The growth of supermassive black holes (SMBHs) over cosmic time is imprinted in their X-ray luminosity that is emitted from the inner central engine of active galactic nuclei (AGN). Observationally, X-rays from AGN can be probed both through deep and wide X-ray surveys, and also through the integrated emission that makes up the cosmic X-ray background (CXB). I will give an overview of our...
eFEDS (the eROSITA Final Equatorial Depth Survey) is a CalPV program of the German eROSITA consortium. Using a field-scan observing strategy, eFEDS covers an area of approximately 130 deg^2 in an equatorial field with comprehensive mult-wavelength coverage, notably with Subaaru HSC, VISTA/VIKING and the GAMA spectroscopic survey. With a total exposure time of around 400ks, eFEDS achieves the...
I will present, on behalf of eroAGN and eROFollow-up WGs the multiwavelength counterparts to the eROSITA sources in eFEDS, including their classification (AGN/star). The talk will also cover predictions on our capability to identify the correct counterparts as a function of Ancillary data coverage and depth of X-ray survey (eRASS:1-8).
As matter accretes onto the central supermassive black holes in active galactic nuclei (AGNs), X-rays are emitted. We present a population synthesis model that accounts for the summed X-ray emission from growing black holes; modulo the efficiency of converting mass to X-rays, this is effectively a record of the accreted mass. We need this population synthesis model to reproduce observed...
We present SRGz - a programming package for doing effective optical cross-match, photometric classification and probabilistic photo-z measurements of SRG extragalactic sources. SRGz is based on competitive empirical machine learning (ML) algorithms: quantile random forest, gradient boosting, deep neural networks. ML-models were trained on SDSS spectral samples of quasars, galaxies and stars...
Nearly all galaxies appear to harbor a supermassive black hole. The origin and properties of initial black hole seeds that grow to produce the detected supermassive black hole population are unconstrained at present, as actively growing seeds are not directly observable near their birth epochs. Nevertheless, some unique signatures of seeding survive and can be discerned in: local scaling...
We discuss the first results of the optical identification the SRG X-ray sources of the 18.5 square degrees Lockman Hole PV-phase survey. We show first spectroscopically confirmed quasar candidates at z~4 the spectra of which were obtained at the 1.6-m telescope AZT-33IK and the 6-m telescope BTA.
We review a fraction of optical identification of X-ray sources in the several wide field broad...
The Astronomical Roentgen Telescope X-ray Concentrator (ART-XC) instrument onboard the Spectrum Röntgen Gamma (SRG) mission has started the all-sky hard X-ray survey since 2019/12/08. The observations of the ecliptic pole regions will reach exceptional depth thanks to the survey design of overlapping exposure in these regions. In anticipation of the ART-XC survey in the North Ecliptic Pole...
Several pieces of evidence have been pilling up in the literature leading towards an evolutionary scenario for AGN, moving past the standard unified model. Part of this amounting evidence is the little overlap of AGN samples selected with various identification criteria. Given the rarity of the AGN population, large and complete samples are needed to assess such an evolutionary model and...
In this report we will present first results of the optical identifications by using 1.5-m Russian-Turkish telescope of the sample of X-Ray sources detected with eRosita and ART-XC onboard SRG in the Lockman Hole region during PV period in November 2019. We will inform also results of SRG orbit's astrometric support observations by using RTT-150 in the period July 2019 - February 2020.
