Oral Abstract

Oral Contribution (O0.3) Hyoyin Gan (Kapteyn Institute)

Exploring noise sources in detecting the first luminous objects with LOFAR

LOFAR (Low Frequency ARray) is a new generation radio interferometer covering the unexplored low-frequency range from 10 to 240 MHz. Among its key science projects, LOFAR-EoR is set to detect the redshifted neutral hydrogen (HI) signal from Epoch of Reionization (EoR) where the first stars, quasars and galaxies formed. The detection has been challenged because of very strong noise including galactic and extragalactic foregrounds, ionospheric and instrumental effects etc. To increase the chance of detecting the HI, it is essential to understand and control sources of noise. In this work, we analysed possible noise sources in LOFAR-EoR. We focused on the foreground and ionospheric effects on noise. The correlations between the estimated noise level and Local Sidereal Time (LST) are analysed to see how foregrounds affect the noise level. We also correlated the noise level with Total Electron Content (TEC) variance to investigate ionospheric effects on noise. From our analysis, we found that there is an interesting correlation between noise and LST.