Kavli Affiliate: David N. Spergel
| First 5 Authors: Bernardita Ried Guachalla, Emmanuel Schaan, Boryana Hadzhiyska, Simone Ferraro, Jessica N. Aguilar
| Summary:
The gas density profile around galaxies, shaped by feedback and affecting the
galaxy lensing signal, is imprinted on the cosmic microwave background (CMB) by
the kinematic Sunyaev-Zel’dovich effect (kSZ). We precisely measure this effect
($S/Napprox 10$) via velocity stacking with $825,283$ spectroscopically
confirmed luminous red galaxies (LRG) from the Dark Energy Spectroscopic
Instrument (DESI) Y1 survey, which overlap with the Atacama Cosmology Telescope
(ACT) Data Release 6 temperature maps over $geq 4,000 text{deg}^2$. We
explore the kSZ dependence with various galaxy parameters. We find no
significant trend with redshift, but clear trends with stellar mass and
absolute magnitude in $g$, $r$, and $z$ bands. We highlight new challenges when
comparing data and hydrodynamical simulations. Our simple and most conservative
analysis suggests that the gas is more extended than the dark matter (99.5%
confidence, i.e. PTE = 0.005). It also hints at a preference for galaxy
formation models with more feedback (Illustris $z=0.5$, PTE = 0.37) rather than
less (Illustris TNG $z=0.8$, PTE = 0.045), though with less statistical
significance. In all cases, a free multiplicative amplitude was fit to the
simulated profiles, and further modeling work is required to firm up these
conclusions. We find consistency between kSZ profiles around spectroscopic and
photometric LRG, with comparable statistical power, thus increasing our
confidence in the photometric analysis. Additionally, we present the first kSZ
measurement around DESI Y1 bright galaxy sample (BGS) and emission-line
galaxies (ELG), whose features match qualitative expectations. Finally, we
forecast $S/N sim 50$ for future stacked kSZ measurements using data from ACT,
DESI Y3, and Rubin Observatory. These measurements will serve as an input for
galaxy formation models and baryonic uncertainties in galaxy lensing.
| Search Query: ArXiv Query: search_query=au:”David N. Spergel”&id_list=&start=0&max_results=3