Abstract
Abstract We present optical spectra with high signal-to-noise ratio of 10 BL Lac objects detected at GeV energies by the Fermi satellite (3FGL catalog), which previous observations suggested are at relatively high redshift. The new observations, obtained at the 10 m Gran Telescopio Canarias, allowed us to find the redshift for J0814.5+2943 (z = 0.703), and we can set a spectroscopic lower limit for J0008.0+4713 (z > 1.659) and J1107.7+0222 (z > 1.0735) on the basis of Mg ii intervening absorption features. In addition we confirm the redshifts for J0505.5+0416 (z = 0.423) and J1450+5200 (z > 2.470). Finally we contradict the previous z estimates for five objects (J0049.7+0237, J0243.5+7119, J0802.0+1005, J1109.4+2411, and J2116.1+3339).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
