Academic Journal
LBCS: The LOFAR Long-Baseline Calibrator Survey
| العنوان: | LBCS: The LOFAR Long-Baseline Calibrator Survey |
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| المؤلفون: | Jackson, N., Tagore, A, A, Moldon, Javier, Deller, Adam, Varenius, E, E, Conway, C, J, Kapinska, A, A, Orrù, E, E, Brentjens, M, M, Carozzi, T., Blaauw, R, Kuper, G, G, Sluman, S, J, Schaap, S, J, Vermaas, Nico, N, Iacobelli, M, M, Shulevski, A., Cerrigone, C, C, ter Veen, S, Fallows, R, Pizzo, P, P, Sipior, M., Anderson, J, J, Avruch, I.M, Bell, M, M, van Bemmel, B, Bentum, M, J, Bonafede, A, A, Morabito, L., Breitling, F, Broderick, J, W, Brouw, W, W, Brüggen, M, M, Corstanje, C, C, de Gasperin, F., de Geus, D, G, Eislöffel, J, J, Engels, D, D, Falcke, H, Garrett, M, G, Griessmeier, Jean-Mathias, Gunst, A, W, van Haarlem, P, P, Heald, H, G, Hoeft, M, M, Hörandel, J, J, Horneffer, A, A, Intema, H, Juette, J, J, Kuniyoshi, M, M, van Leeuwen, J, J, Maat, P, P, Mckean, P, J, Mulcahy, M, D, Munk, M, M, Pandey-Pommier, M., Polatidis, P, G, Reich, R, W, Röttgering, R, J, Rowlinson, A., Scaife, A.M.M, Steinmetz, S, M, Swinbank, S, J, Thoudam, S, Toribio, M.C, Vermeulen, R, Vocks, C, C, van Weeren, R, W, Wise, M, W, Yatawatta, S, Zarka, P. |
| المساهمون: | School of Physics and Astronomy Manchester, University of Manchester Manchester, Netherlands Institute for Radio Astronomy (ASTRON), Departament d'Astronomia i Meteorologia Barcelona, Universitat de Barcelona (UB), Onsala Space Observatory, Dept. of Radio and Space Science, Chalmers University of Technology, Chalmers University of Technology Göteborg, ARC Centre of Excellence for Autonomous Systems (CAS), University of Technology Sydney (UTS), Swedish Institute of Space Physics Uppsala / Kiruna (IRF), Department of Pure Mathematics and Mathematical Statistics (DPMMS), Faculty of mathematics Centre for Mathematical Sciences Cambridge (CMS), University of Cambridge UK (CAM)-University of Cambridge UK (CAM), Department of Astrophysics Nijmegen, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud University Nijmegen -Radboud University Nijmegen, German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ), Newcastle University Newcastle, Joint Institute for VLBI in Europe (JIVE ERIC), University of Hamburg, Leiden Observatory Leiden, Universiteit Leiden = Leiden University, Leibniz-Institut für Astrophysik Potsdam (AIP), Oxford Astrophysics, University of Oxford, University of Southampton, Kapteyn Astronomical Institute Groningen, University of Groningen Groningen, University of Edinburgh (Edin.), Radboud University Nijmegen, Thüringer Landessternwarte Tautenburg (TLS), Hamburger Sternwarte/Hamburg Observatory, Universität Hamburg (UHH), Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales Paris (CNES), Max-Planck-Institut für Radioastronomie (MPIFR), Astronomisches Institut der Ruhr-Universität Bochum, Ruhr University Bochum = Ruhr-Universität Bochum (RUB), National Astronomical Observatory of Japan (NAOJ), Health Service Executive Dublin (HSE), Aalborg University Denmark (AAU), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astrophysikalisches Institut Potsdam (AIP), Princeton University, SRON Netherlands Institute for Space Research (SRON), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), European Project: 283393,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2011-1,RADIONET3(2012) |
| المصدر: | ISSN: 0004-6361. |
| بيانات النشر: | HAL CCSD EDP Sciences |
| سنة النشر: | 2016 |
| المجموعة: | Aix-Marseille Université: HAL |
| مصطلحات موضوعية: | Instrumentation:interferometers- Techniques:interferometric - Surveys - Galaxies:active -Radio continuum:galaxies, [SDU]Sciences of the Universe [physics] |
| الوصف: | International audience ; We outline LBCS (the LOFAR Long-Baseline Calibrator Survey), whose aim is to identify sources suitable for calibrating the highest-resolution observations made with the International LOFAR Telescope, which include baselines >1000 km. Suitable sources must contain significant correlated flux density (50 − 100 mJy) at frequencies around 110–190 MHz on scales of a few hundred milliarcseconds. At least for the 200–300-km international baselines, we find around 1 suitable calibrator source per square degree over a large part of the northern sky, in agreement with previous work. This should allow a randomly selected target to be successfully phase calibrated on the international baselines in over 50% of cases. Products of the survey include calibrator source lists and fringe-rate and delay maps of wide areas – typically a few degrees – around each source. The density of sources with significant correlated flux declines noticeably with baseline length over the range 200–600 km, with good calibrators on the longest baselines appearing only at the rate of 0.5 per square degree. Coherence times decrease from 1–3 minutes on 200-km baselines to about 1 minute on 600-km baselines, suggesting that ionospheric phase variations contain components with scales of a few hundred kilometres. The longest median coherence time, at just over 3 minutes, is seen on the DE609 baseline, which at 227 km is close to being the shortest. We see median coherence times of between 80 and 110 seconds on the four longest baselines (580–600 km), and about 2 minutes for the other baselines. The success of phase transfer from calibrator to target is shown to be influenced by distance, in a manner that suggests a coherence patch at 150-MHz of the order of 1 degree. Although source structures cannot be measured in these observations, we deduce that phase transfer is affected if the calibrator source structure is not known. We give suggestions for calibration strategies and choice of calibrator sources, and describe the access ... |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| Relation: | info:eu-repo/semantics/altIdentifier/arxiv/1608.02133; info:eu-repo/grantAgreement/EC/FP7/283393/EU/Advanced Radio Astronomy in Europe/RADIONET3; ARXIV: 1608.02133; BIBCODE: 2016A&A.595A.86J |
| DOI: | 10.1051/0004-6361/201629016 |
| الاتاحة: | https://insu.hal.science/insu-01433110 https://insu.hal.science/insu-01433110v1/document https://insu.hal.science/insu-01433110v1/file/1608.02133v2-1%20%281%29.pdf https://doi.org/10.1051/0004-6361/201629016 |
| Rights: | info:eu-repo/semantics/OpenAccess |
| رقم الانضمام: | edsbas.9241A0FB |
| قاعدة البيانات: | BASE |
| DOI: | 10.1051/0004-6361/201629016 |
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