부산대학교 도서관

Covering |$\sim 5600\, \deg ^2$| to rms sensitivities of ∼70−100 |$\mu$| Jy beam−1, the LOFAR Two-metre Sky Survey Data Release 2 (LoTSS-DR2) provides the largest low-frequency (∼150 MHz) radio catalogue to date, making it an excellent tool for large-area radio cosmology studies. In this work, we use LoTSS-DR2 sources to investigate the angular two-point correlation function of galaxies within the survey. We discuss systematics in the data and an improved methodology for generating random catalogues, compared to that used for LoTSS-DR1, before presenting the angular clustering for ∼900 000 sources ≥1.5 mJy and a peak signal-to-noise ≥ 7.5 across ∼80 per cent of the observed area. Using the clustering, we infer the bias assuming two evolutionary models. When fitting angular scales of |$0.5 \le \theta \lt 5{^\circ }$|⁠ , using a linear bias model, we find LoTSS-DR2 sources are biased tracers of the underlying matter, with a bias of |$b_{\rm C}= 2.14^{+0.22}_{-0.20}$| (assuming constant bias) and |$b_{\rm E}(z=0)= 1.79^{+0.15}_{-0.14}$| (for an evolving model, inversely proportional to the growth factor), corresponding to |$b_{\rm E}= 2.81^{+0.24}_{-0.22}$| at the median redshift of our sample, assuming the LoTSS Deep Fields redshift distribution is representative of our data. This reduces to |$b_{\rm C}= 2.02^{+0.17}_{-0.16}$| and |$b_{\rm E}(z=0)= 1.67^{+0.12}_{-0.12}$| when allowing preferential redshift distributions from the Deep Fields to model our data. Whilst the clustering amplitude is slightly lower than LoTSS-DR1 (≥2 mJy), our study benefits from larger samples and improved redshift estimates. [ABSTRACT FROM AUTHOR]