The extreme ultraviolet spectrum of the kinetically dominated quasar 3C 270.1

Abstract

Abstract Only a handful of quasars have been identified as kinetically dominated, their long-term time-averaged jet power, $\overline{Q}$, exceeds the bolometric thermal emission, Lbol, associated with the accretion flow. This Letter presents the first extreme ultraviolet (EUV) spectrum of a kinetically dominated quasar, 3C 270.1. The EUV continuum flux density of 3C 270.1 is very steep, $F_{\nu } \sim \nu ^{-\alpha _{{\rm EUV}}}$, αEUV = 2.98 ± 0.15. This value is consistent with the correlation of $\overline{Q}/L_{{\rm bol}}$ and αEUV found in previous studies of the EUV continuum of quasars, the EUV deficit of radio loud quasars. Curiously, although ultraviolet broad absorption line (BAL) troughs in quasar spectra are anticorrelated with $\overline{Q}$, 3C 270.1 has been considered a BAL quasar based on an SDSS spectrum. This claim is examined in terms of the EUV spectrum of O vi and the highest resolution C iv spectrum in the archival data and the SDSS spectrum. First, from [O iii]4959,5007 (IR) observations and the UV spectral lines, it is concluded that the correct redshift for 3C 270.1 is 1.5266. It is then found that the standard measure of broad absorption, BALnicity = 0, for Mg ii 2800, C iv 1549 and O vi 1032 in all epochs.