Detection of missing baryons in galaxy groups with kinetic Sunyaev-Zel'dovich effect

Autor: Lim, Seunghwan, Mo, H. J., Wang, Huiyuan, Yang, Xiaohu
Rok vydání: 2019
Předmět:
Druh dokumentu: Working Paper
DOI: 10.3847/1538-4357/ab63df
Popis: We present the detection of the kinetic Sunyaev-Zel'dovich effect (kSZE) signals from groups of galaxies as a function of halo mass down to $\log (M_{500}/{\rm M_\odot}) \sim 12.3$, using the {\it Planck} CMB maps and stacking about $40,000$ galaxy systems with known positions, halo masses, and peculiar velocities. The signals from groups of different mass are constrained simultaneously to take care of projection effects of nearby halos. The total kSZE flux within halos estimated implies that the gas fraction in halos is about the universal baryon fraction, even in low-mass halos, indicating that the `missing baryons' are found. Various tests performed show that our results are robust against systematic effects, such as contamination by infrared/radio sources and background variations, beam-size effects and contributions from halo exteriors. Combined with the thermal Sunyaev-Zel'dovich effect, our results indicate that the `missing baryons' associated with galaxy groups are contained in warm-hot media with temperatures between $10^5$ and $10^6\,{\rm K}$.
Comment: We replace the submission of the old version of the manuscript (arXiv:1712.08619; same paper, basically) with the manuscript of this new version, and remove this new submission to avoid confusion, which we newly submitted only to make it noticed that there was a very significant revision to the old version although they are still not a separate paper, but same paper
Databáze: arXiv