THE 4 Ms <i>CHANDRA</i> DEEP FIELD-SOUTH NUMBER COUNTS APPORTIONED BY SOURCE CLASS: PERVASIVE ACTIVE GALACTIC NUCLEI AND THE ASCENT OF NORMAL GALAXIES

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dc.contributor.authorLehmer, B. D.
dc.contributor.authorXue, Y. Q.
dc.contributor.authorBrandt, W. N.
dc.contributor.authorAlexander, D. M.
dc.contributor.authorBauer, F. E.
dc.contributor.authorBrusa, M.
dc.contributor.authorComastri, A.
dc.contributor.authorGilli, R.
dc.contributor.authorHornschemeier, A. E.
dc.contributor.authorLuo, B.
dc.contributor.authorPaolillo, M.
dc.contributor.authorPtak, A.
dc.contributor.authorShemmer, O.
dc.contributor.authorSchneider, D. P.
dc.contributor.authorTozzi, P.
dc.contributor.authorVignali, C.
dc.date.accessioned2025-01-20T23:58:00Z
dc.date.available2025-01-20T23:58:00Z
dc.date.issued2012
dc.description.abstractWe present 0.5-2 keV, 2-8 keV, 4-8 keV, and 0.5-8 keV (hereafter soft, hard, ultra-hard, and full bands, respectively) cumulative and differential number-count (log N-log S) measurements for the recently completed approximate to 4 Ms Chandra Deep Field-South (CDF-S) survey, the deepest X-ray survey to date. We implement a new Bayesian approach, which allows reliable calculation of number counts down to flux limits that are factors of approximate to 1.9-4.3 times fainter than the previously deepest number-count investigations. In the soft band (SB), the most sensitive bandpass in our analysis, the approximate to 4 Ms CDF-S reaches a maximum source density of approximate to 27,800 deg(-2). By virtue of the exquisite X-ray and multiwavelength data available in the CDF-S, we are able to measure the number counts from a variety of source populations (active galactic nuclei (AGNs), normal galaxies, and Galactic stars) and subpopulations (as a function of redshift, AGN absorption, luminosity, and galaxy morphology) and test models that describe their evolution. We find that AGNs still dominate the X-ray number counts down to the faintest flux levels for all bands and reach a limiting SB source density of approximate to 14,900 deg(-2), the highest reliable AGN source density measured at any wavelength. We find that the normal-galaxy counts rise rapidly near the flux limits and, at the limiting SB flux, reach source densities of approximate to 12,700 deg(-2) and make up 46% +/- 5% of the total number counts. The rapid rise of the galaxy counts toward faint fluxes, as well as significant normal-galaxy contributions to the overall number counts, indicates that normal galaxies will overtake AGNs just below the approximate to 4 Ms SB flux limit and will provide a numerically significant new X-ray source population in future surveys that reach below the approximate to 4 Ms sensitivity limit. We show that a future approximate to 10 Ms CDF-S would allow for a significant increase in X-ray-detected sources, with many of the new sources being cosmologically distant (z greater than or similar to 0.6) normal galaxies.
dc.fuente.origenWOS
dc.identifier.doi10.1088/0004-637X/752/1/46
dc.identifier.eissn1538-4357
dc.identifier.issn0004-637X
dc.identifier.urihttps://doi.org/10.1088/0004-637X/752/1/46
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/95226
dc.identifier.wosidWOS:000305463400046
dc.issue.numero1
dc.language.isoen
dc.revistaAstrophysical journal
dc.rightsacceso restringido
dc.subjectcosmology: observations
dc.subjectgalaxies: active
dc.subjectgalaxies: starburst
dc.subjectX-rays: galaxies
dc.titleTHE 4 Ms <i>CHANDRA</i> DEEP FIELD-SOUTH NUMBER COUNTS APPORTIONED BY SOURCE CLASS: PERVASIVE ACTIVE GALACTIC NUCLEI AND THE ASCENT OF NORMAL GALAXIES
dc.typeartículo
dc.volumen752
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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