Exploiting the IRT-THESEUS capability to observe lensed Quasars

Abstract

THESEUS is an ESA space based project, aiming to explore the early universe by unveiling a complete census of Gamma-Ray Burst (GRB) population in the first billion years. This goal is expected to be achieved by combined observations of its three instruments: the Soft X-ray Imager (SXI), the X and Gamma Imaging Spectrometer (XGIS) and the InfraRed Telescope (IRT). In particular, the IRT instrument will help to identify, localise and study the afterglow of the GRBs detected by SXI and XGIS, and about $40\%$ of its time will be devoted to an all-sky photometric survey, which will certainly detect a relevant number of extragalactic sources, including Quasars. In this paper, we focus on the capability of IRT-THESEUS Telescope to observe Quasars and, in particular, those objects lensed by foreground galaxies. In our analysis, we consider the Quasar Luminosity Function (QLF) in the infrared band based obtained by the Spitzer Space Telescope imaging survey. Furthermore, by using the mass-luminosity distribution function of galaxies and the galaxy/Quasar redshift distributions, we preformed Monte Carlo simulations to estimate the number of lensed Quasars. We predict that up to $2.14\times 10^5$ Quasars can be observed during gthe IRT-Theseus sky survey, and about $140$ of them could be lensed by foreground galaxies. Detailed studies of these events would provide a powerful probe of the physical properties of Quasars and the mass distribution models of the galaxies.

arXiv comment6 pages, 3 Figures, 2021, Accepted for publication on "Galaxies". Special issue (ISSN 2075-4434). Comments are welcome

References in corpus (10)

• An Observational Determination of the Bolometric Quasar Luminosity Function
• eROSITA Science Book: Mapping the Structure of the Energetic Universe
• Candidate Electromagnetic Counterpart to the Binary Black Hole Merger Gravitational Wave Event S190521g
• The THESEUS space mission concept: science case, design and expected performances
• The COSMOS2015 galaxy stellar mass function: 13 billion years of stellar mass assembly in 10 snapshots
• AGN and QSOs in the eROSITA All-Sky Survey -- Part I: Statistical properties
• Active Galactic Nuclei as seen by the Spitzer Space Telescope
• Broad Iron Emission from Gravitationally Lensed Quasars Observed by Chandra
• The Scales of Gravitational Lensing
• The Infra-Red Telescope on board the THESEUS mission