Near-Infrared Spectroscopy of Seyfert Galaxies. Nuclear Activity and Stellar Population

Almeida, C. Ramos; García, Ana María Pérez; Acosta–Pulido, J. A.

doi:10.1088/0004-637x/694/2/1379

Cited by 51 publications

(52 citation statements)

References 92 publications

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“…The star-formation rate is very large, perhaps as high as 80 M e yr −1 (Privon 2009;Hoffer et al 2012), equivalent to a core-collapse supernova rate of approximately 0.7 yr −1 (Horiuchi et al 2011), so during any given observation it is likely that there are several young supernovae within a few years of explosion. However, it is quite unlikely that we would find a young radio-luminous supernova by sheer chance if star formation in the Cygnus A host is similar to that in other galaxies.…”

Section: Supernova Modelsmentioning

confidence: 99%

Discovery of a Luminous Radio Transient 460 pc from the Central Supermassive Black Hole in Cygnus A

Perley

Dhawan

et al. 2017

ApJ

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We report the appearance of a new radio source at a projected offset of 460 pc from the nucleus of Cygnus A. The flux density of the source (which we designate Cygnus A-2) rose from an upper limit of <0.5 mJy in 1989 to 4 mJy in 2016 (ν = 8.5 GHz), but is currently not varying by more than a few percent per year. The radio luminosity of the source is comparable to the most luminous known supernovae, it is compact in Very Long Baseline Array observations down to a scale of 4 pc, and it is coincident with a near-infrared point source seen in pre-existing adaptive optics and HST observations. The most likely interpretation of this source is that it represents a secondary supermassive black hole in a close orbit around the Cygnus A primary, though an exotic supernova model cannot be ruled out. The gravitational influence of a secondary SMBH at this location may have played an important role in triggering the rapid accretion that has powered the Cygnus A radio jet over the past 10 7 years.

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Section: Supernova Modelsmentioning

confidence: 99%

Discovery of a Luminous Radio Transient 460 pc from the Central Supermassive Black Hole in Cygnus A

Perley

Dhawan

et al. 2017

ApJ

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“…These characteristic X-ray properties, together with high-quality LIRIS near-infrared spectroscopy, allowed this galaxy to be reclassified as an obscured narrow-line Seyfert 1 (Ramos Almeida et al 2008, 2009b.…”

Section: No 2 2010 the Soft X-ray And Narrow-line Emission Of Mrk 5mentioning

confidence: 99%

“…The filters used here are not contaminated by line emission except for the case of F110W, which contains strong Paβ emission. We have used the nuclear near-IR spectrum of Mrk 573 obtained with the LIRIS spectrograph (see Ramos Almeida et al 2009b) to subtract this emission-line contribution. The Paβ nuclear emission (including the broad and narrow components) amounts 3.17×10 −14 erg cm −2 s −1 .…”

Section: Optical and Near-ir Datamentioning

confidence: 99%

THE SOFT X-RAY AND NARROW-LINE EMISSION OF Mrk 573 ON KILOPARSEC SCALES

González‐Martín

Acosta–Pulido

Pérez-García

et al. 2010

ApJ

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We present a study of the circumnuclear region of the nearby Seyfert galaxy Mrk 573 using Chandra, XMM-Newton, and Hubble Space Telescope (HST) data. We have studied the morphology of the soft (<2 keV) X-rays comparing it with the [O iii] and Hα HST images. The soft X-ray emission is resolved into a complex extended region. The X-ray morphology shows a biconical region extending up to 12 arcsec (4 kpc) in projection from the nucleus. A strong correlation between the X-rays and the highly ionized gas seen in the [O iii]λ5007 Å image is reported. Moreover, we have studied the line intensities detected with the XMM-Newton Reflection Grating Spectrometer (RGS) and used them to fit the low-resolution EPIC/XMM-Newton and ACIS/Chandra spectra. The RGS/XMM-Newton spectrum is dominated by emission lines of C vi, O vii, O viii, Fe xvii, and Ne ix, among other highly ionized species. A good fit is obtained using these emission lines found in the RGS/XMM-Newton spectrum as a template for Chandra spectra of the nucleus and extended emission, coincident with the cone-like structures seen in the [O iii]/Hα map. The photoionization model Cloudy provides a reasonable fit for both the nuclear region and the cone-like structures showing that the dominant excitation mechanism is photoionization. For the nucleus the emission is modeled using two phases: a high ionization [log (U) = 1.23] and a low ionization [log (U) = 0.13]. For the high-ionization phase the transmitted and reflected components are in a 1:2 ratio, whereas for the low ionization the reflected component dominates. For the extended emission, we successfully reproduced the emission with two phases. The first phase shows a higher ionization parameter for the northwest (log (U) = 0.9) than for the southeast cone (log (U) = 0.3). Moreover, this phase is transmission dominated for the southeast cone and reflection dominated for the northwest cone. The second phase shows a low-ionization parameter (log (U) = −3) and is rather uniform for northwest and southeast cones and equally distributed in reflection and transmission components. In addition, we have also derived the optical/infrared spectral energy distribution (SED) of the nucleus from high spatial resolution images of Mrk 573. The nuclear optical/infrared SED of the nucleus has been modeled by a clumpy torus model. The torus bolometric luminosity agrees very well with the active galactic nucleus (AGN) luminosity inferred from the observed hard X-ray spectrum. The optical depth along the line of sight expected from the torus modeling indicates a high neutral hydrogen column density in agreement with the classification of the nucleus of Mrk 573 as a Compton-thick AGN.

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“…Paβ, Brγ, [Fe II]; Riffel et al 2010). This barred galaxy, at a distance of 47.2 Mpc, has been extensively studied at different wavelengths (Bower et al 1995;Ramos Almeida et al 2009a;Smirnova et al 2010;Riffel et al 2010;Riffel & Storchi-Bergmann 2011). Our goal is to understand the different mechanisms responsible for the MIR emission in the central kpc of Mrk 1066, including emission from the dusty torus, dust emission from the narrow-line region (NLR) and star formation.…”

mentioning

confidence: 99%

A mid-infrared view of the inner parsecs of the Seyfert galaxy Mrk 1066 using CanariCam/GTC

Almeida

Alonso‐Herrero

Esquej

et al. 2014

Monthly Notices of the Royal Astronomical Society

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We present mid-infrared (MIR) imaging and spectroscopic data of the Seyfert 2 galaxy Mrk 1066 obtained with CanariCam (CC) on the 10.4 m Gran Telescopio CANARIAS (GTC). The galaxy was observed in imaging mode with an angular resolution of 0.24 ′′ (54 pc) in the Si-2 filter (8.7 µm). The image reveals a series of star-forming knots within the central ∼400 pc, after subtracting the dominant active galactic nucleus (AGN) component. We also subtracted this AGN unresolved component from the 8-13 µm spectra of the knots and the nucleus, and measured equivalent widths (EWs) of the 11.3 µm Polycyclic Aromatic Hydrocarbon (PAH) feature which are typical of pure starburst galaxies. This EW is larger in the nucleus than in the knots, confirming that, at least in the case of Mrk 1066, the AGN dilutes, rather than destroys, the molecules responsible for the 11.3 µm PAH emission. By comparing the nuclear GTC/CC spectrum with the Spitzer /IRS spectrum of the galaxy, we find that the AGN component that dominates the continuum emission at λ <15 µm on scales of ∼60 pc (90-100%) decreases to 35-50% when the emission of the central ∼830 pc is considered. On the other hand, the AGN contribution dominates the 15-25 µm emission (75%) on the scales probed by Spitzer /IRS. We reproduced the nuclear infrared emission of the galaxy with clumpy torus models, and derived a torus gas mass of 2×10 5 M ⊙ , contained in a clumpy structure of ∼2 pc radius and with a column density compatible with Mrk 1066 being a Compton-thick candidate, in agreement with X-ray observations. We find a good match between the MIR morphology of Mrk 1066 and the extended Paβ, Brγ and [O III]λ5007 emission. This coincidence implies that the 8.7 µm emission is probing star formation, dust in the narrow-line region, and the oval structure previously detected in the near-infrared. On the other hand, the Chandra soft X-ray morphology does not match any of the previous, contrary to what it is generally assumed for Seyfert galaxies. A thermal origin for the soft X-ray emission, rather than AGN photoionization, is suggested by the different data analyzed here.

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Near-Infrared Spectroscopy of Seyfert Galaxies. Nuclear Activity and Stellar Population

Cited by 51 publications

References 92 publications

Discovery of a Luminous Radio Transient 460 pc from the Central Supermassive Black Hole in Cygnus A

Discovery of a Luminous Radio Transient 460 pc from the Central Supermassive Black Hole in Cygnus A

THE SOFT X-RAY AND NARROW-LINE EMISSION OF Mrk 573 ON KILOPARSEC SCALES

A mid-infrared view of the inner parsecs of the Seyfert galaxy Mrk 1066 using CanariCam/GTC

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