Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2009-08-18
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
accepted by ApJ; 12 pages, 10 figures
Scientific paper
Observations of the HI 21cm transition line promises to be an important probe into the cosmic dark ages and epoch of reionization. One of the challenges for the detection of this signal is the accuracy of the foreground source removal. This paper investigates the extragalactic point source contamination and how accurately the bright sources ($\gtrsim 1$ ~Jy) should be removed in order to reach the desired RMS noise and be able to detect the 21cm transition line. Here, we consider position and flux errors in the global sky-model for these bright sources as well as the frequency independent residual calibration errors. The synthesized beam is the only frequency dependent term included here. This work determines the level of accuracy for the calibration and source removal schemes and puts forward constraints for the design of the cosmic reionization data reduction scheme for the upcoming low frequency arrays like MWA,PAPER, etc. We show that in order to detect the reionization signal the bright sources need to be removed from the data-sets with a positional accuracy of $\sim 0.1$ arc-second. Our results also demonstrate that the efficient foreground source removal strategies can only tolerate a frequency independent antenna based mean residual calibration error of $\lesssim 0.2 %$ in amplitude or $\lesssim 0.2$ degree in phase, if they are constant over each days of observations (6 hours). In future papers we will extend this analysis to the power spectral domain and also include the frequency dependent calibration errors and direction dependent errors (ionosphere, primary beam, etc).
Bhatnagar Shashank
Carilli Chris L.
Datta Animesh
No associations
LandOfFree
Detection of Signals from Cosmic Reionization using Radio Interferometric Signal Processing 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 Detection of Signals from Cosmic Reionization using Radio Interferometric Signal Processing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detection of Signals from Cosmic Reionization using Radio Interferometric Signal Processing will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-215789