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A. Labiano

Publications and source records attributed to A. Labiano.

At least 73 records · Page 4Linked to original sources

Resolving the nuclear obscuring disk in the Compton-thick Seyfert galaxy NGC5643 with ALMA

We present ALMA Band 6 $^{12}$CO(2--1) line and rest-frame 232GHz continuum observations of the nearby Compton-thick Seyfert galaxy NGC5643 with angular resolutions 0.11-0.26arcsec (9-21pc). The CO(2--1) integrated line map reveals emission from the nuclear and circumnuclear region with a two-arm nuclear spiral extending 10arcsec on each side. The circumnuclear CO(2--1) kinematics can be fitted with a rotating disk, although there are regions with large residual velocities and/or velocity dispersions. The CO(2--1) line profiles of these regions show two different velocity components. One is ascribed to the circular component and the other to the interaction of the AGN outflow, as traced by the [O III]5007AA emission, with molecular gas in the disk a few hundred parsecs from the AGN. On nuclear scales, we detected an inclined CO(2--1) disk (diameter 26 pc, FWHM) oriented almost in a north-south direction. The CO(2--1) nuclear kinematics can be fitted with a rotating disk which appears to be tilted with respect to the large scale disk. There are strong non-circular motions in the central 0.2-0.3 arcsec with velocities of up to 110km/s. In the absence of a nuclear bar, these motions could be explained as radial outflows in the nuclear disk. We estimate a total molecular gas mass for the nuclear disk of $M({\rm H}_2)=1.1\times 10^7\,M_\odot$ and an H$_2$ column density toward the location of the AGN of $N({\rm H}_2)\sim 5 \times 10^{23}\,{\rm cm}^{-2}$, for a standard CO-to-H$_2$ conversion factor. We interpret this nuclear molecular gas disk as the obscuring torus of NGC5643 as well as the collimating structure of the ionization cone.

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Spatially resolved cold molecular outflows in ULIRGs

We present new CO(2-1) observations of 3 low-z (~350 Mpc) ULIRG systems (6 nuclei) observed with ALMA at high-spatial resolution (~500 pc). We detect massive cold molecular gas outflows in 5 out of 6 nuclei (0.3-5)x10^8 Msun. These outflows are spatially resolved with deprojected radii of 0.25-1 kpc although high-velocity molecular gas is detected up to ~0.5-1.8 kpc (1-6 kpc deprojected). The mass outflow rates are 12-400 Msun/yr and the inclination corrected average velocity of the outflowing gas 350-550 km/s (v_max = 500-900 km/s). The origin of these outflows can be explained by the nuclear starbursts although the contribution of an obscured AGN can not be completely ruled out. The position angle (PA) of the outflowing gas along the kinematic minor axis of the nuclear molecular disk suggests that the outflow axis is perpendicular to the disk for three of these outflows. Only in one case, the outflow PA is clearly not along the kinematic minor axis. The outflow depletion times are 15-80 Myr which are slightly shorter than the star-formation (SF) depletion times (30-80 Myr). However, we estimate that only 15-30% of the outflowing gas will escape the gravitational potential of the nucleus. The majority of the outflowing gas will return to the disk after 5-10 Myr and become available to form new stars. Therefore, these outflows will not likely quench the nuclear starbursts. These outflows would be consistent with being driven by radiation pressure (momentum-driven) only if the coupling between radiation and dust increases with increasing SF rates. This can be achieved if the dust optical depth is higher in objects with higher SF. The relatively small sizes (<1 kpc) and dynamical times (<3 Myr) of the cold molecular outflows suggests that molecular gas cannot survive longer in the outflow environment or that it cannot form efficiently beyond these distances or times. (Abridged)

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Outflows of hot molecular gas in ultra-luminous infra-red galaxies mapped with VLT-SINFONI

We present the detection and morphological characterization of hot molecular gas outflows in nearby ultra-luminous infrared galaxies, using the near-IR integral-field spectrograph SINFONI on the VLT. We detect outflows observed in the 2.12 micron H$_{2}$ 1-0 S(1) line for three out of four ULIRGs analyzed; IRAS 12112+0305, 14348-1447, and 22491-1808. The outflows are mapped on scales of 0.7-1.6 kpc, show typical outflow velocities of 300-500 km/s, and appear to originate from the nuclear region. The outflows comprise hot molecular gas masses of ~6-8x10$^3$ M(sun). Assuming a hot-to-cold molecular gas mass ratio of 6x10$^{-5}$, as found in nearby luminous IR galaxies, the total (hot+cold) molecular gas mass in these outflows is expected to be ~1x10$^{8}$ M(sun). This translates into molecular mass outflow rates of ~30-85 M(sun)/yr, which is a factor of a few lower than the star formation rate in these ULIRGs. In addition, most of the outflowing molecular gas does not reach the escape velocity of these merger systems, which implies that the bulk of the outflowing molecular gas is re-distributed within the system and thus remains available for future star formation. The fastest H$_{2}$ outflow is seen in the Compton-thick AGN of IRAS 14348-1447, reaching a maximum outflow velocity of ~900 km/s. Another ULIRG, IRAS 17208-0014, shows asymmetric H$_{2}$ line profiles different from the outflows seen in the other three ULIRGs. We discuss several alternative explanations for its line asymmetries, including a very gentle galactic wind, internal gas dynamics, low-velocity gas outside the disk, or two superposed gas disks. We do not detect the hot molecular counterpart to the outflow previously detected in CO(2-1) in IRAS 17208-0014, but we note that our SINFONI data are not sensitive enough to detect this outflow if it has a small hot-to-cold molecular gas mass ratio of < 9x10$^{-6}$.

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The MIRI Medium Resolution Spectrometer calibration pipeline

The Mid-Infrared Instrument (MIRI) Medium Resolution Spectrometer (MRS) is the only mid-IR Integral Field Spectrometer on board James Webb Space Telescope. The complexity of the MRS requires a very specialized pipeline, with some specific steps not present in other pipelines of JWST instruments, such as fringe corrections and wavelength offsets, with different algorithms for point source or extended source data. The MRS pipeline has also two different variants: the baseline pipeline, optimized for most foreseen science cases, and the optimal pipeline, where extra steps will be needed for specific science cases. This paper provides a comprehensive description of the MRS Calibration Pipeline from uncalibrated slope images to final scientific products, with brief descriptions of its algorithms, input and output data, and the accessory data and calibration data products necessary to run the pipeline.

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A SINFONI view of the nuclear activity and circum-nuclear star formation in NGC 4303

We present new maps of emission-line flux distributions and kinematics in both ionized (traced by HI and [FeII] lines) and molecular (H2) gas of the inner 0.7x0.7kpc2 of the galaxy NGC4303, with a spatial resolution 40-80pc and velocity resolution 90-150 km/s obtained from near-IR integral field specroscopy using the VLT instrument SINFONI. The most promiment feature is a 200-250pc ring of circum-nuclear star-forming regions. The emission from ionized and molecular gas shows distinct flux distributions: while the strongest HI and [FeII] emission comes from regions in the west side of the ring (ages~4Myr), the H2 emission is strongest at the nucleus and in the east side of the ring (ages>10Myr). We find that regions of enhanced hot H2 emission are anti-correlated with those of enhanced [FeII] and HI emission, which can be attributed to post starburst regions that do not have ionizing photons anymore but still are hot enough (~2000K) to excite the H2 molecule. The line ratios are consistent with the presence of an AGN at the nucleus. The youngest regions have stellar masses in the range 0.3-1.5E5 MSun and ionized and hot molecular gas masses of ~0.25-1.2E4 Msun and 2.5-5 Msun, respectively. The stellar and gas velocity fields show a rotation pattern, with the gas presenting larger velocity amplitudes than the stars, with a deviation observed for the H2 along the nuclear bar, where increased velocity dispersion is also observed, possibly associated with non circular motions along the bar. The stars in the ring show smaller velocity dispersion than the surroundings, that can be attributed to a cooler dynamics due to their recent formation from cool gas.

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N_H - N_HI correlation in Gigahertz-peaked-spectrum galaxies

With the Westerbork Synthesis Radio Telescope, we performed HI observations of a sample of known X-ray emitting Gigahertz-peaked-spectrum galaxies with compact-symmetric-object morphology (GPS/CSOs) that lacked an HI absorption detection. We combined radio and X-ray data of the full sample of X-ray emitting GPS/CSOs and found a significant, positive correlation between the column densities of the total and neutral hydrogen ($N_{\rm H}$ and $N_{\rm HI}$, respectively). Using a Bayesian approach, we simultaneously quantified the parameters of the $N_{\rm H} - N_{\rm HI}$ relation and the intrinsic spread of the data set. For a specific subset of our sample, we found $N_{\rm H} \propto N_{\rm HI}^b$, with $b=0.93^{+0.49}_{-0.33}$, and $σ_{int} (N_{\rm H})= 1.27^{+1.30}_{-0.40}$. The $N_{\rm H} - N_{\rm HI}$ correlation suggests a connection between the physical properties of the radio and X-ray absorbing gas.

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High-resolution imaging of the molecular outflows in two mergers: IRAS17208-0014 and NGC1614

Galaxy evolution scenarios predict that the feedback of star formation and nuclear activity (AGN) can drive the transformation of gas-rich spiral mergers into ULIRGs, and, eventually, lead to the build-up of QSO/elliptical hosts. We study the role that star formation and AGN feedback have in launching and maintaining the molecular outflows in two starburst-dominated advanced mergers, NGC1614 and IRAS17208-0014, by analyzing the distribution and kinematics of their molecular gas reservoirs. We have used the PdBI array to image with high spatial resolution (0.5"-1.2") the CO(1-0) and CO(2-1) line emissions in NGC1614 and IRAS17208-0014, respectively. The velocity fields of the gas are analyzed and modeled to find the evidence of molecular outflows in these sources and characterize the mass, momentum and energy of these components. While most (>95%) of the CO emission stems from spatially-resolved (~2-3kpc-diameter) rotating disks, we also detect in both mergers the emission from high-velocity line wings that extend up to +-500-700km/s, well beyond the estimated virial range associated with rotation and turbulence. The kinematic major axis of the line wing emission is tilted by ~90deg in NGC1614 and by ~180deg in IRAS17208-0014 relative to their respective rotating disk major axes. These results can be explained by the existence of non-coplanar molecular outflows in both systems. In stark contrast with NGC1614, where star formation alone can drive its molecular outflow, the mass, energy and momentum budget requirements of the molecular outflow in IRAS17208-0014 can be best accounted for by the existence of a so far undetected (hidden) AGN of L_AGN~7x10^11 L_sun. The geometry of the molecular outflow in IRAS17208-0014 suggests that the outflow is launched by a non-coplanar disk that may be associated with a buried AGN in the western nucleus.

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Star formation in z>1 3CR host galaxies as seen by Herschel

We present Herschel (PACS and SPIRE) far-infrared (FIR) photometry of a complete sample of z>1 3CR sources, from the Herschel GT project The Herschel Legacy of distant radio-loud AGN (PI: Barthel). Combining these with existing Spitzer photometric data, we perform an infrared (IR) spectral energy distribution (SED) analysis of these landmark objects in extragalactic research to study the star formation in the hosts of some of the brightest active galactic nuclei (AGN) known at any epoch. Accounting for the contribution from an AGN-powered warm dust component to the IR SED, about 40% of our objects undergo episodes of prodigious, ULIRG-strength star formation, with rates of hundreds of solar masses per year, coeval with the growth of the central supermassive black hole. Median SEDs imply that the quasar and radio galaxy hosts have similar FIR properties, in agreement with the orientation-based unification for radio-loud AGN. The star-forming properties of the AGN hosts are similar to those of the general population of equally massive non-AGN galaxies at comparable redshifts, thus there is no strong evidence of universal quenching of star formation (negative feedback) within this sample. Massive galaxies at high redshift may be forming stars prodigiously, regardless of whether their supermassive black holes are accreting or not.

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Molecular line emission in NGC1068 imaged with ALMA. I An AGN-driven outflow in the dense molecular gas

We investigate the fueling and the feedback of star formation and nuclear activity in NGC1068, a nearby (D=14Mpc) Seyfert 2 barred galaxy, by analyzing the distribution and kinematics of the molecular gas in the disk. We have used ALMA to map the emission of a set of dense molecular gas tracers (CO(3-2), CO(6-5), HCN(4-3), HCO+(4-3) and CS(7-6)) and their underlying continuum emission in the central r ~ 2kpc of NGC1068 with spatial resolutions ~ 0.3"-0.5" (~ 20-35pc). Molecular line and dust continuum emissions are detected from a r ~ 200pc off-centered circumnuclear disk (CND), from the 2.6kpc-diameter bar region, and from the r ~ 1.3kpc starburst (SB) ring. Most of the emission in HCO+, HCN and CS stems from the CND. Molecular line ratios show dramatic order-of-magnitude changes inside the CND that are correlated with the UV/X-ray illumination by the AGN, betraying ongoing feedback. The gas kinematics from r ~ 50pc out to r ~ 400pc reveal a massive (M_mol ~ 2.7 (+0.9, -1.2) x 10^7 Msun) outflow in all molecular tracers. The tight correlation between the ionized gas outflow, the radio jet and the occurrence of outward motions in the disk suggests that the outflow is AGN-driven. The outflow rate estimated in the CND, dM/dt ~ 63 (+21, -37) Msun yr^-1, is an order of magnitude higher than the star formation rate at these radii, confirming that the outflow is AGN-driven. The power of the AGN is able to account for the estimated momentum and kinetic luminosity of the outflow. The CND mass load rate of the CND outflow implies a very short gas depletion time scale of <=1 Myr.

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Fueling the central engine of radio galaxies. III. Molecular gas and star formation efficiency of 3C 293

Aims. We investigate the different manifestations of AGN feedback in the evolved, powerful radio source 3C293 and their impact on the molecular gas of its host galaxy, which harbors young star-forming regions and fast outflows of HI and ionized gas. Methods. We study the distribution and kinematics of the molecular gas of 3C293 using high spatial resolution observations of the CO(1-0) and CO(2-1) lines, and the 3 and 1mm continuum taken with the IRAM PdBI. We mapped the molecular gas of 3C293 and compared it with the dust and star-formation images of the host. We searched for signatures of outflow motions in the CO kinematics, and reexamined the evidence of outflowing gas in the HI spectra. We also derived the star formation rate (SFR) and efficiency (SFE) of the host with all available SFR tracers from the literature, and compared them with the SFE of young and evolved radio galaxies and normal star-forming galaxies. Results. The CO(1-0) emission line shows that the molecular gas in 3C293 is distributed along a massive (2.2E10 Msun) warped disk with diameter of 21 kpc that rotates around the AGN. Our data show that the dust and the star formation are clearly associated with the CO disk. The CO(2-1) emission is located in the inner 7 kpc (diameter) region around the AGN, coincident with the inner part of the CO(1-0) disk. Both the CO(1-0) and CO(2-1) spectra reveal the presence of an absorber against the central regions of 3C293 that is associated with the disk. We do not detect any fast (>500 km/s) outflow motions in the cold molecular gas. The host of 3C293 shows an SFE consistent with the Kennicutt-Schmidt law. The apparently low SFE of evolved radio galaxies may be caused by an underestimation of the SFR and/or an overestimation of the molecular gas densities in these sources. We find no signatures of AGN feedback in the molecular gas of 3C293.

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First X-ray observations of Low-Power Compact Steep Spectrum Sources

We report first X-ray Chandra observations of a sample of seven low luminosity compact (LLC) sources. They belong to a class of young compact steep spectrum (CSS) radio sources. Four of them have been detected, the other three have upper limit estimations for X-ray flux, one CSS galaxy is associated with an X-ray cluster. We have used the new observations together with the observational data for known strong CSS and gigahertz-peaked spectrum (GPS) objects and large scale FRIs and FRIIs to study the relation between morphology, X-ray properties and excitation modes in radio-loud AGNs. We found that: (1) The low power objects fit well to the already established X-ray - radio luminosity correlation for AGNs and occupy the space among, weaker in the X-rays, FRI objects. (2) The high excitation galaxies (HEG) and low excitation galaxies (LEG) occupy distinct locus in the radio/X-ray luminosity plane, notwithstanding their evolutionary stage. This is in agreement with the postulated different origin of the X-ray emission in these two group of objects. (3) We have tested the AGN evolution models by comparing the radio/X-ray luminosity ratio with the size of the sources, and indirectly, with their age. We conclude that the division for two different X-ray emission modes, namely originate in the base of the relativistic jet (FRIs) or in the accretion disk (FRIIs) is already present among the younger compact AGNs. (4) Finally, we found that the CSS sources are less obscured than the more compact GPSs in X-rays. However, the anti-correlation between X-ray column density and radio size does not hold for the whole sample of GPS and CSS objects.

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CSS galaxy embedded within the core of a bright X-ray cluster

We discovered an X-ray cluster in a recent pointed Chandra observation of the radio-loud compact-steep-spectrum source 1321+045 at the redshift of 0.263. 1321+045 is part of larger survey which aims to study the X-rays properties of weak compact radio sources. Compact radio sources are young objects at the beginning of their evolution and if embedded in an X-ray cluster offer unique opportunities to study the cluster heating process.

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An X-ray cooling-core cluster surrounding a low power Compact Steep Spectrum Radio source 1321+045

We discovered an X-ray cluster in a Chandra observation of the compact steep spectrum (CSS) radio source 1321+045 (z=0.263). CSS sources are thought to be young radio objects at the beginning of their evolution and can potentially test the cluster heating process. 1321+045 is a relatively low luminosity source and its morphology consists of two radio lobes on the opposite sides of a radio core with no evidence for jets or hotspots. The optical emission line ratios are consistent with an interstellar medium (ISM) dominated by AGN-photoionization with a small contribution from star formation, and no contributions from shocks. Based on these ratios, we classify 1321+045 as a low excitation galaxy (LEG) and suggest that its radio activity is in a coasting phase. The X-ray emission associated with the radio source is detected with 36.1+/-8.3 counts, but the origin of this emission is highly uncertain. The current X-ray image of the cluster does not show any signatures of a radio source impact on the cluster medium. Chandra detects the cluster emission at >3 sigma level out to ~60 arcsec (~240 kpc). We obtain the best fit beta model parameters of the surface brightness profile of beta=0.58+/-0.2 and a core radius of 9.4^{+1.1}_{-0.9} arcsec. The average temperature of the cluster is equal to kT=4.4^{+0.5}_{-0.3} keV, with a temperature and cooling profile indicative of a cooling core. We measure the cluster luminosity L_(0.5-2 keV)=3x10^{44} erg s^{-1} and mass 1.5x10^{14} M_sun.

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Fueling the central engine of radio galaxies. II. The footprints of AGN feedback on the ISM of 3C 236

Aims: We study the emission of molecular gas in 3C236, a FR II radio source at z~0.1, and search for the footprints of AGN feedback. 3C236 shows signs of a reactivation of its AGN triggered by a recent minor merger episode. Observations have also previously identified an extreme HI outflow in this source. Methods: The IRAM PdBI has been used to study the distribution and kinematics of molecular gas in 3C236 by imaging with high spatial resolution the emission of the 12CO(2-1) line in the nucleus of the galaxy. We have searched for outflow signatures in the CO map. We have also derived the SFR in 3C236 using data available from the literature at UV, optical and IR wavelengths, to determine the star-formation efficiency of molecular gas. Results: The CO emission in 3C236 comes from a spatially resolved 2.6 kpc disk with a regular rotating pattern. Within the limits imposed by the sensitivity and velocity coverage of the CO data, we do not detect any outflow signatures in the cold molecular gas. The disk has a cold gas mass M(H2)~2.1x10^9 Msun. We determine a new value for the redshift of the source zCO=0.09927. The similarity between the CO and HI profiles indicates that the deep HI absorption in 3C236 can be accounted for by a rotating HI structure, restricting the evidence of HI outflow to the most extreme velocities. In the light of the new redshift, the analysis of the ionized gas kinematics reveals a 1000 km/s outflow. As for the CO emitting gas, outflow signatures are nevertheless absent in the warm molecular gas emission traced by infrared H2 lines. The star-formation efficiency in 3C236 is consistent with the value measured in normal galaxies, which follow the canonical KS-law. This result, confirmed to hold in other young radio sources examined in this work, is in stark contrast with the factor of 10-50 lower SFE that seems to characterize evolved powerful radio galaxies.

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Emission line - radio correlation for Low Luminosity Compact sources. Evolution schemes

We present radio and optical analysis of a sample of Low Luminosity Compact (LLC) objects, selected from FIRST survey and observed with MERLIN at L-band and C-band. The main criterion used for selection was luminosity of the objects and approximately one third of the CSS sources from the new sample have a value of radio luminosity comparable to FR\,Is.The analysis of a radio properties of LLC sources show they occupy the space in radio power versus linear size diagram below the main evolutionary path of radio objects. We suggest that many of them might be short-lived objects, and their radio emission may be disrupted several times before becoming FR\,IIs. The optical analysis of the LLC sources were made based on the available SDSS images and spectra. We have classified the sources as high and low excitation galaxies (HEG and LEG, respectively). The optical and radio properties of the LLC sample are in general consistent with brighter CSSs and large-scale radio sources. However, when LLC are added to the other samples, HEG and LEG seem to follow independent, parallel evolutionary tracks. LLC and luminous CSS behave like FR\,II sources, while FR\,I seem to belong to a different group of objects, concerning ionization mechanisms. Based on our results, we propose the independent, parallel evolutionary tracks for HEG and LEG sources, evolving from GPS - CSS - FR.

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A survey of Low Luminosity Compact sources and its implication for evolution of radio-loud AGNs. I. Radio data

We present a new sample of Compact Steep Spectrum (CSS) sources with radio luminosity below 10^26 W/Hz at 1.4 GHz called the low luminosity compact (LLC) objects. The sources have been selected from FIRST survey and observed with MERLIN at L-band and C-band. The main criterion used for selection was luminosity of the objects and approximately one third of the CSS sources from the new sample have a value of radio luminosity comparable to FRIs. About 80% of the sources have been resolved and about 30% of them have weak extended emission and disturbed structures when compared with the observations of higher luminosity CSS sources. We studied correlation between radio power and linear size, and redshift with a larger sample that included also published samples of compact objects and large scale FRIIs and FRIs. The low luminosity compact objects occupy the space in radio power versus linear size diagram below the main evolutionary path of radio objects. We suggest that many of them might be short-lived objects, and their radio emission may be disrupted several times before becoming FRIIs. We conclude that there exists a large population of short-lived low luminosity compact objects unexplored so far and part of them can be precursors of large scale FRIs.

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A survey of Low Luminosity Compact sources and its implication for evolution of radio-loud AGNs. II. Optical analysis

This is the second in a series of papers concerning a new sample of low luminosity compact (LLC) objects. Here we discuss the optical properties of the sample based on Sloan Digital Sky Survey (SDSS) images and spectra. We have generated different diagnostic diagrams and classified the sources as high and low excitation galaxies (HEG and LEG, respectively). We have studied the jet-host interactions, relation between radio and optical line emission and evolution of the radio source within a larger sample that included also the published samples of compact steep spectrum (CSS), gigahertz peaked spectrum (GPS) sources and FRII and FRI objects. The optical and radio properties of the LLC sample are in general consistent with brighter CSS and large-scale radio sources, although the LLC objects have lower values of [OIII] luminosity than the more powerful CSS sources (L_1.4GHz>10^25 W/Hz). However, when LLC are added to the other samples, HEG and LEG seem to follow independent, parallel evolutionary tracks. Regarding ionization mechanisms, LLC and luminous CSS objects behave like FRII sources, while FRI seem to belong to a different group of objects. Based on our results, we propose the independent, parallel evolutionary tracks for HEG and LEG sources, evolving from GPS - CSS - FR.

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Studying the spectral properties of Active Galactic Nuclei in the JWST era

The James Webb Space Telescope (JWST), due to launch in 2014, shall provide an unprecedented wealth of information in the near and mid-infrared wavelengths, thanks to its high-sensitivity instruments and its 6.5 m primary mirror, the largest ever launched into space. NIRSpec and MIRI, the two spectrographs onboard JWST, will play a key role in the study of the spectral features of Active Galactic Nuclei in the 0.6-28 micron wavelength range. This talk aims at presenting an overview of the possibilities provided by these two instruments, in order to prepare the astronomical community for the JWST era.

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