Optical spectroscopy of local type-1 AGN LINERs

Cazzoli, S.; Márquez, I.; Masegosa, J.; Olmo, A. del; Pović, M.; González‐Martín, O.; Balmaverde, B.; Hernández-García, L.; García‐Burillo, S.

doi:10.1093/mnras/sty1811

Cited by 35 publications

(79 citation statements)

References 131 publications

(224 reference statements)

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“…While the first one is most likely associated with cold material in the torus, the latter may be explained as material along the line of sight in the galaxy or as outflows. Recent optical spectroscopy of NGC 1052 show evidence of possible outflows, preferentially seen in [O I], in agreement with the second scenario (Cazzoli et al 2018). However, our X-ray analysis shows an ionisation degree consistent with the neutral state.…”

Section: Absorption and Reflectionsupporting

confidence: 78%

Accretion and jets in a low-luminosity AGN: the nucleus of NGC 1052

Falocco

Larsson

Nandi

2020

A&A

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Aims. We aim to determine the properties of the central region of NGC 1052 using X-ray and radio data. NGC 1052 (z=0.005) has been investigated for decades in different energy bands and shows radio lobes and a low luminosity active galactic nucleus (LLAGN). Methods. We use X-ray images from Chandra and radio images from Very Large Array (VLA) to explore the morphology of the central area. We also study the spectra of the nucleus and the surrounding region using observations from Chandra and XMM-Newton. Results. We find diffuse soft X-ray radiation and hotspots along the radio lobes. The spectrum of the circum-nuclear region is well described by a thermal plasma (T∼ 0.6 keV) and a power law with photon index Γ ∼ 2.3. The nucleus shows a hard power law (Γ ∼ 1.4) modified by complex absorption. A narrow iron Kα line is also clearly detected in all observations, but there is no evidence for relativistic reflection. Conclusions.The extended emission is consistent with originating from extended jets and from jet-triggered shocks in the surrounding medium. The hard power-law emission from the nucleus and the lack of relativistic reflection supports the scenario of inefficient accretion in an Advection Dominated Accretion Flow (ADAF).

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Section: Absorption and Reflectionsupporting

confidence: 78%

Accretion and jets in a low-luminosity AGN: the nucleus of NGC 1052

Falocco

Larsson

Nandi

2020

A&A

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“…We plan to measure emission lines in both new and archival optical spectra of the selected AGNs fitting both narrow and broad lines, as in Cazzoli et al (2018). The measurements will be compared to those in the literature and to the optical/X-ray properties.…”

Section: Main Results and Future Workmentioning

confidence: 99%

Optical variations in changing-look AGNs selected at X-rays

Cazzoli¹,

Masegosa²,

Márquez³

et al. 2019

Proc. IAU

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Recent observations of local AGNs have revealed that many of them show a ‘changing look’ behavior at optical and X-rays wavelengths in the sense of transiting between different AGNs families (e.g. from type-1 to type-2 or vice-versa). In order to pinpoint the possible relation of the changes, we performed optical spectroscopic observations (with CAFOS/CAHA) of 15 changing look AGNs selected at X-rays. Highlights from our spectroscopic study are presented.

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“…The observed value is 221±2 km s −1 , whereas the instrumental broadening is 183±7 km s −1 , thus we obtained σ =124±11 km s −1 . Using this measurement and following the relation in Gültekin et al (2009) Following Cazzoli et al (2018), we estimated the accuracy of the fit as the ratio between the standard deviation values estimated from a wavelength range under the line of interest ε line and that from a portion of the continuum free of both emission and absorption lines, ε c , i.e. ε fit line = ε line /ε c .…”

Section: Clumpymentioning

confidence: 99%

A young and obscured AGN embedded in the giant radio galaxy Mrk 1498

Hernández-García

Panessa

Bassani³

et al. 2019

Monthly Notices of the Royal Astronomical Society

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Mrk 1498 is part of a sample of galaxies with extended emission line regions (extended outwards up to a distance of ∼7 kpc) suggested to be photo-ionized by an AGN that has faded away or that is still active but heavily absorbed. Interestingly, the nucleus of Mrk 1498 is at the center of two giant radio lobes with a projected linear size of 1.1 Mpc. Our multi-wavelength analysis reveals a complex nuclear structure, with a young radio source (Giga-hertz Peaked Spectrum) surrounded by a strong X-ray nuclear absorption, a mid-infrared spectrum that is dominated by the torus emission, plus a circum-nuclear extended emission in the [OIII] image (with radius of ∼ 1 kpc), most likely related to the ionization of the AGN, aligned with the small and large scale radio jet and extended also at X-rays. In addition a large-scale extended emission (up to ∼ 10 kpc) is only visible in [OIII]. These data show conclusive evidence of a heavily absorbed nucleus and has recently restarted its nuclear activity. To explain its complexity, we propose that Mrk 1498 is the result of a merging event or secular processes, such as a minor interaction, that has triggered the nuclear activity and produced tidal streams. The large-scale extended emission that gives place to the actual morphology could either be explained by star formation or outflowing material from the AGN. ble for the broad components in the optical spectra. A dusty structure (often simplified as a torus) of size around 1-10 pc encloses the BLR. This structure attenuates the optical/UV emission and re-emits it in the infrared. Therefore, mid-infrared frequencies are ideal to reveal the properties of the dust in the nuclear region related to the torus, as well as X-rays where the column density measured in the spectrum is thought to be related with absorption by the torus (e.g., González-Martín et al. 2015). X-rays are usually able to penetrate through the dusty torus, allowing to investigate coronal emission at few gravitational radii from the SMBH. At kpc scales the narrow line region (NLR) is present, with clouds moving at v ∼500km/s, the region responsible for the narrow lines in the optical spectra. About 10% of AGN also show strong relativistic jets that imprint their mark at radio frequencies (Kellermann et al. 1989), although a continous distribution in radio powers suggests that AGN are radio emitters at any level (Panessa et al. 2019).

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Optical spectroscopy of local type-1 AGN LINERs

Cited by 35 publications

References 131 publications

Accretion and jets in a low-luminosity AGN: the nucleus of NGC 1052

Accretion and jets in a low-luminosity AGN: the nucleus of NGC 1052

Optical variations in changing-look AGNs selected at X-rays

A young and obscured AGN embedded in the giant radio galaxy Mrk 1498

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