Browsing by Author "Bland-Hawthorn, J."

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    Galaxy And Mass Assembly (GAMA): the signatures of galaxy interactions as viewed from small-scale galaxy clustering
    (2018) Gunawardhan, M. L. P.; Norberg, P.; Zehavi, I.; Farrow, D. J.; Loveday, J.; Hopkins, A. M.; Davie, L. J. M.; Wang, L.; Alpaslan, M.; Bland-Hawthorn, J.; Brough, S.; Holwerda, B. W.; Owers, M. S.; Wrigh, A. H.
    Statistical studies of galaxy-galaxy interactions often utilize net change in physical properties of progenitors as a function of the separation between their nuclei to trace both the strength and the observable time-scale of their interaction. In this study, we use two-point auto-, cross-, and mark-correlation functions to investigate the extent to which small-scale clustering properties of star-forming galaxies can be used to gain physical insight into galaxy-galaxy interactions between galaxies of similar optical brightness and stellar mass. The H α star formers, drawn from the highly spatially complete Galaxy And Mass Assembly (GAMA) survey, show an increase in clustering at small separations. Moreover, the clustering strength shows a strong dependence on optical brightness and stellar mass, where (1) the clustering amplitude of optically brighter galaxies at a given separation is larger than that of optically fainter systems, (2) the small-scale-clustering properties (e.g. the strength, the scale at which the signal relative to the fiducial power law plateaus) of star-forming galaxies appear to differ as a function of increasing optical brightness of galaxies. According to cross- and mark-correlation analyses, the former result is largely driven by the increased dust content in optically bright star-forming galaxies. The latter could be interpreted as evidence of a correlation between interaction-scale and optical brightness of galaxies, where physical evidence of interactions between optically bright star formers, likely hosted within relatively massive haloes, persists over larger separations than those between optically faint star formers.
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    IMF. shape constraints from stellar populations and dynamics from CALIFA
    (2016) Lyubenova, M.; Martın-Navarro, I.; van de Ven, G.; Falcon-Barroso, J.; Galbany, A.; Gallazzi, L.; Garcıa-Benito, R.; Gonzalez Delgado, R.; Husemann, B.; Sánchez Blazquez, Patricia; Marino, R. A.; Mast, D.; Mendez-Abreu, J.; Peletier, R. F. P.; La Barbera, F.; Sanchez, S. F.; Trager, S. C.; van den Bosch, R. C. E.; Vazdekis, A.; Walcher, C. J.; Zhu, L.; Zibetti, S.; Ziegler, B.; Bland-Hawthorn, J.
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    MAGNUM survey: Compact jets causing large turmoil in galaxies. Enhanced line widths perpendicular to radio jets as tracers of jet-ISM interaction
    (2021) Venturi, G.; Cresci, G.; Marconi, A.; Mingozzi, M.; Nardini, E.; Carniani, S.; Mannucci, F.; Marasco, A.; Maiolino, R.; Perna, M.; Treister, E.; Bland-Hawthorn, J.; Gallimore, J.
    Context. Outflows accelerated by active galactic nuclei (AGN) are commonly observed in the form of coherent, mildly collimated high-velocity gas directed along the AGN ionisation cones and kinetically powerful (greater than or similar to 10(44-45) erg s(-1)) jets. Recent works found that outflows can also be accelerated by low-power (less than or similar to 10(44) erg s(-1)) jets, and the most recent cosmological simulations indicate that these are the dominant source of feedback on sub-kiloparsec scales, but little is known about their effect on the galaxy host.Aims. We study the relation between radio jets and the distribution and kinematics of the ionised gas in IC 5063, NGC 5643, NGC 1068, and NGC 1386 as part of our survey of nearby Seyfert galaxies called Measuring Active Galactic Nuclei Under MUSE Microscope (MAGNUM). All these objects host a small-scale (less than or similar to 1 kpc) low-power (less than or similar to 10(44) erg s(-1)) radio jet that has small inclinations (less than or similar to 45 degrees) with respect to the galaxy disc.Methods. We employed seeing-limited optical integral field spectroscopic observations from the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope to obtain flux, kinematic, and excitation maps of the extended ionised gas. We compared these maps with archival radio images and in one case, with Chandra X-ray observations.Results. We detect a strong (up to greater than or similar to 800-1000 km s(-1)) and extended (greater than or similar to 1 kpc) emission-line velocity spread perpendicular to the direction of the AGN ionisation cones and jets in all four targets. The gas excitation in this region of line-width enhancement is entirely compatible with shock ionisation. These broad and symmetric line profiles are not associated with a single coherent velocity of the gas. A 'classical' outflow component with net blueshifted and redshifted motions is also present, but is directed along the ionisation cones and jets.Conclusions. We interpret the observed phenomenon as due to the action of the jets perturbing the gas in the galaxy disc. These intense and extended velocity spreads perpendicular to AGN jets and cones are indeed currently only observed in galaxies hosting a low-power jet whose inclination is sufficiently low with respect to the galaxy disc to impact on and strongly affect its material. In line with cosmological simulations, our results demonstrate that low-power jets are indeed capable of affecting the host galaxy.
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    SPATIALLY. RESOLVED. STAR. FORMATION. MAIN. SEQUENCE. OF. GALAXIES. IN. THE. CALIFA. SURVEY
    (2016) Cano Díaz, M.; Sánchez, S. F.; Zibetti, S.; Ascasibar, Y.; Bland-Hawthorn, J.; Ziegler, B.; González Delgado, R. M.; Walcher, C. J.; García Benito, R.; Sánchez-Blázquez, P.; Mendoza-Pérez, M. A.; Falcón-Barroso, J.; Galbany, L.; Husemann, B.; Kehrig, C.; Marino, R. A.; Mast, D.; López-Cobá, C.; López-Sánchez, Á. R.; Vilchez, J. M.