Volume 371 - 7th Annual Conference on High Energy Astrophysics in Southern Africa (HEASA2019) - AGN I (Chair: Garret Cotter)
Search for high-redshift blazars with Fermi/LAT
M. Kreter,* A. Gokus, M. Kadler, F. Krauss, S. Buson, R. Ojha on behalf of the Fermi-LAT Collaboration, J. Wilms, M. Böttcher
*corresponding author
Full text: pdf
Pre-published on: December 21, 2020
Published on:
Abstract
High-redshift blazars ($z\geq2.5$) are the most powerful class of persistent $\gamma$-ray sources in the Universe. These objects possess the highest jet powers and luminosities and have black hole masses often in excess of $10^9$ solar masses. In addition, high-$z$ blazars are important cosmological probes and serve as test objects for blazar evolution models. Due to their large distance, their high-energy emission is typically scattered to energies below the GeV range, which makes them difficult to study with Fermi/LAT and only the very brightest objects are detectable. Hence, only a small number of high-$z$ blazars could be detected with Fermi/LAT so far. In this work, we present a strategy to increase the detection statistics at redshift $z\geq2.5$ via a search for flaring events in high-$z$ $\gamma$-ray blazars whose long-term averaged flux is just below the sensitivity limit of Fermi/LAT. Seven previously GeV undetected high-$z$ blazars have been identified with a test statistic of TS $\geq\,25$ from their bright monthly outburst periods, while more detections are expected in the future.
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access