We present an analysis of 109 moderate-luminosity (41:9 log L0:5 Y 8:0 keV 43:7) AGNs in the Extended Chan- dra Deep Field-South survey, which is drawn from 5549 galaxies from the COMBO-17 and GEMS surveys having 0:4 z 1:1. These obscured or optically weak AGNs facilitate the study of their host galaxies since the AGNs pro- vide an insubstantial amount of contamination to the galaxy light. We find that the color distribution of AGN host gal- axiesishighlydependenton(1)thestrongcolor-evolutionofluminous(MV <20:7)galaxies,and(2)theinfluenceof 10 Mpc scale structures. When excluding galaxies within the redshift range 0:63 z 0:76, a regime dominated by sources in large-scale structures at z 1⁄4 0:67 and z 1⁄4 0:73, we observe a bimodality in the host galaxy colors. Galaxies hosting AGNs at z k 0:8 preferentially have bluer (rest-frame U V < 0:7) colors than their z P 0:6 counterparts (many of which fall along the red sequence). The fraction of galaxies hosting AGNs peaks in the ‘‘green valley’’ (0:5 < U V < 1:0); this is primarily due to enhanced AGN activity in the redshift interval 0:63 z 0:76. The AGN frac- tion in this redshift and color interval is 12.8% (compared to its ‘‘field’’ value of 7.8%) and reaches a maximum of 14.8% at U V 0:8. We further find that blue, bulge-dominated (Se ́rsic index n > 2:5) galaxies have the highest fraction of AGN (21%) in our sample. We explore the scenario that the evolution of AGN hosts is driven by galaxy mergers and illustrate that an accurate assessment requires a larger area survey since only three hosts may be under- going a merger with timescales P1 Gyr following a starburst phase.

Silverman J.D., Mainieri V., Lehmer B.D., Alexander D.M., Bauer F.E., Bergeron J., et al. (2008). The Evolution of AGN Host Galaxies: From Blue to Red and the Influence of Large-Scale Structures. THE ASTROPHYSICAL JOURNAL, 675, 1025-1040 [10.1086/527283].

The Evolution of AGN Host Galaxies: From Blue to Red and the Influence of Large-Scale Structures

VIGNALI, CRISTIAN;
2008

Abstract

We present an analysis of 109 moderate-luminosity (41:9 log L0:5 Y 8:0 keV 43:7) AGNs in the Extended Chan- dra Deep Field-South survey, which is drawn from 5549 galaxies from the COMBO-17 and GEMS surveys having 0:4 z 1:1. These obscured or optically weak AGNs facilitate the study of their host galaxies since the AGNs pro- vide an insubstantial amount of contamination to the galaxy light. We find that the color distribution of AGN host gal- axiesishighlydependenton(1)thestrongcolor-evolutionofluminous(MV <20:7)galaxies,and(2)theinfluenceof 10 Mpc scale structures. When excluding galaxies within the redshift range 0:63 z 0:76, a regime dominated by sources in large-scale structures at z 1⁄4 0:67 and z 1⁄4 0:73, we observe a bimodality in the host galaxy colors. Galaxies hosting AGNs at z k 0:8 preferentially have bluer (rest-frame U V < 0:7) colors than their z P 0:6 counterparts (many of which fall along the red sequence). The fraction of galaxies hosting AGNs peaks in the ‘‘green valley’’ (0:5 < U V < 1:0); this is primarily due to enhanced AGN activity in the redshift interval 0:63 z 0:76. The AGN frac- tion in this redshift and color interval is 12.8% (compared to its ‘‘field’’ value of 7.8%) and reaches a maximum of 14.8% at U V 0:8. We further find that blue, bulge-dominated (Se ́rsic index n > 2:5) galaxies have the highest fraction of AGN (21%) in our sample. We explore the scenario that the evolution of AGN hosts is driven by galaxy mergers and illustrate that an accurate assessment requires a larger area survey since only three hosts may be under- going a merger with timescales P1 Gyr following a starburst phase.
2008
Silverman J.D., Mainieri V., Lehmer B.D., Alexander D.M., Bauer F.E., Bergeron J., et al. (2008). The Evolution of AGN Host Galaxies: From Blue to Red and the Influence of Large-Scale Structures. THE ASTROPHYSICAL JOURNAL, 675, 1025-1040 [10.1086/527283].
Silverman J.D.; Mainieri V.; Lehmer B.D.; Alexander D.M.; Bauer F.E.; Bergeron J.; Brandt W.N.; Gilli R.; Hasinger G.; Schneider D.P.; Tozzi P.; Vigna...espandi
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/51484
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 141
  • ???jsp.display-item.citation.isi??? 144
social impact