Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
131
result(s) for
"Rodríguez-Ardila, A"
Sort by:
The two-phase gas outflow in the Circinus Galaxy
2020
We employ Multi Unit Spectroscopic Explorer (MUSE) data to study the ionized and very ionized gas phase of the feedback in Circinus, the closest Seyfert 2 galaxy. The analysis of the nebular emission allowed us to detect a remarkable high-ionization gas outflow, out of the galaxy plane, traced by the coronal lines [Fe viii] 6089Å and [Fe x] 6374Å, extending up to 700 parsecs north-west from the nucleus. The gas kinematics reveal expanding gas shells with velocities of a few hundred km s-1, spatially coincident with prominent hard X-ray emission detected by Chandra. Density and temperature sensitive line ratios show that the extended high-ionization gas is characterized by a temperature of up to 18000 K and a gas density of ne > 102 cm−3. We propose two scenarios consistent with the observations to explain the high-ionization component of the outflow: an active galactic nuclei (AGN) ejection that took place ⁓105 yr ago or local gas excitation by shocks produced by the passage of a radio jet.
Journal Article
Kiloparsec-scale jet-driven feedback in AGN probed by highly ionized gas: A MUSE/VLT perspective
by
Fonseca-Faria, M. A.
,
Rodríguez-Ardila, A.
in
Active galactic nuclei
,
Astronomy
,
Contributed Papers
2020
We 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.
Journal Article
Properties of AGN in NIR within the context of the Eigenvector 1
by
dos Santos, D. Dias
,
Marinello, M.
,
Rodríguez-Ardila, A.
in
Astronomy
,
Continuum radiation
,
Contributed Papers
2020
We present a spectral atlas of 70 type-I AGN with the wavelength ranging 0.4–2.5 μm. For 37 sources, this is the first report of NIR spectroscopy in literature. The sample was constructed to study narrow line Seyfert 1 and quasars, with a large range of line widths (800 km s−1 < FWHM < 4000 km s−1) and Fe II intensities (0.2 < R4570 < 2.8). This work presents partial results of an ongoing project that has the objective of modeling the continuum emission and emission lines in order to derive the physics driven the Eigenvector 1 through a panchromatic spectral analysis, with emphasis on strong to super-strong Fe ii emitters. Our results show that hot dust near the sublimation temperature is necessary to explain the 1μm break of the power law component of the continuum. We estimated the hot dust mass and found a weak or absent correlation with the Fe II intensity. Moreover, we found that low ionisation ions are formed in an outer region of the BLR.
Journal Article
The Coronal Emission-Line Region in AGNs: A Hubble Space Telescope View
by
Mazzalay, X.
,
Komossa, S.
,
Rodríguez-Ardila, A.
in
Astronomy
,
Astrophysics
,
Contributed Papers
2009
We present a study of HST/STIS optical spectra of a sample of ten Seyfert galaxies aimed at analyzing the structure and physical properties of the coronal line region. The high spatial resolution provided by STIS (about 7 pc for the closest objects) allowed us to resolve the coronal line region and obtain key information about the kinematics of the coronal-line gas, measure directly its spatial scale, and study the mechanisms that drive the high-ionization lines.
Journal Article
Perfil neuropsicológico en pacientes con ACV isquémico de la arteria cerebral media izquierda
by
Ardila Rodríguez, William A
,
Silva Sieger, Federico A
,
María Rocío Acosta Barreto
in
Ischemia
,
MEDICINE, GENERAL & INTERNAL
,
Neuropsychology
2013
Introducción: el ACV produce alteraciones neuropsicológicas con trastorno de la atención, la orientación, la memoria y la praxis.Objetivo: determinar el perfil neuropsicológico en pacientes con ataque cerebrovascular (ACV) isquémico de la arteria cerebral media izquierda (ACM).Materiales y métodos: se realizó un análisis descriptivo sobre las evaluaciones neuropsicológicas transversales en 4 pacientes, con diagnóstico de ACV isquémico de la ACM izquierda. Se realizó un análisis sobre la base de un procedimiento clínico y no psicométrico, tomando como punto de referencia los ítems de la prueba de Barcelona.Resultados: se encontró que las funciones neuropsicológicas más afectadas fueron: lenguaje espontáneo, prosodia, contenidos informativos, lenguaje automático, lectura en voz alta, comprensión lectora, mecánica de la escritura al dictado, escritura espontánea y velocidad de procesamiento. Las ejecuciones mejor preservadas fueron memoria de trabajo, praxias orofonatorias e ideatorias, repetición, denominación y atención sostenida.Conclusiones: los pacientes con ACV isquémico de la arteria cerebral media izquierda evaluados, presentaron déficits en lenguaje espontáneo, velocidad de procesamiento, gnosias, memoria y atención, y las funciones mejor preservadas fueron memoria de trabajos, denominación y praxias.
Journal Article
Coronal Line Forest AGN -- II. Analysis of the spectral energy distribution
by
Panda, S
,
Riffel, R
,
Rodríguez-Ardila, A
in
Active galactic nuclei
,
Galaxies
,
Infrared analysis
2023
Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are characterized by strong, high-ionization lines, which are in contrast to what is found in typical AGNs. Here, we carry out an infrared analysis aimed at understanding the spectral energy distribution of six sources from this group. In this work, the properties of the dusty torus for these objects are analyzed. To this purpose, we infer the physical and geometrical properties of the dust structure that surrounds the central region by fitting with models the spectral energy distribution (SED) of CLiF AGNs in the infrared. For this analysis, we compare the results of three models: CLUMPY, SKIRTOR and CAT3D-WIND. Using the Bayesian information criterion, SKIRTOR was found to have the most robust fit to the SEDs in five out of six galaxies. The remaining object was best fitted with CLUMPY. The results indicate that these objects are preferentially Type~I sources, supporting the detection of broad components in the permitted lines, likely associated with the BLR in the near-infrared (NIR) spectra. The best SED fitting indicates that the line of sight gives access to the view of the central source for these objects, but the amount of dusty clouds in the same direction is high, suggesting the hypothesis that they obscure the emission of the continuum produced by the central source and that the obscuration makes the coronal lines to not overlap with the continuum.
Physical Conditions and Extension of the Coronal Line Region in IC 5063
by
Fonseca-Faria, M A
,
Rodríguez-Ardila, A
,
Contini, M
in
Active galactic nuclei
,
Integral field spectroscopy
,
Kinematics
2023
We study the ionised and highly ionised gas phases in the Seyfert~2 galaxy IC~5063 by means of VLT/MUSE integral field spectroscopy. Our analysis allowed us to detect a high-ionisation gas outflow traced by the coronal lines [\\ion{Fe}{vii}]~\\(\\lambda\\)6087 and [\\ion{Fe}{x}]~\\(\\lambda\\)6375. Both emissions are found to be extended. The former up to 1.2~kpc and 700~pc NW and SE from the nucleus, respectively. The latter reaches 700~pc NW of the nucleus. This is the first time that [\\ion{Fe}{x}] emission is observed at such distances from the central engine in an active galactic nucleus. The [\\ion{Fe}{vii}]~\\(\\lambda\\)6087 emission peaks at the nucleus, with two secondary peaks at the position of the NW and SE radio-lobes. The gas kinematics is complex, with the coronal emission displaying split line profiles along the radio jet and line widths of several hundreds km~s\\(^{-1}\\). Velocity shifts of up to 600~km~s\\(^{-1}\\) in excess of the systemic velocity of the galaxy are found very close to the radio lobes and along the jet propagation. The extended coronal gas is characterised by temperatures reaching 20000~K and electron densities \\(>10^2\\)~cm\\(^{-3}\\), with the larger values associated to the regions of larger turbulence, likely due to the passage of the radio jet. This hypothesis is supported by photoionisation models that combine the effects of the central engine and shocks. Our work highlights the strong relationship between extended coronal emission and the radio jet, with the former suitably tracing the latter, which in the case of IC~5063, propagates very close to the galaxy disc.
The ionised gas outflow in the Circinus galaxy: kinematics and physical conditions
by
Fonseca-Faria, M A
,
Rodríguez-Ardila, A
,
Contini, M
in
Active galactic nuclei
,
Electron density
,
Emission analysis
2021
We employ MUSE/VLT data to study the ionised and highly ionised gas phases of the feedback in Circinus, the closest Seyfert 2 galaxy to us. The analysis of the nebular emission allowed us to detect a remarkable high-ionisation gas outflow beyond the galaxy plane traced by the coronal lines [Fe VII] \\(\\lambda\\)6089 and [Fe X] \\(\\lambda\\)6374, extending up to 700 pc and 350 pc NW from the nucleus, respectively. This is the first time that the [Fe X] emission is observed at such distances from the central engine in an AGN. The gas kinematics reveals expanding gas shells with velocities of a few hundred km s\\(^{-1}\\), spatially coincident with prominent hard X-ray emission detected by Chandra. Density and temperature sensitive line ratios show that the extended high-ionisation gas is characterized by a temperature reaching 25000 K and an electron density > 10\\(^2\\) cm\\(^{-3}\\). We found that local gas excitation by shocks produced by the passage of a radio jet leads to the spectacular high-ionisation emission in this object. This hypothesis is fully supported by photoionisation models that accounts for the combined effects of the central engine and shocks. They reproduce the observed emission line spectrum at different locations inside and outside of the NW ionisation cone. The energetic outflow produced by the radio jet is spatially located close to an extended molecular outflow recently reported using ALMA which suggests that they both represent different phases of the same feedback process acting on the AGN.
A closer look at NGC 7314 nuclear region: a multiwavelength analysis of the Seyfert nucleus and its surroundings
2022
The central regions of galaxies harbouring active galactic nuclei (AGNs) can be quite complex, especially at high activity, presenting, besides variability, a variety of phenomena related, e.g. to ionization/excitation mechanisms. A detailed study is necessary in order to understand better those objects. For that reason, we performed a multiwavelength analysis of the nuclear region of the nearby Seyfert galaxy NGC 7314, using an optical data cube obtained with the Integral Field Unit from the Gemini Multi-Object Spectrograph, together with Hubble Space Telescope images, X-ray data from the XMM-Newton and the Nuclear Spectroscopic Telescope Array and radio data from Atacama Large Millimeter/Submillimeter Array. The goals were to study the nuclear and circumnuclear emission, the emission of the AGN and the gas kinematics. The optical spectrum shows the emission of a Seyfert nucleus, with broad components in the H\\(\\alpha\\) and H\\(\\beta\\) emission lines, characterising a type 1 AGN, with a spectrum rich in coronal emission lines. The spatial morphology of the [OIII]\\(\\lambda\\)5007 suggests the presence of an ionization cone, west of the nucleus, meanwhile the east cone seems to be obscured by dust. An extended [FeVII]\\(\\lambda\\)6087 emission was also detected, which could be possibly explained by a scenario involving photoionization+shocks mechanisms. X-rays analyses showed that there are variations in the flux; however, we did not detect any variations in the column density along the line of sight. Its variability may be a consequence of changes in the AGN accretion rate.
The size of the Coronal Line Region in Active Galactic Nuclei: a MUSE perspective
by
Riffel, R
,
Fonseca-Faria, M A
,
Prieto, A
in
Active galactic nuclei
,
Emission analysis
,
Excitation
2025
We investigated by means of MUSE/VLT observations the true size of the coronal line region (CLR) in a local sample of nine active galactic nuclei known for displaying prominent coronal emission. Our analysis show that the CLR is extended from several hundred parsecs to a few kiloparsecs in the lines of [Fe VII] (IP=99 eV) and [Fe X] (IP=235 eV). In all cases, the coronal emission is closely aligned along the radio-jet axis and constrained to the limits of the [O III] ionisation cone. Besides the nuclear emission, secondary emission peaks in [Fe VII] and [Fe X] are found along the extended emission, with a shallow decrease of the line intensity with increasing distance from the AGN. Both facts suggest the action of an additional excitation mechanism besides nuclear photoionisation for the origin of the coronal gas. This is further supported by the fact that in some sources the extended coronal emission accounts for more than 50\\% of the total emission and by the high degree of gas excitation in the off-nuclear region. A positive trend between the coronal line luminosity and the jet power points to shocks induced by the jet passage as the key mechanism to produce and excite this gas. We provide the first estimate of the [Fe X] coronal gas size, being in the kpc range. Our results stress the importance of the CLR as a key ingredient that should be fully considered in models trying to explain the physics of the narrow line region in AGN.