Elusive active galactic nuclei

@article{Maiolino2003ElusiveAG,
  title={Elusive active galactic nuclei},
  author={Roberto Maiolino and Andrea Comastri and Roberto Gilli and Neil M. Nagar and Stefano Bianchi and Torsten Boeker and Edward James McBride Colbert and A C Krabbe and Alessandro Marconi and Giorgio Matt and Marco Salvati},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2003},
  volume={344},
  pages={59}
}
A fraction of active galactic nuclei do not show the classical Seyfert-type signatures in their optical spectra, i.e. they are optically 'elusive'. X-ray observations are an optimal tool to identify this class of objects. We combine new Chandra observations with archival X-ray data in order to obtain a first estimate of the fraction of elusive active galactic nuclei (AGN) in local galaxies and to constrain their nature. Our results suggest that elusive AGN have a local density comparable to or… Expand

Figures and Tables from this paper

FITTING LINER NUCLEI WITHIN THE ACTIVE GALACTIC NUCLEUS FAMILY: A MATTER OF OBSCURATION?
In this paper, we study the nuclear obscuration of galaxies hosting low ionization narrow emission regions (LINERs) based on their X-ray and optical emission. They show column densities at softExpand
AEGIS: DEMOGRAPHICS OF X-RAY AND OPTICALLY SELECTED ACTIVE GALACTIC NUCLEI
We develop a new diagnostic method to classify galaxies into active galactic nucleus (AGN) hosts, star-forming galaxies, and absorption-dominated galaxies by combining the [O III]/Hβ ratio withExpand
X-ray selection of Compton-Thick AGN at high redshift
Compton-Thick (CT) active galactic nuclei (AGN) are a key ingredient of cosmic X-ray background (CXB) synthesis models, but are still an elusive component of the AGN population beyond the localExpand
24 MICRON PROPERTIES OF X-RAY-SELECTED ACTIVE GALACTIC NUCLEI
We examine the 24 μm to X-ray color of 157 X-ray-selected active galactic nuclei (AGNs) as a function of X-ray obscuration and optical classification in the Chandra Deep Field-South. The sampleExpand
RBS 1032: a dwarf-nucleated spheroidal galaxy with an intermediate-mass black hole hosted in a globular cluster
We report here the multiwavelength observations of the bright supersoft X-ray source, RBS 1032. Most likely, its optical counterpart is a non-emission-line dwarf galaxy with a prominent nucleus. LineExpand
Narrow Iron Kα Lines in Active Galactic Nuclei: Evolving Populations?
We assemble a sample consisting of 66 active galactic nuclei (AGNs) from the literature and from the XMM-Newton archive in order to investigate the origin of the 6.4 keV narrow iron Kalpha lineExpand
A comparison between the soft X-ray and [O III] morphologies of active galactic nuclei
Several studies of nearby active galactic nuclei (AGNs) have shown that the soft X-ray emission presents a size and morphology resembling that of the narrow-line region (NLR) traced by [O III]. SinceExpand
Elusive AGN in the XMM-Newton bright serendipitous survey
Context. Optical follow-up of X-ray selected sources finds a significant fraction of “optically dull” sources characterized by optical spectra without obvious signature of AGN activity. In manyExpand
Dust in active galactic nuclei. Mid-infrared T-ReCS/Gemini spectra using the new RedCan pipeline
Context. The unified model of active galactic nuclei (AGN) claims that the properties of AGN depend on the viewing angle of the observer with respect to a toroidal distribution of dust surroundingExpand
THE RELATIONSHIP OF HARD X-RAY AND OPTICAL LINE EMISSION IN LOW-REDSHIFT ACTIVE GALACTIC NUCLEI
In this paper we assess the relationship of the population of active galactic nuclei (AGNs) selected by hard X-rays to the traditional population of AGNs with strong optical emission lines. First, weExpand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 42 REFERENCES
“Hidden” Seyfert 2 Galaxies and the X-Ray Background
Obscured active galactic nuclei, which are classified optically as type 2 (narrow line) Seyfert galaxies in the local universe, are by far the most promising candidates for the origin of the hardExpand
Detection of Nuclear X-Ray Sources in Nearby Galaxies with Chandra
We report preliminary results from an arcsecond-resolution X-ray survey of nearby galaxies using the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray Observatory. The total sampleExpand
A Chandra Survey of the Nearest Ultraluminous Infrared Galaxies: Obscured Active Galactic Nuclei or Superstarbursts?
We present initial results from a Chandra survey of a complete sample of the eight nearest (z ≤ 0.04) ultraluminous IR galaxies (ULIRGs) and also include the IR-luminous galaxy NGC 6240 forExpand
THE DISTRIBUTION OF ABSORBING COLUMN DENSITIES AMONG SEYFERT 2 GALAXIES
We use hard X-ray data for an "optimal" sample of Seyfert 2 galaxies to derive the distribution of the gaseous absorbing column densities among obscured active nuclei in the local universe. Of allExpand
Optical Classification of Megamaser Galaxies
We have obtained spectroscopic observations of the nuclear regions of 42 galaxies known to harbor strong OH masers. These megamaser galaxies represent a subsample of FIR (ultra)luminous galaxies,Expand
N-Band Imaging of Seyfert Nuclei and the Mid-Infrared-X-Ray Correlation
We present new mid-infrared (N-band) images of a sample of eight nearby Seyfert galaxies. In all of our targets, we detect a central unresolved source, which in some cases has been identified for theExpand
NGC 4945: The Brightest Seyfert 2 Galaxy at 100 keV
Seyfert 2 galaxies are generally heavily absorbed in soft X-rays, plausibly because of obscuration of the Seyfert nucleus by a thick molecular torus. With a high torus column, 1023 ? NH ? 1025 cm-2,Expand
A Starburst Revealed—Luminous Radio Supernovae in the Nuclei of Arp 220
We report 18 cm VLBI continuum imaging observations of Arp 220, the prototype luminous infrared galaxy (log Lfir = 12.11 L☉). In previous work, we showed that Arp 220 has compact, high-Tb nuclearExpand
SPECTROSCOPIC OBSERVATIONS OF THE STAR FORMATION ACTIVITIES IN THE CENTRAL REGIONS OF EARLY-TYPE SPIRAL GALAXIES
We study the characteristics of central star-forming regions of early-type spiral galaxies by optical spectroscopic observations. The sample consists of 13 galaxies which have ratios of far-infraredExpand
LUMINOUS INFRARED GALAXIES
▪ Abstract At luminosities above 1011 , infrared galaxies become the dominant population of extragalactic objects in the local Universe (z ≲ 0.3), being more numerous than optically selectedExpand
...
1
2
3
4
5
...