Examinando por Autor "Fritz, Jacopo"

Mostrando 1 - 4 de 4
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    GASP XXIX - Unwinding the arms of spiral galaxies via ram-pressure stripping
    (Royal Astronomical Society, 2021) Bellhouse, Callum; Mcgee, Sean L; Smith, Rory; Poggianti, Bianca M; Jaffé, Yara L; Kraljic, Katarina; Franchetto, Andrea; Fritz, Jacopo; Vulcani, Benedetta; Tonnesen, Stephanie; Roediger, Elke; Moretti, Alessia; Gullieuszik, Marco; Shin, Jihye
    We present the first study of the effect of ram pressure ‘unwinding’ the spiral arms of cluster galaxies. We study 11 ram-pressure stripped galaxies from GASP (GAs Stripping Phenomena in galaxies) in which, in addition to more commonly observed ‘jellyfish’ features, dislodged material also appears to retain the original structure of the spiral arms. Gravitational influence from neighbours is ruled out and we compare the sample with a control group of undisturbed spiral galaxies and simulated stripped galaxies. We first confirm the unwinding nature, finding that the spiral arm pitch angle increases radially in 10 stripped galaxies and also simulated face-on and edge-on stripped galaxies. We find only younger stars in the unwound component, while older stars in the disc remain undisturbed. We compare the morphology and kinematics with simulated ram-pressure stripping galaxies, taking into account the estimated inclination with respect to the intracluster medium (ICM) and find that in edge-on stripping, unwinding can occur due to differential ram pressure caused by the disc rotation, causing stripped material to slow and ‘pile up’. In face-on cases, gas removed from the outer edges falls to higher orbits, appearing to ‘unwind’. The pattern is fairly short-lived (<0.5 Gyr) in the stripping process, occurring during first infall and eventually washed out by the ICM wind into the tail of the jellyfish galaxy. By comparing simulations with the observed sample, we find that a combination of face-on and edge-on ‘unwinding’ effects is likely to be occurring in our galaxies as they experience stripping with different inclinations with respect to the ICM.
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    GASP XXXIII. The ability of spatially resolved data to distinguish among the diferent physical mechanisms afecting galaxies in low-density environments
    (American Astronomical Society (Aas), 2021) Vulcani, Benedetta; Poggianti, Bianca M.; Moretti, Alessia; Franchetto, Andrea; Bacchini, Cecilia; Mcgee, Sean; Jaffé, Yara L.; Mingozzi, Matilde; Werle, Ariel; Tomičić, Neven; Fritz, Jacopo; Bettoni, Daniela; Wolter, Anna; Gullieuszik, Marco
    Galaxies inhabit a wide range of environments and therefore are affected by different physical mechanisms. Spatially resolved maps combined with the knowledge of the hosting environment are very powerful for classifying galaxies by physical process. In the context of the GAs Stripping Phenomena in galaxies (GASP), we present a study of 27 non-cluster galaxies: 24 of them were selected for showing asymmetries and disturbances in the optical morphology, suggestive of gas stripping; 3 of them are passive galaxies and were included to characterize the final stages of galaxy evolution. We therefore provide a panorama of the different processes taking place in low-density environments. The analysis of VLT/MUSE data allows us to separate galaxies into the following categories: galaxy–galaxy interactions (2 galaxies), mergers (6), ram pressure stripping (4), cosmic web stripping (2), cosmic web enhancement (5), gas accretion (3), and starvation (3). In one galaxy we identify the combination of merger and ram pressure stripping. Only 6/27 of these galaxies have just a tentative classification. We then investigate where these galaxies are located on scaling relations determined for a sample of undisturbed galaxies. Our analysis shows the successes and limitations of a visual optical selection in identifying the processes that deplete galaxies of their gas content and probes the power of IFU data in pinning down the acting mechanism.
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    Metal-THINGS: On the metallicity and ionization of ULX sources in NGC 925
    (American Astronomical Society, 2021) Lara-López, Maritza A.; Zinchenko, Igor A.; Pilyugin, Leonid S.; Gunawardhana, Madusha L. P.; López-Cruz, Omar; O'Sullivan, Shane P.; Feltre, Anna; Rosado, Margarita; Sánchez-Cruces, Mónica; Chevallard, Jacopo; De Rossi, Maria Emilia; Dib, Sami; Fritz, Jacopo; Fuentes-Carrera, Isaura; Garduño, Luis E.; Ibar, Eduardo
    We present an analysis of the optical properties of three Ultra Luminous X-ray (ULX) sources identified in NGC 925. We use Integral field unit data from the George Mitchel spectrograph in the context of the Metal-THINGS survey. The optical properties for ULX-1 and ULX-3 are presented, while the spaxel associated with ULX-2 had a low S/N, which prevented its analysis. We also report the kinematics and dimensions of the optical nebula associated with each ULX using ancillary data from the PUMA Fabry–Perot spectrograph. A BPT analysis demonstrates that most spaxels in NGC 925 are dominated by star-forming regions, including those associated with ULX-1 and ULX-3. Using the resolved gas-phase metallicities, a negative metallicity gradient is found, consistent with previous results for spiral galaxies, while the ionization parameter tends to increase radially throughout the galaxy. Interestingly, ULX-1 shows a very low gas metallicity for its galactocentric distance, identified by two independent methods, while exhibiting a typical ionization. We find that such low gas metallicity is best explained in the context of the high-mass X-ray binary population, where the low-metallicity environment favors active Roche lobe overflows that can drive much higher accretion rates. An alternative scenario invoking accretion of a low-mass galaxy is not supported by the data in this region. Finally, ULX-3 shows both a high metallicity and ionization parameter, which is consistent with the progenitor being a highly accreting neutron star within an evolved stellar population region.
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    The role of environment on quenching|, star formation and AGN activity
    (Cambridge University Press, 2020) Poggianti, Bianca M.; Bellhouse, Callum; Deb, Tirna; Franchetto; Fritz, Jacopo; George, Koshy; Gullieuszik, Marco; Jaffé, Yara; Moretti, Alessia; Mueller, Ancla; Radovich, Mario; Ramatsok, Pati; Vulcani, Benedetta
    Galaxies undergoing ram pressure stripping in clusters are an excellent opportunity to study the effects of environment on both the AGN and the star formation activity. We report here on the most recent results from the GASP survey. We discuss the AGN-ram pressure stripping connection and some evidence for AGN feedback in stripped galaxies. We then focus on the star formation activity, both in the disks and the tails of these galaxies, and conclude drawing a picture of the relation between multi-phase gas and star formation.