Quantifying Suppression of the Cosmological 21-cm Signal due to Direction Dependent Gain Calibration in Radio Interferometers

Understand

The 21-cm signal of neutral hydrogen - emitted during the Epoch of Reionization - promises to be an important source of information for the study of the infant universe.

• However, its detection is impossible without sufficient mitigation of other strong signals in the data, which requires an accurate knowledge of the instrument.
• Using the result of instrument calibration, a large part of the contaminating signals are removed and the resulting residual data is further analyzed in order to detect the 21-cm signal.
• Direction dependent calibration (DDC) can strongly affect the 21-cm signal, however, its effect has not been precisely quantified.