Galaxy Power Spectrum and Biasing Results from the LOFAR Two-meter Sky Survey (First Data Release)

Abstract

The Low-Frequency Array (LOFAR) Two-meter Sky Survey (LoTSS) is an ongoing survey aiming to observe the entire northern sky, providing an excellent opportunity to study the distribution and evolution of the large-scale structure of the universe. The source catalog from the public LoTSS first data release (DR1) covers 1% of the sky, and shows correlated noise or fluctuations of the flux density calibration on scales of a few degrees. We explore the LoTSS DR1 to understand the survey systematics and data quality of this first data release. We produce catalog mocks to estimate uncertainties, and measure the angular clustering statistics of LoTSS galaxies, which fit the Lambda cold dark matter cosmology reasonably well. We employ a Markov Chain Monte Carlo–based Bayesian analysis to recover the best galaxy biasing scheme and multicomponent source fraction for LoTSS DR1 above 1 mJy assuming different possible redshift templates. After masking some noisy and uneven patches and with suitable flux density cuts, the LOFAR survey appears qualified for large-scale cosmological studies. The upcoming data releases from LOFAR are expected to be deeper and wider, and will therefore provide improved cosmological measurements.