Speaker
Description
By using deep radio source catalogs currently available, we present a new blazar candidate catalog, BROS, which includes 56314 sources located at declination δ>−40∘ and outside the Galactic Plane (|b|>10). We picked up flat-spectrum radio sources of α>−0.5 (α is defined as Fν∝ν^α) from 0.15 GHz TGSS and 1.4 GHz NVSS catalogs. Then, we identified their optical counterparts by cross-matching with the Pan-STARRS1 data. Color-color and color-magnitude plots for the selected flat-spectrum radio sources clearly showed two populations, “quasar-like” and “elliptical-galaxy-like” sequences. We emphasize that the latter population emerged for the first time and is missed by previous CRATES catalog because of the higher radio flux threshold. This BROS catalog is useful to search for counterparts of Fermi extragalactic un-ID objects as well as PeV neutrions detected by IceCube. We also emphasize that this BROS catalog includes nearby (z≤0.3) BL Lac objects, a fraction of which would be TeV emitters and detectable by future Cherenkov Telescope Array. We will soon make this catalog available once published.
