分类： 天文学 >> 天文学 提交时间： 2023-02-19
Martine Lokken
Weiguang Cui
J. Richard Bond
Renée Hložek
Norm Murray
Romeel Davé
Alexander van Engelen
摘要： Upcoming advances in galaxy surveys and cosmic microwave background data will enable measurements of the anisotropic distribution of diffuse gas in filaments and superclusters at redshift $z=1$ and beyond, observed through the thermal Sunyaev-Zel'dovich (tSZ) effect. These measurements will help distinguish between different astrophysical feedback models, account for baryons that appear to be 'missing' from the cosmic census, and present opportunities for using locally-anisotropic tSZ statistics as cosmological probes. This study seeks to guide such future measurements by analysing whether diffuse intergalactic gas is a major contributor to anisotropic tSZ signal in The Three Hundred GIZMO-Simba hydrodynamic simulations. Various definitions are applied to divide concentrated from diffuse gas at $z=1$ and create mock Compton-$y$ maps for the separate components. The maps from 98 simulation snapshots are centred on massive galaxy clusters, oriented by the most prominent galaxy filament axis, and stacked. Results vary significantly depending on the definition used for diffuse gas, indicating that assumptions should be clearly defined when claiming observations of the warm-hot intergalactic medium. In all cases, the diffuse gas is important, contributing 25-60% of the tSZ signal in the far field ($>4 h^{-1}$ comoving Mpc) from the stacked clusters. The gas 1-2 virial radii from halo centres is especially key. Oriented stacking and environmental selections help to amplify the signal from the warm-hot intergalactic medium, which is aligned but less concentrated along the filament axis than the hot halo gas.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Stefania Amodeo
Nicholas Battaglia
Emmanuel Schaan
Simone Ferraro
Emily Moser
Simone Aiola
Jason E. Austermann
James A. Beall
Rachel Bean
Daniel T. Becker
Richard J. Bond
Erminia Calabrese
Victoria Calafut
Steve K. Choi
Edward V. Denison
Mark Devlin
Shannon M. Duff
Adriaan J. Duivenvoorden
Jo Dunkley
Rolando Dünner
摘要： The thermal and kinematic Sunyaev-Zel'dovich effects (tSZ, kSZ) probe the thermodynamic properties of the circumgalactic and intracluster medium (CGM and ICM) of galaxies, groups, and clusters, since they are proportional, respectively, to the integrated electron pressure and momentum along the line-of-sight. We present constraints on the gas thermodynamics of CMASS galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS) using new measurements of the kSZ and tSZ signals obtained in a companion paper. Combining kSZ and tSZ measurements, we measure within our model the amplitude of energy injection $\epsilon M_\star c^2$, where $M_\star$ is the stellar mass, to be $\epsilon=(40\pm9)\times10^{-6}$, and the amplitude of the non-thermal pressure profile to be $\alpha_{\rm Nth}<0.2$ (2$\sigma$), indicating that less than 20% of the total pressure within the virial radius is due to a non-thermal component. We estimate the effects of including baryons in the modeling of weak-lensing galaxy cross-correlation measurements using the best-fit density profile from the kSZ measurement. Our estimate reduces the difference between the original theoretical model and the weak-lensing galaxy cross-correlation measurements in arXiv:1611.08606 by half but does not fully reconcile it. Comparing the tSZ measurements to cosmological simulations, we find that simulations underestimate the CGM pressure at large radii while they fare better in comparison with the kSZ measurements. This suggests that the energy injected via feedback models in the simulations that we compared against does not sufficiently heat the gas at these radii. We do not find significant disagreement at smaller radii. These measurements provide novel tests of current and future simulations. This work demonstrates the power of joint, high signal-to-noise kSZ and tSZ observations, upon which future cross-correlation studies will improve.
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