The LOFAR Two-metre Sky Survey : I. Survey description and preliminary data release
|Author:||Shimwell, T. W.1; Rottgering, H. J. A.1; Best, P. N.2;|
1Leiden Univ, Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands.
2Royal Observ, Inst Astron, SUPA, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland.
3Univ Hertfordshire, Ctr Astrophys Res, Sch Phys Astron & Math, Coll Lane, Hatfield AL10 9AB, Herts, England.
4ASTRON, Postbus 2, NL-7990 AA Dwingeloo, Netherlands.
5CSIRO Astron & Space Sci, 26 Dick Perry Ave, Kensington, WA 6151, Australia.
6Univ Groningen, Kapteyn Astron Inst, Postbus 800, NL-9700 AV Groningen, Netherlands.
7Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany.
8Univ Sydney, Sydney Inst Astron, Sch Phys A28, Sydney, NSW 2006, Australia.
9ARC Ctr Excellence All Sky Astrophys CAASTRO, Sydney, NSW, Australia.
10Univ Hamburg, Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg, Germany.
11Univ Paris Diderot, CNRS, Observ Paris, GEPI, 5 Pl Jules Janssen, F-92190 Meudon, France.
12Rhodes Univ, Dept Phys & Elect, POB 94, ZA-6140 Grahamstown, South Africa.
13Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA.
14INAF, Ist Radioastron, Via Gobetti 101, I-40129 Bologna, Italy.
15Jagiellonian Univ, Astron Observ, Ul Orla 171, PL-30244 Krakow, Poland.
16Chalmers Univ Technol, Onsala Space Observ, Dept Earth & Space Sci, S-43992 Onsala, Sweden.
17Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands.
18Univ Manchester, Jodrell Bank Ctr Astrophys, Sch Phys & Astron, Manchester M13 9PL, Lancs, England.
19Univ Oxford, Astrophys, Denys Wilkinson Bldg,Keble Rd, Oxford OX1 3RH, England.
20Univ Western Cape, Dept Phys & Astron, ZA-7535 Bellville, South Africa.
21Open Univ, Dept Phys & Astron, Walton Hall, Milton Keynes MK7 6AA, Bucks, England.
22Rutherford Appleton Lab, RAL Space, Didcot OX11 0NL, Oxon, England.
23Univ Amsterdam, Astron Inst Anton Pannekoek, Postbus 94249, NL-1090 GE Amsterdam, Netherlands.
24Joint Inst VLBI Europe, Postbus 2, NL-7990 AA Dwingeloo, Netherlands.
25Thuringer Landessternwarte, Sternwarte 5, D-07778 Tautenburg, Germany.
26Univ Orleans OSUC, Stn Radioastron Nancay, Observ Paris, CNRS,INSU USR 704, Route Souesmes, F-18330 Nancay, France.
27Univ Cote Azur, Lab Lagrange, Observ Cote Azur, CNRS, Bvd Observ,CS 34229, F-06304 Nice 4, France.
28Ruhr Univ Bochum, Forschungszentrum Julich, JSC, Astron Inst, D-52425 Julich, Germany.
29Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England.
30Univ Western Australia, ICRAR, 35 Stirling Hwy, Crawley, WA 6009, Australia.
31Univ Portsmouth, Inst Cosmol & Gravitat, Burnaby Rd, Portsmouth PO1 3FX, Hants, England.
32NCU, Torun Ctr Astron, Fac Phys Astron & Informat, Grudziacka 5, PL-87100 Torun, Poland.
33Univ Oulu, Sodankyla Geophys Observ, Tahtelantie 62, Sodankyla 99600, Finland.
34STFC Rutherford Appleton Lab, Harwell Sci & Innovat Campus, Didcot OX11 0QX, Oxon, England.
35Tata Inst Fundamental Res, Natl Ctr Radio Astrophys, Pune 411007, Maharashtra, India.
36Univ Bielefeld, Fak Phys, Postfach 100131, D-33501 Bielefeld, Germany.
37Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany.
38European Southern Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany.
39Univ Cape Town, Dept Astron, ZA-7701 Rondebosch, South Africa.
|Online Access:||PDF Full Text (PDF, 20.2 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2019092529831
|Publish Date:|| 2019-09-25
The LOFAR Two-metre Sky Survey (LoTSS) is a deep 120–168 MHz imaging survey that will eventually cover the entire northern sky. Each of the 3170 pointings will be observed for 8 h, which, at most declinations, is sufficient to produce ~5″ resolution images with a sensitivity of ~100 μJy/beam and accomplish the main scientific aims of the survey, which are to explore the formation and evolution of massive black holes, galaxies, clusters of galaxies and large-scale structure. Owing to the compact core and long baselines of LOFAR, the images provide excellent sensitivity to both highly extended and compact emission. For legacy value, the data are archived at high spectral and time resolution to facilitate subarcsecond imaging and spectral line studies. In this paper we provide an overview of the LoTSS. We outline the survey strategy, the observational status, the current calibration techniques, a preliminary data release, and the anticipated scientific impact. The preliminary images that we have released were created using a fully automated but direction-independent calibration strategy and are significantly more sensitive than those produced by any existing large-area low-frequency survey. In excess of 44 000 sources are detected in the images that have a resolution of 25″, typical noise levels of less than 0.5 mJy/beam, and cover an area of over 350 square degrees in the region of the HETDEX Spring Field (right ascension 10h45m00s to 15h30m00s and declination 45°00′00″ to 57°00′00″).
Astronomy and astrophysics
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
115 Astronomy and space science
T.S. and H.R. acknowledge support from the ERC Advanced Investigator programme NewClusters 321271. P.N.B., J.S., W.L.W., M.J.H., and V.H. are grateful for support from the UK STFC via grants ST/M001229/1, ST/M001008/1, and ST/J001600/1. E.K.M. acknowledges support from the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020. A.D. acknowledges support from the BMBF, through project 05A15STA. M.H. acknowledges financial support by the DFG through the Forschergruppe 1254. R.M. gratefully acknowledge support from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Advanced Grant RADIOLIFE-320745. G.J.W. gratefully acknowledges support from The Leverhulme Trust. J.Z. gratefully acknowledges a South Africa National ResearchFoundation Square Kilometre Array Research Fellowship. LOFAR, the low Frequency Array designed and constructed by ASTRON, has facilities in several countries, which are owned by various parties (each with their own funding sources), and that are collectively operated by the International LOFAR Telescope (ILT) foundation under a joint scientific policy. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. Part of this work was carried out on the Dutch national e-infrastructure with the support of SURF Cooperative through grant e-infra 160022. We gratefully acknowledge support by N. Danezi (SURFsara) and C. Schrijvers (SURFsara).
© ESO, 2017.