GB 1508+5714 is an extremely distant blazar located in the constellation of Draco. It has a redshift of (z) 4.30 and is classified as a radio-loud quasar, first discovered in 1995 by astronomers. The radio spectrum of the source appears as flat, making it a flat-spectrum source but also a bright X-ray source.
Description GB 1508+5714 is variable on the electromagnetic spectrum. It is known to emit a powerful gamma-ray flare in February 2022, detected by the Fermi Gamma-ray Space Telescope, between the 0.1-300 GeV range but its flux is 25 times more brighter. In additional, GB 1508+5714 also displayed optical flares that was shown on both r and i bands when shown by light curves taken from Zwicky Transient Facility. Prolonged gamma activity was detected as well, showing variable flux on timescales.
Radio imaging by Low-Frequency Array (LOFAR) on arcsecond scales, shows the source of GB 1508+5714 is mainly made up of a compact radio core with a flat spectral index of 0.02 ± 0.01 and two emission regions located both west and east directions of the core. Very long baseline interferometry (VLBI), shows the source to be a core-jet structure instead with the core located northeast and a jet component located in southwest direction, with the southernmost faint feature being identified as a radio lobe.
An X-ray jet was discovered by Chandra X-ray Observatory in 2003 with flux and luminosity values measured as 9.2 × 10−15 erg cm−2 s−1 and 1.6 × 1045 erg s−1 respectively. Based on observations, the size of the jet is found to have a projected distance of 25 kiloparsecs with the X-ray emission peaking by 2 arcseconds as it reaches southwest from the core. This emission is possibly caused due to relativistic jet particles and cosmic microwave background photons interacting with each other.
References
External links GB 1508+5714 on SIMBAD GB 1508+5714 on NASA/IPAC Extragalactic Database GB 1508+5714 on HyperLeda