CMB Comptonization by Energetic Nonthermal Electrons in Clusters of Galaxies

Abstract

Use of the Sunyaev-Zeldovich effect as a precise cosmological probe necessitates a realistic assessment of all possible contributions to Comptonization of the cosmic microwave background in clusters of galaxies. We have calculated the additional intensity change due to various possible populations of energetic electrons that have been proposed in order to account for measurements of intracluster radio, nonthermal X-ray and (possibly also) EUV emission. Our properly normalized estimates of (the highly model dependent value of) the predicted intensity change due to these electrons is well below $\sim 6$ and $\sim 35$ of the usual Sunyaev-Zeldovich effect due to electrons in the hot gas in Coma and A2199, respectively. These levels constitute high upper limits since they are based on energetic electron populations whose energy densities are {\it comparable} to those of the thermal gas. The main impact of nonthermal Comptonization is a shift of the crossover frequency (where the thermal effect vanishes) to higher values. Such a shift would have important consequences for our ability to measure cluster peculiar velocities from the kinematic component of the Sunyaev-Zeldovich effect.

15 pages, 2 figures

References in corpus (1)

• Quantification of Uncertainty in the Measurement of Magnetic Fields in Clusters of Galaxies

Cited by in corpus (22)

• Astrophysics with the Spatially and Spectrally Resolved Sunyaev-Zeldovich Effects: A Millimetre/Submillimetre Probe of the Warm and Hot Universe
• Exploring Cluster Physics with High-Resolution Sunyaev-Zel'dovich Effect Images and X-Ray Data: The Case of the Most X-Ray-Luminous Galaxy Cluster RX J1347-1145
• The Non-Thermal Sunyaev-Zel'dovich Effect in Clusters of Galaxies
• Results from a Second RXTE Observation of the Coma Cluster
• Peculiar Velocity Limits from Measurements of the Spectrum of the Sunyaev-Zel'dovich Effect in Six Clusters of Galaxies
• Cosmic Microwave Background Temperature at Galaxy Clusters
• MITO measurements of the Sunyaev-Zeldovich Effect in the Coma cluster of galaxies
• Unveiling the composition of radio plasma bubbles in galaxy clusters with the Sunyaev-Zel'dovich effect
• Constraining the evolution of the CMB temperature with SZ measurements from Planck data
• Modification of cluster radio halo appearance by the thermal Sunyaev-Zeldovich effect
• An Unbiased Measurement of Ho through Cosmic Background Imager Observations of the Sunyaev-Zel'dovich Effect in Nearby Galaxy Clusters
• Exact solution for the Green's function describing time-dependent thermal Comptonization
• Exploring Cosmic Origins with CORE: Cluster Science
• Beyond the Standard Lore of the SZ effect
• An analysis of electron distributions in galaxy clusters by means of the flux ratio of iron lines FeXXV and XXVI
• Reconstructing three-dimensional parameters of galaxy clusters via multifrequency SZ observations
• The influence of magnetic fields on the Sunyaev Zel'dovich effect in clusters of galaxies
• New Horizons in Cosmology with Spectral Distortions of the Cosmic Microwave Background
• Can electron distribution functions be derived through the Sunyaev-Zel'dovich effect?
• Stokes parameters spectral distortions due to the Sunyaev-Zel'dovich effect and an independent estimation of the CMB low multipoles
• Anisotropic thermal Sunyaev-Zel'dovich effect and the possibility of an independent measurement of the CMB dipole, quadrupole and octupole
• On the influence of high energy electron populations on metal abundance estimates in galaxy groups and clusters