The LOFAR Two-metre Sky Survey - II. First data release

Year: 2018

Type: review

Abstract: The LOFAR Two-metre Sky Survey (LoTSS) is an ongoing sensitive, high-resolution 120-168MHz survey of the entire northern sky for which observations are now 20% complete. We present our first full-quality public data release. For this data release 424 square degrees, or 2% of the eventual coverage, in the region of the HETDEX Spring Field (right ascension 10h45m00s to 15h30m00s and declination 45$^\circ$00$'$00$''$ to 57$^\circ$00$'$00$''$) were mapped using a fully automated direction-dependent calibration and imaging pipeline that we developed. A total of 325,694 sources are detected with a signal of at least five times the noise, and the source density is a factor of $\sim 10$ higher than the most sensitive existing very wide-area radio-continuum surveys. The median sensitivity is S$_{\rm 144 MHz} = 71\,μ$Jy beam$^{-1}$ and the point-source completeness is 90% at an integrated flux density of 0.45mJy. The resolution of the images is 6$''$ and the positional accuracy is within 0.2$''$. This data release consists of a catalogue containing location, flux, and shape estimates together with 58 mosaic images that cover the catalogued area. In this paper we provide an overview of the data release with a focus on the processing of the LOFAR data and the characteristics of the resulting images. In two accompanying papers we provide the radio source associations and deblending and, where possible, the optical identifications of the radio sources together with the photometric redshifts and properties of the host galaxies. These data release papers are published together with a further $\sim$20 articles that highlight the scientific potential of LoTSS.

Source: UvA-DARE (University of Amsterdam)

DOI: 10.48550/arxiv.1811.07926

Authors: Shimwell, T. W., Tasse, C., Hardcastle, M. J., Mechev, A. P., Williams, W. L., Best, P. N., Röttgering, H. J. A., Callingham, J. R., Dijkema, T. J., de Gasperin, F., Hoang, D. N., Hugo, B., Mirmont, M., Oonk, J. B. R., Prandoni, I., Rafferty, D., Sabater, J., Smirnov, O., van Weeren, R. J., White, G. J., Atemkeng, M., Bester, L., Bonnassieux, E., Brüggen, M., Brunetti, G., Chyży, K. T., Cochrane, R., Conway, J. E., Croston, J. H., Danezi, A., Duncan, K., Haverkorn, M., Heald, G. H., Iacobelli, M., Intema, H. T., Jackson, N., Jamrozy, M., Jarvis, M. J., Lakhoo, R., Mevius, M., Miley, G. K., Morabito, L., Morganti, R., Nisbet, D., Orrú, E., Perkins, S., Pizzo, R. F., Schrijvers, C., Smith, D. J. B., Vermeulen, R., Wise, M. W., Alegre, L., Bacon, D. J., van Bemmel, I. M., Beswick, R. J., Bonafede, A., Botteon, A., Bourke, S., Brienza, M., Rivera, G. Calistro, Cassano, R., Clarke, A. O., Conselice, C. J., Dettmar, R. J., Drabent, A., Dumba, C., Emig, K. L., Enßlin, T. A., Ferrari, C., Garrett, M. A., Génova-Santos, R. T., Goyal, A., Gürkan, G., Hale, C., Harwood, J. J., Heesen, V., Hoeft, M., Horellou, C., Jackson, C., Kokotanekov, G., Kondapally, R., Kunert-Bajraszewska, M., Mahatma, V., Mahony, E. K., Mandal, S., McKean, J. P., Merloni, A., Mingo, B., Miskolczi, A., Mooney, S., Nikiel-Wroczyński, B., O'Sullivan, S. P., Quinn, J., Reich, W., Roskowiński, C., Rowlinson, A., Savini, F., Saxena, A., Schwarz, D. J., Shulevski, A., Sridhar, S. S., Stacey, H. R., Urquhart, S., van der Wiel, M. H. D., Varenius, E., Webster, B., Wilber, A.

Language: English

Topic: Radio Astronomy Observations and Technology

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Leverhulme Trust, University of Oxford, European Commission, Commonwealth Scientific and Industrial Research Organisation, University of Hertfordshire, National Research Foundation, Science Foundation Ireland, Deutsche Forschungsgemeinschaft, Irish Research Council, Bundesministerium für Bildung und Forschung, Forschungszentrum Jülich, Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Max-Planck-Gesellschaft, Centre National de la Recherche Scientifique, Université d'Orléans, Ministerium für Innovation, Wissenschaft und Forschung des Landes Nordrhein-Westfalen, Observatoire de Paris, Université de Recherche Paris Sciences et Lettres, Science and Technology Facilities Council, FP7 Ideas: European Research Council

OpenAlex ID: W2893487431