scholarly journals Coronal-line forest active galactic nuclei – I. Physical properties of the emission-line regions

2020 ◽  
Vol 500 (2) ◽  
pp. 2666-2684
Author(s):  
F C Cerqueira-Campos ◽  
A Rodríguez-Ardila ◽  
R Riffel ◽  
M Marinello ◽  
A Prieto ◽  
...  
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Infrared Emission ◽  
Ionization Mechanism ◽  
Coronal Line ◽  
Coronal Emission ◽  
High Ionization ◽  
Stellar Velocity

ABSTRACT Coronal-line forest (CLiF) active galactic nuclei (AGNs) are characterized by strong high-ionization lines, which contrasts with what is found in most AGNs. Here, we carry out a multiwavelength analysis aimed at understanding the physical processes in the narrow-line region (NLR) of these objects, and at discovering whether they are indeed a special class of AGNs. By comparing coronal emission-line ratios we conclude that there are no differences between CLiF and non-CLiF AGNs. We derive physical conditions of the NLR gas and we find electron densities in the range of 3.6 × 102 to 1.7 × 104 cm−3 and temperatures of 3.7 × 103 to 6.3 × 104 K, suggesting that the ionization mechanism is associated primarily with photoionization by the AGN. We suggest an NLR dominated by matter-bounded clouds to explain the high-ionization line spectrum observed. The mass of the central black hole, derived from the stellar velocity dispersion, shows that most of the objects have values in the interval 107–108 M⊙. Our results imply that CLiF AGNs are not in a separate category of AGNs. In all optical/near-infrared emission-line properties analysed, they represent an extension to the low/high ends of the distribution within the AGN class.

scholarly journals THE NEAR-INFRARED CORONAL LINE SPECTRUM OF 54 NEARBY ACTIVE GALACTIC NUCLEI

2011 ◽  
Vol 743 (2) ◽  
pp. 100 ◽  
Author(s):  
A. Rodríguez-Ardila ◽  
M. A. Prieto ◽  
J. G. Portilla ◽  
J. M. Tejeiro
Keyword(s):  
Active Galactic Nuclei ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Line Spectrum ◽  
Coronal Line

Iron Is Not Depleted in High-Ionization Nuclear Emission-Line Regions of Active Galactic Nuclei

2003 ◽  
Vol 125 (4) ◽  
pp. 1729-1735 ◽  
Author(s):  
Tohru Nagao ◽  
Takashi Murayama ◽  
Yasuhiro Shioya ◽  
Yoshiaki Taniguchi
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
High Ionization

High-density gas in bipolar outflow sources and active galactic nuclei

1986 ◽  
Vol 64 (4) ◽  
pp. 421-425 ◽  
Author(s):  
S. E. Persson
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Seyfert Galaxy ◽  
Detailed Comparison ◽  
Seyfert Galaxies ◽  
High Density ◽  
Young Stellar Objects ◽  
Molecular Outflow

The highest density regions near the base of the outflow in young stellar objects with bipolar molecular outflows are discussed. Bright emission lines of Ca II and O I characterize the spectra and lead to estimates of n ~ 1010 cm−3, temperatures of a few thousand Kelvins, and mass motions of several hundred kilometres per second. Typically the rate of momentum transfer within this region fails by more than an order of magnitude to provide the force necessary to drive the molecular outflow on the parsec scale. The overall near-infrared spectra of these young stars are similar to those of certain active galactic nuclei having strong Fe II emission.A comparison is made between the Ca II and O I lines in the infrared core source of the bipolar H II region S106 and in the Seyfert galaxy Mrk 42. The spectra are shown to be scaled versions of each other, and we conclude that the physical conditions are broadly similar in the high-density emission-line regions of these two objects. The Ca II lines appear self-reversed in both objects, but possible Ca II absorption in the underlying galaxy in Mrk 42 compromises the detailed comparison of line shapes. Nevertheless, it is likely that the geometries and velocity fields are also analogous. Derived parameters of the emission-line regions in S106 and the Seyfert galaxies I Zw 1 and Mrk 42 are compared.

scholarly journals The near-infrared broad emission line region of active galactic nuclei - II. The 1-μm continuum

2011 ◽  
Vol 414 (1) ◽  
pp. 218-240 ◽  
Author(s):  
Hermine Landt ◽  
Martin Elvis ◽  
Martin J. Ward ◽  
Misty C. Bentz ◽  
Kirk T. Korista ◽  
...  
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Broad Emission ◽  
Line Region ◽  
Broad Emission Line

scholarly journals The Nature of the NIR Emission from Seyfert 1 Galaxies: NGC 4051

1994 ◽  
Vol 159 ◽  
pp. 335-335
Author(s):  
M. Salvati ◽  
G. Calamai ◽  
L.K. Hunt ◽  
G. Del Zanna ◽  
E. Giannuzzo ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Uv Radiation ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Infrared Emission ◽  
Nuclear Radiation ◽  
Rapid Variation ◽  
Nir Emission ◽  
Ngc 4051 ◽  
Near Infrared Emission

The near infrared emission (NIR) of radio quiet active galactic nuclei is commonly attributed to dust, absorbing and re-emitting some of the nuclear UV radiation. The dust can survive only at distances larger than a few light months, and any rapid variation of the nuclear radiation, on timescales of a day or less, will be completely smeared out.

scholarly journals Kiloparsec-scale jet-driven feedback in AGN probed by highly ionized gas: A MUSE/VLT perspective

2019 ◽  
Vol 15 (S359) ◽  
pp. 221-225
Author(s):  
A. Rodríguez-Ardila ◽  
M. A. Fonseca-Faria
Keyword(s):  
Low Power ◽  
Emission Line ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Field Of View ◽  
Coronal Line ◽  
Ionized Gas ◽  
X Ray ◽  
Physical Conditions ◽  
Radio Jets

AbstractWe employ optical spectroscopy from the Multi Unit Spectroscopic Explorer (MUSE) combined with X-ray and radio data to study the highly-ionized gas (HIG) phase of the feedback in a sample of five local nearby Active Galactic Nuclei (AGN). Thanks to the superb field of view and sensitivity of MUSE, we found that the HIG, traced by the coronal line [Fe vii] λ6089, extends to scales not seen before, from 700 pc in Circinus and up to ∼2 kpc in NGC 5728 and NGC 3393. The gas morphology is complex, following closely the radio jet and the X-ray emission. Emission line ratios suggest gas excitation by shocks produced by the passage of the radio jet. This scenario is further supported by the physical conditions derived for the HIG, stressing the importance of the mechanical feedback in AGN with low-power radio jets.

scholarly journals Spatially Resolved Spectroscopy to Confirm or Disprove Dual Active Galactic Nuclei

2013 ◽  
Vol 9 (S304) ◽  
pp. 371-374
Author(s):  
Rosalie C. McGurk ◽  
Claire E. Max ◽  
Anne Medling ◽  
Gregory A. Shields
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Adaptive Optics ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Spatially Resolved ◽  
Spatially Resolved Spectroscopy ◽  
Integral Field Spectrograph ◽  
Guide Star ◽  
Integral Field

AbstractWhen galaxies merge, gas accretes onto both central supermassive black holes. Thus, one expects to see dual active galactic nuclei (AGNs) in a fraction of galaxy mergers. Candidates for galaxies containing dual AGNs have been identified by the presence of double-peaked narrow [O III] emission lines and by high spatial resolution images of close galaxy pairs. 30% of double-peaked narrow [OIII] emission line SDSS AGNs have two spatial components within a 3″ radius. However, spatially resolved spectroscopy is needed to confirm these galaxy pairs as systems with double AGNs. With the Keck 2 Laser Guide Star Adaptive Optics system and the OSIRIS near-infrared integral field spectrograph, we obtained spatially resolved spectra for SDSS J095207.62+255257.2, confirming that it contains a Type 1 and a Type 2 AGN separated by 4.8 kpc (=1.0″). We performed similar integral field and long-slit spectroscopy observations of more spatially separated candidate dual AGNs and will report on the varied results. By assessing what fraction of radio-quiet double-peaked emission line SDSS AGNs are true dual AGNs, we can better constrain the statistics of dual AGNs and characterize physical conditions throughout these interacting AGNs.

scholarly journals The Near‐Infrared Broad Emission Line Region of Active Galactic Nuclei. I. The Observations

2008 ◽  
Vol 174 (2) ◽  
pp. 282-312 ◽  
Author(s):  
Hermine Landt ◽  
Misty C. Bentz ◽  
Martin J. Ward ◽  
Martin Elvis ◽  
Bradley M. Peterson ◽  
...  
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Broad Emission ◽  
Line Region ◽  
Broad Emission Line

scholarly journals Constraints on the production and escape of ionizing radiation from the emission-lines of metal-poor star-forming galaxies

2019 ◽  
Vol 15 (S352) ◽  
pp. 121-122
Author(s):  
A. Plat ◽  
S. Charlot ◽  
G. Bruzual ◽  
A. Feltre ◽  
A. Vidal-Garca ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Emission Line ◽  
Active Galactic Nuclei ◽  
High Redshift ◽  
Galactic Nuclei ◽  
Emission Lines ◽  
High Redshift Galaxies ◽  
Star Forming ◽  
Radiative Shocks ◽  
Metal Poor Star

AbstractTo understand how the nature of the ionizing sources and the leakage of ionizing photons in high-redshift galaxies can be constrained from their emission-line spectra, we compare emission-line models of star-forming galaxies including leakage of ionizing radiation, active galactic nuclei (AGN) and radiative shocks, with observations of galaxies at various redshifts with properties expected to approach those of primeval galaxies.

scholarly journals NEON AND $[{\rm{C}}\,{\rm{II}}]$ 158 μ m EMISSION LINE PROFILES IN DUSTY STARBURSTS AND ACTIVE GALACTIC NUCLEI

2016 ◽  
Vol 226 (1) ◽  
pp. 11 ◽  
Author(s):  
Anahit Samsonyan ◽  
Daniel Weedman ◽  
Vianney Lebouteiller ◽  
Donald Barry ◽  
Lusine Sargsyan
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Line Profiles
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