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

Author

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., and van Weeren, R.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

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 widest deep radio survey ever undertaken. Using deep multi-wavelength data spanning from the ultraviolet to the far-infrared, spectral energy distribution (SED) fitting is carried out for all of the LoTSS-Deep host galaxies using four different SED codes, two of which include modelling of the contributions from an active galactic nucleus (AGN). Comparing the results of the four codes, galaxies that host a radiative AGN are identified, and an optimised consensus estimate of the stellar mass and star-formation rate for each galaxy is derived. Those galaxies with an excess of radio emission over that expected from star formation are then identified, and the LoTSS-Deep sources are divided into four classes: star-forming galaxies, radio-quiet AGN, and radio-loud high-excitation and low-excitation AGN. Ninety-five per cent of the sources can be reliably classified, of which more than two-thirds are star-forming galaxies, ranging from normal galaxies in the nearby Universe to highly-starbursting systems at z>4. Star-forming galaxies become the dominant population below 150-MHz flux densities of about 1 mJy, accounting for 90 per cent of sources at a 150-MHz flux density of 100 microJy. Radio-quiet AGN comprise around 10 per cent of the overall population. Results are compared against the predictions of the SKADS and T-RECS radio sky simulations, and improvements to the simulations are suggested., Comment: Accepted for publication in MNRAS. Catalogues available at www.lofar-surveys.org/deepfields.html. 27 pages

Published
2023
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3. The LOFAR Two Metre Sky Survey: Deep Fields. II. The ELAIS-N1 LOFAR deep field

Author

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., and Zaroubi, S.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena
Abstract

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 most extensive ancillary data. This paper presents the ELAIS-N1 deep field, the deepest of the LoTSS deep fields to date. With an effective observing time of 163.7 hours, it reaches a root mean square (RMS) noise level below 20 microJy/bm in the central region (and below 30 microJy/bm over 10 square degrees). The resolution is 6 arcsecs and 84862 radio sources were detected in the full area (68 sq. deg.) with 74127 sources in the highest quality area at less than 3 degrees from the pointing centre. The observation reaches a sky density of more than 5000 sources per sq. deg. in the central ~5 sq. deg. region. We present the calibration procedure, which addresses the special configuration of some observations and the extended bandwidth covered (115 to 177 MHz; central frequency 146.2 MHz) compared to standard LoTSS. We also describe the methods used to calibrate the flux density scale using cross-matching with sources detected by other radio surveys in the literature. We find the flux density uncertainty related to the flux density scale to be ~6.5%. By studying the variations of the flux density measurements between different epochs, we show that relative flux density calibration is reliable out to about a 3 degree radius, but that additional flux density uncertainty is present for all sources at about the 3 per cent level; this is likely to be associated with residual calibration errors, and is shown to be more significant in datasets with poorer ionosphere conditions. We also provide intra-band spectral indices, which can be useful to detect sources with unusual spectral properties. The final uncertainty in the flux densities is estimated to be ~10% for ELAIS-N1., Comment: Accepted for publication in A&A. This paper is part of the 1st data release of the LoTSS Deep Fields. Electronic data catalogues will be made available on journal publication. 21 pages, 17 figures

Published
2020
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4. The LOFAR Two Metre Sky Survey: Deep Fields Data Release 1 -- III. Host-galaxy identifications and value added catalogues

Author

Kondapally, R., Best, P. N., Hardcastle, M. J., Nisbet, D., Bonato, M., Sabater, J., Duncan, K. J., McCheyne, I., Cochrane, R. K., Bowler, R. A. A., Williams, W. L., Shimwell, T. W., Tasse, C., Croston, J. H., Goyal, A., Jamrozy, M., Jarvis, M. J., Mahatma, V. H., R\öttgering, H. J. A., Smith, D. J. B., Wo\łowska, A., Bondi, M., Brienza, M., Brown, M. J. I., Br\üggen, M., Chambers, K., Garrett, M. A., G\ürkan, G., Huber, M., Kunert-Bajraszewska, M., Magnier, E., Mingo, B., Mostert, R., Nikiel-Wroczy\\ński, B., OŚullivan, S. P., Paladino, R., Ploeckinger, T., Prandoni, I., Rosenthal, M. J., Schwarz, D. J., Shulevski, A., Wagenveld, J. D., and Wang, L.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present the source associations, cross-identifications, and multi-wavelength properties of the faint radio source population detected in the deep tier of the LOFAR Two Metre Sky Survey (LoTSS): the LoTSS Deep Fields. The first LoTSS Deep Fields data release consists of deep radio imaging at 150~MHz of the ELAIS-N1, Lockman Hole, and Bo\"{o}tes fields, down to RMS sensitives of around 20, 22, and 32$~\mu$Jy\,beam$^{-1}$, respectively. These fields are some of the best studied extra-galactic fields in the northern sky, with existing deep, wide-area panchromatic photometry from X-ray to infrared wavelengths, covering a total of $\approx$~26~\mbox{deg$^{2}$}. We first generated improved multi-wavelength catalogues in ELAIS-N1 and Lockman Hole; combined with the existing catalogue for Bo\"{o}tes, we present forced, matched aperture photometry for over 7.2 million sources across the three fields. We identified multi-wavelength counterparts to the radio detected sources, using a combination of the Likelihood Ratio method and visual classification, which greatly enhances the scientific potential of radio surveys and allows for the characterisation of the photometric redshifts and the physical properties of the host galaxies. The final radio-optical cross-matched catalogue consists of 81\,951 radio-detected sources, with counterparts identified and multi-wavelength properties presented for 79\,820 ($>$97\%) sources. We also examine the properties of the host galaxies, and through stacking analysis find that the radio population with no identified counterpart is likely dominated by AGN at $z\sim3-4$. This dataset contains one of the largest samples of radio-selected star-forming galaxies and active galactic nuclei (AGN) at these depths, making it ideal for studying the history of star-formation, and the evolution of galaxies and AGN across cosmic time., Comment: 34 pages, 14 figures and 14 tables. Accepted for publication in A&A special issue. This paper is part of the 1st data release of the LoTSS Deep Fields. Electronic data catalogues will be made available on journal publication

Published
2020
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5. The Compact Linear Collider (CLIC) - 2018 Summary Report

Author

CLIC, The, collaborations, CLICdp, Charles, T. K., Giansiracusa, P. J., Lucas, T. G., Rassool, R. P., Volpi, M., Balazs, C., Afanaciev, K., Makarenko, V., Patapenka, A., Zhuk, I., Collette, C., Boland, M. J., Hoffman, A. C. Abusleme, Diaz, M. A., Garay, F., Chi, Y., He, X., Pei, G., Pei, S., Shu, G., Wang, X., Zhang, J., Zhao, F., Zhou, Z., Chen, H., Gao, Y., Huang, W., Kuang, Y. P., Li, B., Li, Y., Meng, X., Shao, J., Shi, J., Tang, C., Wang, P., Wu, X., Zha, H., Ma, L., Han, Y., Fang, W., Gu, Q., Huang, D., Huang, X., Tan, J., Wang, Z., Zhao, Z., Uggerhøj, U. I., Wistisen, T. N., Aabloo, A., Aare, R., Kuppart, K., Vigonski, S., Zadin, V., Aicheler, M., Baibuz, E., Brücken, E., Djurabekova, F., Eerola, P., Garcia, F., Haeggström, E., Huitu, K., Jansson, V., Kassamakov, I., Kimari, J., Kyritsakis, A., Lehti, S., Meriläinen, A., Montonen, R., Nordlund, K., Österberg, K., Saressalo, A., Väinölä, J., Veske, M., Farabolini, W., Mollard, A., Peauger, F., Plouin, J., Bambade, P., Chaikovska, I., Chehab, R., Delerue, N., Davier, M., Faus-Golfe, A., Irles, A., Kaabi, W., LeDiberder, F., Pöschl, R., Zerwas, D., Aimard, B., Balik, G., Blaising, J. -J., Brunetti, L., Chefdeville, M., Dominjon, A., Drancourt, C., Geoffroy, N., Jacquemier, J., Jeremie, A., Karyotakis, Y., Nappa, J. M., Serluca, M., Vilalte, S., Vouters, G., Bernhard, A., Bründermann, E., Casalbuoni, S., Hillenbrand, S., Gethmann, J., Grau, A., Huttel, E., Müller, A. -S., Peiffer, P., Perić, I., de Jauregui, D. Saez, Emberger, L., Graf, C., Simon, F., Szalay, M., van der Kolk, N., Brass, S., Kilian, W., Alexopoulos, T., Apostolopoulos, T., Gazis, E. N., Gazis, N., Kostopoulos, V., Kourkoulis, S., Heilig, B., Lichtenberger, J., Shrivastava, P., Dayyani, M. K., Ghasem, H., Hajari, S. S., Shaker, H., Ashkenazy, Y., Popov, I., Engelberg, E., Yashar, A., Abramowicz, H., Benhammou, Y., Borysov, O., Borysova, M., Levy, A., Levy, I., Alesini, D., Bellaveglia, M., Buonomo, B., Cardelli, A., Diomede, M., Ferrario, M., Gallo, A., Ghigo, A., Giribono, A., Piersanti, L., Stella, A., Vaccarezza, C., de Blas, J., Franceschini, R., D'Auria, G., Di Mitri, S., Abe, T., Aryshev, A., Fukuda, M., Furukawa, K., Hayano, H., Higashi, Y., Higo, T., Kubo, K., Kuroda, S., Matsumoto, S., Michizono, S., Naito, T., Okugi, T., Shidara, T., Tauchi, T., Terunuma, N., Urakawa, J., Yamamoto, A., Raboanary, R., Luiten, O. J., Stragier, X. F. D., Hart, R., van der Graaf, H., Eigen, G., Adli, E., Lindstrøm, C. A., Lillestøl, R., Malina, L., Pfingstner, J., Sjobak, K. N., Ahmad, A., Hoorani, H., Khan, W. A., Bugiel, S., Bugiel, R., Firlej, M., Fiutowski, T. A., Idzik, M., Moroń, J., Świentek, K. P., de Renstrom, P. Brückman, Krupa, B., Kucharczyk, M., Lesiak, T., Pawlik, B., Sopicki, P., Turbiarz, B., Wojtoń, T., Zawiejski, L. K., Kalinowski, J., Nowak, K., Żarnecki, A. F., Firu, E., Ghenescu, V., Neagu, A. T., Preda, T., Zgura, I. S., Aloev, A., Azaryan, N., Boyko, I., Budagov, J., Chizhov, M., Filippova, M., Glagolev, V., Gongadze, A., Grigoryan, S., Gudkov, D., Karjavine, V., Lyablin, M., Nefedov, Yu., Olyunin, A., Rymbekova, A., Samochkine, A., Sapronov, A., Shelkov, G., Shirkov, G., Soldatov, V., Solodko, E., Trubnikov, G., Tyapkin, I., Uzhinsky, V., Vorozhtov, A., Zhemchugov, A., Levichev, E., Mezentsev, N., Piminov, P., Shatilov, D., Vobly, P., Zolotarev, K., Jelisavčić, I. Božović, Kačarević, G., Dumbelović, G. Milutinović, Pandurović, M., Radulović, M., Stevanović, J., Vukasinović, N., Lee, D. -H., Ayala, N., Benedetti, G., Guenzel, T., Iriso, U., Marti, Z., Perez, F., Pont, M., Trenado, J., Ruiz-Jimeno, A., Vila, I., Calero, J., Dominguez, M., Garcia-Tabares, L., Gavela, D., Lopez, D., Toral, F., Gutierrez, C. Blanch, Boronat, M., Esperante, D., Fullana, E., Fuster, J., García, I., Gimeno, B., Lopez, P. Gomis, González, D., Perelló, M., Ros, E., Villarejo, M. A., Vnuchenko, A., Vos, M., Borgmann, Ch., Brenner, R., Ekelöf, T., Jacewicz, M., Olvegård, M., Ruber, R., Ziemann, V., Aguglia, D., Gonzalvo, J. Alabau, Leon, M. Alcaide, Tehrani, N. Alipour, Anastasopoulos, M., Andersson, A., Andrianala, F., Antoniou, F., Apyan, A., Arominski, D., Artoos, K., Assly, S., Atieh, S., Baccigalupi, C., Sune, R. Ballabriga, Caballero, D. Banon, Barnes, M. J., Garcia, J. Barranco, Bartalesi, A., Bauche, J., Bayar, C., Belver-Aguilar, C., Morell, A. Benot, Bernardini, M., Bett, D. R., Bettoni, S., Bettencourt, M., Bielawski, B., Garcia, O. Blanco, Kraljevic, N. Blaskovic, Bolzon, B., Bonnin, X. A., Bozzini, D., Branger, E., Brondolin, E., Brunner, O., Buckland, M., Bursali, H., Burkhardt, H., Caiazza, D., Calatroni, S., Campbell, M., Lasheras, N. Catalan, Cassany, B., Castro, E., Soares, R. H. Cavaleiro, Bastos, M. Cerqueira, Cherif, A., Chevallay, E., Cilento, V., Corsini, R., Costa, R., Cure, B., Curt, S., Gobbo, A. Dal, Dannheim, D., Daskalaki, E., Deacon, L., Degiovanni, A., De Michele, G., De Oliveira, L., Romano, V. Del Pozo, Delahaye, J. P., Delikaris, D., de Almeida, P. G. Dias, Dobers, T., Doebert, S., Doytchinov, I., Draper, M., Ramos, F. Duarte, Duquenne, M., Plaja, N. Egidos, Elsener, K., Esberg, J., Esposito, M., Evans, L., Fedosseev, V., Ferracin, P., Fiergolski, A., Foraz, K., Fowler, A., Friebel, F., Fuchs, J-F., Gaddi, A., Gamba, D., Fajardo, L. Garcia, Morales, H. Garcia, Garion, C., Gasior, M., Gatignon, L., Gayde, J-C., Gerbershagen, A., Gerwig, H., Giambelli, G., Gilardi, A., Goldblatt, A. N., Anton, S. Gonzalez, Grefe, C., Grudiev, A., Guerin, H., Guillot-Vignot, F. G., Gutt-Mostowy, M. L., Lutz, M. Hein, Hessler, C., Holma, J. K., Holzer, E. B., Hourican, M., Hynds, D., Ikarios, E., Levinsen, Y. Inntjore, Janssens, S., Jeff, A., Jensen, E., Jonker, M., Kamugasa, S. W., Kastriotou, M., Kemppinen, J. M. K., Khan, V., Kieffer, R. B., Klempt, W., Kokkinis, N., Kossyvakis, I., Kostka, Z., Korsback, A., Platia, E. Koukovini, Kovermann, J. W., Kozsar, C-I., Kremastiotis, I., Kröger, J., Kulis, S., Latina, A., Leaux, F., Lebrun, P., Lefevre, T., Leogrande, E., Linssen, L., Liu, X., Cudie, X. Llopart, Magnoni, S., Maidana, C., Maier, A. A., Durand, H. Mainaud, Mallows, S., Manosperti, E., Marelli, C., Lacoma, E. Marin, Marsh, S., Martin, R., Martini, I., Martyanov, M., Mazzoni, S., Mcmonagle, G., Mether, L. M., Meynier, C., Modena, M., Moilanen, A., Mondello, R., Cabral, P. B. Moniz, Irazabal, N. Mouriz, Munker, M., Muranaka, T., Nadenau, J., Navarro, J. G., Quirante, J. L. Navarro, Del Busto, E. Nebo, Nikiforou, N., Ninin, P., Nonis, M., Nisbet, D., Nuiry, F. X., Nürnberg, A., Ögren, J., Osborne, J., Ouniche, A. C., Pan, R., Papadopoulou, S., Papaphilippou, Y., Paraskaki, G., Pastushenko, A., Passarelli, A., Patecki, M., Pazdera, L., Pellegrini, D., Pepitone, K., Codina, E. Perez, Fontenla, A. Perez, Persson, T. H. B., Petrič, M., Pitman, S., Pitters, F., Pittet, S., Plassard, F., Popescu, D., Quast, T., Rajamak, R., Redford, S., Remandet, L., Renier, Y., Rey, S. F., Orozco, O. Rey, Riddone, G., Castro, E. Rodriguez, Roloff, P., Rossi, C., Rossi, F., Rude, V., Ruehl, I., Rumolo, G., Sailer, A., Sandomierski, J., Santin, E., Sanz, C., Bedolla, J. Sauza, Schnoor, U., Schmickler, H., Schulte, D., Senes, E., Serpico, C., Severino, G., Shipman, N., Sicking, E., Simoniello, R., Skowronski, P. K., Mompean, P. Sobrino, Soby, L., Sollander, P., Solodko, A., Sosin, M. P., Spannagel, S., Sroka, S., Stapnes, S., Sterbini, G., Stern, G., Ström, R., Stuart, M. J., Syratchev, I., Szypula, K., Tecker, F., Thonet, P. A., Thrane, P., Timeo, L., Tiirakari, M., Garcia, R. Tomas, Tomoiaga, C. I., Valerio, P., Vaňát, T., Vamvakas, A. L., Van Hoorne, J., Viazlo, O., Pinto, M. Vicente Barreto, Vitoratou, N., Vlachakis, V., Weber, M. A., Wegner, R., Wendt, M., Widorski, M., Williams, O. E., Williams, M., Woolley, B., Wuensch, W., Wulzer, A., Uythoven, J., Xydou, A., Yang, R., Zelios, A., Zhao, Y., Zisopoulos, P., Benoit, M., Sultan, D M S, Riva, F., Bopp, M., Braun, H. H., Craievich, P., Dehler, M., Garvey, T., Pedrozzi, M., Raguin, J. Y., Rivkin, L., Zennaro, R., Guillaume, S., Rothacher, M., Aksoy, A., Nergiz, Z., Yavas, Ö., Denizli, H., Keskin, U., Oyulmaz, K. Y., Senol, A., Ciftci, A. K., Baturin, V., Karpenko, O., Kholodov, R., Lebed, O., Lebedynskyi, S., Mordyk, S., Musienko, I., Profatilova, Ia., Storizhko, V., Bosley, R. R., Price, T., Watson, M. F., Watson, N. K., Winter, A. G., Goldstein, J., Green, S., Marshall, J. S., Thomson, M. A., Xu, B., You, T., Gillespie, W. A., Spannowsky, M., Beggan, C., Martin, V., Zhang, Y., Protopopescu, D., Robson, A., Apsimon, R. J., Bailey, I., Burt, G. C., Dexter, A. C., Edwards, A. V., Hill, V., Jamison, S., Millar, W. L., Papke, K., Casse, G., Vossebeld, J., Aumeyr, T., Bergamaschi, M., Bobb, L., Bosco, A., Boogert, S., Boorman, G., Cullinan, F., Gibson, S., Karataev, P., Kruchinin, K., Lekomtsev, K., Lyapin, A., Nevay, L., Shields, W., Snuverink, J., Towler, J., Yamakawa, E., Boisvert, V., West, S., Jones, R., Joshi, N., Bett, D., Bodenstein, R. M., Bromwich, T., Burrows, P. N., Christian, G. B., Gohil, C., Korysko, P., Paszkiewicz, J., Perry, C., Ramjiawan, R., Roberts, J., Coates, T., Salvatore, F., Bainbridge, A., Clarke, J. A., Krumpa, N., Shepherd, B. J. A., Walsh, D., Chekanov, S., Demarteau, M., Gai, W., Liu, W., Metcalfe, J., Power, J., Repond, J., Weerts, H., Xia, L., Zupan, J., Wells, J. D., Zhang, Z., Adolphsen, C., Barklow, T., Dolgashev, V., Franzi, M., Graf, N., Hewett, J., Kemp, M., Kononenko, O., Markiewicz, T., Moffeit, K., Neilson, J., Nosochkov, Y., Oriunno, M., Phinney, N., Rizzo, T., Tantawi, S., Wang, J., Weatherford, B., White, G., and Woodley, M.

Subjects
Physics - Accelerator Physics
Abstract

The Compact Linear Collider (CLIC) is a TeV-scale high-luminosity linear $e^+e^-$ collider under development at CERN. Following the CLIC conceptual design published in 2012, this report provides an overview of the CLIC project, its current status, and future developments. It presents the CLIC physics potential and reports on design, technology, and implementation aspects of the accelerator and the detector. CLIC is foreseen to be built and operated in stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively. CLIC uses a two-beam acceleration scheme, in which 12 GHz accelerating structures are powered via a high-current drive beam. For the first stage, an alternative with X-band klystron powering is also considered. CLIC accelerator optimisation, technical developments and system tests have resulted in an increased energy efficiency (power around 170 MW) for the 380 GeV stage, together with a reduced cost estimate at the level of 6 billion CHF. The detector concept has been refined using improved software tools. Significant progress has been made on detector technology developments for the tracking and calorimetry systems. A wide range of CLIC physics studies has been conducted, both through full detector simulations and parametric studies, together providing a broad overview of the CLIC physics potential. Each of the three energy stages adds cornerstones of the full CLIC physics programme, such as Higgs width and couplings, top-quark properties, Higgs self-coupling, direct searches, and many precision electroweak measurements. The interpretation of the combined results gives crucial and accurate insight into new physics, largely complementary to LHC and HL-LHC. The construction of the first CLIC energy stage could start by 2026. First beams would be available by 2035, marking the beginning of a broad CLIC physics programme spanning 25-30 years., Comment: 112 pages, 59 figures; published as CERN Yellow Report Monograph Vol. 2/2018; corresponding editors: Philip N. Burrows, Nuria Catalan Lasheras, Lucie Linssen, Marko Petri\v{c}, Aidan Robson, Daniel Schulte, Eva Sicking, Steinar Stapnes

Published
2018
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6. The LOFAR Two-metre Sky Survey - II. First data release

Author

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

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The LOFAR Two-metre Sky Survey (LoTSS) is an ongoing sensitive, high-resolution 120-168MHz survey of the entire northern sky for which observations are now 20% complete. We present our first full-quality public data release. For this data release 424 square degrees, or 2% of the eventual coverage, in the region of the HETDEX Spring Field (right ascension 10h45m00s to 15h30m00s and declination 45$^\circ$00$'$00$''$ to 57$^\circ$00$'$00$''$) were mapped using a fully automated direction-dependent calibration and imaging pipeline that we developed. A total of 325,694 sources are detected with a signal of at least five times the noise, and the source density is a factor of $\sim 10$ higher than the most sensitive existing very wide-area radio-continuum surveys. The median sensitivity is S$_{\rm 144 MHz} = 71\,\mu$Jy beam$^{-1}$ and the point-source completeness is 90% at an integrated flux density of 0.45mJy. The resolution of the images is 6$''$ and the positional accuracy is within 0.2$''$. This data release consists of a catalogue containing location, flux, and shape estimates together with 58 mosaic images that cover the catalogued area. In this paper we provide an overview of the data release with a focus on the processing of the LOFAR data and the characteristics of the resulting images. In two accompanying papers we provide the radio source associations and deblending and, where possible, the optical identifications of the radio sources together with the photometric redshifts and properties of the host galaxies. These data release papers are published together with a further $\sim$20 articles that highlight the scientific potential of LoTSS., Comment: 16 figures, 1 table and 22 pages. This paper is part of the LOFAR surveys data release 1 and has been accepted for publication in a special edition of A&A that will appear in Feb 2019, volume 622. The catalogues and images from the data release will be publicly available on lofar-surveys.org upon publication of the journal

Published
2018
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7. The LOFAR Two-metre Sky Survey IV. First Data Release: Photometric redshifts and rest-frame magnitudes

Author

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., and van Weeren, R. J.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

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 Spring Field (10h45m00s $<$ right ascension $<$ 15h30m00s and 45$^\circ$00$'$00$'$ $<$ declination $<$ 57$^\circ$00$'$00$''$) with a median sensitivity of 71$\mu$Jy/beam and a resolution of 6$''$. In this paper we present photometric redshifts (photo-$z$) for 94.4% of optical sources over this region that are detected in the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) 3$\pi$ steradian survey. Combining the Pan-STARRS optical data with mid-infrared photometry from the Wide-field Infrared Survey Explorer, we estimate photo-$z$s using a novel hybrid photometric redshift methodology optimised to produce the best possible performance for the diverse sample of radio continuum selected sources. For the radio-continuum detected population, we find an overall scatter in the photo-$z$ of 3.9% and an outlier fraction ($\left | z_{\rm{phot}} - z_{\rm{spec}} \right | / (1+z_{\rm{spec}}) > 0.15$) of 7.9%. We also find that, at a given redshift, there is no strong trend in photo-$z$ quality as a function of radio luminosity. However there are strong trends as a function of redshift for a given radio luminosity, a result of selection effects in the spectroscopic sample and/or intrinsic evolution within the radio source population. Additionally, for the sample of sources in the LoTSS First Data Release with optical counterparts, we present rest-frame optical and mid-infrared magnitudes based on template fits to the consensus photometric (or spectroscopic when available) redshift., Comment: 16 figures, 1 table and 18 pages. This paper is part of the LOFAR surveys Data Release 1 and has been accepted for publication in a special edition of A&A that will appear in Feb 2019, Volume 622. The catalogues and images from the data release will be publicly available at http://www.lofar-surveys.org upon publication of the volume

Published
2018
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8. The LOFAR Two-metre Sky Survey (LoTSS) III. First Data Release: optical/IR identifications and value-added catalogue

Author

Williams, W. L., Hardcastle, M. J., Best, P. N., Sabater, J., Croston, J. H., Duncan, K. J., Shimwell, T. W., Röttgering, H. J. A., Nisbet, D., Gürkan, G., Alegre, L., Cochrane, R. K., Goyal, A., Hale, C. L., Jackson, N., Jamrozy, M., Kondapally, R., Kunert-Bajraszewska, M., Mahatma, V. H., Mingo, B., Morabito, L. K., Prandoni, I., Roskowinski, C., Shulevski, A., Smith, D. J. B., Tasse, C., Urquhart, S., Webster, B., White, G. J., Beswick, R. J., Callingham, J. R., Chyży, K. T., de Gasperin, F., Harwood, J. J., Hoeft, M., Iacobelli, M., McKean, J. P., Mechev, A. P., Miley, G. K., Schwarz, D. J., and van Weeren, R. J.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

The LOFAR Two-metre Sky Survey (LoTSS) is an ongoing sensitive, high-resolution 120-168 MHz survey of the Northern sky with diverse and ambitious science goals. Many of the scientific objectives of LoTSS rely upon, or are enhanced by, the association or separation of the sometimes incorrectly catalogued radio components into distinct radio sources, and the identification and characterisation of the optical counterparts to these sources. Here we present the source associations and optical and/or IR identifications for sources in the first data release, which are made using a combination of statistical techniques and visual association and identification. We document in detail the colour- and magnitude-dependent likelihood ratio method used for statistical identification as well as the Zooniverse project, called LOFAR Galaxy Zoo, used for the visual classification. We describe the process used to select which of these two different methods is most appropriate for each LoTSS source. The final LoTSS-DR1-IDs value-added catalogue presented contains 318,520 radio sources, of which 231,716 (73%) have optical and/or IR identifications in Pan-STARRS and WISE. The value-added catalogue is available online at https://lofar-surveys.org/, as part of this data release., Comment: 8 figures, 5 tables and 23 pages. This paper is part of the LOFAR surveys data release 1 and has been accepted for publication in a special edition of A&A that will appear in Feb 2019, volume 622. The catalogues and images from the data release will be publicly available at https://lofar-surveys.org/ upon publication in the journal

Published
2018
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9. LOFAR-Bo\'otes: Properties of high- and low-excitation radio galaxies at $0.5 < z < 2.0$

Author

Williams, W. L., Rivera, G. Calistro, Best, P. N., Hardcastle, M. J., Röttgering, H. J. A., Duncan, K. J., de Gasperin, F., Jarvis, M. J., Miley, G. K., Mahony, E. K., Morabito, L. K., Nisbet, D. M., Prandoni, I., Smith, D. J. B., Tasse, C., and White, G. J.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

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 Bo\"otes field. To achieve this we match low-frequency radio sources from deep $150$-MHz LOFAR observations to an $I$-band-selected catalogue of galaxies, for which we have derived photometric redshifts, stellar masses and rest-frame colours. We present spectral energy distribution (SED) fitting to determine the mid-infrared AGN contribution for the radio sources and use this information to classify them as High- versus Low-Excitation Radio Galaxies (HERGs and LERGs) or Star-Forming galaxies. Based on these classifications we construct luminosity functions for the separate redshift ranges going out to $z = 2$. From the matched radio-optical catalogues, we select a sub-sample of $624$ high power ($P_{150\mathrm{\,MHz}}>10^{25}$ W Hz$^{-1}$) radio sources between $0.5 \leq z < 2$. For this sample, we study the fraction of galaxies hosting HERGs and LERGs as a function of stellar mass and host galaxy colour. The fraction of HERGs increases with redshift, as does the fraction of sources in galaxies with lower stellar masses. We find that the fraction of galaxies that host LERGs is a strong function of stellar mass as it is in the local Universe. This, combined with the strong negative evolution of the LERG luminosity functions over this redshift range, is consistent with LERGs being fuelled by hot gas in quiescent galaxies., Comment: 25 pages, 21 figures, accepted for publication in MNRAS

Published
2017
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10. The WEAVE-LOFAR Survey

Author

Smith, D. J. B., Best, P. N., Duncan, K. J., Hatch, N. A., Jarvis, M. J., Röttgering, H. J. A., Simpson, C. J., Stott, J. P., Cochrane, R. K., Coppin, K. E., Dannerbauer, H., Davis, T. A., Geach, J. E., Hale, C. L., Hardcastle, M. J., Hatfield, P. W., Houghton, R. C. W., Maddox, N., McGee, S. L., Morabito, L., Nisbet, D., Pandey-Pommier, M., Prandoni, I., Saxena, A., Shimwell, T. W., Tarr, M., van Bemmel, I., Verma, A., White, G. J., and Williams, W. L.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

In these proceedings we highlight the primary scientific goals and design of the WEAVE-LOFAR survey, which will use the new WEAVE spectrograph on the 4.2m William Herschel Telescope to provide the primary source of spectroscopic information for the LOFAR Surveys Key Science Project. Beginning in 2018, WEAVE-LOFAR will generate more than 10$^6$ R=5000 365-960 nm spectra of low-frequency selected radio sources, across three tiers designed to efficiently sample the redshift-luminosity plane, and produce a data set of enormous legacy value. The radio frequency selection, combined with the high multiplex and throughput of the WEAVE spectrograph, make obtaining redshifts in this way very efficient, and we expect that the redshift success rate will approach 100 per cent at $z < 1$. This unprecedented spectroscopic sample - which will be complemented by an integral field component - will be transformational in key areas, including studying the star formation history of the Universe, the role of accretion and AGN-driven feedback, properties of the epoch of reionisation, cosmology, cluster haloes and relics, as well as the nature of radio galaxies and protoclusters. Each topic will be addressed in unprecedented detail, and with the most reliable source classifications and redshift information in existence., Comment: 10 pages, 4 figures, proceedings of the SF2A conference, Lyon, 2016

Published
2016

11. Bacteriophage Utilization in Animal Hygiene

Author

Klopatek, Sarah, Callaway, Todd R., Wickersham, Tryon, Sheridan, T. G., Nisbet, D. J., Harper, David R., editor, Abedon, Stephen T., editor, Burrowes, Benjamin H., editor, and McConville, Malcolm L., editor

Published
2021
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12. Updated baseline for a staged Compact Linear Collider

Author

CLIC, The, collaborations, CLICdp, Boland, M. J., Felzmann, U., Giansiracusa, P. J., Lucas, T. G., Rassool, R. P., Balazs, C., Charles, T. K., Afanaciev, K., Emeliantchik, I., Ignatenko, A., Makarenko, V., Shumeiko, N., Patapenka, A., Zhuk, I., Hoffman, A. C. Abusleme, Gutierrez, M. A. Diaz, Gonzalez, M. Vogel, Chi, Y., He, X., Pei, G., Pei, S., Shu, G., Wang, X., Zhang, J., Zhao, F., Zhou, Z., Chen, H., Gao, Y., Huang, W., Kuang, Y. P., Li, B., Li, Y., Shao, J., Shi, J., Tang, C., Wu, X., Ma, L., Han, Y., Fang, W., Gu, Q., Huang, D., Huang, X., Tan, J., Wang, Z., Zhao, Z., Laštovička, T., Uggerhoj, U., Wistisen, T. N., Aabloo, A., Eimre, K., Kuppart, K., Vigonski, S., Zadin, V., Aicheler, M., Baibuz, E., Brücken, E., Djurabekova, F., Eerola, P., Garcia, F., Haeggström, E., Huitu, K., Jansson, V., Karimaki, V., Kassamakov, I., Kyritsakis, A., Lehti, S., Meriläinen, A., Montonen, R., Niinikoski, T., Nordlund, K., Österberg, K., Parekh, M., Törnqvist, N. A., Väinölä, J., Veske, M., Farabolini, W., Mollard, A., Napoly, O., Peauger, F., Plouin, J., Bambade, P., Chaikovska, I., Chehab, R., Davier, M., Kaabi, W., Kou, E., LeDiberder, F., Pöschl, R., Zerwas, D., Aimard, B., Balik, G., Baud, J. -P., Blaising, J. -J., Brunetti, L., Chefdeville, M., Drancourt, C., Geoffroy, N., Jacquemier, J., Jeremie, A., Karyotakis, Y., Nappa, J. M., Vilalte, S., Vouters, G., Bernard, A., Peric, I., Gabriel, M., Simon, F., Szalay, M., van der Kolk, N., Alexopoulos, T., Gazis, E. N., Gazis, N., Ikarios, E., Kostopoulos, V., Kourkoulis, S., Gupta, P. D., Shrivastava, P., Arfaei, H., Dayyani, M. K., Ghasem, H., Hajari, S. S., Shaker, H., Ashkenazy, Y., Abramowicz, H., Benhammou, Y., Borysov, O., Kananov, S., Levy, A., Levy, I., Rosenblat, O., D'Auria, G., Di Mitri, S., Abe, T., Aryshev, A., Higo, T., Makida, Y., Matsumoto, S., Shidara, T., Takatomi, T., Takubo, Y., Tauchi, T., Toge, N., Ueno, K., Urakawa, J., Yamamoto, A., Yamanaka, M., Raboanary, R., Hart, R., van der Graaf, H., Eigen, G., Zalieckas, J., Adli, E., Lillestøl, R., Malina, L., Pfingstner, J., Sjobak, K. N., Ahmed, W., Asghar, M. I., Hoorani, H., Bugiel, S., Dasgupta, R., Firlej, M., Fiutowski, T. A., Idzik, M., Kopec, M., Kuczynska, M., Moron, J., Swientek, K. P., Daniluk, W., Krupa, B., Kucharczyk, M., Lesiak, T., Moszczynski, A., Pawlik, B., Sopicki, P., Wojtoń, T., Zawiejski, L., Kalinowski, J., Krawczyk, M., Żarnecki, A. F., Firu, E., Ghenescu, V., Neagu, A. T., Preda, T., Zgura, I-S., Aloev, A., Azaryan, N., Budagov, J., Chizhov, M., Filippova, M., Glagolev, V., Gongadze, A., Grigoryan, S., Gudkov, D., Karjavine, V., Lyablin, M., Olyunin, A., Samochkine, A., Sapronov, A., Shirkov, G., Soldatov, V., Solodko, A., Solodko, E., Trubnikov, G., Tyapkin, I., Uzhinsky, V., Vorozhtov, A., Levichev, E., Mezentsev, N., Piminov, P., Shatilov, D., Vobly, P., Zolotarev, K., Jelisavcic, I. Bozovic, Kacarevic, G., Lukic, S., Milutinovic-Dumbelovic, G., Pandurovic, M., Iriso, U., Perez, F., Pont, M., Trenado, J., Aguilar-Benitez, M., Calero, J., Garcia-Tabares, L., Gavela, D., Gutierrez, J. L., Lopez, D., Toral, F., Moya, D., Jimeno, A. Ruiz, Vila, I., Argyropoulos, T., Gutierrez, C. Blanch, Boronat, M., Esperante, D., Faus-Golfe, A., Fuster, J., Martinez, N. Fuster, Muñoz, N. Galindo, García, I., Navarro, J. Giner, Ros, E., Vos, M., Brenner, R., Ekelöf, T., Jacewicz, M., Ögren, J., Olvegård, M., Ruber, R., Ziemann, V., Aguglia, D., Tehrani, N. Alipour, Andersson, A., Andrianala, F., Antoniou, F., Artoos, K., Atieh, S., Sune, R. Ballabriga, Barnes, M. J., Garcia, J. Barranco, Bartosik, H., Belver-Aguilar, C., Morell, A. Benot, Bett, D. R., Bettoni, S., Blanchot, G., Garcia, O. Blanco, Bonnin, X. A., Brunner, O., Burkhardt, H., Calatroni, S., Campbell, M., Lasheras, N. Catalan, Bastos, M. Cerqueira, Cherif, A., Chevallay, E., Constance, B., Corsini, R., Cure, B., Curt, S., Dalena, B., Dannheim, D., De Michele, G., De Oliveira, L., Deelen, N., Delahaye, J. P., Dobers, T., Doebert, S., Draper, M., Ramos, F. Duarte, Dubrovskiy, A., Elsener, K., Esberg, J., Esposito, M., Fedosseev, V., Ferracin, P., Fiergolski, A., Foraz, K., Fowler, A., Friebel, F., Fuchs, J-F., Rojas, C. A. Fuentes, Gaddi, A., Fajardo, L. Garcia, Morales, H. Garcia, Garion, C., Gatignon, L., Gayde, J-C., Gerwig, H., Goldblatt, A. N., Grefe, C., Grudiev, A., Guillot-Vignot, F. G., Gutt-Mostowy, M. L., Hauschild, M., Hessler, C., Holma, J. K., Holzer, E., Hourican, M., Hynds, D., Levinsen, Y. Inntjore, Jeanneret, B., Jensen, E., Jonker, M., Kastriotou, M., Kemppinen, J. M. K., Kieffer, R. B., Klempt, W., Kononenko, O., Korsback, A., Platia, E. Koukovini, Kovermann, J. W., Kozsar, C-I., Kremastiotis, I., Kulis, S., Latina, A., Leaux, F., Lebrun, P., Lefevre, T., Linssen, L., Cudie, X. Llopart, Maier, A. A., Durand, H. Mainaud, Manosperti, E., Marelli, C., Lacoma, E. Marin, Martin, R., Mazzoni, S., Mcmonagle, G., Mete, O., Mether, L. M., Modena, M., Münker, R. M., Muranaka, T., Del Busto, E. Nebot, Nikiforou, N., Nisbet, D., Nonglaton, J-M., Nuiry, F. X., Nürnberg, A., Olvegard, M., Osborne, J., Papadopoulou, S., Papaphilippou, Y., Passarelli, A., Patecki, M., Pazdera, L., Pellegrini, D., Pepitone, K., Codina, E. Perez, Fontenla, A. Perez, Persson, T. H. B., Petrič, M., Pitters, F., Pittet, S., Plassard, F., Rajamak, R., Redford, S., Renier, Y., Rey, S. F., Riddone, G., Rinolfi, L., Castro, E. Rodriguez, Roloff, P., Rossi, C., Rude, V., Rumolo, G., Sailer, A., Santin, E., Schlatter, D., Schmickler, H., Schulte, D., Shipman, N., Sicking, E., Simoniello, R., Skowronski, P. K., Mompean, P. Sobrino, Soby, L., Sosin, M. P., Sroka, S., Stapnes, S., Sterbini, G., Ström, R., Syratchev, I., Tecker, F., Thonet, P. A., Timeo, L., Timko, H., Garcia, R. Tomas, Valerio, P., Vamvakas, A. L., Vivoli, A., Weber, M. A., Wegner, R., Wendt, M., Woolley, B., Wuensch, W., Uythoven, J., Zha, H., Zisopoulos, P., Benoit, M., Pinto, M. Vicente Barreto, Bopp, M., Braun, H. H., Divall, M. Csatari, Dehler, M., Garvey, T., Raguin, J. Y., Rivkin, L., Zennaro, R., Aksoy, A., Nergiz, Z., Pilicer, E., Tapan, I., Yavas, O., Baturin, V., Kholodov, R., Lebedynskyi, S., Miroshnichenko, V., Mordyk, S., Profatilova, I., Storizhko, V., Watson, N., Winter, A., Goldstein, J., Green, S., Marshall, J. S., Thomson, M. A., Xu, B., Gillespie, W. A., Pan, R., Tyrk, M. A, Protopopescu, D., Robson, A., Apsimon, R., Bailey, I., Burt, G., Constable, D., Dexter, A., Karimian, S., Lingwood, C., Buckland, M. D., Casse, G., Vossebeld, J., Bosco, A., Karataev, P., Kruchinin, K., Lekomtsev, K., Nevay, L., Snuverink, J., Yamakawa, E., Boisvert, V., Boogert, S., Boorman, G., Gibson, S., Lyapin, A., Shields, W., Teixeira-Dias, P., West, S., Jones, R., Joshi, N., Bodenstein, R., Burrows, P. N., Christian, G. B., Gamba, D., Perry, C., Roberts, J., Clarke, J. A., Collomb, N. A., Jamison, S. P., Shepherd, B. J. A., Walsh, D., Demarteau, M., Repond, J., Weerts, H., Xia, L., Wells, J. D., Adolphsen, C., Barklow, T., Breidenbach, M., Graf, N., Hewett, J., Markiewicz, T., McCormick, D., Moffeit, K., Nosochkov, Y., Oriunno, M., Phinney, N., Rizzo, T., Tantawi, S., Wang, F., Wang, J., White, G., and Woodley, M.

Subjects
Physics - Accelerator Physics, High Energy Physics - Experiment
Abstract

The Compact Linear Collider (CLIC) is a multi-TeV high-luminosity linear e+e- collider under development. For an optimal exploitation of its physics potential, CLIC is foreseen to be built and operated in a staged approach with three centre-of-mass energy stages ranging from a few hundred GeV up to 3 TeV. The first stage will focus on precision Standard Model physics, in particular Higgs and top-quark measurements. Subsequent stages will focus on measurements of rare Higgs processes, as well as searches for new physics processes and precision measurements of new states, e.g. states previously discovered at LHC or at CLIC itself. In the 2012 CLIC Conceptual Design Report, a fully optimised 3 TeV collider was presented, while the proposed lower energy stages were not studied to the same level of detail. This report presents an updated baseline staging scenario for CLIC. The scenario is the result of a comprehensive study addressing the performance, cost and power of the CLIC accelerator complex as a function of centre-of-mass energy and it targets optimal physics output based on the current physics landscape. The optimised staging scenario foresees three main centre-of-mass energy stages at 380 GeV, 1.5 TeV and 3 TeV for a full CLIC programme spanning 22 years. For the first stage, an alternative to the CLIC drive beam scheme is presented in which the main linac power is produced using X-band klystrons., Comment: 57 pages, 27 figures, 12 tables, published as CERN Yellow Report. Updated version: Minor layout changes for print version

Published
2016
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14. The mass fraction of AGN and the Fundamental Plane of black hole activity from a large X-ray selected sample of LINERs

Author

Nisbet, D. M. and Best, P. N.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

A sample of 576 X-ray selected LINERs was constructed by combining data from the 3XMM-DR4 and SDSS-DR7 catalogues. The sample was used to investigate the fraction of galaxies hosting a LINER, finding that the fraction is a strong function of both stellar mass and black hole mass (scaling to the power of 1.6 +/- 0.2 and 0.6 +/- 0.1 respectively) and that it rises close to unity at the highest black hole masses and lowest X-ray luminosities. After obtaining radio flux densities from the FIRST survey, the sample was also used to investigate the Fundamental Plane of black hole activity - a scale-invariant relationship between black hole mass, X-ray luminosity and radio luminosity that is believed to hold across at least nine orders of magnitude of mass. There are key advantages in using only LINERs for the derivation as these are the counterparts of the "low-hard" X-ray binaries for which the relationship is tightest. The Fundamental Plane was found to be log (L_R / erg/s) = (0.65 +/- 0.07) log (L_X / 10^42 erg/s) + (0.69 +/- 0.10) log (M_BH / 10^8 M_solar) + (38.35 +/- 0.10). The scatter around the plane was 0.73 +/- 0.03 dex, too large to suggest that the Fundamental Plane can be used as a tool to estimate black hole mass from the observables of X-ray and radio luminosity. The black hole mass scaling is sensitive to the slope of the mass - velocity dispersion relation and, in order to achieve consistency with X-ray binaries, the analysis favours a steep gradient for this relationship, as found in recent research.

Published
2015
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17. Lead time performance in the supply chain : a case study of the equipment supply environment of the offshore oil exploration and production industry on the UK continental shelf

Author

Nisbet, D. J. and Christopher, Martin

Subjects
338.0068
Abstract

This research study is an examination of the influencing factors on lead time performance in a capital equipment supply environment. The research is being undertaken as a case study of the capital equipment supply environment of the offshore oil exploration and production industry on the UK Continental Shelf. The study methodology is justified as a case supply environment, with multiple sources of data from research instruments including: exploratory and detailed interviews and structured survey methods. The literature review examines time-based approaches to supply chain improvement and the literature related to supply chain integration. Relevant literature related to supply chain systems/structures and relationships/infrastructure are examined as potential influencing factors on lead time performance. A background of the generic case environment is provided, along with relevant literature related to the supply chain in oil exploration and production. The results of a survey of the state of integration of the offshore supply chain are presented and analysed, followed by the results of a structured mail survey within the capital equipment environment. The survey information is used to inform the Case Research phase and define a division of the case environment related to different complexity levels. Individual cases are analysed based on the framework from the literature review and refined from the survey phase. The research questions are addressed at the level of each individual case and propositions derived which are then validated based on cross-case comparisons. Aspects of literature that are supported by the study are discussed along with those areas where there is a contribution to literature. Contribution to supply chain theory is justified related to the derivation of a Types Classification Model as a means of understanding the generic nature of a capital equipment supply chain. Contribution to methodology is justified, based on the use of a supply environment for study and the use of a supply chain trace-back method.

Published
2000

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

Author

Best, P N, primary, Kondapally, R, additional, Williams, W L, additional, Cochrane, R K, additional, Duncan, K J, additional, Hale, C L, additional, Haskell, P, additional, Małek, K, additional, McCheyne, I, additional, Smith, D J B, additional, Wang, L, additional, Botteon, A, additional, Bonato, M, additional, Bondi, M, additional, Rivera, G Calistro, additional, Gao, F, additional, Gürkan, G, additional, Hardcastle, M J, additional, Jarvis, M J, additional, Mingo, B, additional, Miraghaei, H, additional, Morabito, L K, additional, Nisbet, D, additional, Prandoni, I, additional, Röttgering, H J A, additional, Sabater, J, additional, Shimwell, T, additional, Tasse, C, additional, and van Weeren, R, additional

Published
2023
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21. Biofabrication of functional bone tissue: defining tissue-engineered scaffolds from nature.

Author

Rifai, A, Weerasinghe, DK, Tilaye, GA, Nisbet, D, Hodge, JM, Pasco, JA, Williams, LJ, Samarasinghe, RM, Williams, RJ, Rifai, A, Weerasinghe, DK, Tilaye, GA, Nisbet, D, Hodge, JM, Pasco, JA, Williams, LJ, Samarasinghe, RM, and Williams, RJ

Abstract

Damage to bone leads to pain and loss of movement in the musculoskeletal system. Although bone can regenerate, sometimes it is damaged beyond its innate capacity. Research interest is increasingly turning to tissue engineering (TE) processes to provide a clinical solution for bone defects. Despite the increasing biomimicry of tissue-engineered scaffolds, significant gaps remain in creating the complex bone substitutes, which include the biochemical and physical conditions required to recapitulate bone cells' natural growth, differentiation and maturation. Combining advanced biomaterials with new additive manufacturing technologies allows the development of 3D tissue, capable of forming cell aggregates and organoids based on natural and stimulated cues. Here, we provide an overview of the structure and mechanical properties of natural bone, the role of bone cells, the remodelling process, cytokines and signalling pathways, causes of bone defects and typical treatments and new TE strategies. We highlight processes of selecting biomaterials, cells and growth factors. Finally, we discuss innovative tissue-engineered models that have physiological and anatomical relevance for cancer treatments, injectable stimuli gels, and other therapeutic drug delivery systems. We also review current challenges and prospects of bone TE. Overall, this review serves as guide to understand and develop better tissue-engineered bone designs.

Published
2023

35. The LOFAR Two-meter Sky Survey: Deep Fields Data Release 1

Author

Sabater, J., Best, P. N., Tasse, C., Hardcastle, M. J., Shimwell, T. W., Nisbet, D., Jelić, Vibor, Callingham, J. R., Röttgering, 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., and Zaroubi, S.

Subjects
surveys, catalogs, radio continuum: general, radio continuum: galaxies, Physics, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract

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 μJy beam−1 over several tens of square degrees in areas that have the most extensive ancillary data. This paper presents the ELAIS-N1 deep field, the deepest of the LoTSS deep fields to date. With an effective observing time of 163.7 h, it reaches a root mean square noise level of ≲20 μJy beam−1 in the central region (and below 30 μJy beam−1 over 10 square degrees). The resolution is ~6 arcsecs and 84 862 radio sources were detected in the full area (68 square degrees) with 74 127 sources in the highest quality area at less than 3 degrees from the pointing centre. The observation reaches a sky density of more than 5000 sources per square degree in the central region (~5 square degrees). We present the calibration procedure, which addresses the special configuration of some observations and the extended bandwidth covered (115-177 MHz ; central frequency 146.2 MHz) compared to standard LoTSS. We also describe the methods used to calibrate the flux density scale using cross-matching with sources detected by other radio surveys in the literature. We find the flux density uncertainty related to the flux density scale to be ~6.5 per cent. By studying the variations of the flux density measurements between different epochs, we show that relative flux density calibration is reliable out to about a 3 degree radius, but that additional flux density uncertainty is present for all sources at about the 3 per cent level ; this is likely to be associated with residual calibration errors, and is shown to be more significant in datasets with poorer ionosphere conditions. We also provide intra-band spectral indices, which can be useful to detect sources with unusual spectral properties. The final uncertainty in the flux densities is estimated to be ~10 per cent for ELAIS-N1.

Published
2021

36. III. Host-galaxy identifications and value added catalogues

Author

Kondapally, R., Best, P. N., Hardcastle, M. J., Nisbet, D., Bonato, M., Sabater, J., Duncan, K. J., McCheyne, I., Cochrane, R. K., Bowler, R. A. A., Williams, W. L., Shimwell, T. W., Tasse, C., Croston, J. H., Goyal, A., Jamrozy, M., Jarvis, M. J., Mahatma, V. H., Röttgering, H. J. A., Smith, D. J. B., Wołowska, A., Bondi, M., Brienza, M., Brown, M. J. I., Brüggen, M., Chambers, K., Garrett, M. A., Gürkan, G., Huber, M., Kunert-Bajraszewska, M., Magnier, E., Mingo, B., Mostert, R., Nikiel-Wroczyński, B., O’Sullivan, S. P., Paladino, R., Ploeckinger, T., Prandoni, I., Rosenthal, M. J., Schwarz, D. J., Shulevski, A., Wagenveld, J. D., and Wang, L.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present the source associations, cross-identifications, and multi-wavelength properties of the faint radio source population detected in the deep tier of the LOFAR Two Metre Sky Survey (LoTSS): the LoTSS Deep Fields. The first LoTSS Deep Fields data release consists of deep radio imaging at 150 MHz of the ELAIS-N1, Lockman Hole, and Boötes fields, down to RMS sensitives of around 20, 22, and 32 μJy beam−1, respectively. These fields are some of the best studied extra-galactic fields in the northern sky, with existing deep, wide-area panchromatic photometry from X-ray to infrared wavelengths, covering a total of ≈26 deg2. We first generated improved multi-wavelength catalogues in ELAIS-N1 and Lockman Hole; combined with the existing catalogue for Boötes, we present forced, matched aperture photometry for over 7.2 million sources across the three fields. We identified multi-wavelength counterparts to the radio detected sources, using a combination of the Likelihood Ratio method and visual classification, which greatly enhances the scientific potential of radio surveys and allows for the characterisation of the photometric redshifts and the physical properties of the host galaxies. The final radio-optical cross-matched catalogue consists of 81 951 radio-detected sources, with counterparts identified and multi-wavelength properties presented for 79 820 (>97%) sources. We also examine the properties of the host galaxies, and through stacking analysis find that the radio population with no identified counterpart is likely dominated by active galactic nuclei (AGN) at z ~ 3−4. This dataset contains one of the largest samples of radio-selected star-forming galaxies and AGN at these depths, making it ideal for studying the history of star-formation, and the evolution of galaxies and AGN across cosmic time.

Published
2021

37. State-Wide Utilization and Performance of Traditional and Cell-Free DNA-Based Prenatal Testing Pathways: The Victorian Perinatal Record Linkage (PeRL) Study.

Author

Lindquist A., Hui L., Poulton A., Kluckow E., Hutchinson B., Pertile M.D., Bonacquisto L., Gugasyan L., Kulkarni A., Harraway J., Howden A., McCoy R., Da Silva Costa F., Menezes M., Palma-Dias R., Nisbet D., Martin N., Bethune M., Poulakis Z., Halliday J., Lindquist A., Hui L., Poulton A., Kluckow E., Hutchinson B., Pertile M.D., Bonacquisto L., Gugasyan L., Kulkarni A., Harraway J., Howden A., McCoy R., Da Silva Costa F., Menezes M., Palma-Dias R., Nisbet D., Martin N., Bethune M., Poulakis Z., and Halliday J.

Published
2021

42. The LOFAR Two-meter Sky Survey: Deep Fields Data Release 1

Author

Sabater, J., primary, Best, P. N., additional, Tasse, C., additional, Hardcastle, M. J., additional, Shimwell, T. W., additional, Nisbet, D., additional, Jelic, V., additional, Callingham, J. R., additional, Röttgering, H. J. A., additional, Bonato, M., additional, Bondi, M., additional, Ciardi, B., additional, Cochrane, R. K., additional, Jarvis, M. J., additional, Kondapally, R., additional, Koopmans, L. V. E., additional, O’Sullivan, S. P., additional, Prandoni, I., additional, Schwarz, D. J., additional, Smith, D. J. B., additional, Wang, L., additional, Williams, W. L., additional, and Zaroubi, S., additional

Published
2021
Full Text
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43. The LOFAR Two-meter Sky Survey: Deep Fields Data Release 1

Author

Kondapally, R., primary, Best, P. N., additional, Hardcastle, M. J., additional, Nisbet, D., additional, Bonato, M., additional, Sabater, J., additional, Duncan, K. J., additional, McCheyne, I., additional, Cochrane, R. K., additional, Bowler, R. A. A., additional, Williams, W. L., additional, Shimwell, T. W., additional, Tasse, C., additional, Croston, J. H., additional, Goyal, A., additional, Jamrozy, M., additional, Jarvis, M. J., additional, Mahatma, V. H., additional, Röttgering, H. J. A., additional, Smith, D. J. B., additional, Wołowska, A., additional, Bondi, M., additional, Brienza, M., additional, Brown, M. J. I., additional, Brüggen, M., additional, Chambers, K., additional, Garrett, M. A., additional, Gürkan, G., additional, Huber, M., additional, Kunert-Bajraszewska, M., additional, Magnier, E., additional, Mingo, B., additional, Mostert, R., additional, Nikiel-Wroczyński, B., additional, O’Sullivan, S. P., additional, Paladino, R., additional, Ploeckinger, T., additional, Prandoni, I., additional, Rosenthal, M. J., additional, Schwarz, D. J., additional, Shulevski, A., additional, Wagenveld, J. D., additional, and Wang, L., additional

Published
2021
Full Text
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44. Linac4 design report

Author

Vretenar, Maurizio, Vollaire, J, Scrivens, R, Rossi, C, Roncarolo, F, Ramberger, S, Raich, U, Puccio, B, Nisbet, D, Mompo, R, Mathot, S, Martin, C, Lopez-Hernandez, L A, Lombardi, A, Lettry, J, Lallement, J B, Kozsar, I, Hansen, J, Gerigk, F, Funken, A, Fuchs, J F, Dos Santos, N, Calviani, M, Buzio, M, Brunner, O, Body, Y, Baudrenghien, P, Bauche, J, and Zickler, T

Subjects
Physics::Instrumentation and Detectors, Physics::Accelerator Physics, Nuclear Experiment, Accelerators and Storage Rings
Abstract

Linear accelerator 4 (Linac4) is designed to accelerate negative hydrogen ions for injection into the Proton Synchrotron Booster (PSB). It will become the source of proton beams for the Large Hadron Collider (LHC) after the long shutdown in 2019–2020. Linac4 will accelerate H– ions, consisting of a hydrogen atom with an additional electron, to 160 MeV energy and then inject them into the PSB, which is part of the LHC injection chain. The new accelerator comprises an ion source and four types of accelerating structures. The particles are accelerated first to 3 MeV energy by a Radio-Frequency Quadrupole (RFQ), then to 50 MeV by three Drift Tube Linacs (DTL) tanks, then to 100 MeV by seven Cell-Coupled Drift Tube Linac (CCDTL) modules, and finally to 160 MeV by twelve Pi-Mode Structures (PIMS). A chopper line placed between the RFQ and the first DTL tank modulates the linac beam at the PSB injection frequency. Linac4 includes transfer and measurement lines up to the PSB injection, where the ions are stripped of their two electrons to leave only protons. Linac4 is 76 metres long and located 12 metres below ground. The first low-energy beams were produced in 2013 and after the commissioning of all accelerating structures the milestone energy of 160 MeV was reached in 2016. Linac4 will be connected to the PSB during the long shutdown of 2019–20, after which it will replace the 50 MeV Linac2 as source of protons for the LHC. The Linac4 is a key element in the project to increase the luminosity of the LHC during the next decade.

Published
2020

47. A minimum estimate of the prevalence of 22q11 deletion syndrome and other chromosome abnormalities in a combined prenatal and postnatal cohort.

Author

Martin N., Howden A., McCoy R., Costa F.D.S., Menezes M., Palma-Dias R., Nisbet D., Bethune M., Halliday J., Poulakis Z., Hui L., Poulton A., Kluckow E., Lindquist A., Hutchinson B., Pertile M.D., Bonacquisto L., Gugasyan L., Kulkarni A., Harraway J., Martin N., Howden A., McCoy R., Costa F.D.S., Menezes M., Palma-Dias R., Nisbet D., Bethune M., Halliday J., Poulakis Z., Hui L., Poulton A., Kluckow E., Lindquist A., Hutchinson B., Pertile M.D., Bonacquisto L., Gugasyan L., Kulkarni A., and Harraway J.

Abstract

STUDY QUESTION: What is the frequency of major chromosome abnormalities in a population-based diagnostic data set of genomic tests performed on miscarriage, fetal and infant samples in a state with >73 000 annual births? SUMMARY ANSWER: The overall frequency of major chromosome abnormalities in the entire cohort was 28.2% (2493/8826), with a significant decrease in the detection of major chromosome abnormalities with later developmental stage, from 50.9% to 21.3% to 15.6% of tests in the miscarriage, prenatal and postnatal cohorts, respectively. WHAT IS KNOWN ALREADY: Over the past decade, technological advances have revolutionized genomic testing at every stage of reproduction. Chromosomal microarrays (CMAs) are now the gold standard of chromosome assessment in prenatal diagnosis and pediatrics. STUDY DESIGN, SIZE, DURATION: A population-based cohort study including all chromosome analysis was performed in the Australian state of Victoria during a 24-month period from January 2015 to December 2016. All samples obtained via invasive prenatal diagnosis and postnatal samples from pregnancy tissue and infants <=12 months of age were included. PARTICIPANTS/MATERIALS, SETTING, METHODS: A research collaboration of screening and diagnostic units in the Australian state of Victoria was formed (the Perinatal Record Linkage collaboration), capturing all instances of prenatal and postnatal chromosome testing performed in the state. Victoria has over 73 000 births per annum and a median maternal age of 31.5 years. We analyzed our population-based diagnostic data set for (i) chromosome assessment of miscarriage, prenatal diagnosis and postnatal samples; (ii) testing indications and diagnostic yields for each of these cohorts; (iii) and the combined prenatal/infant prevalence of 22q11.2 deletion syndrome (DS) as a proportion of all births >=20 weeks gestation. MAIN RESULTS AND THE ROLE OF CHANCE: During the 24-month study period, a total of 8826 chromosomal analyses were performe

Published
2020

48. Statewide performance of traditional and cell-free DNA-based prenatal testing pathways: The Victorian Perinatal Record Linkage (PeRL) study.

Author

Martin N., Poulton A., Lindquist A., Kluckow E., Hutchinson B., Pertile M., Bonacquisto L., Gugasyan L., Kulkarni A., Harraway J., Howden A., Hui L., Halliday J., Poulakis Z., Bethune M., McCoy R., Da Silva Costa F., Menezes M., Palma-Dias R., Nisbet D., Martin N., Poulton A., Lindquist A., Kluckow E., Hutchinson B., Pertile M., Bonacquisto L., Gugasyan L., Kulkarni A., Harraway J., Howden A., Hui L., Halliday J., Poulakis Z., Bethune M., McCoy R., Da Silva Costa F., Menezes M., Palma-Dias R., and Nisbet D.

Abstract

Introduction: This study aimed to ascertain the real-world utilisation and performance of various prenatal screening pathways, and to report the numbers of major chromosome abnormalities detected after a low-risk screening result. Method(s): Retrospective study of women resident in Victoria, Australia, undergoing screening or prenatal diagnosis in 2015. Patient-funded cell-free (cf) DNA referrals were merged with statewide results for combined frst-trimester screening (CFTS), second-trimester serum screening (STSS) and invasive diagnostic procedures. Postnatal cytogenetic were used to ascertain cases of false-negative screening results. Individual record linkage was performed with LinkageWizTM. Result(s): In 2015, 66146 women accessed at least one form of aneuploidy screening. Of the 61810 (94.6%) women with complete linkage data, 20.1% used cfDNA as their primary screen; 73.2% used CFTS alone; 5.3% had STSS, and 1.3% used both CFTS and cfDNA. CFTS had a combined sensitivity for trisomies 21/13/18 of 85.29% (95% CI 77.15-90.88) for a screen-positive rate (SPR) of 2.94%; cfDNA screening had 100% (95% CI 93.47-100.0) sensitivity and a 1.21% SPR for trisomies 21/13/18. The risk of any major chromosome abnormality after a low risk screening result was 1 in 1188 for CFTS and 1 in 717 for cfDNA (p = 0.08). Discussion(s): In 2015, 1 in 5 Victorian women chose self-funded cfDNA as a frst-line test. While the sensitivity of cfDNA for trisomies 21/18/13 was superior to CFTS, there was no statistically signifcant diference in the risk of any major chromosome abnormality after low-risk CFTS or cfDNA result.

Published
2020

49. State-wide performance of traditional and cell-free DNA based prenatal testing pathways: The Victorian Perinatal Record Linkage (PeRL) study.

Author

Poulakis Z., Pertile M.D., Gugasyan L., Kulkarni A., Harraway J., Howden A., McCoy R., Da Silva Costa F., Menezes M., Palma-Dias R., Nisbet D., Martin N., Bethune M., Halliday J., Hui L., Lindquist A., Poulton A., Kluckow E., Hutchinson B., Bonacquisto L., Poulakis Z., Pertile M.D., Gugasyan L., Kulkarni A., Harraway J., Howden A., McCoy R., Da Silva Costa F., Menezes M., Palma-Dias R., Nisbet D., Martin N., Bethune M., Halliday J., Hui L., Lindquist A., Poulton A., Kluckow E., Hutchinson B., and Bonacquisto L.

Abstract

Objectives: To perform individual record-linkage of women undergoing prenatal screening and/or prenatal and postnatal diagnosis to analyse the performance of different screening strategies, and report the residual risks of any major chromosome abnormality following a low risk result. Method(s): Retrospective study of women resident in Victoria, Australia, undergoing screening or prenatal diagnosis in 2015. Patientfunded cell-free (cf) DNA referrals from multiple providers were merged with statewide results for combined first trimester screening (CFTS), second trimester serum screening (STSS) and invasive diagnostic procedures. Postnatal cytogenetic results from products of conception and infants up to 12 months of age were used to ascertain cases of false negative screening results. Individual record-linkage was performed with LinkageWizTM and statistical analyses with STATA v14.0. Result(s): In 2015, 66,146 women (83.6% total births) accessed at least one form of aneuploidy screening. Of the 61,810 (94.6%) women with complete linkage data, 20.1% used cfDNA as their primary screen; 73.2% used CFTS alone; 5.3% had STSS, and 1.3% used both CFTS and cfDNA. Of women with a high risk CFTS result (>1 in 300), 11.6% (178) had additional screening with cfDNA and of these, 10 had fetal aneuploidy confirmed on prenatal diagnosis. CFTS had a combined sensitivity for trisomies 21/13/18 of 87.95% (95% CI 79.22-93.32) for a screen positive rate (SPR) of 2.94%; cfDNA screening had 100% (95% CI 93.47-100.0) sensitivity and a 1.21% SPR for trisomies 21/13/18. When high risk cfDNA results for any chromosome abnormality and failed cfDNA tests were treated as screen positives, the SPR increased to 2.42%. The risk of any major chromosome abnormality after a low risk screening result was 1 in 1188 for CFTS and 1 in 717 for cfDNA (p = 0.08). Conclusion(s): In a population with primary screening with government-subsidized CFTS or self-funded cfDNA available, approximately 1 in 5 women chos

Published
2020

50. Association between timing of diagnosis of trisomy 21, 18, and 13 and maternal socioeconomic status in Victoria, Australia: A population-based cohort study from 2015 to 2016.

Author

Nisbet D., Menezes M., Palma-Dias R., Hui L., Kluckow E., Halliday J., Poulton A., Lindquist A., Hutchinson B., Bethune M., Bonacquisto L., Da Silva Costa F., Gugasyan L., Harraway J., Howden A., Kulkarni A., Martin N., Poulakis Z., Pertile M.D., McCoy R., Nisbet D., Menezes M., Palma-Dias R., Hui L., Kluckow E., Halliday J., Poulton A., Lindquist A., Hutchinson B., Bethune M., Bonacquisto L., Da Silva Costa F., Gugasyan L., Harraway J., Howden A., Kulkarni A., Martin N., Poulakis Z., Pertile M.D., and McCoy R.

Abstract

Objectives: To explore the association between timing of diagnosis of common autosomal trisomies, maternal age and socioeconomic status (SES). Method(s): Retrospective study of all prenatal and postnatal cytogenetic diagnoses of trisomy 21 (T21), trisomy 18 (T18) and trisomy 13 (T13) in Victoria, Australia, in 2015-16, stratified by timing of diagnosis (prenatal <17 weeks gestation, prenatal > 17 weeks gestation, postnatal <12 months of age), maternal age and SES region (as assigned by postcode). Utilisation of prenatal testing following a liveborn T21 infant was ascertained via record linkage. Result(s): There were 160,230 total births and 817 diagnoses of T21 (n = 571), T18 (n = 139) and T13 (n = 107). The overall and livebirth prevalences of T21 were 3.56 and 0.47 per 1000 births, respectively. Compared with women from disadvantaged SES regions, women from advantaged SES regions were more likely to have a prenatal diagnosis of a trisomy before 17 weeks than after 17 weeks (p < 0.01) and less likely to have a liveborn T21 infant than a prenatal diagnosis (p < 0.01). There was a significant trend to higher livebirth rates of T21 with lower SES (p = 0.004). The majority (68.5%) of women who gave birth to a live infant with T21 did not utilise any prenatal screening or diagnostic testing. Conclusion(s): There is a significant relationship between lower SES, later prenatal diagnosis of trisomy, and higher livebirth rate of T21 in Victoria, Australia. The majority of livebirths with T21 were not preceded by any prenatal screening, suggesting significant disparities in utilization according to maternal SES.

Published
2020

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