Redshift measurement of the BL-Lac gamma-ray blazar PKS 1424+240

ROVERO, A.; DONZELLI, C.J.; PICHEL, A.; MURIEL, H.

The Hague

Conferencia; The 34th International Cosmic Ray Conference; 2015

University of Groningen

PKS 1424+240 is a BL-Lac blazar with unknown redshift detected at high-energy gamma rays by Fermi-LAT with a hard spectrum. It was first detected at very-high-energy by VERITAS and latter confirmed by MAGIC. Attempts to find limits on its redshift include three estimations by modeling gamma-ray observations, and one obtained by analyzing Lyb and Lyg absorption lines observed in the far-UV spectra (from HST/COS) caused by absorbing gas along the line of sight. They allowed to constrain the redshift range to 0:6