Browsing by Author "Katsianis, A."

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    Orientation effects on cool gas absorption from gravitational-arc tomography of a z=0.77 disc galaxy
    (2022) Fernandez-Figueroa, A.; Lopez, S.; Tejos, N.; Berg, T. A. M.; Ledoux, C.; Noterdaeme, P.; Afruni, A.; Barrientos, L. F.; Gonzalez-Lopez, J.; Hamel, M.; Johnston, E. J.; Katsianis, A.; Sharon, K.; Solimano, M.
    We use spatially resolved spectroscopy of a distant giant gravitational arc to test orientation effects on Mg ii absorption equivalent width (EW) and covering fraction () in the circumgalactic medium of a foreground star-forming galaxy (G1) at z similar to 0.77. Forty-two spatially-binned arc positions uniformly sample impact parameters (D) to G1 between 10 and 30 kpc and azimuthal angles alpha between 30 degrees and 90 degrees (minor axis). We find an EW-D anticorrelation, akin to that observed statistically in quasar absorber studies, and an apparent correlation of both EW and with alpha, revealing a non-isotropic gas distribution. In line with our previous results on Mg ii kinematics suggesting the presence of outflows in G1, at minimum a simple 3D static double-cone model (to represent the trace of bipolar outflows) is required to recreate the EW spatial distribution. The D and alpha values probed by the arc cannot confirm the presence of a disc, but the data highly disfavour a disc alone. Our results support the interpretation that the EW-alpha correlation observed statistically using other extant probes is partly shaped by bipolar metal-rich winds.
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    Telltale signs of metal recycling in the circumgalactic medium of a z 0.77 galaxy
    (2021) Tejos, N.; López, S.; Ledoux, C.; Fernández-Figueroa, A.; Rivas, N.; Sharon, K.; Johnston, E. J.; Florian, M. K.; D'Ago, G.; Katsianis, A.; Barrientos, F.; Berg, T.; Corro-Guerra, F.; Hamel, M.; Moya-Sierralta, C.; Poudel, S.; Rigby, J. R.; Solimano, M.
    We present gravitational-arc tomography of the cool-warm enriched circumgalactic medium (CGM) of an isolated galaxy ('G1') at z approximate to 0.77. Combining VLT/MUSE adaptive-optics and Magellan/MagE echelle spectroscopy, we obtain partially resolved kinematics of Mg II in absorption and [O II] in emission. The unique arc configuration allows us to probe 42 spatially independent arc positions transverse to G1, plus four positions in front of it. The transverse positions cover G1's minor and major axes at impact parameters of approximate to 10-30 and approximate to 60kpc, respectively. We observe a direct kinematic connection between the cool-warm enriched CGM (traced by Mg II) and the interstellar medium (traced by [O II]). This provides strong evidence for the existence of an extended disc that co-rotates with the galaxy out to tens of kiloparsecs. The Mg II velocity dispersion (sigma approximate to 30-100 km s(-1), depending on position) is of the same order as the modelled galaxy rotational velocity (v(rot) approximate to 80 km s(-1)), providing evidence for the presence of a turbulent and pressure-supported CGM component. We regard the absorption to be modulated by a galactic-scale outflow, as it offers a natural scenario for the observed line-of-sight dispersion and asymmetric profiles observed against both the arcs and the galaxy. An extended enriched co-rotating disc together with the signatures of a galactic outflow, are telltale signs of metal recycling in the z similar to 1 CGM.