Abstract
The advent of the Square Kilometer Array (SKA) will have unprecedented impact on the study of magnetic fields in galaxy clusters. This instrument will be able to perform all-sky surveys in polarization, allowing us to build a rotation-measure (RM) grid based on an enormous number of sources. However, it is not always obvious how to extract correct information about the strength and the structure of magnetic fields from the RM grid. The simulations presented here help us to investigate this topic as they consist of full-Stokes idealized (because we did not add thermal noise) images of a pair of galaxy clusters between 950–1760 GHz, i.e., the SKA1-MID band 2. These images include not just cluster-embedded radio sources but also foreground and background discrete radio sources populating the simulated portion of the universe. To study the magnetic fields of the simulated galaxy clusters, we applied the RM synthesis technique on the simulated images and compared the “true” cluster RM values with those inferred from RM synthesis. The accuracy of our methodology is guarantee by the excellent agreement that we observed when we considered only the signal from the background radio sources. The presence of a Faraday screen, foreground, and cluster sources, introduces degeneracies and/or ambiguities that make the interpretation of the results more difficult.
Highlights
Cosmic magnetism is one of five scientific cases that drove the design and the construction of the Square Kilometer Array1 (SKA)
We present numerical simulations obtained with FARADAY [10], a software package developed for intracluster magnetic-field studies
We assumed the “cosmological” of Reference [13] evolved in redshift according to Reference [14]; we integrated the cosmological active galactic nuclei (AGN) and star-forming galaxies (SFGs) radio luminosity function (RLF) along the simulated portion of the universe to compute the number of background and foreground radio sources of each specific type; we assigned the redshift from the cumulative distribution function of the redshift-evolved RLFs; for the luminosity, morphology, and spectro-polarimetry properties, we proceeded in the same way as for the cluster-embedded sources
Summary
Cosmic magnetism is one of five scientific cases that drove the design and the construction of the Square Kilometer Array (SKA). The observation of the Faraday rotation effect on background radio sources is indirect proof of the presence of a magnetic field embedded in the intracluster medium (ICM). This effect consists of the rotation ∆Ψ of the polarization plane of a linearly polarized signal (the one from the background radio source) as it crosses a magnetized plasma (the ICM). This rotation depends on square wavelength λ2 and on the so-called rotation measure (RM): ∆Ψ = RM × λ2. By observing the signal at different https://www.skatelescope.org/
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
