Telltale signs of metal recycling in the circumgalactic medium of a z ∼ 0.77 galaxy

Abstract

We present gravitational-arc tomography of the cool-warm enriched circumgalactic medium (CGM) of an isolated galaxy (“G1”) at z ≈ 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 4 positions in front of it. The transverse positions cover G1’s minor and major axes at impact parameters of ≈10 − 30 kpc and ≈60 kpc, 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 (σ ≈ 30 − 100 km s−1, depending on position) is of the same order as the modeled galaxy rotational velocity (vrot ≈ 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 ∼ 1 CGM.

Multiphase turbulence in galactic haloes: effect of the driving

“…Moreover, we observe strong converging and diverging motions in these media -such as expanding X-ray cavities around AGN-inflated bubbles (Wise et al 2007;Biava et al 2021;Tiwari & Singh 2022), compressive waves during galaxy infall and passages (Churazov et al 2003(Churazov et al , 2021, gas sloshing and cold fronts (Botteon et al 2021;Gendron-Marsolais et al 2021;Ichinohe et al 2021;Ubertosi et al 2021;Ueda et al 2021;Brienza et al 2022), which indicate density contrasts and compressive motions in the ICM. Similarly, galactic outflows consisting of radially expanding motions driven by diverging flows such as stellar winds, supernova bubbles, super-bubbles and AGNs can also drive compressive motions in the disk-halo interface and the CGM (Mulcahy et al 2017;Das et al 2019;Tejos et al 2021). The evolution of these compressive motions and their role in the thermodynamics of the halo gas could be very different from the divergence-free forcing studied in current literature.…”

Revealing the nature of a Lyman-$α$ halo in a strongly-lensed interacting system at $z=2.92$

“…This setup provides a field of view (FoV) of 1 ×1 with a pixelscale of 0.2 , and a wavelength range of 4600 to 9350 Å with a resolving power of R ∼ 1770 at 4800 Å (the wavelength of Lyα emission at z ∼ 2.92). A subset of these data were already presented by Tejos et al (2021), and in this paper we followed similar reduction steps. The main difference is that Tejos et al only combined 20 exposures (six were discarded due to slightly suboptimal seeing) to create the final stacked datacube, while here we used the full set of 26 exposures to reach deeper in Lyα surface brightness.…”

“…At the same time, it enables the identification of lensed image pairs and the positions of the cluster members that are in-1 With σ computed as the standard deviation of a sample of 5000 flux measurements from randomly placed 1 apertures in blank sky regions. cluded in the development of the lens model (Dai et al 2020;Tejos et al 2021).…”

“…Good approximations of the amount and direction of the distortion at any given position are obtained by modeling the cluster as a collection of parametric dark matter profiles and then constraining the model to predict the positions of image pairs identified in the data. In this paper, we use the lens model presented in Tejos et al (2021), therefore we refer the reader to that work for further details. Briefly, the modeling was done using the Lenstool software (Jullo & Kneib 2009) following the procedure described in Sharon et al (2020).…”

“…The presence of a second strong-lensing cluster at the same redshift only 157 to the South of SGASJ1226 motivated the addition of a cluster-scale PIEMD at that position, contributing shear to the overall lensing potential. Finally, a perturber on top of the West part of arc A.1, plus the z = 0.77 galaxy between A.1 and B (labeled G1 in Tejos et al 2021, see Fig. 2) were included as individual components.…”