Detalles de publicación
PP 020153
Optical spectral characterization of the the TeV extremeblazar 2WHSP J073326.7+515354
(1) Universidad de La Laguna (ULL), Dpto. de Astrofısica, Tenerife, Spain
(2) IAC Tenerife, Spain
The emission from the relativistic jets in blazars usually outshines their host galaxies, challenging the determination of their distances and the characterization of the stellar population. The situation becomes more favorable in the case of the extreme blazars (EHBLs), for which the bulk of the emission of the relativistic jets is emitted at higher energies, unveiling the optical emission from the host galaxy. The distance de-termination is fundamental for the study of the intrinsic characteristics of the blazars,especially to estimate the intrinsic gamma-ray spectra distorted due to the interaction with the Extragalactic Background Light. In this work we report on the properties of 2WHSP J073326.7+515354 host galaxy in the optical band, which is one of the few EHBLs detected at TeV energies. We present the first measurement of the dis-tance of the source,z=0.06504±0.00002(velocity dispersion σ=237±9 km s^¨{−1}). We also perform a detailed study of the stellar population of its host galaxy. We find that the mass-weighted mean stellar age is 11.72±0.06 Gyr and the mean metallicity [M/H]=0.159±0.016. In addition, a morphological study of the host galaxy is also carried out. The surface brightness distribution is modelled by a composition of a dominant classical bulge (Re=3.77±1′′or equivalently 4.74 kpc) plus an unresolved source which corresponds to the active nucleus. The black hole mass is estimated using both the mass relation with the velocity dispersion and the absolute magnitude from the bulge yielding comparable results:(4.8±0.9)×10^8 M and (3.7±1.0)×10^8 M_{Sun},respectively.

