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1. Identifying transient and variable sources in radio images

Author: Rowlinson, A., Stewart, A.J., Broderick, J.W., Swinbank, J.D., Wijers, R.A.M.J. (Ralph), Carbone, D., Cendes, Y.N., Fender, R.P., Horst, A.J. van der, Molenaar, G.J., Scheers, L.H.A. (Bart), Staley, T.D., Farrell, S.A. (Sean), Grießmeier, J.-M., Bell, M.R. (Michael), Eislöffel, J., Law, C.J., Leeuwen, J. van, Zarka, P., Rowlinson, A., Stewart, A.J., Broderick, J.W., Swinbank, J.D., Wijers, R.A.M.J. (Ralph), Carbone, D., Cendes, Y.N., Fender, R.P., Horst, A.J. van der, Molenaar, G.J., Scheers, L.H.A. (Bart), Staley, T.D., Farrell, S.A. (Sean), Grießmeier, J.-M., Bell, M.R. (Michael), Eislöffel, J., Law, C.J., Leeuwen, J. van, and Zarka, P.
Abstract: With the arrival of a number of wide-field snapshot image-plane radio transient surveys, there will be a huge influx of images in the coming years making it impossible to manually analyse the datasets. Automated pipelines to process the information stored in the images are being developed, such as the LOFAR Transients Pipeline, outputting light curves and various transient parameters. These pipelines have a number of tuneable parameters that require training to meet the survey requirements. This paper utilises both observed and s
Published: 2019
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2. Identifying transient and variable sources in radio images

Author: Rowlinson, A., Stewart, A.J., Broderick, J.W., Swinbank, J.D., Wijers, R.A.M.J. (Ralph), Carbone, D., Cendes, Y.N., Fender, R.P., Horst, A.J. van der, Molenaar, G.J., Scheers, L.H.A. (Bart), Staley, T.D., Farrell, S.A. (Sean), Grießmeier, J.-M., Bell, M.R. (Michael), Eislöffel, J., Law, C.J., Leeuwen, J. van, Zarka, P., Rowlinson, A., Stewart, A.J., Broderick, J.W., Swinbank, J.D., Wijers, R.A.M.J. (Ralph), Carbone, D., Cendes, Y.N., Fender, R.P., Horst, A.J. van der, Molenaar, G.J., Scheers, L.H.A. (Bart), Staley, T.D., Farrell, S.A. (Sean), Grießmeier, J.-M., Bell, M.R. (Michael), Eislöffel, J., Law, C.J., Leeuwen, J. van, and Zarka, P.
Abstract: With the arrival of a number of wide-field snapshot image-plane radio transient surveys, there will be a huge influx of images in the coming years making it impossible to manually analyse the datasets. Automated pipelines to process the information stored in the images are being developed, such as the LOFAR Transients Pipeline, outputting light curves and various transient parameters. These pipelines have a number of tuneable parameters that require training to meet the survey requirements. This paper utilises both observed and simulated datasets to demonstrate different machine learning strategies that can be used to train these parameters. We use a simple anomaly detection algorithm and a penalised logistic regression algorithm. The datasets used are from LOFAR observations and we process the data using the LOFAR Transients Pipeline; however the strategies developed are applicable to any light curve datasets at different frequencies and can be adapted to different automated pipelines. These machine learning strategies are publicly available as PYTHON tools that can be downloaded and adapted to different datasets (https://github.com/AntoniaR/TraP_ML_tools).
Published: 2019
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3. Fast in-database cross-matching of high-cadence, high-density source lists with an up-to-date sky model

Author: Scheers, L.H.A. (Bart), Bloemen, S., Mühleisen, H.F. (Hannes), Schellart, P., Van Elteren, A. (Arjen), Kersten, M.L. (Martin), Groot, P.J., Scheers, L.H.A. (Bart), Bloemen, S., Mühleisen, H.F. (Hannes), Schellart, P., Van Elteren, A. (Arjen), Kersten, M.L. (Martin), and Groot, P.J.
Abstract: Coming high-cadence wide-field optical telescopes will image hundreds of thousands of sources per minute. Besides inspecting the near real-time data streams for transient and variability events, the accumulated data archive is a wealthy laboratory for making complementary scientific discoveries. The goal of this work is to optimise column-oriented database techniques to enable the construction of a full-source and light-curve database for large-scale surveys, that is accessible by the astronomical community. We adopted LOFAR's Transients Pipeline as the baseline and modified it to enable the processing of optical images that have much higher source densities. The pipeline adds new source lists to the archive database, while cross-matching them with the known cataloguedsources in order to build a full light-curve archive. We investigated several techniques of indexing and partitioning the largest tables, allowing for faster positional source look-ups in the cross matching algorithms. We monitored all query run times in long-term pipeline runs where we processed a subset of IPHAS data that have image source density peaks over 170,000 per field of view (500,000 deg−2). Our analysis demonstrates that horizontal table partitions of declination widths of one-degree control the query run times. Usage of an index strategy where the partitions are densely sorted according to source declination yields another improvement. Most queries run in sublinear time and a few (<20%) run in linear time, because of dependencies on input source-list and result-set size. We observed that for this logical database partitioning schema the limiting cadence the pipeline achieved with processing IPHAS data is 25 s.
Published: 2018
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4. Fast in-database cross-matching of high-cadence, high-density source lists with an up-to-date sky model

Author: Scheers, L.H.A. (Bart), Bloemen, S., Mühleisen, H.F. (Hannes), Schellart, P., Van Elteren, A. (Arjen), Kersten, M.L. (Martin), Groot, P.J., Scheers, L.H.A. (Bart), Bloemen, S., Mühleisen, H.F. (Hannes), Schellart, P., Van Elteren, A. (Arjen), Kersten, M.L. (Martin), and Groot, P.J.
Abstract: Coming high-cadence wide-field optical telescopes will image hundreds of thousands of sources per minute. Besides inspecting the near real-time data streams for transient and variability events, the accumulated data archive is a wealthy laboratory for making complementary scientific discoveries. The goal of this work is to optimise column-oriented database techniques to enable the construction of a full-source and light-curve database for large-scale surveys, that is accessible by the astronomical community. We adopted LOFAR's Transients Pipeline as the baseline and modified it to enable the processing of optical images that have much higher source densities. The pipeline adds new source lists to the archive database, while cross-matching them with the known cataloguedsources in order to build a full light-curve archive. We investigated several techniques of indexing and partitioning the largest tables, allowing for faster positional source look-ups in the cross matching algorithms. We monitored all query run times in long-term pipeline runs where we processed a subset of IPHAS data that have image source density peaks over 170,000 per field of view (500,000 deg−2). Our analysis demonstrates that horizontal table partitions of declination widths of one-degree control the query run times. Usage of an index strategy where the partitions are densely sorted according to source declination yields another improvement. Most queries run in sublinear time and a few (<20%) run in linear time, because of dependencies on input source-list and result-set size. We observed that for this logical database partitioning schema the limiting cadence the pipeline achieved with processing IPHAS data is 25 s.
Published: 2018
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5. Low-radio-frequency eclipses of the redback pulsar J2215+5135 observed in the image plane with LOFAR

Author: Broderick, J.W., Fender, R.P., Breton, R.P., Stewart, A.J., Rowlinson, A., Swinbank, J.D., Hessels, J.W.T., Staley, T.D., Horst, A.J. van der, Bell, M.E., Carbone, D., Cendes, Y.N., Corbel, S., Eislöffel, J., Falcke, H., Grießmeier, J.-M., Hassall, T.E., Jonker, P., Kramer, M., Kuniyoshi, M., Law, C.J., Markoff, S., Molenaar, G.J., Pietka, M., Scheers, L.H.A. (Bart), Serylak, M., Stappers, B.W., Veen, S. (Sander) ter, Leeuwen, J. van, Wijers, R.A.M.J. (Ralph), Wijnands, R., Wise, M.W. (Michael), Zarka, P., Broderick, J.W., Fender, R.P., Breton, R.P., Stewart, A.J., Rowlinson, A., Swinbank, J.D., Hessels, J.W.T., Staley, T.D., Horst, A.J. van der, Bell, M.E., Carbone, D., Cendes, Y.N., Corbel, S., Eislöffel, J., Falcke, H., Grießmeier, J.-M., Hassall, T.E., Jonker, P., Kramer, M., Kuniyoshi, M., Law, C.J., Markoff, S., Molenaar, G.J., Pietka, M., Scheers, L.H.A. (Bart), Serylak, M., Stappers, B.W., Veen, S. (Sander) ter, Leeuwen, J. van, Wijers, R.A.M.J. (Ralph), Wijnands, R., Wise, M.W. (Michael), and Zarka, P.
Published: 2016
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6. LOFAR MSSS: detection of a low-frequency radio transient in 400 h of monitoring of the North Celestial Pole

Author: Stewart, A.J., Fender, R.P., Broderick, J.W., Hassall, T.E., Muñoz-Darias, T., Rowlinson, A., Swinbank, J.D., Staley, T.D., Molenaar, G.J., Scheers, L.H.A. (Bart), Grobler, T.L., Pietka, M., Heald, G., McKean, J.P., Bell, M.E., Bonafede, A., Breton, R.P., Carbone, D., Cendes, Y.N., Clarke, A.O., Corbel, S., De Gasperin, F., Eislöffel, J., Falcke, H., Ferrari, C., Grießmeier, J.-M., Hardcastle, M.J., Heesen, V., Hessels, J.W.T., Horneffer, A., Iacobelli, M., Jonker, P., Karastergiou, A., Kokotanekov, G., Kondratiev, V.I., Kuniyoshi, M., Law, C.J., Leeuwen, J. van, Markoff, S., Miller-Jones, J.C.A., Mulcahy, D.D., Orru, E., Pandey-Pommier, M., Pratley, L., Rol, E., Röttgering, H.J.A., Scaife, A.M.M., Shulevski, A., Sobey, C.A., Stappers, B.W., Tasse, C., Horst, A.J. van der, Velzen, S. van, Weeren, R.J. van, Wijers, R.A.M.J. (Ralph), Wijnands, R., Wise, M.W. (Michael), Zarka, P., Alexov, A., Anderson, J., Asgekar, A., Avruch, I.M., Bentum, M.J., Bernardi, G., Best, P., Breitling, F., Brüggen, M., Butcher, H.R., Ciardi, B., Conway, J.E., Corstanje, A., Geus, E. de, Deller, A., Duscha, S., Frieswijk, W., Garrett, M.A., Gunst, A.W., Haarlem, M.P. van, Hoeft, M., Hörandel, J.R. (Jörg), Juette, E., Kuper, G., Loose, M., Maat, P., McFadden, R., McKay-Bukowski, D., Moldon, J., Munk, H., Norden, M.J., Paas, H., Polatidis, A.G., Schwarz, D., Sluman, J., Smirnov, O., Steinmetz, M., Thoudam, S., Toribio, M.C., Vermeulen, R., Vocks, C., Wijnholds, S.J., Wucknitz, O., Yatawatta, S., Stewart, A.J., Fender, R.P., Broderick, J.W., Hassall, T.E., Muñoz-Darias, T., Rowlinson, A., Swinbank, J.D., Staley, T.D., Molenaar, G.J., Scheers, L.H.A. (Bart), Grobler, T.L., Pietka, M., Heald, G., McKean, J.P., Bell, M.E., Bonafede, A., Breton, R.P., Carbone, D., Cendes, Y.N., Clarke, A.O., Corbel, S., De Gasperin, F., Eislöffel, J., Falcke, H., Ferrari, C., Grießmeier, J.-M., Hardcastle, M.J., Heesen, V., Hessels, J.W.T., Horneffer, A., Iacobelli, M., Jonker, P., Karastergiou, A., Kokotanekov, G., Kondratiev, V.I., Kuniyoshi, M., Law, C.J., Leeuwen, J. van, Markoff, S., Miller-Jones, J.C.A., Mulcahy, D.D., Orru, E., Pandey-Pommier, M., Pratley, L., Rol, E., Röttgering, H.J.A., Scaife, A.M.M., Shulevski, A., Sobey, C.A., Stappers, B.W., Tasse, C., Horst, A.J. van der, Velzen, S. van, Weeren, R.J. van, Wijers, R.A.M.J. (Ralph), Wijnands, R., Wise, M.W. (Michael), Zarka, P., Alexov, A., Anderson, J., Asgekar, A., Avruch, I.M., Bentum, M.J., Bernardi, G., Best, P., Breitling, F., Brüggen, M., Butcher, H.R., Ciardi, B., Conway, J.E., Corstanje, A., Geus, E. de, Deller, A., Duscha, S., Frieswijk, W., Garrett, M.A., Gunst, A.W., Haarlem, M.P. van, Hoeft, M., Hörandel, J.R. (Jörg), Juette, E., Kuper, G., Loose, M., Maat, P., McFadden, R., McKay-Bukowski, D., Moldon, J., Munk, H., Norden, M.J., Paas, H., Polatidis, A.G., Schwarz, D., Sluman, J., Smirnov, O., Steinmetz, M., Thoudam, S., Toribio, M.C., Vermeulen, R., Vocks, C., Wijnholds, S.J., Wucknitz, O., and Yatawatta, S.
Published: 2016
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7. New methods to constrain the radio transient rate: results from a survey of four fields with LOFAR

Author: Carbone, D., Horst, A.J. van der, Wijers, R.A.M.J. (Ralph), Swinbank, J.D., Rowlinson, A., Broderick, J.W., Cendes, Y.N., Stewart, A.J., Bell, M.E., Corbel, S., Eislöffel, J., Fender, R.P., Grießmeier, (J.M.), Hessels, J.W.T., Jonker, P., Kramer, M., Law, C.J., Miller-Jones, J.C.A., Pietka, M., Scheers, L.H.A. (Bart), Stappers, B.W., Leeuwen, J. van, Wijnands, R., Wise, M.W. (Michael), Zarka, P., Carbone, D., Horst, A.J. van der, Wijers, R.A.M.J. (Ralph), Swinbank, J.D., Rowlinson, A., Broderick, J.W., Cendes, Y.N., Stewart, A.J., Bell, M.E., Corbel, S., Eislöffel, J., Fender, R.P., Grießmeier, (J.M.), Hessels, J.W.T., Jonker, P., Kramer, M., Law, C.J., Miller-Jones, J.C.A., Pietka, M., Scheers, L.H.A. (Bart), Stappers, B.W., Leeuwen, J. van, Wijnands, R., Wise, M.W. (Michael), and Zarka, P.
Abstract: We report on the results of a search for radio transients between 115 and 190 MHz with the LOw-Frequency ARray (LOFAR). Four fields have been monitored with cadences between 15 minutes and several months. A total of 151 images were obtained, giving a total survey area of 2275 deg2. We analysed our data using standard LOFAR tools and searched for radio transients using the LOFAR Transients Pipeline (TraP). No credible radio transient candidate has been detected; however, we are able to set upper limits on the surface density of radio transient sources at low radio frequencies. We also show that low-frequency radio surveys are more sensitive to steep-spectrum coherent transient sources than GHz radio surveys. We used two new statistical methods to determine the upper limits on the transient surface density. One is free of assumptions on the flux distribution of the sources, while the other assumes a power-law distribution in flux and sets more stringent constraints on the transient surface density. Both of these methods provide better constraints than the approach used in previous works. The best value for the upper limit we can set for the transient surface density, using the method assuming a power-law flux distribution, is 1.3 · 10-3 deg-2 for transients brighter than 0.3 Jy with a time-scale of 15 min, at a frequency of 150 MHz. We also calculated for the first time upper limits for the transient surface density for transients of different time-scales. We find that the results can differ by orders of magnitude from previously reported, simplified estimates.
Published: 2016
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8. 3MeerLICHT and BlackGEM: custom-built telescopes to detect faint optical transients

Author: Bloemen, S. (Steven), Groot, P.J. (Paul J.), Woudt, P. (Patrick), Wolt, M.K. (Marc Klein), Mcbride, V. (Vanessa), Nelemans, G. (Gijs), Körding, E. (Elmar), Pretorius, M.L. (Magaretha L.), Roelfsema, R. (Ronald), Bettonvil, F. (Felix), Balster, H. (Harry), Bakker, R. (Roy), Dolron, P. (Peter), Van Elteren, A. (Arjen), Elswijk, E. (Eddy), Engels, A. (Arno), Fender, R.P., Fokker, M. (Marc), Haan, M. (Menno De), Hagoort, K. (Klaas), De Hoog, J. (Jasper), Horst, R.T. (Rik Ter), Van Der Kevie, G. (Giel), Lowski, S.L.K. (Stanis Law Koz), Kragt, J. (Jan), Lech, G. (Grzegorz), Le Poole, R. (Rudolf), Lesman, D. (Dirk), Morren, J. (Johan), Navarro, R. (Ramon), Paalberends, W.-J. (Willem-Jelle), Paterson, K.G. (Kerry), Laszek, R.P. (Rafal Paw), Pessemier, W. (Wim), Raskin, G. (Gert), Rutten, H. (Harrie), Scheers, L.H.A. (Bart), Schuil, M. (Menno), Sybilski, P.W. (Piotr W.), Bloemen, S. (Steven), Groot, P.J. (Paul J.), Woudt, P. (Patrick), Wolt, M.K. (Marc Klein), Mcbride, V. (Vanessa), Nelemans, G. (Gijs), Körding, E. (Elmar), Pretorius, M.L. (Magaretha L.), Roelfsema, R. (Ronald), Bettonvil, F. (Felix), Balster, H. (Harry), Bakker, R. (Roy), Dolron, P. (Peter), Van Elteren, A. (Arjen), Elswijk, E. (Eddy), Engels, A. (Arno), Fender, R.P., Fokker, M. (Marc), Haan, M. (Menno De), Hagoort, K. (Klaas), De Hoog, J. (Jasper), Horst, R.T. (Rik Ter), Van Der Kevie, G. (Giel), Lowski, S.L.K. (Stanis Law Koz), Kragt, J. (Jan), Lech, G. (Grzegorz), Le Poole, R. (Rudolf), Lesman, D. (Dirk), Morren, J. (Johan), Navarro, R. (Ramon), Paalberends, W.-J. (Willem-Jelle), Paterson, K.G. (Kerry), Laszek, R.P. (Rafal Paw), Pessemier, W. (Wim), Raskin, G. (Gert), Rutten, H. (Harrie), Scheers, L.H.A. (Bart), Schuil, M. (Menno), and Sybilski, P.W. (Piotr W.)
Abstract: We present the MeerLICHT and BlackGEM telescopes, which are wide-field optical telescopes that are currently being built to study transient phenomena, gravitational wave counterparts and variable stars. The telescopes have 65 cm primary mirrors and a 2.7 square degree field-of-view. The MeerLICHT and BlackGEM projects have different science goals, but will use identical telescopes. The first telescope, MeerLICHT, will be commissioned at Sutherland (South Africa) in the first quarter of 2017. It will co-point with MeerKAT to collect optical data commensurate with the radio observations. After careful analysis of MeerLICHT's performance, three telescopes of the same type will be commissioned in La Silla (Chile) in 2018 to form phase I of the BlackGEM array. BlackGEM aims at detecting and characterizing optical counterparts of gravitational wave events detected by Advanced LIGO and Virgo. In this contribution we present an overview of the science goals, the design and the status of the two projects.
Published: 2016
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9. Column store for GWAC: a high-cadence, high-density, large-scale astronomical light curve pipeline and distributed shared-nothing database

Author: Wan, M. (Meng), Wu, C. (Chao), Wang, J. (Jing), Qiu, Y. (Yujia), Xin, L. (Liping), Mullender, K.S. (Sjoerd), Mühleisen, H.F. (Hannes), Scheers, L.H.A. (Bart), Zhang, Y. (Ying), Nes, N.J. (Niels), Kersten, M.L. (Martin), Huang, Y. (Yongpan), Deng, J. (Jinsong), Wei, J. (Jianyan), Wan, M. (Meng), Wu, C. (Chao), Wang, J. (Jing), Qiu, Y. (Yujia), Xin, L. (Liping), Mullender, K.S. (Sjoerd), Mühleisen, H.F. (Hannes), Scheers, L.H.A. (Bart), Zhang, Y. (Ying), Nes, N.J. (Niels), Kersten, M.L. (Martin), Huang, Y. (Yongpan), Deng, J. (Jinsong), and Wei, J. (Jianyan)
Published: 2016
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10. MonetDB Jul2015-SP2 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), and Koutsourakis, P. (Panagiotis)
Published: 2016

11. MonetDB Jun2016 feature release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Döhmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, Stalinov, S.G. (Svetlin), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Döhmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, and Stalinov, S.G. (Svetlin)
Published: 2016

12. MonetDB Jun2016-SP2 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Döhmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, Stalinov, S.G. (Svetlin), Leo, D. (Dean) De, Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Döhmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, Stalinov, S.G. (Svetlin), and Leo, D. (Dean) De
Published: 2016

13. MonetDB Jul2015-SP3 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Döhmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Döhmen, T.R. (Till), Kruit, B.B. (Benno), and Wits, A. (Abe)
Published: 2016

14. MonetDB Jun2016-SP1 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Döhmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, Stalinov, S.G. (Svetlin), Leo, D. (Dean) De, Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Döhmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, Stalinov, S.G. (Svetlin), and Leo, D. (Dean) De
Published: 2016

15. MonetDB Jul2015-SP4 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Döhmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Döhmen, T.R. (Till), Kruit, B.B. (Benno), and Wits, A. (Abe)
Published: 2016

16. The BlackGEM array in search of black hole mergers: integrated performance modelling

Author: Roelfsema, P.R. (Pieter), Klein Wolt, M. (Marc), Bloemen, S. (Steven), Groot, P. (Paul), Bettonvil, F. (Felix), Balster, H. (Harry), Dolron, P. (Peter), Van Elteren, A. (Arjen), Engels, A. (Arno), De Haan, M. (Menno), Ter Horst, R. (Rik), Kragt, J. (Jan), Navarro, R. (Ramon), Nelemans, G. (Gijs), Paalberends, W.J. (Willem Jelle), Pal, S. (Sari), Raskin, G. (Gert), Rutten, H. (Harrie), Scheers, L.H.A. (Bart), Schuil, M. (Menno), Sybilski, P. (Piotr), Roelfsema, P.R. (Pieter), Klein Wolt, M. (Marc), Bloemen, S. (Steven), Groot, P. (Paul), Bettonvil, F. (Felix), Balster, H. (Harry), Dolron, P. (Peter), Van Elteren, A. (Arjen), Engels, A. (Arno), De Haan, M. (Menno), Ter Horst, R. (Rik), Kragt, J. (Jan), Navarro, R. (Ramon), Nelemans, G. (Gijs), Paalberends, W.J. (Willem Jelle), Pal, S. (Sari), Raskin, G. (Gert), Rutten, H. (Harrie), Scheers, L.H.A. (Bart), Schuil, M. (Menno), and Sybilski, P. (Piotr)
Published: 2016
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17. 3MeerLICHT and BlackGEM: custom-built telescopes to detect faint optical transients

Author: Bloemen, S. (Steven), Groot, P.J. (Paul J.), Woudt, P. (Patrick), Wolt, M.K. (Marc Klein), Mcbride, V. (Vanessa), Nelemans, G. (Gijs), Körding, E. (Elmar), Pretorius, M.L. (Magaretha L.), Roelfsema, R. (Ronald), Bettonvil, F. (Felix), Balster, H. (Harry), Bakker, R. (Roy), Dolron, P. (Peter), Van Elteren, A. (Arjen), Elswijk, E. (Eddy), Engels, A. (Arno), Fender, R.P., Fokker, M. (Marc), Haan, M. (Menno De), Hagoort, K. (Klaas), De Hoog, J. (Jasper), Horst, R.T. (Rik Ter), Van Der Kevie, G. (Giel), Lowski, S.L.K. (Stanis Law Koz), Kragt, J. (Jan), Lech, G. (Grzegorz), Le Poole, R. (Rudolf), Lesman, D. (Dirk), Morren, J. (Johan), Navarro, R. (Ramon), Paalberends, W.-J. (Willem-Jelle), Paterson, K.G. (Kerry), Laszek, R.P. (Rafal Paw), Pessemier, W. (Wim), Raskin, G. (Gert), Rutten, H. (Harrie), Scheers, L.H.A. (Bart), Schuil, M. (Menno), Sybilski, P.W. (Piotr W.), Bloemen, S. (Steven), Groot, P.J. (Paul J.), Woudt, P. (Patrick), Wolt, M.K. (Marc Klein), Mcbride, V. (Vanessa), Nelemans, G. (Gijs), Körding, E. (Elmar), Pretorius, M.L. (Magaretha L.), Roelfsema, R. (Ronald), Bettonvil, F. (Felix), Balster, H. (Harry), Bakker, R. (Roy), Dolron, P. (Peter), Van Elteren, A. (Arjen), Elswijk, E. (Eddy), Engels, A. (Arno), Fender, R.P., Fokker, M. (Marc), Haan, M. (Menno De), Hagoort, K. (Klaas), De Hoog, J. (Jasper), Horst, R.T. (Rik Ter), Van Der Kevie, G. (Giel), Lowski, S.L.K. (Stanis Law Koz), Kragt, J. (Jan), Lech, G. (Grzegorz), Le Poole, R. (Rudolf), Lesman, D. (Dirk), Morren, J. (Johan), Navarro, R. (Ramon), Paalberends, W.-J. (Willem-Jelle), Paterson, K.G. (Kerry), Laszek, R.P. (Rafal Paw), Pessemier, W. (Wim), Raskin, G. (Gert), Rutten, H. (Harrie), Scheers, L.H.A. (Bart), Schuil, M. (Menno), and Sybilski, P.W. (Piotr W.)
Abstract: We present the MeerLICHT and BlackGEM telescopes, which are wide-field optical telescopes that are currently being built to study transient phenomena, gravitational wave counterparts and variable stars. The telescopes have 65 cm primary mirrors and a 2.7 square degree field-of-view. The MeerLICHT and BlackGEM projects have different science goals, but will use identical telescopes. The first telescope, MeerLICHT, will be commissioned at Sutherland (South Africa) in the first quarter of 2017. It will co-point with MeerKAT to collect optical data commensurate with the radio observations. After careful analysis of MeerLICHT's performance, three telescopes of the same type will be commissioned in La Silla (Chile) in 2018 to form phase I of the BlackGEM array. BlackGEM aims at detecting and characterizing optical counterparts of gravitational wave events detected by Advanced LIGO and Virgo. In this contribution we present an overview of the science goals, the design and the status of the two projects.
Published: 2016
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18. LOFAR MSSS: detection of a low-frequency radio transient in 400 h of monitoring of the North Celestial Pole

Author: Stewart, A.J., Fender, R.P., Broderick, J.W., Hassall, T.E., Muñoz-Darias, T., Rowlinson, A., Swinbank, J.D., Staley, T.D., Molenaar, G.J., Scheers, L.H.A. (Bart), Grobler, T.L., Pietka, M., Heald, G., McKean, J.P., Bell, M.E., Bonafede, A., Breton, R.P., Carbone, D., Cendes, Y.N., Clarke, A.O., Corbel, S., De Gasperin, F., Eislöffel, J., Falcke, H., Ferrari, C., Grießmeier, J.-M., Hardcastle, M.J., Heesen, V., Hessels, J.W.T., Horneffer, A., Iacobelli, M., Jonker, P., Karastergiou, A., Kokotanekov, G., Kondratiev, V.I., Kuniyoshi, M., Law, C.J., Leeuwen, J. van, Markoff, S., Miller-Jones, J.C.A., Mulcahy, D.D., Orru, E., Pandey-Pommier, M., Pratley, L., Rol, E., Röttgering, H.J.A., Scaife, A.M.M., Shulevski, A., Sobey, C.A., Stappers, B.W., Tasse, C., Horst, A.J. van der, Velzen, S. van, Weeren, R.J. van, Wijers, R.A.M.J. (Ralph), Wijnands, R., Wise, M.W. (Michael), Zarka, P., Alexov, A., Anderson, J., Asgekar, A., Avruch, I.M., Bentum, M.J., Bernardi, G., Best, P., Breitling, F., Brüggen, M., Butcher, H.R., Ciardi, B., Conway, J.E., Corstanje, A., Geus, E. de, Deller, A., Duscha, S., Frieswijk, W., Garrett, M.A., Gunst, A.W., Haarlem, M.P. van, Hoeft, M., Hörandel, J.R. (Jörg), Juette, E., Kuper, G., Loose, M., Maat, P., McFadden, R., McKay-Bukowski, D., Moldon, J., Munk, H., Norden, M.J., Paas, H., Polatidis, A.G., Schwarz, D., Sluman, J., Smirnov, O., Steinmetz, M., Thoudam, S., Toribio, M.C., Vermeulen, R., Vocks, C., Wijnholds, S.J., Wucknitz, O., Yatawatta, S., Stewart, A.J., Fender, R.P., Broderick, J.W., Hassall, T.E., Muñoz-Darias, T., Rowlinson, A., Swinbank, J.D., Staley, T.D., Molenaar, G.J., Scheers, L.H.A. (Bart), Grobler, T.L., Pietka, M., Heald, G., McKean, J.P., Bell, M.E., Bonafede, A., Breton, R.P., Carbone, D., Cendes, Y.N., Clarke, A.O., Corbel, S., De Gasperin, F., Eislöffel, J., Falcke, H., Ferrari, C., Grießmeier, J.-M., Hardcastle, M.J., Heesen, V., Hessels, J.W.T., Horneffer, A., Iacobelli, M., Jonker, P., Karastergiou, A., Kokotanekov, G., Kondratiev, V.I., Kuniyoshi, M., Law, C.J., Leeuwen, J. van, Markoff, S., Miller-Jones, J.C.A., Mulcahy, D.D., Orru, E., Pandey-Pommier, M., Pratley, L., Rol, E., Röttgering, H.J.A., Scaife, A.M.M., Shulevski, A., Sobey, C.A., Stappers, B.W., Tasse, C., Horst, A.J. van der, Velzen, S. van, Weeren, R.J. van, Wijers, R.A.M.J. (Ralph), Wijnands, R., Wise, M.W. (Michael), Zarka, P., Alexov, A., Anderson, J., Asgekar, A., Avruch, I.M., Bentum, M.J., Bernardi, G., Best, P., Breitling, F., Brüggen, M., Butcher, H.R., Ciardi, B., Conway, J.E., Corstanje, A., Geus, E. de, Deller, A., Duscha, S., Frieswijk, W., Garrett, M.A., Gunst, A.W., Haarlem, M.P. van, Hoeft, M., Hörandel, J.R. (Jörg), Juette, E., Kuper, G., Loose, M., Maat, P., McFadden, R., McKay-Bukowski, D., Moldon, J., Munk, H., Norden, M.J., Paas, H., Polatidis, A.G., Schwarz, D., Sluman, J., Smirnov, O., Steinmetz, M., Thoudam, S., Toribio, M.C., Vermeulen, R., Vocks, C., Wijnholds, S.J., Wucknitz, O., and Yatawatta, S.
Published: 2016
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19. New methods to constrain the radio transient rate: results from a survey of four fields with LOFAR

Author: Carbone, D., Horst, A.J. van der, Wijers, R.A.M.J. (Ralph), Swinbank, J.D., Rowlinson, A., Broderick, J.W., Cendes, Y.N., Stewart, A.J., Bell, M.E., Corbel, S., Eislöffel, J., Fender, R.P., Grießmeier, (J.M.), Hessels, J.W.T., Jonker, P., Kramer, M., Law, C.J., Miller-Jones, J.C.A., Pietka, M., Scheers, L.H.A. (Bart), Stappers, B.W., Leeuwen, J. van, Wijnands, R., Wise, M.W. (Michael), Zarka, P., Carbone, D., Horst, A.J. van der, Wijers, R.A.M.J. (Ralph), Swinbank, J.D., Rowlinson, A., Broderick, J.W., Cendes, Y.N., Stewart, A.J., Bell, M.E., Corbel, S., Eislöffel, J., Fender, R.P., Grießmeier, (J.M.), Hessels, J.W.T., Jonker, P., Kramer, M., Law, C.J., Miller-Jones, J.C.A., Pietka, M., Scheers, L.H.A. (Bart), Stappers, B.W., Leeuwen, J. van, Wijnands, R., Wise, M.W. (Michael), and Zarka, P.
Abstract: We report on the results of a search for radio transients between 115 and 190 MHz with the LOw-Frequency ARray (LOFAR). Four fields have been monitored with cadences between 15 minutes and several months. A total of 151 images were obtained, giving a total survey area of 2275 deg2. We analysed our data using standard LOFAR tools and searched for radio transients using the LOFAR Transients Pipeline (TraP). No credible radio transient candidate has been detected; however, we are able to set upper limits on the surface density of radio transient sources at low radio frequencies. We also show that low-frequency radio surveys are more sensitive to steep-spectrum coherent transient sources than GHz radio surveys. We used two new statistical methods to determine the upper limits on the transient surface density. One is free of assumptions on the flux distribution of the sources, while the other assumes a power-law distribution in flux and sets more stringent constraints on the transient surface density. Both of these methods provide better constraints than the approach used in previous works. The best value for the upper limit we can set for the transient surface density, using the method assuming a power-law flux distribution, is 1.3 · 10-3 deg-2 for transients brighter than 0.3 Jy with a time-scale of 15 min, at a frequency of 150 MHz. We also calculated for the first time upper limits for the transient surface density for transients of different time-scales. We find that the results can differ by orders of magnitude from previously reported, simplified estimates.
Published: 2016
Full Text: View/download PDF

20. MonetDB Jun2016-SP2 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Doehmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, Stalinov, S.G. (Svetlin), Leo, D. (Dean) De, Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Doehmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, Stalinov, S.G. (Svetlin), and Leo, D. (Dean) De
Published: 2016

21. MonetDB Jun2016-SP1 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Doehmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, Stalinov, S.G. (Svetlin), Leo, D. (Dean) De, Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Doehmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, Stalinov, S.G. (Svetlin), and Leo, D. (Dean) De
Published: 2016

22. MonetDB Jul2015-SP3 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Doehmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Doehmen, T.R. (Till), Kruit, B.B. (Benno), and Wits, A. (Abe)
Published: 2016

23. Column store for GWAC: a high-cadence, high-density, large-scale astronomical light curve pipeline and distributed shared-nothing database

Author: Wan, M. (Meng), Wu, C. (Chao), Wang, J. (Jing), Qiu, Y. (Yujia), Xin, L. (Liping), Mullender, K.S. (Sjoerd), Mühleisen, H.F. (Hannes), Scheers, L.H.A. (Bart), Zhang, Y. (Ying), Nes, N.J. (Niels), Kersten, M.L. (Martin), Huang, Y. (Yongpan), Deng, J. (Jinsong), Wei, J. (Jianyan), Wan, M. (Meng), Wu, C. (Chao), Wang, J. (Jing), Qiu, Y. (Yujia), Xin, L. (Liping), Mullender, K.S. (Sjoerd), Mühleisen, H.F. (Hannes), Scheers, L.H.A. (Bart), Zhang, Y. (Ying), Nes, N.J. (Niels), Kersten, M.L. (Martin), Huang, Y. (Yongpan), Deng, J. (Jinsong), and Wei, J. (Jianyan)
Published: 2016
Full Text: View/download PDF

24. MonetDB Jun2016 feature release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Doehmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, Stalinov, S.G. (Svetlin), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Doehmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Ferreira, P.E. (Pedro) Silva, and Stalinov, S.G. (Svetlin)
Published: 2016

25. MonetDB Jul2015-SP4 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Doehmen, T.R. (Till), Kruit, B.B. (Benno), Wits, A. (Abe), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Doehmen, T.R. (Till), Kruit, B.B. (Benno), and Wits, A. (Abe)
Published: 2016

26. MonetDB Jul2015-SP2 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), Koutsourakis, P. (Panagiotis), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Raasveldt, M. (Mark), and Koutsourakis, P. (Panagiotis)
Published: 2016

27. The LOFAR Multifrequency Snapshot Sky Survey (MSSS). I. Survey description and first results

Author: Heald, G., Pizzo, R., et al, not CWI, Scheers, L.H.A. (Bart), Heald, G., Pizzo, R., et al, not CWI, and Scheers, L.H.A. (Bart)
Published: 2015
Full Text: View/download PDF

28. Huge Radio Telescope Gets New Database

Author: Nedev, D.G. (Dimitar), Scheers, L.H.A. (Bart), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Nedev, D.G. (Dimitar), Scheers, L.H.A. (Bart), Rijke, J.A. (Arjen) de, and Zhang, Y. (Ying)
Published: 2015

29. Huge Radio Telescope Gets New Database

Author: Nedev, D.G. (Dimitar), Scheers, L.H.A. (Bart), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Nedev, D.G. (Dimitar), Scheers, L.H.A. (Bart), Rijke, J.A. (Arjen) de, and Zhang, Y. (Ying)
Published: 2015

30. The LOFAR Transients Pipeline

Author: Swinbank, J.D., Staley, T.D., Molenaar, G.J., Rol, E., Rowlinson, A., Scheers, L.H.A. (Bart), Spreeuw, H., Bell, M.E., Broderick, J.W., Carbone, D., Garsden, H., Horst, A.J. van der, Law, C.J., Wise, M.W. (Michael), Breton, R.P., Cendes, Y.N., Corbel, S., Eislöffel, J., Falcke, H., Fender, R.P., Grießmeier, J.-M., Hessels, J.W.T., Stappers, B.W., Stewart, A.J., Wijers, R.A.M.J. (Ralph), Wijnands, R., Zarka, P., Swinbank, J.D., Staley, T.D., Molenaar, G.J., Rol, E., Rowlinson, A., Scheers, L.H.A. (Bart), Spreeuw, H., Bell, M.E., Broderick, J.W., Carbone, D., Garsden, H., Horst, A.J. van der, Law, C.J., Wise, M.W. (Michael), Breton, R.P., Cendes, Y.N., Corbel, S., Eislöffel, J., Falcke, H., Fender, R.P., Grießmeier, J.-M., Hessels, J.W.T., Stappers, B.W., Stewart, A.J., Wijers, R.A.M.J. (Ralph), Wijnands, R., and Zarka, P.
Abstract: Current and future astronomical survey facilities provide a remarkably rich opportunity for transient astronomy, combining unprecedented fields of view with high sensitivity and the ability to access previously unexplored wavelength regimes. This is particularly true of LOFAR, a recently-commissioned, low-frequency radio interferometer, based in the Netherlands and with stations across Europe. The identification of and response to transients is one of LOFAR’s key science goals. However, the large data volumes which LOFAR produces, combined with the scientific requirement for rapid response, make automation essential. To support this, we have developed the LOFAR Transients Pipeline, or TraP. The TraP ingests multi-frequency image data from LOFAR or other instruments and searches it for transients and variables, providing automatic alerts of significant detections and populating a lightcurve database for further analysis by astronomers. Here, we discuss the scientific goals of the TraP and how it has been designed to meet them. We describe its implementation, including both the algorithms adopted to maximize performance as well as the development methodology used to ensure it is robust and reliable, particularly in the presence of artefacts typical of radio astronomy imaging. Finally, we report on a series of tests of the pipeline carried out using simulated LOFAR observations with a known population of transients.
Published: 2015
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31. Pulsar polarisation below 200 MHz: Average profiles and propagation effects

Author: Noutsos, A., Sobey, C.A., Kondratiev, V.I., Weltevrede, P., Verbiest, J.P.W., Karastergiou, A., Kramer, M., Kuniyoshi, M., Alexov, A., Breton, R.P., Bilous, A.V., Cooper, S., Falcke, H., Grießmeier, J.-M., Hassall, T.E., Hessels, J.W.T., Keane, E.F., Oslowski, S., Pilia, M., Serylak, M., Stappers, B.W., Veen, S. (Sander) ter, Leeuwen, J. (Joeri) van, Zagkouris, K., Anderson, K., Baehren, L., Bell, M.E., Broderick, J.W., Carbone, D., Cendes, Y.N., Coenen, T., Corbel, S., Eislöffel, J., Fender, R.P., Garsden, H., Jonker, P., Law, C.J., Markoff, S., Masters, J., Miller-Jones, J.C.A., Molenaar, G.J., Osten, R., Pietka, M., Rol, E., Rowlinson, A., Scheers, L.H.A. (Bart), Spreeuw, H., Staley, T.D., Stewart, A.J., Swinbank, J.D., Wijers, R.A.M.J. (Ralph), Wijnands, R., Wise, M.W. (Michael), Zarka, P., Horst, A.J. van der, Noutsos, A., Sobey, C.A., Kondratiev, V.I., Weltevrede, P., Verbiest, J.P.W., Karastergiou, A., Kramer, M., Kuniyoshi, M., Alexov, A., Breton, R.P., Bilous, A.V., Cooper, S., Falcke, H., Grießmeier, J.-M., Hassall, T.E., Hessels, J.W.T., Keane, E.F., Oslowski, S., Pilia, M., Serylak, M., Stappers, B.W., Veen, S. (Sander) ter, Leeuwen, J. (Joeri) van, Zagkouris, K., Anderson, K., Baehren, L., Bell, M.E., Broderick, J.W., Carbone, D., Cendes, Y.N., Coenen, T., Corbel, S., Eislöffel, J., Fender, R.P., Garsden, H., Jonker, P., Law, C.J., Markoff, S., Masters, J., Miller-Jones, J.C.A., Molenaar, G.J., Osten, R., Pietka, M., Rol, E., Rowlinson, A., Scheers, L.H.A. (Bart), Spreeuw, H., Staley, T.D., Stewart, A.J., Swinbank, J.D., Wijers, R.A.M.J. (Ralph), Wijnands, R., Wise, M.W. (Michael), Zarka, P., and Horst, A.J. van der
Abstract: Aims: We present the highest-quality polarisation profiles to date of 16 non-recycled pulsars and four millisecond pulsars, observed below 200 MHz with the LOFAR high-band antennas. Based on the observed profiles, we perform an initial investigation of expected observational effects resulting from the propagation of polarised emission in the pulsar magnetosphere and the interstellar medium. Methods: The polarisation data presented in this paper have been calibrated for the geometric-projection and beam-shape effects that distort the polarised information as detected with the LOFAR antennas. We have used RM Synthesis to determine the amount of Faraday rotation in the data at the time of the observations. The ionospheric contribution to the measured Faraday rotation was estimated using a model of the ionosphere. To study the propagation effects, we have compared our low-frequency polarisation observations with archival data at 240, 400, 600, and 1400 MHz. Results: The predictions of magnetospheric birefringence in pulsars have been tested using spectra of the pulse width and fractional polarisation from multifrequency data. The derived spectra offer only partial support for the expected effects of birefringence on the polarisation properties, with only about half of our sample being consistent with the model's predictions. It is noted that for some pulsars these measurements are contaminated by the effects of interstellar scattering. For a number of pulsars in our sample, we have observed significant variations in the amount of Faraday rotation as a function of pulse phase, which is possibly an artefact of scattering. These variations are typically two orders of magnitude smaller than that observed at 1400 MHz by Noutsos et al. (2009), for a different sample of southern pulsars. In this paper we present a possible explanation for the difference in magnitude of this effect between the two frequencies, based on scattering. Finally, we have estimated the magnetospheric e
Published: 2015

32. Spin-off CWI pakt gigantische stroom astro-data aan

Author: Nedev, D.G. (Dimitar), Scheers, L.H.A. (Bart), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Nedev, D.G. (Dimitar), Scheers, L.H.A. (Bart), Rijke, J.A. (Arjen) de, and Zhang, Y. (Ying)
Published: 2015

33. MonetDB Oct2014-SP3 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, and Sidirourgos, E. (Eleftherios)
Published: 2015

34. MonetDB Jul2015 feature release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, and Sidirourgos, E. (Eleftherios)
Published: 2015

35. MonetDB Oct2014-SP4 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, and Sidirourgos, E. (Eleftherios)
Published: 2015

36. MonetDB Oct2014-SP2 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. (Sándor), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Ivanova, M.G. (Milena), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. (Sándor), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), and Ivanova, M.G. (Milena)
Published: 2015

37. MonetDB Jul2015-SP1 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), and Koopmanschap, R.A. (Richard)
Published: 2015

38. Huge Radio Telescope Gets New Database

Author: Nedev, D.G. (Dimitar), Scheers, L.H.A. (Bart), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Nedev, D.G. (Dimitar), Scheers, L.H.A. (Bart), Rijke, J.A. (Arjen) de, and Zhang, Y. (Ying)
Published: 2015

39. Spin-off CWI pakt gigantische stroom astro-data aan

Author: Nedev, D.G. (Dimitar), Scheers, L.H.A. (Bart), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Nedev, D.G. (Dimitar), Scheers, L.H.A. (Bart), Rijke, J.A. (Arjen) de, and Zhang, Y. (Ying)
Published: 2015

40. Pulsar polarisation below 200 MHz: Average profiles and propagation effects

Author: Noutsos, A., Sobey, C.A., Kondratiev, V.I., Weltevrede, P., Verbiest, J.P.W., Karastergiou, A., Kramer, M., Kuniyoshi, M., Alexov, A., Breton, R.P., Bilous, A.V., Cooper, S., Falcke, H., Grießmeier, J.-M., Hassall, T.E., Hessels, J.W.T., Keane, E.F., Oslowski, S., Pilia, M., Serylak, M., Stappers, B.W., Veen, S. (Sander) ter, Leeuwen, J. (Joeri) van, Zagkouris, K., Anderson, K., Baehren, L., Bell, M.E., Broderick, J.W., Carbone, D., Cendes, Y.N., Coenen, T., Corbel, S., Eislöffel, J., Fender, R.P., Garsden, H., Jonker, P., Law, C.J., Markoff, S., Masters, J., Miller-Jones, J.C.A., Molenaar, G.J., Osten, R., Pietka, M., Rol, E., Rowlinson, A., Scheers, L.H.A. (Bart), Spreeuw, H., Staley, T.D., Stewart, A.J., Swinbank, J.D., Wijers, R.A.M.J. (Ralph), Wijnands, R., Wise, M.W. (Michael), Zarka, P., Horst, A.J. van der, Noutsos, A., Sobey, C.A., Kondratiev, V.I., Weltevrede, P., Verbiest, J.P.W., Karastergiou, A., Kramer, M., Kuniyoshi, M., Alexov, A., Breton, R.P., Bilous, A.V., Cooper, S., Falcke, H., Grießmeier, J.-M., Hassall, T.E., Hessels, J.W.T., Keane, E.F., Oslowski, S., Pilia, M., Serylak, M., Stappers, B.W., Veen, S. (Sander) ter, Leeuwen, J. (Joeri) van, Zagkouris, K., Anderson, K., Baehren, L., Bell, M.E., Broderick, J.W., Carbone, D., Cendes, Y.N., Coenen, T., Corbel, S., Eislöffel, J., Fender, R.P., Garsden, H., Jonker, P., Law, C.J., Markoff, S., Masters, J., Miller-Jones, J.C.A., Molenaar, G.J., Osten, R., Pietka, M., Rol, E., Rowlinson, A., Scheers, L.H.A. (Bart), Spreeuw, H., Staley, T.D., Stewart, A.J., Swinbank, J.D., Wijers, R.A.M.J. (Ralph), Wijnands, R., Wise, M.W. (Michael), Zarka, P., and Horst, A.J. van der
Abstract: Aims: We present the highest-quality polarisation profiles to date of 16 non-recycled pulsars and four millisecond pulsars, observed below 200 MHz with the LOFAR high-band antennas. Based on the observed profiles, we perform an initial investigation of expected observational effects resulting from the propagation of polarised emission in the pulsar magnetosphere and the interstellar medium. Methods: The polarisation data presented in this paper have been calibrated for the geometric-projection and beam-shape effects that distort the polarised information as detected with the LOFAR antennas. We have used RM Synthesis to determine the amount of Faraday rotation in the data at the time of the observations. The ionospheric contribution to the measured Faraday rotation was estimated using a model of the ionosphere. To study the propagation effects, we have compared our low-frequency polarisation observations with archival data at 240, 400, 600, and 1400 MHz. Results: The predictions of magnetospheric birefringence in pulsars have been tested using spectra of the pulse width and fractional polarisation from multifrequency data. The derived spectra offer only partial support for the expected effects of birefringence on the polarisation properties, with only about half of our sample being consistent with the model's predictions. It is noted that for some pulsars these measurements are contaminated by the effects of interstellar scattering. For a number of pulsars in our sample, we have observed significant variations in the amount of Faraday rotation as a function of pulse phase, which is possibly an artefact of scattering. These variations are typically two orders of magnitude smaller than that observed at 1400 MHz by Noutsos et al. (2009), for a different sample of southern pulsars. In this paper we present a possible explanation for the difference in magnitude of this effect between the two frequencies, based on scattering. Finally, we have estimated the magnetospheric e
Published: 2015

41. The LOFAR Transients Pipeline

Author: Swinbank, J.D., Staley, T.D., Molenaar, G.J., Rol, E., Rowlinson, A., Scheers, L.H.A. (Bart), Spreeuw, H., Bell, M.E., Broderick, J.W., Carbone, D., Garsden, H., Horst, A.J. van der, Law, C.J., Wise, M.W. (Michael), Breton, R.P., Cendes, Y.N., Corbel, S., Eislöffel, J., Falcke, H., Fender, R.P., Grießmeier, J.-M., Hessels, J.W.T., Stappers, B.W., Stewart, A.J., Wijers, R.A.M.J. (Ralph), Wijnands, R., Zarka, P., Swinbank, J.D., Staley, T.D., Molenaar, G.J., Rol, E., Rowlinson, A., Scheers, L.H.A. (Bart), Spreeuw, H., Bell, M.E., Broderick, J.W., Carbone, D., Garsden, H., Horst, A.J. van der, Law, C.J., Wise, M.W. (Michael), Breton, R.P., Cendes, Y.N., Corbel, S., Eislöffel, J., Falcke, H., Fender, R.P., Grießmeier, J.-M., Hessels, J.W.T., Stappers, B.W., Stewart, A.J., Wijers, R.A.M.J. (Ralph), Wijnands, R., and Zarka, P.
Abstract: Current and future astronomical survey facilities provide a remarkably rich opportunity for transient astronomy, combining unprecedented fields of view with high sensitivity and the ability to access previously unexplored wavelength regimes. This is particularly true of LOFAR, a recently-commissioned, low-frequency radio interferometer, based in the Netherlands and with stations across Europe. The identification of and response to transients is one of LOFAR’s key science goals. However, the large data volumes which LOFAR produces, combined with the scientific requirement for rapid response, make automation essential. To support this, we have developed the LOFAR Transients Pipeline, or TraP. The TraP ingests multi-frequency image data from LOFAR or other instruments and searches it for transients and variables, providing automatic alerts of significant detections and populating a lightcurve database for further analysis by astronomers. Here, we discuss the scientific goals of the TraP and how it has been designed to meet them. We describe its implementation, including both the algorithms adopted to maximize performance as well as the development methodology used to ensure it is robust and reliable, particularly in the presence of artefacts typical of radio astronomy imaging. Finally, we report on a series of tests of the pipeline carried out using simulated LOFAR observations with a known population of transients.
Published: 2015
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42. MonetDB Jul2015 feature release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, and Sidirourgos, E. (Eleftherios)
Published: 2015

43. MonetDB Oct2014-SP3 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, and Sidirourgos, E. (Eleftherios)
Published: 2015

44. MonetDB Oct2014-SP4 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, and Sidirourgos, E. (Eleftherios)
Published: 2015

45. MonetDB Oct2014-SP2 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. A. B. C. (Sándor), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Ivanova, M.G. (Milena), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. A. B. C. (Sándor), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), and Ivanova, M.G. (Milena)
Published: 2015

46. MonetDB Jul2015-SP1 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Koopmanschap, R.A. (Richard), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), and Koopmanschap, R.A. (Richard)
Published: 2015

47. MonetDB Jan2014-SP2 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. (Sándor), Kyzirakos, K. (Konstantinos), Dinther, M.H.M. (Martin) van, Nedev, D.G. (Dimitar), Alvanaki, F. (Foteini), Cijvat, C.P. (Robin), Sidirourgos, E. (Eleftherios), Ivanova, M.G. (Milena), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. (Sándor), Kyzirakos, K. (Konstantinos), Dinther, M.H.M. (Martin) van, Nedev, D.G. (Dimitar), Alvanaki, F. (Foteini), Cijvat, C.P. (Robin), Sidirourgos, E. (Eleftherios), and Ivanova, M.G. (Milena)
Published: 2014

48. MonetDB Jan2014-SP1 bugfix release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Idreos, S. (Stratos), Sidirourgos, E. (Eleftherios), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. (Sándor), Kyzirakos, K. (Konstantinos), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Idreos, S. (Stratos), Sidirourgos, E. (Eleftherios), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. (Sándor), and Kyzirakos, K. (Konstantinos)
Published: 2014

49. MonetDB Jan2014 feature release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Idreos, S. (Stratos), Sidirourgos, E. (Eleftherios), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. (Sándor), Kyzirakos, K. (Konstantinos), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Idreos, S. (Stratos), Sidirourgos, E. (Eleftherios), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. (Sándor), and Kyzirakos, K. (Konstantinos)
Published: 2014

50. MonetDB Oct2014 feature release

Author: Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. (Sándor), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), Ivanova, M.G. (Milena), Kersten, M.L. (Martin), Boncz, P.A. (Peter), Nes, N.J. (Niels), Manegold, S. (Stefan), Mullender, K.S. (Sjoerd), Rijke, J.A. (Arjen) de, Zhang, Y. (Ying), Pirk, H. (Holger), Pham, M.-D. (Minh-Duc), Scheers, L.H.A. (Bart), Petraki, E. (Eleni), Sellam, T.H.J. (Thibault), Kargin, Y. (Yagiz), Gawade, M.M. (Mrunal), Mühleisen, H.F. (Hannes), Héman, S. (Sándor), Kyzirakos, K. (Konstantinos), Nedev, D.G. (Dimitar), Cijvat, C.P. (Robin), Alvanaki, F. (Foteini), Dinther, M.H.M. (Martin) van, Sidirourgos, E. (Eleftherios), and Ivanova, M.G. (Milena)
Published: 2014

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