16 research outputs found
Unexplored outflows in nearby low luminosity AGNs: the case of NGC 1052
Outflows play a central role in galaxy evolution shaping the properties of
galaxies. Understanding outflows and their effects in low luminosity AGNs, such
as LINERs, is essential (e.g. they are a numerous AGN population in the local
Universe). We obtained VLT/MUSE and GTC/MEGARA optical IFS-data for NGC1052,
the prototypical LINER. The stars are distributed in a dynamically hot disc,
with a centrally peaked velocity dispersion map and large observed velocity
amplitudes. The ionised gas, probed by the primary component is detected up to
30arcsec (3.3 kpc) mostly in the polar direction with blue and red
velocities (V250 km/s). The velocity dispersion map shows a
notable enhancement (90 km/s) crossing the galaxy along the major
axis of rotation in the central 10arcsec. The secondary component has a bipolar
morphology, velocity dispersion larger than 150 km/s and velocities up to 660
km/s. A third component is detected but not spatially resolved. The maps of the
NaD absorption indicate optically thick neutral gas with a velocity field
consistent with a slow rotating disc (V = 7712 km/s) but the
velocity dispersion map is off-centred without any counterpart in the flux map.
We found evidence of an ionised gas outflow with mass of 1.60.6
10 Msun, and mass rate of 0.40.2 Msun/yr. The outflow is propagating
in a cocoon of gas with enhanced turbulence and might be triggering the onset
of kpc-scale buoyant bubbles (polar emission). Taking into account the energy
and kinetic power of the outflow (1.30.9 10 erg and
8.83.5 10 erg/s, respectively) as well as its alignment
with both the jet and the cocoon, and that the gas is collisionally ionised, we
consider that the outflow is jet-powered, although some contribution from the
AGN is possible.Comment: A&A accepted 04/04/2022, 31 pages, 12 figures and 3 appendixe
Severe Asthma Standard-of-Care Background Medication Reduction With Benralizumab: ANDHI in Practice Substudy
Background: The phase IIIb, randomized, parallel-group, placebo-controlled ANDHI double-blind (DB) study extended understanding of the efficacy of benralizumab for patients with severe eosinophilic asthma. Patients from ANDHI DB could join the 56-week ANDHI in Practice (IP) single-arm, open-label extension substudy. Objective: Assess potential for standard-of-care background medication reductions while maintaining asthma control with benralizumab. Methods: Following ANDHI DB completion, eligible adults were enrolled in ANDHI IP. After an 8-week run-in with benralizumab, there were 5 visits to potentially reduce background asthma medications for patients achieving and maintaining protocol-defined asthma control with benralizumab. Main outcome measures for non-oral corticosteroid (OCS)-dependent patients were the proportions with at least 1 background medication reduction (ie, lower inhaled corticosteroid dose, background medication discontinuation) and the number of adapted Global Initiative for Asthma (GINA) step reductions at end of treatment (EOT). Main outcomes for OCS-dependent patients were reductions in daily OCS dosage and proportion achieving OCS dosage of 5 mg or lower at EOT. Results: For non-OCS-dependent patients, 53.3% (n = 208 of 390) achieved at least 1 background medication reduction, increasing to 72.6% (n = 130 of 179) for patients who maintained protocol-defined asthma control at EOT. A total of 41.9% (n = 163 of 389) achieved at least 1 adapted GINA step reduction, increasing to 61.8% (n = 110 of 178) for patients with protocol-defined EOT asthma control. At ANDHI IP baseline, OCS dosages were 5 mg or lower for 40.4% (n = 40 of 99) of OCS-dependent patients. Of OCS-dependent patients, 50.5% (n = 50 of 99) eliminated OCS and 74.7% (n = 74 of 99) achieved dosages of 5 mg or lower at EOT. Conclusions: These findings demonstrate benralizumab's ability to improve asthma control, thereby allowing background medication reduction
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Outflows in low luminosity active galactic nuclei
[EN] This thesis is aimed to provide insights into the relevance of feedback processes in galaxies
harbouring at its centre an Active Galactic Nucleus (AGN). Feedback is believed to impact
the evolution of galaxies by regulating the star formation and AGN activity. In particular,
these processes can be triggered by outflows, that are detected with various tracers related to
different gas phases (e.g. ionised or hot gas). In this thesis, we focused on the exploration
of the processes at the low end of the AGN luminosity function, in particular with Low-
Ionisation Nuclear Emission-line Regions (LINERs). These objects are the largest AGN
family in the Local Universe, representing more than 60% of the local population (Ho 2008).
Their relative faintness make their detection and characterisation more difficult than for
other AGN types, although their proximity gives these objects an advantage, since spatially
resolved studies can be made. This is specially important for the characterisation of feedback
processes, particularly in the search for outflows.
During the last 20 years, outflows have been detected in a variety of systems, from starforming
galaxies to AGNs. The increasing number of works dedicated to the study of
feedback processes seem to conclude that outflows are ubiquitous in both types of galaxies.
Many efforts now are dedicated to analysing their properties and evaluating their impact
in the evolution of the host galaxy from pc to kpc-scales. However, in the case of AGNs
their study has been mainly focused on luminous systems, where outflows are expected to be
more powerful and thus easier to detect and characterise. Nevertheless, it remains unclear if
outflows are also common or even ubiquitous in LINERs, as this AGN population has been
largely unstudied.
In this thesis we address this topic with three different methodologies that will be described
along the corresponding chapters.
Optical spectroscopy of type-2 LINERs. We first present the analysis of long-slit spectroscopic
data for nine type-2 LINERs obtained with the Hubble Space Telescope (HST) and
the Palomar Survey. This work complements the previous work by Cazzoli et al. (2018) on
type-1 LINERs. The objectives are twofold: (i) detect a broad line region component in the
Balmer emission lines, and (ii) search for outflows as a broad (σ ≤ 500 km s−1), blueshiftedcomponent in the emission lines. We detected a broad component for 67% of the HST spectra
and 25% of the Palomar spectra. As for the outflows, we found that 35% of the type-2
LINERs are good candidates to host them.
A search for ionised gas outflows in an Hα imaging atlas of nearby LINERs. We then
systematically searched for outflows in a sample of 70 nearby LINERs by analysing the
ionised gas distribution in these systems, using proprietary ALFOSC/NOT and archival HST
narrow band imaging. We were able to identify the main morphologies of the Hα gas and
detect possible outflows as extended gas for 32% of the objects. Afterwards, by combining
imaging with kinematic data from the literature, we found that ∼50% of the local LINERs
host an outflow in different gas phases. These results indicated that outflows are common in
low luminosity AGNs as LINERs.
Analysis of the candidate outflows in LINERs with MEGARA/GTC integral field spectroscopic
data (IFS). Finally, we used IFS data to confirm or not the outflow candidates
identified from the previous two works on a spatially-resolved basis. For that purpose we
used MEGARA/GTC data of nine LINERs in three spectral bands in the optical range. We
study as a first case the prototypical LINER NGC1052 (complementing with proprietary
MUSE/VLT data). We detected in this object an ionised gas outflow probably driven by the
jet, propagating in a region of turbulent gas, and triggering kpc-scale bubbles.
Then we analysed the other eight objects, finding a kinematical signatures of an ionised gas
outflow in four of these LINERs (i.e. 50%). The LINER NGC4438 is the only object in our
sample for which we found three resolved kinematical components in all the emission lines
with the MEGARA data. These probe the gaseous disc and an outflow with a bubble-like
structure, previously detected with high spatial resolution imaging.[ES] Esta tesis tiene como objetivo proporcionar información sobre la relevancia de los procesos de
retroalimentación en galaxias que poseen en su centro un núcleo activo de galaxias (AGN en
inglés). Se cree que los procesos de retroalimentación afectan a la evolución de las galaxias
a través de la regulación de la formación estelar y de la actividad nuclear. En particular, estos
procesos se pueden desencadenar por los llamados ‘outflows’, los cuales se detectan usando
varios trazadores relacionados con las distintas fases del gas (por ejemplo, gas ionizado o
caliente). En esta tesis nos centramos en la exploración de estos procesos en el límite inferior
de luminosidad en los AGNs, en particular en las llamadas regiones nucleares de líneas de
emisión de baja ionización (LINERs por sus siglas en inglés). Estos objetos son la familia
más numerosa de AGNs que encontramos en el Universo Local, representando a más del
60% de la población local (Ho 2008). Su relativa debilidad hace que sean más dificiles de
detectar y caracterizar que otros tipos de AGNs, aunque su proximidad les da la ventaja de
permitir realizar estudios espacialmente resueltos. Esto aplica especialmente para el análisis
de procesos de retroalimentación y, en particular, para la búsqueda de ‘outflows’.
Durante los últimos 20 años se han detectado ‘outflows’ en una gran variedad de sistemas,
tanto galaxias con formación estelar como en AGNs. El aumento del número de trabajos
dedicados al estudio de procesos de retroalimentación parecen concluir que los ‘outflows’
aparecen de manera ubicua en los sistemas anteriormente mencionados. Hay muchos
esfuerzos dedicados al análisis de sus propiedades y a evaluar su impacto en la evolución de
la galaxia anfitriona en escalas de pc a kpc. Sin embargo, en el caso de los AGNs los estudios
se han centrado en los sistemas más luminosos, donde se espera que los ‘outflows’ sean más
poderosos y, por tanto, más fácil de detectar y caracterizar. Aún no está claro si los ‘outflows’
son también comunes, o incluso su presencia ubicua, en LINERs, ya que su presencia
en esta población de AGNs ha sido en gran medida no explorada.
En esta tesis abordamos este tema utilizando tres metodologías distintas que se van describiendo
en los capítulos.
Espectroscopía óptica de LINERs de tipo 2: Presentamos en primer lugar el análisis de
datos de espectroscopía de rendija larga de nueve LINERs de tipo 2, obtenidos con el Telescopio Espacial Hubble (HST) y de la muestra del Palomar. Este trabajo complementa al
estudio anterior de Cazzoli et al. (2018) con LINERs de tipo 1. Los objetivos principales
son dos: (i) detectar en las líneas de emisión de Balmer una componente ancha originada en
la región de líneas anchas, y (ii) buscar indicadores de ‘outflows’ en las líneas de emisión
como una componente ancha (σ‘ 500 km s−1) desplazada hacia el azul. Detectamos una
componente ancha en las líneas de Balmer en el 67% de los espectros del HST y en el 25%
de los espectros del Palomar. En cuanto a los ‘outflows’, encontramos que el 35% de los
LINER de tipo 2 son buenos candidatos para albergarlos.
Una búsqueda de ‘outflows’ en gas ionizado en un atlas de imágenes de Hα de LINERs
cercanos. A continuación, buscamos sistemáticamente ‘outflows’ en una muestra de 70
LINERs cercanos, analizando la distribución del gas ionizado en estos sistemas con imágenes
de ALFOSC/NOT e imágenes de archivo del HST de banda estrecha. Pudimos identificar las
principales morfologías del gas Hα y detectar posibles ‘outflows’ en forma de gas extendido
en el 32% de los objetos. Después, combinando las imágenes con datos cinemáticos de la
literatura, descubrimos que el 50% de los LINER locales tienen ‘outflows’ que se detectan en
distintas fases del gas. Estos resultados indican que los ‘outflows’ son comunes en AGNs de
baja luminosidad, como los LINERs.
Análisis de LINERs candidatos a tener ‘outflows’ con datos de espectroscopía de campo
integral (IFS) con MEGARA/GTC. Por último, utilizamos los datos de IFS para confirmar
o no los candidatos a ‘outflows’ identificados en los dos trabajos anteriores, pero esta vez
resolviendo la emisión espacialmente. Para ello utilizamos los datos de MEGARA/GTC
de nueve LINERs en tres bandas espectrales distintas en el rango óptico. Estudiamos
como primer caso el prototípico LINER NGC1052 (complementando con datos propios
de MUSE/VLT). Detectamos en este objeto un ‘outflow’ en gas ionizado, probablemente
impulsado por un ‘jet’, que se propaga en una región de gas turbulento provocando burbujas
a escalas de kpc.
A continuación analizamos los otros ocho objetos de la muestra. Encontramos indicaciones
cinemáticas de la presencia de ‘outflows’ de gas ionizado en cuatro de estos LINERs (es
decir, el 50%). El LINER NGC 4438 es el único objeto de nuestra muestra para el que
detectamos, con datos de MEGARA, tres componentes cinemáticas espacialmente resueltas
en todas las líneas de emisión. Estas se relacionan con el disco de gas de la galaxia y con un
‘outflow’ con forma de burbuja, que ya había sido detectado anteriormente con imágenes de
alta resolución espacial.With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.Peer reviewe
Optical spectroscopy of type-1 LINERs
IAU Symposium 356 on 'Nuclear Activity in Galaxies Across Cosmic Time', Addis Ababa (Ethiopia), October 7-11, 2019
IAA : Información y actualidad astronómica (70) (2023)
¿Agujeros negros o estrellas negras?.- SO-IAAA. Objetivo final: ¡terminar con un nuevo comienzo!.- El Moby Dick de ... Laura Hermosa Muñoz (CAB, INTA-CSIC).- Deconstrucción, Misión DART.- Historias ... Lo que la ciencia unió y separó.- ActualidadEste número ha contado con el apoyo económico de la Agencia Estatal de Investigación (Ministerio de Ciencia, Innovación y Universidades) a través de la acreditación de Centro de Excelencia Severo Ochoa para el Instituto de Astrofísica de Andalucía (SEV-2017-0709). La página web de esta revista ha sido financiada por la Sociedad Española de Astronomía (SEA).Peer reviewe
Optical spectroscopy of type 2 LINERs
Context. Type 2 Low-ionization Nuclear Emission-line Regions (LINERs) have been optically classified with the Palomar data as not presenting a broad component in the Balmer emission lines that are associated with the broad-line region (BLR) of the active galactic nuclei (AGN).Aims. We aim to unveil the presence of different kinematic components of emission lines in the nuclear region of a sample of local (z <= 0.022) type 2 LINERs. We focus on the analysis of the true nature of LINERs by means of the detection (or nondetection) of a broad component that originated in the BLR of the AGN. Additionally, we search for the possible presence of nonrotational motions such as outflows in these LINERs.Methods. We applied a decomposition of the nuclear emission lines using an spectroscopic analysis of the optical spectra of nine type 2 LINERs of intermediate-resolution spectroscopic data retrieved from the Hubble Space Telescope (HST) archive. The study is completed with archival spectra from the Double Spectrograph from the Palomar Observatory.Results. The emission line fitting reveals the presence of a broad component associated with the BLR in six out of the nine galaxies for the space-based data, and for two out of the eight from the ground-based spectra. The velocity dispersion for two galaxies (NGC 4486 and NGC 4594) measured in HST/STIS data suggest the presence of outflows.Conclusions. The results indicate that the spatial resolution plays a major role in the detection of the BLR, as it appears diluted in the ground-based data (even after removing stellar contribution). This is also true for the emission line diagnostics, as the contaminant light contributes to lower emission line ratios toward the star-forming area of standard BPTs. We propose to reclassify NGC 4594 as a type 1 LINER, since a BLR component is seen in both space- and ground-based spectra. We find ambiguous results for the BLR component of NGC 4486. The modest outflow detection in our sample may indicate that they are not as frequent as seen for type 1 LINERs.© ESO 2020We acknowledge financial support from the Spanish Ministerio de Ciencia, Innovacion y Universidades (MCIU) under the grant AYA2016-76682-C3, and from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709). LHM acknowledge financial support under the grant BES-2017-082471. We acknowledge O. Reyes-Amador for his useful help on this work. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. We acknowledge the usage of the HyperLeda database (http://leda.univ-lyon1.fr).This work has made extensive use of IRAF and Python, particularly with astropy (http://www.astropy.org) (Astropy Collaboration 2013, 2018), matplotlib (Hunter 2007), numpy and lmfitPeer reviewe
Optical spectroscopy of type-2 LINERs
IAU Symposium 356 on 'Nuclear Activity in Galaxies Across Cosmic Time', Addis Ababa (Ethiopia), October 7-11, 2019.Low-Ionisation Nuclear Emission-line Regions (LINERs) are the least luminous and
the most numerous among the local population of Active Galactic Nuclei (AGN). They can
be classified as type-1 or type-2 if their optical spectra show or do not show, respectively, a
broad component. It is associated with the presence of a Broad Line Region (BLR) in these
systems. However, recent studies have proven that the classification of type-1 LINERs may be
controversial, since space- and ground-based spectroscopy provide contradicting results on the
presence of very broad components (Cazzoli et al. 2018). We have studied the nuclear spectra of
9 type-2 LINERs with intermediate spectral resolution HST/STIS data. We present the results
on our analysis of the different spectral components, and discuss the eventual presence of BLR
components in type-2 LINER galaxies, together with the possible presence of outflows, both in
comparison with type-1 LINERs. We hav
Unexplored outflows in nearby low luminosity AGNs. The case of NGC 1052
Context. Multi-phase outflows play a central role in galaxy evolution shaping the properties of galaxies. Understanding outflows and their effects in low luminosity active galactic nuclei (AGNs), such as low ionisation nuclear emission line regions (LINERs), is essential. LINERs bridge the gap between normal and active galaxies, being the most numerous AGN population in the local Universe.
Aims: Our goal is to analyse the kinematics and ionisation mechanisms of the multi-phase gas of NGC 1052, the prototypical LINER, in order to detect and map the ionised and neutral phases of the putative outflow.
Methods: We obtained Very Large Telescope MUSE and Gran Telescopio Canarias MEGARA optical integral field spectroscopy data for NGC 1052. In addition to stellar kinematics maps, by modelling spectral lines with multiple Gaussian components, we obtained flux, kinematic, and excitation maps of both ionised and neutral gas.
Results: The stars are distributed in a dynamically hot disc (V/σ ∼ 1.2), with a centrally peaked velocity dispersion map (σc = 201 ± 10 km s−1) and large observed velocity amplitudes (ΔV = 167 ± 19 km s−1). The ionised gas, probed by the primary component is detected up to ∼30″ (∼3.3 kpc) mostly in the polar direction with blue and red velocities (∣V∣ < 250 km s−1). The velocity dispersion map shows a notable enhancement (σ > 90 km s−1) crossing the galaxy along the major axis of rotation in the central 10″. The secondary component has a bipolar morphology, velocity dispersion larger than 150 km s−1, and velocities up to 660 km s−1. A third component is detected with MUSE (and barely with MEGARA), but it is not spatially resolved. The broad-line region (BLR) component (used to model the broad Hα emission only) has a full width at half maximum of 2427 ± 332 and 2350 ± 470 km s−1 for MUSE and MEGARA data, respectively. The maps of the NaD absorption indicate optically thick neutral gas with complex kinematics. The velocity field is consistent with a slow rotating disc (ΔV = 77 ± 12 km s−1), but the velocity dispersion map is off-centred without any counterpart in the (centrally peaked) flux map.
Conclusions: We found evidence of an ionised gas outflow (secondary component) with a mass of 1.6 ± 0.6 × 105 M⊙, and mass rate of 0.4 ± 0.2 M⊙ yr−1. The outflow is propagating in a cocoon of gas with enhanced turbulence and might be triggering the onset of kiloparsec-scale buoyant bubbles (polar emission), both probed by the primary component. Taking into account the energy and kinetic power of the outflow (1.3 ± 0.9 × 1053 erg and 8.8 ± 3.5 × 1040 erg s−1, respectively) as well as its alignment with both the jet and the cocoon, and that the gas is collisionally ionised (due to gas compression), we consider that the most likely power source of the outflow is the jet, although some contribution from the AGN is possible. The hints of the presence of a neutral gas outflow are weak
Kinematic and metallicity properties of the Aquarius dwarf galaxy from FORS2 MXU spectroscopy
International audienceContext. Dwarf galaxies found in isolation in the Local Group (LG) are unlikely to have interacted with the large LG spirals, and therefore environmental effects such as tidal and ram-pressure stripping should not be the main drivers of their evolution. Aims. We provide insight into the internal mechanisms shaping LG dwarf galaxies by increasing our knowledge of the internal properties of isolated systems. Here we focus on the evolved stellar component of the Aquarius dwarf galaxy, whose kinematic and metallicity properties have only recently started to be explored. Methods. Spectroscopic data in the region of the near-infrared Ca II triplet lines has been obtained with FORS2 at the Very Large Telescope for 53 red giant branch (RGB) stars. These data are used to derive line-of-sight (l.o.s.) velocities and [Fe/H] of the individual RGB stars. Results. We derive a systemic velocity of −142.2 +1.8 −1.8 km s −1 , in agreement with previous determinations from both the HI gas and stars. The internal kinematics of Aquarius appears to be best modelled by a combination of random motions (l.o.s. velocity dispersion of 10.3 +1.6 −1.3 km s −1 ) and linear rotation (with a gradient −5.0 +1.6 −1.9 km s −1 arcmin −1 ) along a PA = 139 +17 −27 deg, broadly consistent with the optical projected major axis. This rotation signal is significantly misaligned or even counter-rotating to that derived from the HI gas. We also find the tentative presence of a mild negative metallicity gradient and indications that the metal-rich stars have a colder velocity dispersion than the metal-poor ones. Conclusions. This work represents a significant improvement with respect to previous measurements of the RGB stars of Aquarius as it doubles the number of member stars already studied in the literature. We speculate that the misaligned rotation between the HI gas and evolved stellar component might have been the result of recent accretion of HI gas, or re-accretion after gas-loss due to internal stellar feedback