Does the AGN unified model evolve with redshift? Using the X-ray background to predict the mid-infrared emission of AGNs

D. R. Ballantyne, Y. Shi, George H. Rieke, J. L. Donley, C. Papovich, J. R. Rigby

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Deep X-ray surveys by Chandra and XMM-Newton have resolved about 80% of the 2-10 keV cosmic extragalactic X-ray background (CXRB) into point sources, the majority of which are obscured AGNs. The obscuration might be connected to processes within the host galaxy, possibly the star formation rate. Here we use the results of CXRB synthesis calculations as input to detailed CLOUDY simulations in order to predict the evolution of AGN properties at several mid-IR wavelengths. Computations were performed for three different evolutions of the AGN type 2/type 1 ratio betweenz = 0 and 1, where the ratio increased as (1 + z)0.9, as (1 + z)0.3, and with one model having no redshift evolution. Models were calculated with the inner radius of the absorbing gas and dust at 1 or at 10 pc. Comparing the results of the calculations to combined X-ray and Spitzer data of AGNs show that the predicted spectral energy distributions are a good description of average AGNs found in the deep surveys. The existing data indicate that the mid-IR emission from an average AGN is best described by models in which the attenuating material is ∼ 10 pc from the central engine. We present the expected Spitzer cumulative number count distributions and the evolution of the total AGN (type 1+type 2) luminosity function (LF) between z = 0 and 1 at rest frame 8 and 30 μm for the three evolutionary scenarios. The mid-IR AGN LF will be an excellent tool to measure the evolution of the covering factor of the gas and dust from z ∼ 0 to 1.

Original languageEnglish (US)
Pages (from-to)1070-1088
Number of pages19
JournalAstrophysical Journal
Volume653
Issue number2 I
DOIs
StatePublished - Dec 20 2006

Fingerprint

x rays
dust
luminosity
occultation
XMM-Newton telescope
star formation rate
spectral energy distribution
gases
gas
newton
point sources
point source
engines
engine
coverings
galaxies
wavelength
radii
synthesis
wavelengths

Keywords

  • Galaxies: active
  • Galaxies: evolution
  • Galaxies: formation
  • Galaxies: Seyfert
  • Infrared: galaxies
  • X-rays: galaxies

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Does the AGN unified model evolve with redshift? Using the X-ray background to predict the mid-infrared emission of AGNs. / Ballantyne, D. R.; Shi, Y.; Rieke, George H.; Donley, J. L.; Papovich, C.; Rigby, J. R.

In: Astrophysical Journal, Vol. 653, No. 2 I, 20.12.2006, p. 1070-1088.

Research output: Contribution to journalArticle

Ballantyne, D. R. ; Shi, Y. ; Rieke, George H. ; Donley, J. L. ; Papovich, C. ; Rigby, J. R. / Does the AGN unified model evolve with redshift? Using the X-ray background to predict the mid-infrared emission of AGNs. In: Astrophysical Journal. 2006 ; Vol. 653, No. 2 I. pp. 1070-1088.
@article{23070c8a5da24ef3a0037d7a8fa21803,
title = "Does the AGN unified model evolve with redshift? Using the X-ray background to predict the mid-infrared emission of AGNs",
abstract = "Deep X-ray surveys by Chandra and XMM-Newton have resolved about 80{\%} of the 2-10 keV cosmic extragalactic X-ray background (CXRB) into point sources, the majority of which are obscured AGNs. The obscuration might be connected to processes within the host galaxy, possibly the star formation rate. Here we use the results of CXRB synthesis calculations as input to detailed CLOUDY simulations in order to predict the evolution of AGN properties at several mid-IR wavelengths. Computations were performed for three different evolutions of the AGN type 2/type 1 ratio betweenz = 0 and 1, where the ratio increased as (1 + z)0.9, as (1 + z)0.3, and with one model having no redshift evolution. Models were calculated with the inner radius of the absorbing gas and dust at 1 or at 10 pc. Comparing the results of the calculations to combined X-ray and Spitzer data of AGNs show that the predicted spectral energy distributions are a good description of average AGNs found in the deep surveys. The existing data indicate that the mid-IR emission from an average AGN is best described by models in which the attenuating material is ∼ 10 pc from the central engine. We present the expected Spitzer cumulative number count distributions and the evolution of the total AGN (type 1+type 2) luminosity function (LF) between z = 0 and 1 at rest frame 8 and 30 μm for the three evolutionary scenarios. The mid-IR AGN LF will be an excellent tool to measure the evolution of the covering factor of the gas and dust from z ∼ 0 to 1.",
keywords = "Galaxies: active, Galaxies: evolution, Galaxies: formation, Galaxies: Seyfert, Infrared: galaxies, X-rays: galaxies",
author = "Ballantyne, {D. R.} and Y. Shi and Rieke, {George H.} and Donley, {J. L.} and C. Papovich and Rigby, {J. R.}",
year = "2006",
month = "12",
day = "20",
doi = "10.1086/508801",
language = "English (US)",
volume = "653",
pages = "1070--1088",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2 I",

}

TY - JOUR

T1 - Does the AGN unified model evolve with redshift? Using the X-ray background to predict the mid-infrared emission of AGNs

AU - Ballantyne, D. R.

AU - Shi, Y.

AU - Rieke, George H.

AU - Donley, J. L.

AU - Papovich, C.

AU - Rigby, J. R.

PY - 2006/12/20

Y1 - 2006/12/20

N2 - Deep X-ray surveys by Chandra and XMM-Newton have resolved about 80% of the 2-10 keV cosmic extragalactic X-ray background (CXRB) into point sources, the majority of which are obscured AGNs. The obscuration might be connected to processes within the host galaxy, possibly the star formation rate. Here we use the results of CXRB synthesis calculations as input to detailed CLOUDY simulations in order to predict the evolution of AGN properties at several mid-IR wavelengths. Computations were performed for three different evolutions of the AGN type 2/type 1 ratio betweenz = 0 and 1, where the ratio increased as (1 + z)0.9, as (1 + z)0.3, and with one model having no redshift evolution. Models were calculated with the inner radius of the absorbing gas and dust at 1 or at 10 pc. Comparing the results of the calculations to combined X-ray and Spitzer data of AGNs show that the predicted spectral energy distributions are a good description of average AGNs found in the deep surveys. The existing data indicate that the mid-IR emission from an average AGN is best described by models in which the attenuating material is ∼ 10 pc from the central engine. We present the expected Spitzer cumulative number count distributions and the evolution of the total AGN (type 1+type 2) luminosity function (LF) between z = 0 and 1 at rest frame 8 and 30 μm for the three evolutionary scenarios. The mid-IR AGN LF will be an excellent tool to measure the evolution of the covering factor of the gas and dust from z ∼ 0 to 1.

AB - Deep X-ray surveys by Chandra and XMM-Newton have resolved about 80% of the 2-10 keV cosmic extragalactic X-ray background (CXRB) into point sources, the majority of which are obscured AGNs. The obscuration might be connected to processes within the host galaxy, possibly the star formation rate. Here we use the results of CXRB synthesis calculations as input to detailed CLOUDY simulations in order to predict the evolution of AGN properties at several mid-IR wavelengths. Computations were performed for three different evolutions of the AGN type 2/type 1 ratio betweenz = 0 and 1, where the ratio increased as (1 + z)0.9, as (1 + z)0.3, and with one model having no redshift evolution. Models were calculated with the inner radius of the absorbing gas and dust at 1 or at 10 pc. Comparing the results of the calculations to combined X-ray and Spitzer data of AGNs show that the predicted spectral energy distributions are a good description of average AGNs found in the deep surveys. The existing data indicate that the mid-IR emission from an average AGN is best described by models in which the attenuating material is ∼ 10 pc from the central engine. We present the expected Spitzer cumulative number count distributions and the evolution of the total AGN (type 1+type 2) luminosity function (LF) between z = 0 and 1 at rest frame 8 and 30 μm for the three evolutionary scenarios. The mid-IR AGN LF will be an excellent tool to measure the evolution of the covering factor of the gas and dust from z ∼ 0 to 1.

KW - Galaxies: active

KW - Galaxies: evolution

KW - Galaxies: formation

KW - Galaxies: Seyfert

KW - Infrared: galaxies

KW - X-rays: galaxies

UR - http://www.scopus.com/inward/record.url?scp=33846372219&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33846372219&partnerID=8YFLogxK

U2 - 10.1086/508801

DO - 10.1086/508801

M3 - Article

AN - SCOPUS:33846372219

VL - 653

SP - 1070

EP - 1088

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2 I

ER -