Infrared Selection of Obscured Active Galactic Nuclei in the COSMOS Field
arXiv:1711.00471 · doi:10.3847/1538-4365/aa97da
Abstract
We present a study of the connection between black hole accretion, star formation, and galaxy morphology at z<=2.5. We focus on active galactic nuclei (AGNs) selected by their mid-IR power-law emission. By fitting optical to far-IR photometry with state-of-the-art spectral energy distribution (SED) techniques, we derive stellar masses, star formation rates, dust properties, and AGN contributions in galaxies over the whole COSMOS field. We find that obscured AGNs lie within or slightly above the star-forming sequence. We confirm our previous finding about compact host galaxies of obscured AGNs at z~1, and find that galaxies with 20-50% AGN contributions tend to have smaller sizes, by ~25-50%, compared to galaxies without AGNs. Furthermore, we find that a high merger fraction of up to 0.5 is appropriate for the most luminous (log (LIR/Lsun) ~ 12.5) AGN hosts and non-AGN galaxies, but not for the whole obscured AGN sample. Moreover, merger fraction depends on the total and star-forming infrared luminosity, rather than the decomposed AGN infrared luminosity. Our results suggest that major mergers are not the main driver of AGN activity, and therefore obscured AGNs might be triggered by internal mechanisms, such as secular processes, disk instabilities, and compaction in a particular evolutionary stage. We make the SED modeling results publicly available.
Accepted for publication in ApJS
References in corpus (30)
- The Cosmic Evolution Survey (COSMOS) -- Overview
- Star Formation in AEGIS Field Galaxies since z=1.1 : The Dominance of Gradually Declining Star Formation, and the Main Sequence of Star-Forming Galaxies
- Cold streams in early massive hot haloes as the main mode of galaxy formation
- A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
- A simple model to interpret the ultraviolet, optical and infrared emission from galaxies
- COSMOS Photometric Redshifts with 30-bands for 2-deg2
- The Herschel view of the dominant mode of galaxy growth from z=4 to the present day
- Compaction and Quenching of High-z Galaxies in Cosmological Simulations: Blue and Red Nuggets
- An ALMA survey of Sub-millimeter Galaxies in the Extended Chandra Deep Field South: Physical properties derived from ultraviolet-to-radio modelling
- The bulk of the black hole growth since z~1 occurs in a secular universe: No major merger-AGN connection
- Stellar Masses and SFRs for 1M Galaxies from SDSS and WISE
- Growing supermassive black holes in the late stages of galaxy mergers are heavily obscured
- Optical spectroscopy and X-ray detections of a sample of quasars and AGN selected in the mid-infrared from two Spitzer wide-area surveys
- X-shooter reveals powerful outflows in z~1.5 X-ray selected obscured quasi stellar objects
- Host galaxies of luminous z0.6 quasars: Major mergers are not prevalent at the highest AGN luminosities
- AEGIS: Host Galaxy Morphologies of X-ray and Infrared-selected AGN at 0.2 < z < 1.2
- Widespread and Hidden Active Galactic Nuclei in Star-Forming Galaxies at Redshift > 0.3
- Compton thick active galactic nuclei in Chandra surveys
- The role of AGN in the colour transformation of galaxies at redshifts z~1
- The MOSDEF survey: AGN multi-wavelength identification, selection biases and host galaxy properties
- The M_BH - M_star relation for X-ray obscured, red QSOs at 1.2< z <2.6
- Compton Thick AGN in the XMM-COSMOS survey
- The host galaxies of X-ray selected Active Galactic Nuclei to z=2.5: Structure, star-formation and their relationships from CANDELS and Herschel/PACS
- The Angular Clustering of Infrared-Selected Obscured and Unobscured Quasars
- Resolving the AGN and host emission in the mid-infrared using a model-independent spectral decomposition
- Star formation of far-IR AGN and non-AGN galaxies in the green valley: possible implication of AGN positive feedback
- Type 2 AGN host galaxies in the Chandra-COSMOS Legacy Survey: No Evidence of AGN-driven Quenching
- Clustering of infrared-bright dust-obscured galaxies revealed by the Hyper Suprime-Cam and WISE
- Obscured Active Galactic Nuclei triggered in compact star-forming galaxies
- An extinction free AGN selection by 18-band SED fitting in mid-infrared in the AKARI NEP deep field