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Durret, F.; Adami, C.; Lobo, C.

doi:10.1023/a:1024694700730

Cited by 13 publications

(19 citation statements)

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“…In addition to the known three compact components and diffuse emission aligned along the minor axis of NGC 7319, the new image formed from the VLA archive data also shows, for the first time, emission of extent ≈20 arcsec perfectly aligned with the strong bar at a PA of 142 • (Durret 1994), which is also the position angle of the major axis of the optical Seyfert galaxy. Assuming a heliocentric systemic velocity of 6740 km s −1 , this corresponds to ∼9.7 kpc for H 0 = 65 km s −1 Mpc −1 .…”

Section: Radiomentioning

confidence: 58%

“…There is no evidence of a jet as is often the case. However, the size, luminosity and spiral host galaxy of NGC 7319 is consistent with it being a Seyfert 2 galaxy (Durret 1994). The asymmetric arm ratio of 1:3.1 for the distances between the core (component B) and the two hotspots (components A and C, respectively) possibly indicates that material to the northeast is blocking the outflow of plasma in that direction, whereas plasma outflow to the southwest is much less inhibited.…”

Section: Stephan Quintet's Radio Detectionsmentioning

confidence: 71%

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MERLIN observations of Stephan's Quintet

Xanthopoulos

Muxlow

Thomasson

et al. 2004

Monthly Notices of the Royal Astronomical Society

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We present MERLIN L-band images of the compact galaxy group, Stephan's Quintet. The Seyfert 2 galaxy, NGC 7319, the brightest member of the compact group, is seen to have a triple radio structure typical of many extra-galactic radio sources which have a flat spectrum core and two steep spectrum lobes with hot spots. The two lobes are asymmetrically distributed on opposite sides of the core along the minor axis of the galaxy. Ultraviolet emission revealed in a high resolution HRC/ACS HST image is strongly aligned with the radio plasma and we interpret the intense star formation in the core and north lobe as an event induced by the collision of the north radio jet with over-dense ambient material. In addition, a re-mapping of archive VLA L-band observations reveals more extended emission along the major axis of the galaxy which is aligned with the optical axis. Images formed from the combined MERLIN and archive VLA data reveal more detailed structure of the two lobes and hot spots.Comment: Completely revised version with new HST data included, to appear in MNRA

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Section: Radiomentioning

confidence: 58%

Section: Stephan Quintet's Radio Detectionsmentioning

confidence: 71%

MERLIN observations of Stephan's Quintet

Xanthopoulos

Muxlow

Thomasson

et al. 2004

Monthly Notices of the Royal Astronomical Society

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“…The reason for models with dust can not explain the observed flux of the lines considered is probably because gas clouds in the high-ionization part of NLRs are dusty free, as suggested by Nagao et al (2003). Radovich & Rafanelli (1996), Osterbrock (1981), González Delgado & Pérez (1996), Osterbrock & Dahari (1983), Phillips et al (1983), Goodrich & Osterbrock (1983), Shuder (1980), Durret & Bergeron (1988), and Shuder & Osterbrock (1981). Several metallicity indicators have been proposed to estimate the metallicity using strong emission-lines from the gas phase of objects without a direct determination of an electron temperature.…”

Section: Model Parametersmentioning

confidence: 99%

Metallicity evolution of AGNs from UV emission lines based on a new index

Dors

Cardaci

Hägele

et al. 2014

Monthly Notices of the Royal Astronomical Society

101

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We analyzed the evolution of the metallicity of the gas with the redshift for a sample of AGNs in a very wide redshift range (0 < z < 4) using ultraviolet emission-lines from the narrow-line regions (NLRs) and photoionization models. The new index C43=log[(C iv+C iii])/He ii] is suggested as a metallicity indicator for AGNs. Based on this indicator, we confirmed the no metallicity evolution of NLRs with the redshift pointed out by previous works. We found that metallicity of AGNs shows similar evolution than the one predicted by cosmic semi-analytic models of galaxy formation set within the Cold Dark Matter merging hierarchy (for z 3). Our results predict a mean metallicity for local objects in agreement with the solar value (12+log(O/H)=8.69).This value is about the same that the maximum oxygen abundance value derived for the central parts of local spiral galaxies. Very low metallicity log(Z/Z ⊙ ) ≈ −0.8 for some objects in the range 1.5 < z < 3 is derived.

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“…NGC 7682 is a Seyfert 2 galaxy (Huchra & Burg 1992) in interaction with NGC 7683 (Arp 1966). Ionized gas in Hα + [N II] and [O III] is detected on scales of kpc in this galaxy (Brodie et al 1987;Durret 1994). In the NIR, only K-band spectroscopy was previously reported by Imanishi & Alonso-Herrero (2004).…”

Section: Ngc 7682mentioning

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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Untitled

Cited by 13 publications

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MERLIN observations of Stephan's Quintet

MERLIN observations of Stephan's Quintet

Metallicity evolution of AGNs from UV emission lines based on a new index

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

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