Browsing by Author "Baldi, R. D."

Now showing 1 - 6 of 6
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    Extended X-Ray Emission around FR II Radio Galaxies: Hot Spots, Lobes, and Galaxy Clusters
    (2021) Jimenez-Gallardo, A.; Massaro, F.; Paggi, A.; D'Abrusco, R.; Prieto, M. A.; Pena-Herazo, H. A.; Berta, V; Ricci, F.; Stuardi, C.; Wilkes, B. J.; O'Dea, C. P.; Baum, S. A.; Kraft, R. P.; Forman, W. R.; Jones, C.; Mingo, B.; Liuzzo, E.; Balmaverde, B.; Capetti, A.; Missaglia, V; Hardcastle, M. J.; Baldi, R. D.; Morabito, L. K.
    We present a systematic analysis of the extended X-ray emission discovered around 35 FR II radio galaxies from the revised Third Cambridge Catalog (3CR) Chandra Snapshot Survey with redshifts between 0.05 and 0.9. We aimed to (i) test for the presence of extended X-ray emission around FR II radio galaxies, (ii) investigate whether the extended emission origin is due to inverse Compton (IC) scattering of seed photons arising from the cosmic microwave background (CMB) or thermal emission from an intracluster medium (ICM), and (iii) test the impact of this extended emission on hot-spot detection. We investigated the nature of the extended X-ray emission by studying its morphology and compared our results with low-frequency radio observations (i.e., similar to 150 MHz) in the TGSS and LOFAR archives, as well as with optical images from Pan-STARRS. In addition, we optimized a search for X-ray counterparts of hot spots in 3CR FR II radio galaxies. We found statistically significant extended emission (>3 sigma confidence level) along the radio axis of similar to 90% and in the perpendicular direction of similar to 60% of the galaxies in our sample. We confirmed the detection of seven hot spots in the 0.5-3 keV energy range. In the cases where the emission in the direction perpendicular to the radio axis is comparable to that along the radio axis, we suggest that the underlying radiative process is thermal emission from the ICM. Otherwise, the dominant radiative process is likely nonthermal IC/CMB emission from lobes. We found that nonthermal IC/CMB is the dominant process in similar to 70% of the sources in our sample, while thermal emission from the ICM dominates in similar to 15% of them.
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    Raining in MKW 3 s: A Chandra-MUSE Analysis of X-Ray Cold Filaments around 3CR 318.1
    (2021) Jimenez-Gallardo, A.; Massaro, F.; Balmaverde, B.; Paggi, A.; Capetti, A.; Forman, W. R.; Kraft, R. P.; Baldi, R. D.; Mahatma, V. H.; Mazzucchelli, C.; Missaglia, V.; Ricci, F.; Venturi, G.; Baum, S. A.; Liuzzo, E.; O'Dea, C. P.; Prieto, M. A.; Rottgering, H. J. A.; Sani, E.; Sparks, W. B.; Tremblay, G. R.; van Weeren, R. J.; Wilkes, B. J.; Harwood, J. J.; Mazzotta, P.; Kuraszkiewicz, J.
    We present the analysis of X-ray and optical observations of gas filaments observed in the radio source 3CR 318.1, associated with NGC 5920, the brightest cluster galaxy (BCG) of MKW 3 s, a nearby cool core galaxy cluster. This work is one of the first X-ray and optical analyses of filaments in cool core clusters carried out using MUSE observations. We aim at identifying the main excitation processes responsible for the emission arising from these filaments. We complemented the optical VLT/MUSE observations, tracing the colder gas phase, with X-ray Chandra observations of the hotter highly ionized gas phase. Using the MUSE observations, we studied the emission line intensity ratios along the filaments to constrain the physical processes driving the excitation, and, using the Chandra observations, we carried out a spectral analysis of the gas along these filaments. We found a spatial association between the X-ray and optical morphology of these filaments, which are colder and have lower metal abundance than the surrounding intracluster medium (ICM), as already seen in other BCGs. Comparing with previous results from the literature for other BCGs, we propose that the excitation process that is most likely responsible for these filaments emission is a combination of star formation and shocks, with a likely contribution from self-ionizing, cooling ICM. Additionally, we conclude that the filaments most likely originated from AGN-driven outflows in the direction of the radio jet.
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    The MURALES survey : III. Completing the MUSE observations of 37 3C low- z radio galaxies
    (2021) Balmaverde, B.; Capetti, A.; Marconi, A.; Venturi, Giacomo; Chiaberge, M.; Baldi, R. D.; Baum, S.; Gilli, R.; Grandi, P.; Meyer, E. T.; Miley, G.; O'Dea, C.; Sparks, W.; Torresi, E.; Tremblay, G.
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    The MURALES survey IV. Searching for nuclear outflows in 3C radio galaxies at z < 0.3 with MUSE observations
    (2021) Speranza, G.; Balmaverde, B.; Capetti, A.; Massaro, F.; Tremblay, G.; Marconi, A.; Venturi, G.; Chiaberge, M.; Baldi, R. D.; Baum, S.; Grandi, P.; Meyer, E. T.; O'Dea, C.; Sparks, W.; Terrazas, B. A.; Torresi, E.
    We analyze VLT/MUSE observations of 37 radio galaxies from the Third Cambridge catalogue (3C) with redshift < 0.3 searching for nuclear outflows of ionized gas. These observations are part of the MURALES project (a MUse RAdio Loud Emission line Snapshot survey), whose main goal is to explore the feedback process in the most powerful radio-loud AGN. We applied a nonparametric analysis to the [O III] lambda 5007 emission line, whose asymmetries and high-velocity wings reveal signatures of outflows. We find evidence of nuclear outflows in 21 sources, with velocities between similar to 400 and 1000 km s(-1), outflowing masses of similar to 10(5) - 10(7) M-circle dot, and a kinetic energy in the range similar to 10(53) - 10(56) erg. In addition, evidence for extended outflows is found in the 2D gas velocity maps of 13 sources of the subclasses of high-excitation (HEG) and broad-line (BLO) radio galaxies, with sizes between 0.4 and 20 kpc. We estimate a mass outflow rate in the range 0.4-30 M-circle dot yr(-1) and an energy deposition rate of (E)over dot(kin) similar to 10(42) - 10(45) erg s(-1). Comparing the jet power, the nuclear luminosity of the active galactic nucleus, and the outflow kinetic energy rate, we find that outflows of HEGs and BLOs are likely radiatively powered, while jets likely only play a dominant role in galaxies with low excitation. The low loading factors we measured suggest that these outflows are driven by momentum and not by energy. Based on the gas masses, velocities, and energetics involved, we conclude that the observed ionized outflows have a limited effect on the gas content or the star formation in the host. In order to obtain a complete view of the feedback process, observations exploring the complex multiphase structure of outflows are required.
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    The MURALES survey V. Jet-induced star formation in 3C 277.3 (Coma A)
    (2022) Capetti, A.; Balmaverde, B.; Tadhunter, C.; Marconi, A.; Venturi, G.; Chiaberge, M.; Baldi, R. D.; Baum, S.; Gilli, R.; Grandi, P.; Meyer, E. T.; Miley, G.; O'Dea, C.; Sparks, W.; Torresi, E.; Tremblay, G.
    We present observations obtained with the VLT/MUSE optical integral field spectrograph of the radio source 3C 277.3, located at a redshift of 0.085 and associated with the galaxy Coma A. An emission line region fully enshrouds the double-lobed radio source, which is similar to 60 kpc x 90 kpc in size. Based on the emission line ratios, we identified five compact knots in which the gas ionization is powered by young stars located as far as similar to 60 kpc from the host. The emission line filaments surrounding the radio emission are compatible with ionization from fast shocks (with a velocity of 350-500 km s(-1)), but a contribution from star formation occurring at the edges of the radio source is likely. Coma A might be a unique example in the local Universe in which the expanding outflow triggers star formation throughout the whole radio source.
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    The MURALES survey VI. Properties and origin of the extended line emission structures in radio galaxies
    (2022) Balmaverde, B.; Capetti, A.; Baldi, R. D.; Baum, S.; Chiaberge, M.; Gilli, R.; Jimenez-Gallardo, A.; Marconi, A.; Massaro, F.; Meyer, E.; O'Dea, C.; Speranza, G.; Torresi, E.; Venturi, G.
    This is the sixth paper presenting the results of the MUse RAdio Loud Emission line Snapshot survey. We observed 37 radio sources from the 3C sample with z < 0.3 and a declination <20 degrees with the Multi Unit Spectroscopic Explorer optical integral field spectrograph at the Very Large Telescope. Here, we focus on the properties of the extended emission line regions (EELRs) that can be studied with unprecedented detail thanks to the depth of these observations. Line emission in the ten FR Is is, in most cases, confined to within less than or similar to 4kpc, while large-scale (greater than or similar to 4 kpc) ionized gas is seen in all but two of the 26 FR Its. It usually takes the form of elongated or filamentary structures, typically extending between 10 and 30 kpc, but also reaching distances of similar to 80 kpc. We find that the large-scale ionized gas structures show a tendency to be oriented at large angles from the radio axis, and that the gas on a scale of a few kiloparsecs from the nucleus often shows ordered rotation with a kinematical axis forming a median angle of 65 degrees with the radio axis. We also discuss the velocity field and ionization properties of the EELRs. The observed emission line structures appear to be associated with gaseous "superdisks" that formed after a gas-rich merger. The different properties of the EELR can be explained with a combination of the source evolutionary state and the orientation of the superdisk with respect to the radio axis. The general alignment between the superdisks and radio axis might be produced by stable and coherent accretion maintained over long timescales.