Assessment of post-calibrated data in HERA observations.

Project Description:

Standard calibration observations are carried out by pointing the array towards a point source with known properties, i.e., calibrators. However, HERA, being a transit array and also only observing in drift-scan mode, means that it does not track any source. Thus, the calibration requirements are different. The observed sources used for calibration move across the primary beam as the Earth rotates relative to the celestial sphere. Thus, the primary beam response of HERA antennas needs to be modelled accurately to avoid any bias in the derivation of antenna gain solutions during calibration. With the newly deployed broadband feeds, covering the 46 − 234 MHz range and extending the observing range to the Cosmic Dawn epoch the current primary models do not fully characterise the primary beam response (e.g., Fagnoni et al., 2021b), and this inevitably imparts errors to the calibrated data. This project aims to assess the extent of calibration errors in the post-calibrated HERA data and to find post-calibration analysis techniques that can be used to reduce these errors.

Research Area:

Astronomy

Project Level:

Honours

This Project Is Offered At The Following Node(s):

(NWU)

Special Requirements:

-Basic experience/knowledge in mathematical programming in Python.