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

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

La Haya

Conferencia; 34th International Cosmic Ray Conference; 2015

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 bymodeling 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