The LOFAR Two-metre Sky Survey IV. First Data Release: Photometric redshifts and rest-frame magnitudes

Duncan, Kenneth J; Sabater, J.; Röttgering, H. J. A.; Jarvis, M. J.; Smith, D. J. B.; Best, P. N.; Callingham, J. R.; Cochrane, R.; Croston, J. H.; Hardcastle, M. J.; Mingo, B.; Morabito, L.; Nisbet, D.; Prandoni, I.; Shimwell, T. W.; Tasse, C.; White, G. J.; Williams, W. L.; Alegre, L.; Chyży, K. T.; Gürkan, G.; Hoeft, M.; Kondapally, R.; Mechev, A. P.; Miley, G. K.; Schwarz, D. J.; Weeren, R. J. van

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Author

Duncan, Kenneth J

Sabater, J.

Röttgering, H. J. A.

Jarvis, M. J.

Smith, D. J. B.

Best, P. N.

Callingham, J. R.

Cochrane, R.

Croston, J. H.

Hardcastle, M. J.

Mingo, B.

Morabito, L.

Nisbet, D.

Prandoni, I.

Shimwell, T. W.

Tasse, C.

White, G. J.

Williams, W. L.

Alegre, L.

Chyży, K. T.

Gürkan, G.

Hoeft, M.

Kondapally, R.

Mechev, A. P.

Miley, G. K.

Schwarz, D. J.

Weeren, R. J. van

Abstract

The LOFAR Two-metre Sky Survey (LoTSS) is a sensitive, high-resolution 120-168 MHz survey of the Northern sky. The LoTSS First Data Release (DR1) presents 424 square degrees of radio continuum observations over the HETDEX Spring Field (10h45m00s $ 0.15$) of 7.9%. We also find that, at a given redshift, there is no strong trend in photo-$z$ quality as a function of radio luminosity. However there are strong trends as a function of redshift for a given radio luminosity, a result of selection effects in the spectroscopic sample and/or intrinsic evolution within the radio source population. Additionally, for the sample of sources in the LoTSS First Data Release with optical counterparts, we present rest-frame optical and mid-infrared magnitudes based on template fits to the consensus photometric (or spectroscopic when available) redshift.