Orientation effects on cool gas absorption from gravitational-arc tomography of a <i>z</i> = 0.77 disc galaxy

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 (???) in the circumgalactic medium foreground star-forming galaxy (G1) at z ? 0.77. Forty-two spatially-binned positions uniformly sample impact parameters (D) G1 between 10 30 kpc azimuthal angles ? 30° 90° (minor axis). find an EW-D anticorrelation, akin that observed statistically quasar absorber studies, apparent correlation both EW ??? with ?, revealing non-isotropic gas distribution. In line our previous results kinematics suggesting presence outflows G1, minimum simple 3D static double-cone model (to represent trace bipolar outflows) is required recreate spatial The D values probed by cannot confirm disc, but data highly disfavour disc alone. Our support interpretation EW-? using other extant probes partly shaped metal-rich winds.