1. CGM 2 + CASBaH: The Mass Dependence of H i Ly α –Galaxy Clustering and the Extent of the CGM.
- Author
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Wilde, Matthew C., Tchernyshyov, Kirill, Werk, Jessica K., Tripp, Todd M., Burchett, Joseph N., Prochaska, J. Xavier, Tejos, Nicolas, Lehner, Nicolas, Bordoloi, Rongmon, O'Meara, John M., Tumlinson, Jason, and Howk, J. Christopher
- Subjects
GALACTIC evolution ,INTERSTELLAR medium ,STELLAR mass ,ASTRONOMICAL models ,GALACTIC redshift ,GAUSSIAN function - Abstract
We combine data sets from the CGM
2 and CASBaH surveys to model a transition point, Rcross , between circumgalactic and intergalactic media (CGM and IGM, respectively). In total, our data consist of 7244 galaxies at z < 0.5 with precisely measured spectroscopic redshifts, all having impact parameters of 0.01–20 comoving Mpc from 28 QSO sightlines with high-resolution UV spectra that cover H i Ly α. Our best-fitting model is a two-component model that combines a 3D absorber–galaxy cross-correlation function with a simple Gaussian profile at inner radii to represent the CGM. By design, this model gives rise to a determination of Rcross as a function of galaxy stellar mass, which can be interpreted as the boundary between the CGM and IGM. For galaxies with 108 ≤ M⋆ / M⊙ ≤ 1010.5 , we find that Rcross (M⋆ ) ≈ 2.0 ± 0.6 Rvir . Additionally, we find excellent agreement between Rcross (M⋆ ) and the theoretically determined splashback radius for galaxies in this mass range. Overall, our results favor models of galaxy evolution at z < 0.5 that distribute T ≈ 104 K gas to distances beyond the virial radius. [ABSTRACT FROM AUTHOR]- Published
- 2023
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