A sample of Seyfert-2 galaxies with ultra-luminous galaxy-wide NLRs -- Quasar light echos?

Abstract

We report the discovery of Seyfert-2 galaxies in SDSS-DR8 with galaxy-wide, ultra-luminous narrow-line regions (NLRs) at redshifts z=0.2-0.6. With a space density of 4.4 per cubic Gpc at z~0.3, these "Green Beans" (GBs) are amongst the rarest objects in the Universe. We are witnessing an exceptional and/or short-lived phenomenon in the life cycle of AGN. The main focus of this paper is on a detailed analysis of the GB prototype galaxy J2240-0927 (z=0.326). Its NLR extends over 26x44 kpc and is surrounded by an extended narrow-line region (ENLR). With a total [OIII]5008 luminosity of (5.7+/-0.9)x10e43 erg/s, this is one of the most luminous NLR known around any type-2 galaxy. Using VLT/XSHOOTER we show that the NLR is powered by an AGN, and we derive resolved extinction, density and ionization maps. Gas kinematics is disturbed on a global scale, and high velocity outflows are absent or faint. This NLR is unlike any other NLR or extended emission line region (EELR) known. Spectroscopy with Gemini/GMOS reveals extended, high luminosity [OIII] emission also in other GBs. WISE 24micron luminosities are 5-50 times lower than predicted by the [OIII] fluxes, suggesting that the NLRs reflect earlier, very active quasar states that have strongly subsided in less than a galaxies' light crossing time. These light echos are about 100 times more luminous than any other such light echo known to date. X-ray data are needed for photo-ionization modeling and to verify the light echos.

This is an update of our previous submission (1211.7098). Apart from layout it is identical to the publication in ApJ. Compared to v1 (1211.7098) type settings and language errors have been corrected. We also added 4 more redshifts, confirming 3 sources (objects #002, #017, #21) and rejecting one (#020, low-z HII region)

References in corpus (12)

• The Host Galaxies and Classification of Active Galactic Nuclei
• K-corrections and filter transformations in the ultraviolet, optical, and near infrared
• A Compact Supermassive Binary Black Hole System
• Evidence for powerful AGN winds at high redshift: Dynamics of galactic outflows in radio galaxies during the "Quasar Era"
• Emission-line Diagnostics of Low Metallicity AGN
• A Candidate Sub-Parsec Supermassive Binary Black Hole System
• Active Galactic Nucleus Pairs from the Sloan Digital Sky Survey. I. The Frequency on ~ 5-100 kpc Scales
• Size and properties of the narrow-line region in Seyfert-1 galaxies from spatially-resolved optical spectroscopy
• The flux ratio of the [OIII] 5007,4959 lines in AGN: Comparison with theoretical calculations
• Extended Emission-Line Regions: Remnants of Quasar Superwinds?
• The Sudden Death of the Nearest Quasar
• Mass, Light and Colour of the Cosmic Web in the Supercluster SCL2243-0935 (z=0.447)

Cited by in corpus (31)

• Kiloparsec-scale outflows are prevalent among luminous AGN: outflows and feedback in the context of the overall AGN population
• Fueling AGN II: Spatially Resolved Molecular Inflows and Outflows
• Molecular outflows in local galaxies: Method comparison and a role of intermittent AGN driving
• The weirdest SDSS galaxies: results from an outlier detection algorithm
• Fading AGN Candidates: AGN Histories and Outflow Signatures
• Sizes and Kinematics of Extended Narrow-Line Regions in Luminous Obscured AGN Selected by Broadband Images
• HST Imaging of Fading AGN Candidates I: Host-Galaxy Properties and Origin of the Extended Gas
• The Close AGN Reference Survey (CARS). A massive multi-phase outflow impacting the edge-on galaxy HE1353-1917
• Astronomia ex machina: a history, primer, and outlook on neural networks in astronomy
• The Quasar Feedback Survey: Discovering hidden Radio-AGN and their connection to the host galaxy ionised gas
• Exploring SMBH Assembly with Semi-analytic Modelling
• ALMA Observations of a Candidate Molecular Outflow in an Obscured Quasar
• Radio Galaxy Zoo: A Search for Hybrid Morphology Radio Galaxies
• About AGN ionization echoes, thermal echoes, and ionization deficits in low redshift Lyman-alpha blobs
• High resolution spectroscopy of the extended narrow-line region of IC 5063 and NGC 7212
• NuSTAR Observations of AGN with Low Observed X-ray to [OIII] Luminosity Ratios: Heavily Obscured AGN or Turned-Off AGN?
• Double-peak emission line galaxies in the SDSS catalogue. A minor merger sequence
• The "Green Bean" Galaxy SDSS J224024.1--092748: Unravelling the emission signature of a quasar ionization echo
• Cooling timescale of dust tori in dying active galactic nuclei
• Machine Learning Approach to Integral Field Unit Spectroscopy Observations: I. HII Region Kinematics
• Do you see what I see? Exploring the consequences of luminosity limits in black hole-galaxy evolution studies
• XMM-Newton RGS spectroscopy of the M31 bulge. I: Evidences for a past AGN half a million years ago
• Galaxy evolution across the optical emission-line diagnostic diagrams?
• A Machine Learning Approach to Integral Field Unit Spectroscopy Observations: II. HII Region LineRatios
• NuSTAR hard X-ray data and Gemini 3D spectra reveal powerful AGN and outflow histories in two low-redshift Lyman-$\alpha$ blobs
• Finding of a population of active galactic nuclei showing a significant luminosity decline in the past $\sim 10^{3-4}$ yrs
• An interacting galaxy pair at the origin of a light echo
• Spatially-resolved spectroscopy of narrow-line Seyfert 1 host galaxies
• Understanding Lyman-alpha Nebulae at Low Redshift I: The Sizes, Powering, and Kinematics of "Green Bean" Galaxies
• JWST's PEARLS: A z=6 quasar in a train-wreck galaxy merger system
• QSO MUSEUM III: the circumgalactic medium in Ly$\alpha$ emission around 120 $z\sim 3$ quasars covering the SDSS parameter space. Witnessing the instantaneous AGN feedback on halo scales