Orientation effects on cool gas absorption from gravitational-arc tomography of a z = 0.77 disc galaxy. Issue 2 (18th October 2022)

• Record Type: Journal Article
• Authors: 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
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 517:Issue 2(2022)
• Page Start: 2214
• Page End: 2220
• Publication Date: 2022-10-18
• Subjects: galaxies: clusters: individual (SGAS J1226 + 2152) -- galaxies: evolution -- galaxies: formation -- intergalactic medium; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac2851
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: 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 (〈κ〉) 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 α between 30° and 90° (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 〈κ〉 with α, 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 α 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-α correlation observed statistically using other extant probes is partly shaped by bipolar metal-rich winds.