Bibliographic Details
| Title: |
CGM$^2$ $+$ CASBaH: The Mass Dependence of H~I Ly$\alpha$-Galaxy Clustering and the Extent of the CGM |
| Authors: |
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, Howk, J. Christopher |
| Publication Year: |
2023 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - Astrophysics of Galaxies |
| More Details: |
We combine datasets from the CGM$^{2}$ and CASBaH surveys to model a transition point, $R_{\rm cross}$, 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$\alpha$. Our best-fitting model is an exclusionary 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 $R_{\rm cross}$ as a function of galaxy stellar mass, which can be interpreted as the boundary between the CGM and IGM. For galaxies with $10^8 \leq M_{\star}/M_{\odot} \leq 10^{10.5}$, we find that $R_{\rm cross}(M_{\star}) \approx 2 \pm 0.6 R_{\rm vir}$. Additionally, we find excellent agreement between $R_{\rm cross}(M_{\star})$ 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 $T \approx 10^{4}$K gas to distances beyond the virial radius.
Comment: Submitted to ApJ, 17 pages, 8 figures |
| Document Type: |
Working Paper |
| DOI: |
10.3847/1538-4357/acc85b |
| Access URL: |
http://arxiv.org/abs/2301.02718 |
| Accession Number: |
edsarx.2301.02718 |
| Database: |
arXiv |
