| Other designations | |
| 4C39.49, PGC 59214, UGC 10599 | |
Markarian 501 (or Mrk 501) is a galaxy with a spectrum extending to the highest energy gamma rays.[4] It is a blazar or BL Lac object, which is an active galactic nucleus with a jet that is shooting towards the Earth. The object has a redshift of z = 0.034.[5]
Mrk 501 is an extremely variable source of gamma rays, undergoing violent outbursts.[5] During an outburst in 1997, it was the brightest object in the sky in the very-high-energy gamma ray region of the spectrum, at energies above 1011 eV (100 GeV).[6]
The galaxy hosting the blazar was studied and catalogued by Benjamin Markarian in 1974.[7] It was first determined to be a very high energy gamma ray emitter in 1996 by John Quinn at the Whipple Observatory.[5][8]
- ^ a b Ochsenbein, F.; Bauer, P.; Marcout, J. (10 April 2000). "The VizieR database of astronomical catalogues". Astronomy & Astrophysics Supplement Series. 143: 23–32. arXiv:astro-ph/0002122. Bibcode:2000A&AS..143...23O. doi:10.1051/aas:2000169. S2CID 17377096.
- ^ a b c "Results for Mrk 501". MARKARIAN2 – Markarian Galaxies Optical Database. Archived from the original on 2010-06-23. Retrieved 2011-12-06. Data base query page is at [1]. Fill in Mrk 501 for name and click start search at bottom of page.
- ^ "Parameter Display for single row in Markarian Galaxies Optical Database".
- ^ Aharonian, F. A. (1999). "The time averaged TeV energy spectrum of Mkn 501 of the extraordinary 1997 outburst as measured with the stereoscopic Cherenkov telescope system of HEGRA" (PDF). Astronomy and Astrophysics. 349: 11–28. arXiv:astro-ph/9903386. Bibcode:1999A&A...349...11A.
- ^ a b c Cite error: The named reference
accwas invoked but never defined (see the help page). - ^ Protheroe, Ray J.; C.L. Bhat; P. Fleury; E. Lorenz; M. Teshima; T.C. Weekes (12 October 1997). "Very high energy gamma rays from Markarian 501". arXiv:astro-ph/9710118.
- ^ Markaryan, B. E.; V. A. Lipovetskii (1974). "Galaxies with ultraviolet continuum V". Astrophysics. 8 (2): 89–99. Bibcode:1972Ap......8...89M. doi:10.1007/BF01002156. ISSN 0571-7256. S2CID 122248004.
- ^ Quinn J, Akerlof CW, Biller S, Buckley J, Carter-Lewis DA, Cawley MF, Catanese M, Connaughton V, et al. (10 January 1996). "Detection of Gamma Rays with E > 300 GeV from Markarian 501". The Astrophysical Journal Letters. 465 (2): L83–L86. Bibcode:1996ApJ...456L..83Q. doi:10.1086/309878.
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