The Cosmic Ultraviolet Baryon Survey (CUBS) VI: Connecting Physical Properties of the Cool Circumgalactic Medium to Galaxies at $z\approx 1$

Abstract

This paper presents a new sample of 19 unique galaxies and galaxy groups at $z\approx 1$ from the CUBS program, which is designated as the CUBSz1 sample. In this CUBSz1 sample, nine galaxies or galaxy groups show absorption features, while ten systems do not have detectable absorption with 2-$\sigma$ upper limits of log$N$(HeI)/cm${}^{-2}\lesssim 13.5$ and log$N$(OV)/cm${}^{-2}\lesssim 13.3$. Environmental properties of the galaxies, including galaxy overdensities, the total stellar mass and gravitational potential summed over all nearby neighbors, and the presence of local ionizing sources, are found to have a significant impact on the observed CGM absorption properties. Specifically, massive galaxies and galaxies in overdense regions exhibit a higher rate of incidence of absorption. At the same time, the observed CGM absorption properties in galaxy groups appear to be driven by the galaxy closest to the QSO sightline, rather than by the most massive galaxy or by mass-weighted properties. We introduce a total projected gravitational potential $\psi$, defined as $-\psi /G=\sum M_{\mathrm{halo}}/d_{\mathrm{proj}}$ summed over all group members, to characterize the overall galaxy environment. This projected gravitational potential correlates linearly with the maximum density detected in each sightline, consistent with higher-pressure gas being confined in deeper gravitational potential wells. In addition, we find that the radial profile of cool gas density exhibits a general decline from the inner regions to the outskirts, being in pressure balance with the hot halo. Finally, we note that the ionizing flux from nearby galaxies can generate an elevated $N$(HI)/$N$(HeI) ratio, which in turn provides a unique diagnostic of possible local sources contributing to the ionizing radiation field.

17 pages, 11 figures and 1 table in the main text; 40 figures and 1 table in the appendix; accepted for publication in MNRAS

References in corpus (26)

• Array Programming with NumPy
• The Circumgalactic Medium
• Galaxy Groups in the SDSS DR4: I. The Catalogue and Basic Properties
• The MUSE second-generation VLT instrument
• Strong Nebular Line Ratios in the Spectra of z~2-3 Star-forming Galaxies: First Results from KBSS-MOSFIRE
• The COS-Halos Survey: Physical Conditions and Baryonic Mass in the Low-Redshift Circumgalactic Medium
• Characterizing the Circumgalactic Medium of Nearby Galaxies with HST/COS and HST/STIS Absorption-Line Spectroscopy
• Metal-line absorption around $z\approx$2.4 star-forming galaxies in the Keck Baryonic Structure Survey
• On the possible environmental effect in distributing heavy elements beyond individual gaseous halos
• Cooling flow solutions for the circumgalactic medium
• MUSE Analysis of Gas around Galaxies (MAGG) -- II: Metal-enriched halo gas around z~1 galaxies
• The extent of chemically enriched gas around star-forming dwarf galaxies
• A Complete Census of Circumgalactic MgII at Redshift z<~ 0.5
• Galaxy Clusters in the Line of Sight to Background Quasars: I. Survey Design and Incidence of MgII Absorbers at Cluster Redshifts
• The Cosmic Ultraviolet Baryon Survey (CUBS) -- III. Physical properties and elemental abundances of Lyman limit systems at $z<1$
• The Line-of-Sight Proximity Effect and the Mass of Quasar Host Halos
• The Properties of the Galactic Hot Gaseous Halo from X-ray Emission
• MUSEQuBES: Characterizing the circumgalactic medium of redshift $\approx 3.3$ Ly$\alpha$ emitters
• The Cosmic Ultraviolet Baryon Survey (CUBS) V: On the Thermodynamic Properties of the Cool Circumgalactic Medium at $z<1$
• Circumgalactic Pressure Profiles Indicate Precipitation-Limited Atmospheres for $M_{\ast }\sim 10^9$$-$$10^{11.5}{M}_{\odot }$
• Cloud-by-cloud, multiphase, Bayesian modeling: Application to four weak, low ionization absorbers
• The Cosmic Ultraviolet Baryon Survey (CUBS) IV: The Complex Multiphase Circumgalactic Medium as Revealed by Partial Lyman Limit Systems
• Gauging Metallicity of Diffuse Gas Under An Uncertain Ionizing Radiation Field
• The relationship between gas and galaxies at z<1 using the Q0107 quasar triplet
• Physical Conditions of Five O VI Absorption Systems Towards PG $1522+101$
• Galaxy cluster photons alter the ionisation state of the nearby warm-hot intergalactic medium

Cited by in corpus (10)

• Directly constraining the spatial coherence of the $z\sim 1$ circumgalactic medium
• MUSE Analysis of Gas around Galaxies (MAGG) -- VI. The cool and enriched gas environment of z$\gtrsim$3 Ly$\alpha$ emitters
• Metal line emission around z<1 galaxies
• Upper Limits on the Mass of Cool Gas in the Circumgalactic Medium of Dwarf Galaxies
• CRexit: how different cosmic ray transport modes affect thermal instability in the circumgalactic medium
• KBSS-InCLOSE I: Design and First Results from the Inner CGM of QSO Line Of Sight Emitting Galaxies at z~2-3
• Misty, patchy, and turbulent: constraining the cool circumgalactic medium with mCC
• A Global Census of Metals in the Universe
• FEASTS and MHONGOOSE: HI Column Density Distribution at $z=0$ for $N_{\mathrm{HI}}>10^{17.8}{\mathrm{cm}}^{-2}$
• The Thermodynamic and Kinematic Evolution of Circumgalactic Gas around $z=1$ in the IllustrisTNG model