PKS 1424-418
| PKS 1424-418 | |
|---|---|
The blazar PKS 1424-418 | |
| Observation data (J2000.0 epoch) | |
| Constellation | Centaurus |
| Right ascension | 14h 27m 56.297s |
| Declination | −42° 06′ 19.438″ |
| Redshift | 1.522000 |
| Heliocentric radial velocity | 456,824 km/s |
| Distance | 9.439 Gly |
| Apparent magnitude (V) | 17.7 |
| Apparent magnitude (B) | 18.48 |
| Characteristics | |
| Type | Blazar; HPQ, FRSQ |
| Other designations | |
| LEDA 2827996, PMN J1427-4206, 4FGL J1427.9-4206, WMAP 191, G4Jy 1168 | |
PKS 1424-418 is a blazar located in the constellation of Centaurus. It has a redshift of 1.522 and was first discovered in 1971 by astronomer Keith Peter Tritton who identified the object as ultraviolet-excessive. This object is also highly polarized with a compact radio source. The radio spectrum of this source appears flat, making it a flat-spectrum radio quasar.
PKS 1424-418 is found optically variable on the electromagnetic spectrum. It is a strong source of gamma rays. Between 2008 and 2011, PKS 1424-418 showed four phases of bright flares at GeV energies. The flares have a high correlation between the energy ranges with the exception of one flare that occurred at the same time it showed low gamma activity. In April 2013, it underwent a major gamma ray outburst with its peak flux reaching values of F(> 100 MeV) > 3 x 10−6 ph cm−2 s−1. According to Large Area Telescope observations, this emission originated beyond its broad-line region. A near-infrared flare was witnessed in PKS 1424–418 in January 2018. In August 2022, it once again displayed an episode of rapid flaring activity in both gamma ray and optical bands.
PKS 1424-418 contains a radio structure, comprising a strong radio core and a weaker component with a position angle of 260°. Further observations also showed the core has a size of 0.4 mas with extended emission at both the core's position and northwest. In addition, the core has a flat spectral index of -0.04. A jet is seen extending west from the core before becoming diffused.
Between May 2009 and September 2019, the gamma ray emission from PKS 1424-418 was found to undergo a quasi-periodic oscillation with a 353-day flux oscillation period. A 355-day period with high significance level is also confirmed by adopting time domain methods. This might be explained by orbital motion of a binary supermassive black hole system with the mass of a primary black hole being M ~ 3.5 x 108 - 5.5 x 109 Mʘ.