How to Identify and Separate Bright Galaxy Clusters from the Low-frequency Radio Sky?

Details How to Identify and Separate Bright Galaxy Clusters from the Low-frequency Radio Sky? How to Identify and Separate Bright Galaxy Clusters from the Low-frequency Radio Sky?

2010-08-19

arxiv.org/abs/1008.3391v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

35 pages, 10 figures, Accepted for publication in The Astrophysical Journal

Scientific paper

In this work we simulate the $50-200$ MHz radio sky that is constrained in the field of view ($5^{\circ}$ radius) of the 21 Centimeter Array (21CMA), by carrying out Monte-Carlo simulations to model redshifted cosmological reionization signals and strong contaminating foregrounds, including emissions from our Galaxy, galaxy clusters, and extragalactic point sources. As an improvement of previous works, we consider in detail not only random variations of morphological and spectroscopic parameters within the ranges allowed by multi-band observations, but also evolution of radio halos in galaxy clusters, assuming that relativistic electrons are re-accelerated in the ICM in merger events and lose energy via both synchrotron emission and inverse Compton scattering with CMB photons. By introducing a new approach designed on the basis of independent component analysis (ICA) and wavelet detection algorithm, we prove that, with a cumulative observation of one month with the 21CMA array, about $80\%$ of galaxy clusters with central brightness temperatures of $> 10~{\rm K}$ at 65 MHz can be safely identified and separated from the overwhelmingly bright foreground. We find that the morphological and spectroscopic distortions are extremely small as compared to the input simulated clusters, and the reduced $\chi^2$ of brightness temperature profiles and spectra are controlled to be $\lesssim 0.5$ and $\lesssim 1.3$, respectively. These results robustly indicate that in the near future a sample of dozens of bright galaxy clusters will be disentangled from the foreground in 21CMA observations, the study of which will greatly improve our knowledge about cluster merger rates, electron acceleration mechanisms in cluster radio halos, and magnetic field in the ICM.

Affiliated with

Also associated with

No associations

Rating

How to Identify and Separate Bright Galaxy Clusters from the Low-frequency Radio Sky? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with How to Identify and Separate Bright Galaxy Clusters from the Low-frequency Radio Sky?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and How to Identify and Separate Bright Galaxy Clusters from the Low-frequency Radio Sky? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-80085