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Now showing items 13052-13071 of 24193

    • The LOFAR Two-metre Sky Survey - I. Survey Description and Preliminary Data Release 

      Shimwell, T. W.; Röttgering, H. J. A.; Best, P. N.; Williams, W. L.; Dijkema, T. J.; Gasperin, F. de; Hardcastle, M. J.; Heald, G. H.; Hoang, D. N.; Horneffer, A.; Intema, H.; Mahony, E. K.; Mandal, S.; Mechev, A. P.; Morabito, L.; Oonk, J. B. R.; Rafferty, D.; Retana-Montenegro, E.; Sabater, J.; Tasse, C.; Weeren, R. J. van; Brüggen, M.; Brunetti, G.; Chyży, K. T.; Conway, J. E.; Haverkorn, M.; Jackson, N.; Jarvis, M. J.; McKean, J. P.; Miley, G. K.; Morganti, R.; White, G. J.; Wise, M. W.; Bemmel, I. M. van; Beck, R.; Brienza, M.; Bonafede, A.; Rivera, G. Calistro; Cassano, R.; Clarke, A. O.; Cseh, D.; Deller, A.; Drabent, A.; Driel, W. van; Engels, D.; Falcke, H.; Ferrari, C.; Fröhlich, S.; Garrett, M. A.; Harwood, J. J.; Heesen, V.; Hoeft, M.; Horellou, C.; Israel, F. P.; Kapińska, A. D.; Kunert-Bajraszewska, M.; McKay, D. J.; Mohan, N. R.; Orrú, E.; Pizzo, R. F.; Prandoni, I.; Schwarz, D. J.; Shulevski, A.; Sipior, M.; Smith, D. J. B.; Sridhar, S. S.; Steinmetz, M.; Stroe, A.; Varenius, E.; Werf, P. P. van der; Zensus, J. A.; Zwart, J. T. L. (2017-02-09)
      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 hrs, which, at most declinations, is sufficient ...

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

      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.; Gasperin, F. de; Hoang, D. N.; Hugo, B.; Mirmont, M.; Oonk, J. B. R.; Prandoni, I.; Rafferty, D.; Sabater, J.; Smirnov, O.; Weeren, R. J. van; 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.; Smith, D. J. B.; Harwood, J. J.; Heesen, V.; Mahatma, V.; Mingo, B. (2018-09-12)
      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. ...

    • The LOFAR Two-metre Sky Survey -- V. Second data release 

      Shimwell, T. W.; Hardcastle, M. J.; Tasse, C.; Best, P. N.; Röttgering, H. J. A.; Williams, W. L.; Botteon, A.; Drabent, A.; Mechev, A.; Shulevski, A.; Weeren, R. J. van; Bester, L.; Brüggen, M.; Brunetti, G.; Callingham, J. R.; Chyży, K. T.; Conway, J. E.; Dijkema, T. J.; Duncan, K.; Gasperin, F. de; Hale, C. L.; Haverkorn, M.; Hugo, B.; Jackson, N.; Mevius, M.; Miley, G. K.; Morabito, L. K.; Morganti, R.; Offringa, A.; Oonk, J. B. R.; Rafferty, D.; Sabater, J.; Smith, D. J. B.; Schwarz, D. J.; Smirnov, O.; O'Sullivan, S. P.; Vedantham, H.; White, G. J.; Albert, J. G.; Alegre, L.; Asabere, B.; Bacon, D. J.; Bonafede, A.; Bonnassieux, E.; Brienza, M.; Bilicki, M.; Bonato, M.; Rivera, G. Calistro; Cassano, R.; Cochrane, R.; Croston, J. H.; Cuciti, V.; Dallacasa, D.; Danezi, A.; Dettmar, R. J.; Gennaro, G. Di; Edler, H. W.; Enßlin, T. A.; Emig, K. L.; Franzen, T. M. O.; García-Vergara, C.; Grange, Y. G.; Gürkan, G.; Hajduk, M.; Heald, G.; Heesen, V.; Hoang, D. N.; Hoeft, M.; Horellou, C.; Iacobelli, M.; Jamrozy, M.; Jelić, V.; Kondapally, R.; Kukreti, P.; Kunert-Bajraszewska, M.; Magliocchetti, M.; Mahatma, V.; Małek, K.; Mandal, S.; Massaro, F.; Meyer-Zhao, Z.; Mingo, B.; Mostert, R. I. J.; Nair, D. G.; Nakoneczny, S. J.; Nikiel-Wroczyński, B.; Orrú, E.; Pajdosz-Śmierciak, U.; Pasini, T.; Prandoni, I.; Piggelen, H. E. van; Rajpurohit, K.; Retana-Montenegro, E.; Riseley, C. J.; Rowlinson, A.; Saxena, A.; Schrijvers, C.; Sweijen, F.; Siewert, T. M.; Timmerman, R.; Vaccari, M.; Vink, J.; West, J. L.; Wołowska, A.; Zhang, X.; Zheng, J. (2022-02-25)
      In this data release from the ongoing LOw-Frequency ARray (LOFAR) Two-metre Sky Survey we present 120a 168 MHz images covering 27% of the northern sky. Our coverage is split into two regions centred at approximately 12h45m ...

    • The LOFAR Two-Metre Sky Survey : VI. Optical identifications for the second data release 

      Hardcastle, M. J.; Horton, M. A.; Williams, W. L.; Duncan, K. J.; Alegre, L.; Barkus, B.; Croston, J. H.; Dickinson, H.; Osinga, E.; Röttgering, H. J. A.; Sabater, J.; Shimwell, T. W.; Smith, D. J. B.; Best, P. N.; Botteon, A.; Brüggen, M.; Drabent, A.; Gasperin, F. de; Gürkan, G.; Hajduk, M.; Hale, C. L.; Hoeft, M.; Jamrozy, M.; Kunert-Bajraszewska, M.; Kondapally, R.; Magliocchetti, M.; Mahatma, V. H.; Mostert, R. I. J.; O'Sullivan, S. P.; Pajdosz-Śmierciak, U.; Petley, J.; Pierce, J. C. S.; Prandoni, I.; Schwarz, D. J.; Shulewski, A.; Siewert, T. M.; Stott, J. P.; Tang, H.; Vaccari, M.; Zheng, X.; Bailey, T.; Desbled, S.; Goyal, A.; Gonano, V.; Hanset, M.; Kurtz, W.; Lim, S. M.; Mielle, L.; Molloy, C. S.; Roth, R.; Terentev, I. A.; Torres, M. (2023-10-01)
      The second data release of the LOFAR Two-Metre Sky Survey (LoTSS) covers 27% of the northern sky, with a total area of ∼5700 deg1. The high angular resolution of LOFAR with Dutch baselines (6 arcsec) allows us to carry out ...

    • The LOFAR Two-metre Sky Survey Deep Fields Data Release 1 V. Survey description, source classifications and host galaxy properties 

      Best, P. N.; Kondapally, R.; Williams, W. L.; Cochrane, R. K.; Duncan, K. J.; Hale, C. L.; Haskell, P.; Malek, K.; McCheyne, I.; Smith, D. J. B.; Wang, L.; Botteon, A.; Bonato, M.; Bondi, M.; Rivera, G. Calistro; Gao, F.; Gurkan, G.; Hardcastle, M. J.; Jarvis, M. J.; Mingo, B.; Miraghaei, H.; Morabito, L. K.; Nisbet, D.; Prandoni, I.; Rottgering, H. J. A.; Sabater, J.; Shimwell, T.; Tasse, C.; Weeren, R. van (2023-04-29)
      Source classifications, stellar masses and star formation rates are presented for 80,000 radio sources from the first data release of the Low Frequency Array Two-metre Sky Survey (LoTSS) Deep Fields, which represents the ...

    • The LOFAR Two-metre Sky Survey Deep fields: : The star formation rate - radio luminosity relation at low frequencies 

      Smith, D. J. B.; Haskell, P.; Gürkan, G.; Best, P. N.; Hardcastle, M. J.; Kondapally, R.; Williams, W.; Duncan, K. J.; Cochrane, R. K.; McCheyne, I.; Röttgering, H. J. A.; Sabater, J.; Shimwell, T. W.; Tasse, C.; Bonato, M.; Bondi, M.; Jarvis, M. J.; Leslie, S. K.; Prandoni, I.; Wang, L. (2021-04-07)
      In this paper, we investigate the relationship between 150 MHz luminosity and the star-formation rate - the SFR-L150 MHz relation - using 150 MHz measurements for a near-infrared selected sample of 118 517 z < 1 galaxies. ...

    • The LOFAR Two-metre Sky Survey Deep Fields: Data release 1. IV. Photometric redshifts and stellar masses 

      Duncan, K. J.; Kondapally, R.; Brown, M. J. I.; Best, P. N.; Röttgering, H. J. A.; Bondi, M.; Bowler, R. A. A.; Cochrane, R. K.; Gürkan, G.; Hardcastle, M. J.; Jarvis, M. J.; Kunert-Bajraszewska, M.; Leslie, S. K.; Małek, K.; Morabito, L. K.; O'Sullivan, S. P.; Prandoni, I.; Sabater, J.; Shimwell, T. W.; Smith, D. J. B.; Wang, L.; Wołowska, A. (2021-04-07)
      The Low Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS) is a sensitive, high-resolution 120-168 MHz survey split across multiple tiers over the northern sky. The first LoTSS Deep Fields data release consists of deep ...

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

      Duncan, Kenneth J; Sabater, J.; Röttgering, H. J. A.; Jarvis, M. J.; Smith, D. J. B.; Best, P. N.; Callingham, J. R.; Cochrane, R.; Croston, J. H.; Hardcastle, M. J.; Mingo, B.; Morabito, L.; Nisbet, D.; Prandoni, I.; Shimwell, T. W.; Tasse, C.; White, G. J.; Williams, W. L.; Alegre, L.; Chyży, K. T.; Gürkan, G.; Hoeft, M.; Kondapally, R.; Mechev, A. P.; Miley, G. K.; Schwarz, D. J.; Weeren, R. J. van (2018-11-19)
      The LOFAR Two-metre Sky Survey (LoTSS) is a sensitive, high-resolution 120-168 MHz survey of the Northern sky. The LoTSS First Data Release (DR1) presents 424 square degrees of radio continuum observations over the HETDEX ...

    • The LOFAR Two-metre Sky Survey: Deep Fields: : II. The ELAIS-N1 LOFAR deep field 

      Sabater, J.; Best, P. N.; Tasse, C.; Hardcastle, M. J.; Shimwell, T. W.; Nisbet, D.; Jelic, V.; Callingham, J. R.; Rottgering, H. J. A.; Bonato, M.; Bondi, M.; Ciardi, B.; Cochrane, R. K.; Jarvis, M. J.; Kondapally, R.; Koopmans, L. V. E.; O'Sullivan, S. P.; Prandoni, I.; Schwarz, D. J.; Smith, D. J. B.; Wang, L.; Williams, W. L.; Zaroubi, S. (2021-04-07)
      The LOFAR Two-metre Sky Survey (LoTSS) will cover the full northern sky and, additionally, aims to observe the LoTSS deep fields to a noise level of ~10 microJy/bm over several tens of square degrees in areas that have the ...

    • The LOFAR Two-metre Sky Survey: the radio view of the cosmic star formation history 

      Cochrane, R. K.; Kondapally, R.; Best, P. N.; Sabater, J.; Duncan, K. J.; Smith, D. J. B.; Hardcastle, M. J.; Röttgering, H. J. A.; Prandoni, I.; Haskell, P.; Gürkan, G.; Miley, G. K. (2023-05-26)
      We present a detailed study of the cosmic star formation history over $90$ per cent of cosmic time ($0\lesssim z\lesssim4$), using deep, radio continuum observations that probe star formation activity independent of dust. ...

    • The LOFAR view of FR0 radio galaxies 

      Capetti, A.; Brienza, M.; Baldi, R. D.; Giovannini, G.; Morganti, R.; Hardcastle, M. J.; Rottgering, H. J. A.; Brunetti, G. F.; Best, P. N.; Miley, G. (2020-10-09)
      We explore the low-frequency radio properties of the sources in the Fanaroff-Riley class 0 catalog (FR0CAT) as seen by the LOw Frequency ARray (LOFAR) observations at 150 MHz. This sample includes 104 compact radio active ...

    • The LOFAR view of giant, early-type galaxies: radio emission from active nuclei and star formation 

      Capetti, A.; Brienza, M.; Balmaverde, B.; Best, R. D. P. N.; Baldi, R. D.; Drabent, A.; Gurkan, G.; Rottgering, H. J. A.; Tasse, C.; Webster, B. (2022-02-17)
      We studied the properties and the origin of the radio emission in the most luminous, early-type galaxies (ETGs) in the nearby Universe (MK ≤ −25, recession velocity ≤7500 km s−1), as seen by the 150 MHz Low-Frequency ARray ...

    • LOFAR view of NGC 3998, a sputtering AGN 

      Sridhar, Sarrvesh S.; Morganti, Raffaella; Nyland, Kristina; Frank, Bradley S.; Harwood, Jeremy; Oosterloo, Tom (2020-02-18)
      Low-power radio sources dominate the radio sky. They tend to be small in size and dominated by their cores, but the origin of their properties and the evolution of their radio plasma are not well constrained. Interestingly, ...

    • The LOFAR window on star-forming galaxies and AGN - curved radio SEDs and IR-radio correlation at 0 < z < 2.5 

      Rivera, G. Calistro; Williams, W. L.; Hardcastle, M. J.; Duncan, K. J.; Röttgering, H.~J.~A.; Best, Philip N.; Brüggen, Marcus; Chyzy, K.T.; Conselice, C. J.; De Gasperin, Francesco; Engels, D.; Gürkan, G.; Intema, Huib T.; Jarvis, M. J.; Mahony, E. K.; Miley, G.K.; Morabito, L. K.; Prandoni, I.; Sabater, J.; Smith, D. J. B.; Tasse, C.; van der Werf, P.; White, Glenn J. (2017-08-11)
      We present a study of the low-frequency radio properties of star forming (SF) galaxies and active galactic nuclei (AGN) up to redshift $z=2.5$. The new spectral window probed by the Low Frequency Array (LOFAR) allows us ...

    • LOFAR, VLA, and Chandra observations of the Toothbrush galaxy cluster 

      Van Weeren, R. J.; Brunetti, G.; Brüggen, M.; Andrade-Santos, F.; Ogrean, G. A.; Williams, W. L.; Röttgering, H. J. A.; Dawson, W. A.; Forman, W.R.; Gasperin, F. de; Hardcastle, M.J.; Jones, C.; Miley, G.K.; Rafferty, D. A.; Rudnick, L.; Sabater, J.; Sarazin, C.L.; Shimwell, T. W.; Bonafede, A.; Best, P. N.; Bîrzan, L.; Cassano, R.; Chyży, K. T.; Croston, J. H.; Dijkema, T. J.; Ensslin, T.; Ferrari, C.; Heald, G.; Hoeft, M.; Horellou, C.; Jarvis, M.J.; Kraft, R.P.; Mevius, M.; Intema, H. T.; Murray, S. S.; Orrú, E.; Pizzo, R.; Sridhar, S. S.; Simionescu, A.; Stroe, A.; Tol, S. van der; White, G.J. (2016-02-22)
      We present deep LOFAR observations between 120-181 MHz of the "Toothbrush" (RX J0603.3+4214), a cluster that contains one of the brightest radio relic sources known. Our LOFAR observations exploit a new and novel calibration ...

    • LOFAR-Boötes : Properties of high- and low-excitation radio galaxies at 0.5 < z < 2.0 

      Williams, W. L.; Rivera, G. Calistro; Best, Philip N.; Hardcastle, M. J.; Röttgering, H.~J.~A.; Duncan, K. J.; De Gasperin, Francesco; Jarvis, M. J.; Miley, G.K.; Mahony, E. K.; Morabito, L. K.; Nisbet, D. M.; Prandoni, I.; Smith, D. J. B.; Tasse, C.; White, Glenn J. (2018-04-11)
      This paper presents a study of the redshift evolution of radio-loud active galactic nuclei (AGN) as a function of the properties of their galaxy hosts in the Boötes field. To achieve this we match low-frequency radio sources ...

    • A LOFAR-IRAS cross-match study : the far-infrared radio correlation and the 150-MHz luminosity as a star-formation rate 

      Wang, L.; Gao, F.; Duncan, K. J.; Williams, W. L.; Rowan-Robinson, M.; Sabater, J.; Shimwell, T. W.; Bonato, M.; Calistro-Rivera, G.; Chyzy, K. T.; Farrah, D.; Gurkan Uygun, Gulay; Hardcastle, M. J.; McCheyne, I.; Prandoni, I.; Read, S. C.; Rottgering, H. J. A.; Smith, D. J. B. (2019-11-01)
      Aims. We aim to study the far-infrared radio correlation (FIRC) at 150 MHz in the local Universe (at a median redshift z~0:05) and improve the use of the rest-frame 150-MHz luminosity, L150, as a star-formation rate (SFR) ...

    • LOFAR/H-ATLAS: A deep low-frequency survey of the Herschel-ATLAS North Galactic Pole field 

      Hardcastle, M. J.; Gürkan, G.; Weeren, R. J. van; Williams, W. L.; Best, P. N.; Gasperin, F. de; Rafferty, D. A.; Read, S. C.; Sabater, J.; Shimwell, T. W.; Smith, D. J. B.; Tasse, C.; Bourne, N.; Brienza, M.; Brüggen, M.; Brunetti, G.; Chyży, K. T.; Conway, J.; Dunne, L.; Eales, S. A.; Maddox, S. J.; Jarvis, M. J.; Mahony, E. K.; Morganti, R.; Prandoni, I.; Röttgering, H. J. A.; Valiante, E.; White, G. J. (2016-10-21)
      We present LOFAR High-Band Array (HBA) observations of the Herschel-ATLAS North Galactic Pole survey area. The survey we have carried out, consisting of four pointings covering around 142 square degrees of sky in the ...

    • LOFAR/H-ATLAS: The low-frequency radio luminosity - star-formation rate relation 

      Gurkan, Gulay; Hardcastle, Martin J.; Smith, Daniel; Best, Philip N.; Bourne, Nathan; Calistro-Rivera, Gabriela; Heald, George; Jarvis, Matt J.; Prandoni, Isabella; Rottgering, Huub J. A.; Sabater, Jose; Shimwell, Tim; Tasse, Cyril; Williams, Wendy L. (2018-04-11)
      Radio emission is a key indicator of star-formation activity in galaxies, but the radio luminosity-star formation relation has to date been studied almost exclusively at frequencies of 1.4 GHz or above. At lower radio ...

    • Logarithmic simulated annealing for computer-assisted x-ray diagnosis 

      Albrecht, A.; Steinhofel, K.; Taupitz, M.; Wong, C.K. (2001)
      We present a new stochastic learning algorithm and first results of computational experiments on fragments of liver CT images. The algorithm is designed to compute a depth-three threshold circuit, where the first layer is ...