TeV-peaked candidate BL Lac objects
arXiv:1911.05027 · doi:10.1093/mnras/stz3018
Abstract
BL Lac objects can be extreme in two ways: with their synchrotron emission, peaking beyond 1 keV in their spectral energy distribution, or with their gamma-ray emission, peaking at multi-TeV energies up to and beyond 10-20 TeV, like 1ES 0229+200. This second type of extreme BL Lacs --which we can name "TeV-peaked BL Lacs" is not well explained by the usual synchrotron self-Compton scenarios for BL Lacs. These sources are also important as probes for the intergalactic diffuse infrared background and cosmic magnetic fields, as well as possible sites of production of ultra-high-energy cosmic rays and neutrinos. However, all these studies are hindered by their still very limited number. Here I propose a new, simple criterium to select the best candidates for TeV observations, specifically aimed at this peculiar type of BL Lac objects by combining X-ray, gamma-ray and infrared data. It is based on the observation of a clustering towards a high X-ray to GeV gamma-ray flux ratio, and it does not rely on the radio flux or X-ray spectrum. This makes it suitable to find TeV-peaked sources also with very faint radio emission. Taking advantage of the Fermi all-sky gamma-ray survey applied to the ROMA-BZCAT and Sedentary Survey samples, I produce an initial list of 47 TeV-peaked candidates for observations with present and future air-Cherenkov telescopes.
9 pages, 2 figures, accepted for publication in MNRAS
References in corpus (14)
- eROSITA Science Book: Mapping the Structure of the Energetic Universe
- The 5th edition of the Roma-BZCAT. A short presentation
- New constraints on the Mid-IR EBL from the HESS discovery of VHE gamma rays from 1ES 0229+200
- The extragalactic background light revisited and the cosmic photon-photon opacity
- Formation of hard VHE gamma-ray spectra of blazars due to internal photon-photon absorption
- Discovery of VHE gamma-rays from the distant BL Lac 1ES 0347-121
- The Hard VHE Gamma-ray Emission in High-Redshift TeV Blazars: Comptonization of Cosmic Microwave Background Radiation in an Extended Jet?
- 2WHSP: A catalog of HE and VHE gamma-ray blazars and blazar candidates
- A new hard X-ray selected sample of extreme high-energy peaked BL Lac objects and their TeV gamma-ray properties
- 1WHSP: an IR-based sample of 1,000 VHE -ray blazar candidates
- An emerging population of BL Lacs with extreme properties: towards a class of EBL and cosmic magnetic field probes?
- A GeV-TeV Measurement of the Extragalactic Background Light
- Blazar halos as probe for extragalactic magnetic fields and maximal acceleration energy
- On the correct intrinsic VHE properties of the BL Lac H 2356-309