The deep look onto the hard X-ray sky: The Swift - INTEGRAL X-ray (SIX) survey

Abstract

The super-massive black-holes in the centers of Active Galactic Nuclei (AGNs) are surrounded by obscuring matter that can block the nuclear radiation. Depending on the amount of blocked radiation, the flux from the AGN can be too faint to be detected by currently flying hard X-ray (above 15 keV) missions. At these energies only ~1% of the intensity of the Cosmic X-ray Background (CXB) can be resolved into point-like sources that are AGNs. In this work we address the question of the undetected sources contributing to the CXB with a very sensitive and new hard X-ray survey: the SIX survey that is obtained with the new approach of combining the Swift/BAT and INTEGRAL/IBIS X-ray observations. We merge the observations of both missions. This enhances the exposure time and reduces systematic uncertainties. As a result we obtain a new survey over a wide sky area of 6200 deg^2 that is more sensitive than the surveys of Swift/BAT or INTEGRAL/IBIS alone. Our sample comprises 113 sources: 86 AGNs (Seyfert-like and blazars), 5 galaxies, 2 clusters of galaxies, 3 Galactic sources, 3 previously detected unidentified X-ray sources, and 14 unidentified sources. The scientific outcome from the study of the sample has been properly addressed to study the evolution of AGNs at redshift below 0.4. We do not find any evolution using the 1/V_max method. Our sample of faint sources are suitable targets for the new generation hard X-ray telescopes with focusing techniques.

ApJS accepted

References in corpus (14)

• The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era
• Massive molecular outflows and negative feedback in ULIRGs observed by Herschel-PACS
• Absorption Properties and Evolution of Active Galactic Nuclei
• Swift BAT Survey of AGN
• The XMM-Newton wide-field survey in the COSMOS field. The point-like X-ray source catalogue
• The Luminosity Function of X-ray Selected Active Galactic Nuclei: Evolution of Supermassive Black Holes at High Redshift
• Cosmic X-ray background and Earth albedo Spectra with Swift/BAT
• X-ray properties of an Unbiased Hard X-ray Detected Sample of AGN
• BAT X-ray Survey - III: X-ray Spectra and Statistical Properties
• Investigating on the nuclear obscuration in two types of Seyfert 2 galaxies
• The sensitivity of coded mask telescopes
• BAT X-ray Survey - I: Methodology and X-ray Identification
• Probing the Transition Between the Synchrotron and Inverse-compton Spectral Components of 1ES 1959+650
• Compton thick AGN in the Suzaku era

Cited by in corpus (11)

• The NuSTAR View of Nearby Compton-thick AGN: The Cases of NGC 424, NGC 1320 and IC 2560
• The NuSTAR Serendipitous Survey: The 40 month Catalog and the Properties of the Distant High Energy X-ray Source Population
• NuSTAR J033202-2746.8: direct constraints on the Compton reflection in a heavily obscured quasar at z~2
• 3C 279 in Outburst in June 2015: A Broadband-SED Study Based on the INTEGRAL Detection
• The NuSTAR Extragalactic Survey: Average broad-band X-ray spectral properties of the NuSTAR detected AGN
• Hard X-ray properties of radio-selected blazars
• Hard X-Ray broadband spectroscopy of Mrk 876: characterizing its spectrum
• Exploring the MeV Sky with a Combined Coded Mask and Compton Telescope: The Galactic Explorer with a Coded Aperture Mask Compton Telescope (GECCO)
• A multifrequency characterization of the extragalactic hard X-ray sky
• Swift-XRT follow-up analysis of unidentified hard X-ray sources
• Evidence of Heavy Obscuration in the Low-Luminosity AGN NGC 4941