Subaru Spectropolarimetry of Markarian 573: The Hidden High-Ionization Nuclear Emission-Line Region inside the Dusty Torus

Nagao, Tohru; Kawabata, Koji S.; Murayama, Takashi; Ohyama, Youichi; Taniguchi, Yoshiaki; Shioya, Yasuhiro; Sumiya, Ryoko; Sasaki, S.

doi:10.1086/424936

Cited by 10 publications

(10 citation statements)

References 54 publications

(72 reference statements)

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“…These features are characteristics of only type 1 galaxies, as they are produced in the BLR. Nagao et al (2004) reported spectropolarimetric observations of the NLR of this source and found that it shows not only scattered broad H emission but also various narrow forbidden emission lines. The degree of polarization of the latter features is positively correlated with the ionization potential of the corresponding ion and the critical density of the corresponding transition.…”

Section: Resultsmentioning

confidence: 99%

Demystifying the coronal-line region of active galactic nuclei: spatially resolved spectroscopy with theHubble Space Telescope

Mazzalay¹,

Rodríguez-Ardila²,

Komossa³

2010

Monthly Notices of the Royal Astronomical Society

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We present an analysis of Space Telescope Imaging Spectrograph (STIS)/Hubble Space Telescope optical spectra of a sample of 10 Seyfert galaxies aimed at studying the structure and physical properties of the coronal-line region (CLR). The high spatial resolution provided by STIS allowed us to resolve the CLR and obtain key information about the kinematics of the CL gas, measure directly its spatial scale, and study the mechanisms that drive the high-ionization lines. We find CLRs extending from just a few parsecs (∼10 pc) up to 230 pc in radius, consistent with the bulk of the coronal lines (CLs) originating between the broad-line region and narrow-line region (NLR), and extending into the NLR in the case of [Fe VII] and [Ne V] lines. The CL profiles strongly vary with the distance to the nucleus. We observed line splitting in the core of some of the galaxies. Line peak shifts, both redshift and blueshift, typically reached 500 km s −1 , and even higher velocities (1000 km s −1 ) in some of the galaxies. In general, CLs follow the same pattern of rotation curves as low-ionization lines like [O III]. From a direct comparison between the radio and the CL emission we find that neither the strength nor the kinematics of the CLs scales in any obvious and strong way with the radio jets. Moreover, the similarity of the flux distributions and kinematics of the CLs and low-ionization lines, the low temperatures derived for the gas, and the success of photoionization models to reproduce, within a factor of a few, the observed line ratios, point towards photoionization as the main driving mechanism of CLs.

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Section: Resultsmentioning

confidence: 99%

Demystifying the coronal-line region of active galactic nuclei: spatially resolved spectroscopy with theHubble Space Telescope

Mazzalay¹,

Rodríguez-Ardila²,

Komossa³

2010

Monthly Notices of the Royal Astronomical Society

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“…It is also known for the bright highionization emission lines displayed in its optical nuclear spectrum (Durret 1994). Spectropolarimetric observations by Nagao et al (2004) show prominent scattered broad Hα emission and various narrow forbidden emission lines, the degree of polarization of the latter ones correlated with the ionization potential of the corresponding line. They interpret this correlation in terms of obscuration of the stratified NLR by the optically and geometrically thick dusty torus.…”

Section: Notes On Individual Objectsmentioning

confidence: 96%

A 0.8–2.4μm spectral atlas of active galactic nuclei

Riffel

Rodríguez-Ardila²,

Pastoriza

2006

A&A

199

286

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Aims. We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN) of all degrees of activity in the wavelength interval of 0.8-2.4 µm, including the fluxes of the observed emission lines. We analyze the spectroscopic properties of the continuum and emission line spectra of the sources. Methods. In order to exclude aperture and seeing effects we used near-infrared spectroscopy in the short cross-dispersed mode (SXD, 0.8-2.4 µm), taking the JHK-bands spectra simultaneously.Results. We present the most extensive NIR spectral atlas of AGN to date. This atlas offers a suitable database for studying the continuum and line emission properties of these objects in a region full of interesting features. The shape of the continuum of QSOs and Sy 1's are similar, being essentially flat in the H and K bands, while a strong variation is found in the J band. In Seyfert 2 galaxies, the continuum in the Fλ × λ space smoothly decreases in flux from 1.2 µm redwards in almost all sources. In J, it smoothly rises bluewards in some sources, while in others a small decrease in flux is observed. The spectra are dominated by strong emission

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“…This component is narrower than the Paβ broad component (FWHM∼1700 km s −1 ), although both measurements are consistent within the errors (see Table 3). Spectropolarimetric observations (Nagao et al 2004) reveal prominent scattered broad Hα emission, together with the optical Fe II multiplet. The measured [Fe II]1.257/1.644 µm line ratio for Mrk 573 indicates a negligible extinction towards the NLR, likely allowing to see more internal regions.…”

Section: A2 Mrk 573mentioning

confidence: 97%

“…This component is narrower than the Paβ broad component (FWHM∼1700 km s −1 ), although both measurements are consistent within the errors (see Table 3). Spectropolarimetric observations (Nagao et al 2004) With respect to the molecular content, the H 2 emission is very weak in Mrk 573, and the most likely excitation mechanism is UV fluorescence according to the H 2 1-0S(1)/2-1S(1) ratio (see Figure 11).…”

Section: A2 Mrk 573mentioning

confidence: 99%

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

Almeida

García

Acosta–Pulido

2009

ApJ

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Near-infrared spectroscopic data for the five Seyfert galaxies with jet-gas interaction Mrk 348, Mrk 573, Mrk 1066, NGC 7212, and NGC 7465, taken with the LIRIS near-infrared camera/spectrometer at the William Herschel Telescope (WHT) are reported. The long-slit spectra reveal the characteristic strong emission lines of this type of objects. Many forbidden transitions and hydrogen recombination lines are employed here to study the excitation and ionization mechanisms that are dominating the narrow-line region emission of these objects, that is affected by the radio-jet interaction. Several absorption features are also detected in the H and K bands of these galaxies, allowing us to identify the spectral types that are producing them. We find that the continuum can be reproduced by a combination of late-type stellar templates plus a Blackbody component associated to host dust, mainly contributing to the K band emission. The detection of the permitted O I and Fe II lines and broad components of the hydrogen recombination lines in the spectra of Mrk 573 and NGC 7465 allows the reclassification of these two galaxies that are not canonical Type-2 Seyferts: Mrk 573 is confirmed to be an obscured Narrow-line Seyfert 1 and NGC 7465 is revealed for the first time as a Type-1 LINER through its near-infrared spectrum.

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Subaru Spectropolarimetry of Markarian 573: The Hidden High-Ionization Nuclear Emission-Line Region inside the Dusty Torus

Cited by 10 publications

References 54 publications

Demystifying the coronal-line region of active galactic nuclei: spatially resolved spectroscopy with theHubble Space Telescope

Demystifying the coronal-line region of active galactic nuclei: spatially resolved spectroscopy with theHubble Space Telescope

A 0.8–2.4μm spectral atlas of active galactic nuclei

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

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