OI 287
Quasar in the constellation Gemini
From Wikipedia, the free encyclopedia
OI 287 is a quasar[2] located in the constellation of Gemini. The redshift of the object is (z) 0.444[1] and it was first discovered as a highly polarized object by astronomers in January 1981,[3] but it also has been classified as a blazar in a 1982 study.[4]
| OI 287 | |
|---|---|
SDSS image of OI 287 | |
| Observation data (J2000.0 epoch) | |
| Constellation | Gemini |
| Right ascension | 07h 55m 37.03s[1] |
| Declination | +25° 42′ 39.02″[1] |
| Redshift | 0.444241[1] |
| Heliocentric radial velocity | 133,180 km/s ± 12[1] |
| Distance | 4.779 Gly |
| Apparent magnitude (V) | 18.04 |
| Apparent magnitude (B) | 18.50 |
| Characteristics | |
| Type | BLLAC[1] |
| Size | ~240,000 ly (73.7 kpc) (estimated)[1] |
| Other designations | |
| B2 0752+25A, NVSS J075537+254236, SDSS J075537.02+254238.9, THING 587732156852142361, 2MASS J07553702+2542389[1] LEDA 3506791 | |
Description
The source of OI 287 has a double-lobed structure based on Very Large Array (VLA) observations made in 1984, however at that time it was unresolved.[5] Radio maps made at 20 and 6 centimeters (cm), would reveal the source has a twin-jet structure, depicted as oscillating. The radio spectrum of the source also has a steep appearance between frequencies of 0.36 and 5 GHz. There is a radio core present with an inverted spectrum between 1.4 and 5 GHz but no variability of its flux density.[4] The core is lowly polarized with polarization levels of only 0.25%.[6]
The host galaxy of OI 287 has a circular appearance with an M-R apparent magnitude of -23.0 based on optical imaging.[7] However a study published in 1998, suggested it has a disk morphology when observed through near-infrared imaging, displaying the presence of radio emission. The host is also described as slightly elongated towards its companion located 4.9 kiloparsecs away from it.[8]
The optical spectrum of OI 287 shows the presence of rich emission lines featuring both narrow and broad Balmer components, as well as detections of doubly ionized oxygen [O III] emission. The optical continuum of the spectrum is found to be increasing sharply towards the near-infrared, but gets flatter at around 10 microns.[9] A broad-line region was located inside the quasar, described as having an obscured appearance, with its accretion disk also likely obscured as well. The mass range of the torus is 105–107 M☉ and the total thickness of the narrow-line region is approximately 2 × 10−8 parsecs. The supermassive black hole located in the center of OI 287 has an estimated mass of 1.46+1.89−0.82 × 109 M☉.[10]