3C_66A Knowpia

3C 66A
3C 66A
	Hubble Legacy Archive WFPC2 image of 3C 66A; (brightest object on the far right)
Observation data (Epoch J2000)
Constellation	Andromeda
Right ascension	02h 22m 39.612s
Declination	+43° 02′ 07.80″
Redshift	0.444
Distance	4.5 billion light-years; (Light travel time); 5.4 billion light-years; (present)
Type	BLLAC
Apparent magnitude (V)	15.5
Other designations
	2E 558, 2EG J0220+4228, B3 0219+428A, QSO B0219+4248
	See also: Quasar, List of quasars

3C 66A is a blazar^[1]^[2] located in the constellation Andromeda.

The "distance" of a far away galaxy depends on the distance measurement used. With a redshift of 0.444,^[1]^[2] light from this active galaxy is estimated to have taken around 4.5 billion years to reach Earth.^[2] But as a result of the expansion of the Universe, the present (co-moving) distance to this galaxy is about 5.4 billion light-years (1647 Mpc).^[2] Even at this great distance this blazar has an apparent magnitude of about 15.5.^[1] Although 0.444 is used as the common redshift value, 0.3347 is a new strict lower limit "inferred through observing the far-UV absorption by the low-z IGM."^[3]

3C 66A underwent an optical outburst in 2007 August, as monitored by the Tuorla blazar monitoring program.^[4] The event was monitored by the Whole Earth Blazar Telescope project.

References edit

^ ^a ^b ^c ^d ^e ^f ^g ^h "3C 66A". SIMBAD Astronomical Database. Retrieved 2010-04-01.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ "NASA/IPAC Extragalactic Database". Results for 3C 066A. Retrieved 2010-04-01.
^ Furniss, Amy (May 10, 2013). "THE FIRM REDSHIFT LOWER LIMIT OF THE MOST DISTANT TeV-DETECTED BLAZAR PKS 1424+240". Astrophysical Journal Letters. 768 (2): L31. arXiv:1304.4859. Bibcode:2013ApJ...768L..31F. doi:10.1088/2041-8205/768/2/L31. S2CID 21291053.
^ Errando, Manel; Lindfors, Elina; Mazin, Daniel; Prandini, Elisa; Tavecchio, Fabrizio (2009). "A TeV source in the 3C 66A/B region". arXiv:0907.0994 [astro-ph.HE].