PKS 0420-014
| PKS 0420-014 | |
|---|---|
 The blazar PKS 0420-014. | |
| Observation data (J2000.0 epoch) | |
| Constellation | Eridanus |
| Right ascension | 04h 23m 15.800s |
| Declination | −01° 20′ 33.066″ |
| Redshift | 0.916090 |
| Heliocentric radial velocity | 264,637 km/s |
| Distance | 7.437 Gly |
| Apparent magnitude (V) | 17.0 |
| Apparent magnitude (B) | 17.5 |
| Characteristics | |
| Type | Blazar, BL Lac, HPQ |
| Other designations | |
| FASTT 159, LEDA 75147, 4FGL J0423.3-0120, OA 129, IRAS 04207-0127, QSO B0420-014, INTREF 181, PKS 0420-01 | |
PKS 0420-014 is a blazar[1] located in the constellation of Eridanus. This is a high polarized quasar[2][3] with a redshift of (z) 0.915,[4] first discovered as an astronomical radio source by astronomers in 1975.[5] The radio spectrum of this source appears to be flat, making it a flat-spectrum radio quasar (FRSQ).[6][7]
Description
[edit]PKS 0420-014 is found to be violently variable on the electromagnetic spectrum from long-centimeter to short-millimeter wavelengths.[8] It is a source of gamma ray activity,[9][8][10] showing a high flux at (E>100 MeV) of (0.8 ± -0.2) 10-6 photons cm s-2 at the time of its high state, upon being observed by Large Area Telescope in January 2010.[11]
Additionally, optical flares were observed in PKS 0420-014 apart from gamma ray activity. In 1979 it showed a flare displays an increasing magnitude of 1.3 in 5 days, which was followed by a decreasing magnitude of 1.7 in 23 days. Its flare recorded between February and March 1992, was the highest observed optical state observed during the period EGRET recorded the highest gamma ray flux density.[12] Subsequent flares were detected in July 2012[13] and in October 2020, where it reached 15.25 magnitudes on both days after in a state of quiescent.[2]
The source of PKS 0420-014 at mas resolutions shows a symmetrical and unresolved core. This is interpreted as the case of either the jet being aligned near the line of sight or a "naked" core. At lambda observations at 7 millimeters, the source is resolved into a core and a bent jet[14] while at kiloparsec scales, it shows a structure extending directly south out by 25" with a weak secondary component located northeast of the core.[15]
The jet of PKS 0420-014 is strongly dominated by a radio core in parsec-scales, indicating the presence of a multicomponent substructure in its core. There are two moving components in the jet's innermost part, which one of them located near the core, exhibits a slower motion and is accelerating beyond 0.2 mas as soon its trajectory switches from -100° to -175°. A bright outer component located from the core, is also shown to move ballistically along -72° at a similar speed to the inner component.[16] There are also five other jet components displaying superluminal motion at βapp ~ 2-14c, with all of them following a common curved path within the jet.[8]
It is suggested that the source for the flux density variations in PKS 0420-014 is the presence of a binary supermassive black hole system with masses about 7 x 107 Mʘ and 2.1 x 108 Mʘ which they have a rotation period of 150 years.[17] This gravitational influence of this binary system likely results the precession of its accretion disk as well as both motion of the ejection of plasma from the black hole. As accretion disk is percessed, the magnetic field lines and relativistic beaming are both perturbated.[8]
References
[edit]- ^ D'Ammando, F. (2021-09-01). "Swift follow-up observations of the blazar PKS 0420-014". The Astronomer's Telegram. 14889: 1. Bibcode:2021ATel14889....1D.
- ^ a b "Optical Flare of the Quasar 0420-014". The Astronomer's Telegram. Retrieved 2024-11-08.
- ^ Torniainen, I.; Tornikoski, M.; Teräsranta, H.; Aller, M. F.; Aller, H. D. (2005-05-13). "Long term variability of gigahertz-peaked spectrum sources and candidates" (PDF). Astronomy & Astrophysics. 435 (3): 839–856. doi:10.1051/0004-6361:20041886. ISSN 0004-6361.
- ^ Zhou, J. F.; Hong, X. Y.; Jiang, D. R.; Venturi, T. (2000-09-20). "Two Classes of Radio Flares in the Blazar PKS 0420−014". The Astrophysical Journal. 541 (1): L13–L16. doi:10.1086/312889. ISSN 0004-637X.
- ^ McGimsey, B. Q.; Smith, A. G.; Scott, R. L.; Leacock, R. J.; Edwards, P. L.; Hackney, R. L.; Hackney, K. R. (November 1975). "Optical behavior of 20 violently variable extragalactic radio sources". The Astronomical Journal. 80: 895. doi:10.1086/111825. ISSN 0004-6256.
- ^ Elsaesser, D.; Jorstad, S. G.; Scherbantin, C. Pauley A.; Kunkel, L.; Schneider, L.; Kadler, M.; Eppel, F.; Roesch, F.; Heidemann, K. Mannheim M.; Domann, O.; Kimmel, L.; Goldbach, R.; Wehr, F.; Scheuermayer, D.; Seufert, J. (2023-03-01). "Brightening of the quasar PKS 0420-014 across the electromagnetic spectrum". The Astronomer's Telegram. 15935: 1. Bibcode:2023ATel15935....1E.
- ^ Rani, Bindu; Gupta, Alok C.; Joshi, U. C.; Ganesh, S.; Wiita, Paul J. (2011-03-10). "Optical intraday variability studies of 10 low energy peaked blazars". Monthly Notices of the Royal Astronomical Society. 413 (3): 2157–2172. doi:10.1111/j.1365-2966.2011.18288.x. ISSN 0035-8711.
- ^ a b c d Britzen, S.; Witzel, A.; Krichbaum, T.P.; Campbell, R.M; Wagner, S.J.; Qian, S.J. (2000). "Three-year VLBI monitoring of PKS 0420-014". Astronomy & Astrophysics. 360: 65–75. Bibcode:2000A&A...360...65B.
- ^ Radecke, H. -D.; Bertsch, D. L.; Dingus, B. L.; Fichtel, C. E.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Lin, Y. C.; Mattox, J. R.; Mayer-Hasselwander, H. A.; Michelson, P. F.; von Montigny, C.; Nolan, P. L.; Schneid, E. (1995-01-01). "EGRET Detection of the Blazar PKS 0420-014". The Astrophysical Journal. 438: 659. Bibcode:1995ApJ...438..659R. doi:10.1086/175109. ISSN 0004-637X.
- ^ Wagner, S. J.; Camenzind, M.; Dreissigacker, O.; Borgeest, U.; Britzen, S.; Brinkmann, W.; Hopp, U.; Schramm, K. -J.; von Linde, J. (1995-06-01). "Simultaneous optical and gamma-ray flaring in PKS 0420-014. Implications for emission processes and rotating jet models". Astronomy and Astrophysics. 298: 688. Bibcode:1995A&A...298..688W. ISSN 0004-6361.
- ^ "Fermi LAT detection of increased gamma-ray activity of two blazars PKS 0420-01 and BL Lacertae". The Astronomer's Telegram. Retrieved 2024-11-08.
- ^ Xie, G. Z.; Li, K. H.; Bai, J. M.; Dai, B. Z.; Liu, W. W.; Zhang, X.; Xing, S. Y. (2001-02-10). "Search for Short Variability Timescale of the GeV Gamma-Ray–Loud Blazars". The Astrophysical Journal. 548 (1): 200–212. doi:10.1086/318670. ISSN 0004-637X.
- ^ "Optical flaring in PKS 0420-014". The Astronomer's Telegram. Retrieved 2024-11-08.
- ^ Rantakyrö, F. T.; Backer, D. C.; Booth, R. S.; Carlstrom, J. E.; Emerson, D. T.; Grewing, M.; Hirabayashi, H.; Hodges, M. W.; Inoue, M.; Kobayashi, H.; Krichbaum, T. P.; Kus, A. J.; Moran, J. M.; Morimoto, M.; Padin, S. (1998-09-01). "50 μas resolution VLBI images of AGN's at λ3 mm" (PDF). Astronomy and Astrophysics Supplement Series. 131 (3): 451–467. doi:10.1051/aas:1998282. ISSN 0365-0138.
- ^ Jorstad, Svetlana G.; Marscher, Alan P.; Mattox, John R.; Wehrle, Ann E.; Bloom, Steven D.; Yurchenko, Alexei V. (June 2001). "Multiepoch Very Long Baseline Array Observations of EGRET-detected Quasars and BL Lacertae Objects: Superluminal Motion of Gamma-Ray Bright Blazars". The Astrophysical Journal Supplement Series. 134 (2): 181–240. doi:10.1086/320858. ISSN 0067-0049.
- ^ Jorstad, Svetlana G.; Marscher, Alan P.; Lister, Matthew L.; Stirling, Alastair M.; Cawthorne, Timothy V.; Gear, Walter K.; Gómez, José L.; Stevens, Jason A.; Smith, Paul S.; Forster, James R.; Robson, E. Ian (October 2005). "Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Jet Kinematics from Bimonthly Monitoring with the Very Long Baseline Array". The Astronomical Journal. 130 (4): 1418–1465. doi:10.1086/444593. ISSN 0004-6256.
- ^ Britzen, S.; Roland, J.; Laskar, J.; Kokkotas, K.; Campbell, R. M.; Witzel, A. (August 2001). "On the origin of compact radio sources - The binary black hole model applied to the gamma-bright quasar PKS 0420–014" (PDF). Astronomy & Astrophysics. 374 (3): 784–799. doi:10.1051/0004-6361:20010685. ISSN 0004-6361.
