Orientation effects on cool gas absorption from gravitational-arc tomography of a z = 0.77 disc galaxy
| Autor: | A Fernandez-Figueroa, S Lopez, N Tejos, T A M Berg, C Ledoux, P Noterdaeme, A Afruni, L F Barrientos, J Gonzalez-Lopez, M Hamel, E J Johnston, A Katsianis, K Sharon, M Solimano |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Popis: | We use spatially-resolved spectroscopy of a distant giant gravitational arc to test orientation effects on MgII absorption equivalent width (EW) and covering fraction (kappa) in the circumgalactic medium of a foreground star-forming galaxy (G1) at z~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 and 90 degrees (minor axis). We find an EW-D anti-correlation, akin to that observed statistically in quasar absorber studies, and an apparent correlation of both EW and kappa with alpha, revealing a non-isotropic gas distribution. In line with our previous results on MgII kinematics suggesting the presence of outflows in G1, at minimum a simple 3-D 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 disfavor 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. Accepted in Monthly Notices of the Royal Astronomical Society |
| Databáze: | OpenAIRE |
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