3C 66B

3C 66B is an elliptical radio galaxy^[6][9] located in the constellation Andromeda. With an estimated redshift of 0.021258,^[2] the galaxy is about 240.7 Mly (73.79 Mpc) away.^[3] It has an angular separation of 6′ from the blazar 3C 66A,^[9] but the two are most likely unrelated.^[10] 3C 66B is an outlying member of Abell 347, which is part of the Perseus–Pisces Supercluster.^[11]

3C 66B
Hubble Legacy Archive visible light image of 3C 66B
Observation data (J2000 epoch)
Constellation	Andromeda
Right ascension	02h 23m 11.4112s[1]
Declination	+42° 59′ 31.385″[1]
Redshift	0.021258[2]
Heliocentric radial velocity	6,367 km/s[2]
Distance	240.67 ± 0.82 Mly (73.79 ± 0.25 Mpc)[3]
Group or cluster	Abell 0347[2]
Apparent magnitude (V)	15.0[4]
Characteristics
Type	E[2]
Apparent size (V)	3.0′ × 3.0′[5]
Notable features	FRI RG,[6] gamma-ray source[7]
Other designations
3C 66, 4C 42.07, QSO B0220+427[8], MAGIC J0223+430, 2MASX J02231141+4259313, UGC 1841, LEDA 9067, PGC 9067[7]

Observations

This is a giant elliptical galaxy that is classified as a low-luminosity Fanaroff and Riley class 1 radio galaxy. Maps of the radio structure suggested that the emission is being shaped by the motion of the galaxy through an ambient medium.^[12] A strong jet and counter-jet extend about 330 thousand light-years (100 kpc) from the nucleus.^[13][14] These jets have been observed in radio,^[15] infrared,^[16] optical,^[12] ultraviolet,^[17] and X-ray bands.^[18] Gamma ray emission has been detected coming from the direction of this galaxy, which were most likely emitted from the core region.^[19]

Observations with the Hubble Space Telescope in 1990 showed that the jet has a filamentary, double-stranded structure.^[12][20] When viewed in the optical, the northern jet shows four knots along its length, all of which are polarized, thus indicating a synchrotron basis.^[21]

Very-long-baseline interferometry measurements of the galaxy's radio-emitting core demonstrated elliptical motion with a period of 1.05±0.03 years. This strongly suggested that a supermassive black hole binary (SMBHB) was located at the center of 3C 66B.^[22] This motion was expected to emit gravitational waves that would cause fluctuations in the pulse arrival times from the pulsar PSR B1855+09. However, no such signature was found.^[23] Numerical simulations indicated this detection method may only be valid for an orbital eccentricity below 0.03.^[24]

Messier 87 (M87), about 55 million light-years away, is the largest giant elliptical galaxy near the Earth, and also contains an active galactic nucleus. The smooth jet of 3C 66B rivals that of M87.^[25]

Gallery

• 
  Hubble Near-UV image of the jet coming out of 3C 66B
• 
  NRAO VLA image of 3C 66B