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793 results on '"Cheetham, T."'

1. The SARAO MeerKAT 1.3 GHz Galactic Plane Survey

Author

Goedhart, S., Cotton, W. D., Camilo, F., Thompson, M. A., Umana, G., Bietenholz, M., Woudt, P. A., Anderson, L. D., Bordiu, C., Buckley, D. A. H., Buemi, C. S., Bufano, F., Cavallaro, F., Chen, H., Chibueze, J. O., Egbo, D., Frank, B. S., Hoare, M. G., Ingallinera, A., Irabor, T., Kraan-Korteweg, R. C., Kurapati, S., Leto, P., Loru, S., Mutale, M., Obonyo, W. O., Plavin, A., Rajohnson, S. H. A., Rigby, A., Riggi, S., Seidu, M., Serra, P., Smart, B. M., Stappers, B. W., Steyn, N., Surnis, M., Trigilio, C., Williams, G. M., Abbott, T. D., Adam, R. M., Asad, K. M. B., Baloyi, T., Bauermeister, E. F., Bennet, T. G. H., Bester, H., Botha, A. G., Brederode, L. R. S., Buchner, S., Burger, J. P., Cheetham, T., Cloete, K., de Villiers, M. S., de Villiers, D. I. L., Toit, L. J. du, Esterhuyse, S. W. P., Fanaroff, B. L., Fourie, D. J., Gamatham, R. R. G., Gatsi, T. G., Geyer, M., Gouws, M., Gumede, S. C., Heywood, I., Hokwana, A., Hoosen, S. W., Horn, D. M., Horrell, L. M. G., Hugo, B. V., Isaacson, A. I., Józsa, G. I. G., Jonas, J. L., Jordaan, J. D. B. L., Joubert, A. F., Julie, R. P. M., Kapp, F. B., Kriek, N., Kriel, H., Krishnan, V. K., Kusel, T. W., Legodi, L. S., Lehmensiek, R., Lord, R. T., Macfarlane, P. S., Magnus, L. G., Magozore, C., Main, J. P. L., Malan, J. A., Manley, J. R., Marais, S. J., Maree, M. D. J., Martens, A., Maruping, P., McAlpine, K., Merry, B. C., Mgodeli, M., Millenaar, R. P., Mokone, O. J., Monama, T. E., New, W. S., Ngcebetsha, B., Ngoasheng, K. J., Nicolson, G. D., Ockards, M. T., Oozeer, N., Passmoor, S. S., Patel, A. A., Peens-Hough, A., Perkins, S. J., Ramaila, A. J. T., Ratcliffe, S. M., Renil, R., Richter, L. L., Salie, S., Sambu, N., Schollar, C. T. G., Schwardt, L. C., Schwartz, R. L., Serylak, M., Siebrits, R., Sirothia, S. K., Slabber, M. J., Smirnov, O. M., Tiplady, A. J., van Balla, T. J., van der Byl, A., Van Tonder, V., Venter, A. J., Venter, M., Welz, M. G., and Williams, L. P.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We present the SARAO MeerKAT Galactic Plane Survey (SMGPS), a 1.3 GHz continuum survey of almost half of the Galactic Plane (251\deg $\le l \le$ 358\deg and 2\deg $\le l \le$ 61\deg at $|b| \le 1.5\deg $). SMGPS is the largest, most sensitive and highest angular resolution 1 GHz survey of the Plane yet carried out, with an angular resolution of 8" and a broadband RMS sensitivity of $\sim$10--20 $\mu$ Jy/beam. Here we describe the first publicly available data release from SMGPS which comprises data cubes of frequency-resolved images over 908--1656 MHz, power law fits to the images, and broadband zeroth moment integrated intensity images. A thorough assessment of the data quality and guidance for future usage of the data products are given. Finally, we discuss the tremendous potential of SMGPS by showcasing highlights of the Galactic and extragalactic science that it permits. These highlights include the discovery of a new population of non-thermal radio filaments; identification of new candidate supernova remnants, pulsar wind nebulae and planetary nebulae; improved radio/mid-IR classification of rare Luminous Blue Variables and discovery of associated extended radio nebulae; new radio stars identified by Bayesian cross-matching techniques; the realisation that many of the largest radio-quiet WISE HII region candidates are not true HII regions; and a large sample of previously undiscovered background HI galaxies in the Zone of Avoidance., Comment: Accepted for publication in MNRAS. The data release is live and links can be found in the Data Availability Statement in the paper

Published
2023

2. The 1.28 GHz MeerKAT Galactic Center Mosaic

Author

Heywood, I., Rammala, I., Camilo, F., Cotton, W. D., Yusef-Zadeh, F., Abbott, T. D., Adam, R. M., Adams, G., Aldera, M. A., Asad, K. M. B., Bauermeister, E. F., Bennett, T. G. H., Bester, H. L., Bode, W. A., Botha, D. H., Botha, A. G., Brederode, L. R. S., Buchner, S., Burger, J. P., Cheetham, T., de Villiers, D. I. L., Dikgale-Mahlakoana, M. A., Toit, L. J. du, Esterhuyse, S. W. P., Fanaroff, B. L., February, S., Fourie, D. J., Frank, B. S., Gamatham, R. R. G., Geyer, M., Goedhart, S., Gouws, M., Gumede, S. C., Hlakola, M. J., Hokwana, A., Hoosen, S. W., Horrell, J. M. G., Hugo, B., Isaacson, A. I., Józsa, G. I. G., Jonas, J. L., Joubert, A. F., Julie, R. P. M., Kapp, F. B., Kenyon, J. S., Kotzé, P. P. A., Kriek, N., Kriel, H., Krishnan, V. K., Lehmensiek, R., Liebenberg, D., Lord, R. T., Lunsky, B. M., Madisa, K., Magnus, L. G., Mahgoub, O., Makhaba, A., Makhathini, S., Malan, J. A., Manley, J. R., Marais, S. J., Martens, A., Mauch, T., Merry, B. C., Millenaar, R. P., Mnyandu, N., Mokone, O. J., Monama, T. E., Mphego, M. C., New, W. S., Ngcebetsha, B., Ngoasheng, K. J., Ockards, M. T., Oozeer, N., Otto, A. J., Passmoor, S. S., Patel, A. A., Peens-Hough, A., Perkins, S. J., Ramaila, A. J. T., Ramanujam, N. M. R., Ramudzuli, Z. R., Ratcliffe, S. M., Robyntjies, A., Salie, S., Sambu, N., Schollar, C. T. G., Schwardt, L. C., Schwartz, R. L., Serylak, M., Siebrits, R., Sirothia, S. K., Slabber, M., Smirnov, O. M., Sofeya, L., Taljaard, B., Tasse, C., Tiplady, A. J., Toruvanda, O., Twum, S. N., van Balla, T. J., van der Byl, A., van der Merwe, C., Van Tonder, V., Van Wyk, R., Venter, A. J., Venter, M., Wallace, B. H., Welz, M. G., Williams, L. P., and Xaia, B.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

The inner $\sim$200 pc region of the Galaxy contains a 4 million M$_{\odot}$ supermassive black hole (SMBH), significant quantities of molecular gas, and star formation and cosmic ray energy densities that are roughly two orders of magnitude higher than the corresponding levels in the Galactic disk. At a distance of only 8.2 kpc, the region presents astronomers with a unique opportunity to study a diverse range of energetic astrophysical phenomena, from stellar objects in extreme environments, to the SMBH and star-formation driven feedback processes that are known to influence the evolution of galaxies as a whole. We present a new survey of the Galactic center conducted with the South African MeerKAT radio telescope. Radio imaging offers a view that is unaffected by the large quantities of dust that obscure the region at other wavelengths, and a scene of striking complexity is revealed. We produce total intensity and spectral index mosaics of the region from 20 pointings (144 hours on-target in total), covering 6.5 square degrees with an angular resolution of 4$"$,at a central frequency of 1.28 GHz. Many new features are revealed for the first time due to a combination of MeerKAT's high sensitivity, exceptional $u,v$-plane coverage, and geographical vantage point. We highlight some initial survey results, including new supernova remnant candidates, many new non-thermal filament complexes, and enhanced views of the Radio Arc Bubble, Sgr A and Sgr B regions. This project is a SARAO public legacy survey, and the image products are made available with this article., Comment: 29 pages, 15 figures, 3 tables, accepted for publication in the The Astrophysical Journal. Replacement arXiv version with higher quality figures

Published
2022
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3. The MeerKAT Galaxy Cluster Legacy Survey I. Survey Overview and Highlights

Author

Knowles, K., Cotton, W. D., Rudnick, L., Camilo, F., Goedhart, S., Deane, R., Ramatsoku, M., Bietenholz, M. F., Brüggen, M., Button, C., Chen, H., Chibueze, J. O., Clarke, T. E., de Gasperin, F., Ianjamasimanana, R., Józsa, G. I. G., Hilton, M., Kesebonye, K. C., Kolokythas, K., Kraan-Korteweg, R. C., Lawrie, G., Lochner, M., Loubser, S. I., Marchegiani, P., Mhlahlo, N., Moodley, K., Murphy, E., Namumba, B., Oozeer, N., Parekh, V., Pillay, D. S., Passmoor, S. S., Ramaila, A. J. T., Ranchod, S., Retana-Montenegro, E., Sebokolodi, L., Sikhosana, S. P., Smirnov, O., Thorat, K., Venturi, T., Abbott, T. D., Adam, R. M., Adams, G., Aldera, M. A., Bauermeister, E. F., Bennett, T. G. H., Bode, W. A., Botha, D. H., Botha, A. G., Brederode, L. R. S., Buchner, S., Burger, J. P., Cheetham, T., de Villiers, D. I. L., Dikgale-Mahlakoana, M. A., Toit, L. J. du, Esterhuyse, S. W. P., Fadana, G., Fanaroff, B. L., Fataar, S., Foley, A. R., Fourie, D. J., Frank, B. S., Gamatham, R. R. G., Gatsi, T. G., Geyer, M., Gouws, M., Gumede, S. C., Heywood, I., Hlakola, M. J., Hokwana, A., Hoosen, S. W., Horn, D. M., Horrell, J. M. G., Hugo, B. V., Isaacson, A. R., Jonas, J. L., Jordaan, J. D. B., Joubert, A. F., Julie, R. P. M., Kapp, F. B., Kasper, V. A., Kenyon, J. S., Kotzé, P. P. A., Kotze, A. G., Kriek, N., Kriel, H., Krishnan, V. K., Kusel, T. W., Legodi, L. S., Lehmensiek, R., Liebenberg, D., Lord, R. T., Lunsky, B. M., Madisa, K., Magnus, L. G., Main, J. P. L., Makhaba, A., Makhathini, S., Malan, J. A., Manley, J. R., Marais, S. J., Maree, M. D. J., Martens, A., Mauch, T., McAlpine, K., Merry, B. C., Millenaar, R. P., Mokone, O. J., Monama, T. E., Mphego, M. C., New, W. S., Ngcebetsha, B., Ngoasheng, K. J., Ockards, M. T., Otto, A. J., Patel, A. A., Peens-Hough, A., Perkins, S. J., Ramanujam, N. M., Ramudzuli, Z. R., Ratcliffe, S. M., Renil, R., Robyntjies, A., Rust, A. N., Salie, S., Sambu, N., Schollar, C. T. G., Schwardt, L. C., Schwartz, R. L., Serylak, M., Siebrits, R., Sirothia, S. K., Slabber, M., Sofeya, L., Taljaard, B., Tasse, C., Tiplady, A. J., Toruvanda, O., Twum, S. N., van Balla, T. J., van der Byl, A., van der Merwe, C., van Dyk, C. L., Van Tonder, V., Van Wyk, R., Venter, A. J., Venter, M., Welz, M. G., Williams, L. P., and Xaia, B.

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

MeerKAT's large number of antennas, spanning 8 km with a densely packed 1 km core, create a powerful instrument for wide-area surveys, with high sensitivity over a wide range of angular scales. The MeerKAT Galaxy Cluster Legacy Survey (MGCLS) is a programme of long-track MeerKAT L-band (900-1670 MHz) observations of 115 galaxy clusters, observed for $\sim$6-10 hours each in full polarisation. The first legacy product data release (DR1), made available with this paper, includes the MeerKAT visibilities, basic image cubes at $\sim$8" resolution, and enhanced spectral and polarisation image cubes at $\sim$8" and 15" resolutions. Typical sensitivities for the full-resolution MGCLS image products are $\sim$3-5 {\mu}Jy/beam. The basic cubes are full-field and span 4 deg^2. The enhanced products consist of the inner 1.44 deg^2 field of view, corrected for the primary beam. The survey is fully sensitive to structures up to $\sim$10' scales and the wide bandwidth allows spectral and Faraday rotation mapping. HI mapping at 209 kHz resolution can be done at $0

Published
2021
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4. The 1.28 GHz MeerKAT DEEP2 Image

Author

Mauch, T., Cotton, W. D., Condon, J. J., Matthews, A. M., Abbott, T. D., Adam, R. M., Aldera, M. A., Asad, K. M. B., Bauermeister, E. F., Bennett, T. G. H., Bester, H., Botha, D. H., Brederode, L. R. S., Brits, Z. B., Buchner, S. J., Burger, J. P., Camilo, F., Chalmers, J. M., Cheetham, T., de Villiers, D., de Villiers, M. S., Dikgale-Mahlakoana, M. A., Toit, L. J. du, Esterhuyse, S. W. P., Fadana, G., Fanaroff, B. L., Fataar, S., February, S., Frank, B. S., Gamatham, R. R. G., Geyer, M., Goedhart, S., Gounden, S., Gumede, S. C., Heywood, I., Hlakola, M. J., Horrell, J. M. G., Hugo, B., Isaacson, A. R., Józsa, G. I. G., Jonas, J. L., Julie, R. P. M., Kapp, F. B., Kasper, V. A., Kenyon, J. S., Kotzé, P. P. A., Kriek, N., Kriel, H., Kusel, T. W., Lehmensiek, R., Loots, A., Lord, R. T., Lunsky, B. M., Madisa, K., Magnus, L. G., Main, J. P. L., Malan, J. A., Manley, J. R., Marais, S. J., Martens, A., Merry, B., Millenaar, R., Mnyandu, N., Moeng, I. P. T., Mokone, O. J., Monama, T. E., Mphego, M. C., New, W. S., Ngcebetsha, B., Ngoasheng, K. J., Ockards, M. T. O., Oozeer, N., Otto, A. J., Patel, A. A., Peens-Hough, A., Perkins, S. J., Ramaila, A. J. T., Ramudzuli, Z. R., Renil, R., Richter, L. L., Robyntjies, A., Salie, S., Schollar, C. T. G., Schwardt, L. C., Serylak, M., Siebrits, R., Sirothia, S. K., Smirnov, O. M., Sofeya, L., Stone, G., Taljaard, B., Tasse, C., Theron, I. P., Tiplady, A. J., Toruvanda, O., Twum, S. N., van Balla, T. J., van der Byl, A., van der Merwe, C., Van Tonder, V., Wallace, B. H., Welz, M. G., Williams, L. P., and Xaia, B.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We present the confusion-limited 1.28 GHz MeerKAT DEEP2 image covering one $\approx 68'$ FWHM primary beam area with $7.6''$ FWHM resolution and $0.55 \pm 0.01$ $\mu$Jy/beam rms noise. Its J2000 center position $\alpha=04^h 13^m 26.4^s$, $\delta=-80^\circ 00' 00''$ was selected to minimize artifacts caused by bright sources. We introduce the new 64-element MeerKAT array and describe commissioning observations to measure the primary beam attenuation pattern, estimate telescope pointing errors, and pinpoint $(u,v)$ coordinate errors caused by offsets in frequency or time. We constructed a 1.4 GHz differential source count by combining a power-law count fit to the DEEP2 confusion $P(D)$ distribution from $0.25$ to $10$ $\mu$Jy with counts of individual DEEP2 sources between $10$ $\mu$Jy and $2.5$ mJy. Most sources fainter than $S \sim 100$ $\mu$Jy are distant star-forming galaxies obeying the FIR/radio correlation, and sources stronger than $0.25$ $\mu$Jy account for $\sim93\%$ of the radio background produced by star-forming galaxies. For the first time, the DEEP2 source count has reached the depth needed to reveal the majority of the star formation history of the universe. A pure luminosity evolution of the 1.4 GHz local luminosity function consistent with the Madau & Dickinson (2014) model for the evolution of star-forming galaxies based on UV and infrared data underpredicts our 1.4 GHz source count in the range $-5 \lesssim \log[S(\mathrm{Jy})] \lesssim -4$., Comment: 20 pages, 18 figures. Accepted for publication in ApJ

Published
2019
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7. Inflation of 430-parsec bipolar radio bubbles in the Galactic Centre by an energetic event

Author

Heywood, I., Camilo, F., Cotton, W. D., Yusef-Zadeh, F., Abbott, T. D., Adam, R. M., Aldera, M. A., Bauermeister, E. F., Booth, R. S., Botha, A. G., Botha, D. H., Brederode, L. R. S., Brits, Z. B., Buchner, S. J., Burger, J. P., Chalmers, J. M., Cheetham, T., de Villiers, D., Dikgale-Mahlakoana, M. A., Toit, L. J. du, Esterhuyse, S. W. P., Fanaroff, B. L., Foley, A. R., Fourie, D. J., Gamatham, R. R. G., Goedhart, S., Gounden, S., Hlakola, M. J., Hoek, C. J., Hokwana, A., Horn, D. M., Horrell, J. M. G., Hugo, B., Isaacson, A. R., Jonas, J. L., Jordaan, J. D. B. L., Joubert, A. F., Józsa, G. I. G., Julie, R. P. M., Kapp, F. B., Kenyon, J. S., Kotzé, P. P. A., Kriel, H., Kusel, T. W., Lehmensiek, R., Liebenberg, D., Loots, A., Lord, R. T., Lunsky, B. M., Macfarlane, P. S., Magnus, L. G., Magozore, C. M., Mahgoub, O., Main, J. P. L., Malan, J. A., Malgas, R. D., Manley, J. R., Maree, M. D. J., Merry, B., Millenaar, R., Mnyandu, N., Moeng, I. P. T., Monama, T. E., Mphego, M. C., New, W. S., Ngcebetsha, B., Oozeer, N., Otto, A. J., Passmoor, S. S., Pate, A. A., Peens-Hough, A., Perkins, S. J., Ratcliffe, S. M., Renil, R., Rust, A., Salie, S., Schwardt, L. C., Serylak, M., Siebrits, R., Sirothia, S. K., Smirnov, O. M., Sofeya, L., Swart, P. S., Tasse, C., Taylor, D. T., Theron, I. P., Thorat, K., Tiplad, A. J., Tshongweni, S., van Balla, T. J., van der Byl, A., van der Merwe, C., van Dyk, C. L., Van Rooyen, R., Van Tonder, V., Van Wyk, R., Wallace, B. H., Welz, M. G., and Williams, L. P.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

The Galactic Centre contains a supermassive black hole with a mass of 4 million suns within an environment that differs markedly from that of the Galactic disk. While the black hole is essentially quiescent in the broader context of active galactic nuclei, X-ray observations have provided evidence for energetic outbursts from its surroundings. Also, while the levels of star formation in the Galactic Centre have been approximately constant over the last few hundred Myr, there is evidence of elevated short-duration bursts, strongly influenced by interaction of the black hole with the enhanced gas density present within the ring-like Central Molecular Zone at Galactic longitude |l| < 0.7 degrees and latitude |b| < 0.2 degrees. The inner 200 pc region is characterized by large amounts of warm molecular gas, a high cosmic ray ionization rate, unusual gas chemistry, enhanced synchrotron emission, and a multitude of radio-emitting magnetised filaments, the origin of which has not been established. Here we report radio imaging that reveals bipolar bubbles spanning 1 degree x 3 degrees (140 parsecs x 430 parsecs), extending above and below the Galactic plane and apparently associated with the Galactic Centre. The structure is edge-brightened and bounded, with symmetry implying creation by an energetic event in the Galactic Centre. We estimate the age of the bubbles to be a few million years, with a total energy of 7 x 10^52 ergs. We postulate that the progenitor event was a major contributor to the increased cosmic-ray density in the Galactic Centre, and is in turn the principal source of the relativistic particles required to power the synchrotron emission of the radio filaments within and in the vicinity of the bubble cavities., Comment: 25 pages, 3 figures, 3 tables, authors' version of a Letter published in Nature on 11 September 2019

Published
2019
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8. Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR

Author

Camilo, F., Scholz, P., Serylak, M., Buchner, S., Merryfield, M., Kaspi, V. M., Archibald, R. F., Bailes, M., Jameson, A., van Straten, W., Sarkissian, J., Reynolds, J. E., Johnston, S., Hobbs, G., Abbott, T. D., Adam, R. M., Adams, G. B., Alberts, T., Andreas, R., Asad, K. M. B., Baker, D. E., Baloyi, T., Bauermeister, E. F., Baxana, T., Bennett, T. G. H., Bernardi, G., Booisen, D., Booth, R. S., Botha, D. H., Boyana, L., Brederode, L. R. S., Burger, J. P., Cheetham, T., Conradie, J., Conradie, J. P., Davidson, D. B., de Bruin, G., de Swardt, B., de Villiers, C., de Villiers, D. I. L., de Villiers, M. S., de Villiers, W., de Waal, C., Dikgale, M. A., Toit, G. du, Toit, L. J. du, Esterhuyse, S. W. P., Fanaroff, B., Fataar, S., Foley, A. R., Foster, G., Fourie, D., Gamatham, R., Gatsi, T., Geschke, R., Goedhart, S., Grobler, T. L., Gumede, S. C., Hlakola, M. J., Hokwana, A., Hoorn, D. H., Horn, D., Horrell, J., Hugo, B., Isaacson, A., Jacobs, O., van Rensburg, J. P. Jansen, Jonas, J. L., Jordaan, B., Joubert, A., Joubert, F., Jozsa, G. I. G., Julie, R., Julius, C. C., Kapp, F., Karastergiou, A., Karels, F., Kariseb, M., Karuppusamy, R., Kasper, V., Knox-Davies, E. C., Koch, D., Kotze, P. P. A., Krebs, A., Kriek, N., Kriel, H., Kusel, T., Lamoor, S., Lehmensiek, R., Liebenberg, D., Liebenberg, I., Lord, R. T., Lunsky, B., Mabombo, N., Macdonald, T., Macfarlane, P., Madisa, K., Mafhungo, L., Magnus, L. G., Magozore, C., Mahgoub, O., Main, J. P. L., Makhathini, S., Malan, J. A., Malgas, P., Manley, J. R., Manzini, M., Marais, L., Marais, N., Marais, S. J., Maree, M., Martens, A., Matshawule, S. D., Matthysen, N., Mauch, T., Nally, L. D. Mc, Merry, B., Millenaar, R. P., Mjikelo, C., Mkhabela, N., Mnyandu, N., Moeng, I. T., Mokone, O. J., Monama, T. E., Montshiwa, K., Moss, V., Mphego, M., New, W., Ngcebetsha, B., Ngoasheng, K., Niehaus, H., Ntuli, P., Nzama, A., Obies, F., Obrocka, M., Ockards, M. T., Olyn, C., Oozeer, N., Otto, A. J., Padayachee, Y., Passmoor, S., Patel, A. A., Paula, S., Peens-Hough, A., Pholoholo, B., Prozesky, P., Rakoma, S., Ramaila, A. J. T., Rammala, I., Ramudzuli, Z. R., Rasivhaga, M., Ratcliffe, S., Reader, H. C., Renil, R., Richter, L., Robyntjies, A., Rosekrans, D., Rust, A., Salie, S., Sambu, N., Schollar, C. T. G., Schwardt, L., Seranyane, S., Sethosa, G., Sharpe, C., Siebrits, R., Sirothia, S. K., Slabber, M. J., Smirnov, O., Smith, S., Sofeya, L., Songqumase, N., Spann, R., Stappers, B., Steyn, D., Steyn, T. J., Strong, R., Struthers, A., Stuart, C., Sunnylall, P., Swart, P. S., Taljaard, B., Tasse, C., Taylor, G., Theron, I. P., Thondikulam, V., Thorat, K., Tiplady, A., Toruvanda, O., van Aardt, J., van Balla, T., Heever, L. van den, van der Byl, A., van der Merwe, C., van der Merwe, P., van Niekerk, P. C., van Rooyen, R., van Staden, J. P., van Tonder, V., van Wyk, R., Wait, I., Walker, A. L., Wallace, B., Welz, M., Williams, L. P., Xaia, B., Young, N., and Zitha, S.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100x larger than during its dormant state. The X-ray flux one month after reactivation was at least 800x larger than during quiescence, and has been decaying exponentially on a 111+/-19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation., Comment: Published in ApJ (2018 April 5); 13 pages, 4 figures

Published
2018
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9. Maternal and neonatal outcomes of antihypertensive treatment in pregnancy: a retrospective cohort study

Author

Dublin, Sascha, primary, Akosile, Mary, additional, Avalos, Lyndsay, additional, Cheetham, T. Craig, additional, Easterling, Thomas, additional, Chen, Lu, additional, Holt, Victoria, additional, Nance, Nerissa, additional, Bider-Canfield, Zoe, additional, Neugebauer, Romain, additional, Reynolds, Kristi, additional, Badon, Sylvia, additional, and Shortreed, Susan, additional

Published
2024
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10. Engineering and Science Highlights of the KAT-7 Radio Telescope

Author

Foley, A. R., Alberts, T., Armstrong, R P., Barta, A., Bauermeister, E. F., Bester, H., Blose, S., Booth, R. S., Botha, D. H., Buchner, S. J., Carignan, C., Cheetham, T., Cloete, K., Coreejes, G., Crida, R. C., Cross, S. D., Curtolo, F., Dikgale, A., de Villiers, M. S., Toit, L. J. du, Esterhuyse, S. W. P., Fanaroff, B., Fender, R. P., Fijalkowski, M., Fourie, D., Frank, B., George, D., Gibbs, P., Goedhart, S., Grobbelaar, J., Gumede, S. C., Herselman, P., Hess, K. M., Hoek, N., Horrell, J., Jonas, J. L., Jordaan, J. D. B., Julie, R., Kapp, F., Kotzé, P., Kusel, T., Langman, A., Lehmensiek, R., Liebenberg, D., Liebenberg, I. J. V., Loots, A., Lord, R. T., Lucero, D. M., Ludick, J., Macfarlane, P., Madlavana, M., Magnus, L., Magozore, C., Malan, J. A., Manley, J. R., Marais, L., Marais, N., Marais, S. J., Maree, M., Martens, A., Mokone, O., Moss, V., Mthembu, S., New, W., Nicholson, G. D., van Niekerk, P. C., Oozeer, N., Passmoor, S. S., Peens-Hough, A., Pińska, A. B., Prozesky, P., Rajan, S., Ratcliffe, S., Renil, R., Richter, L. L., Rosekrans, D., Rust, A., Schröder, A. C., Schwardt, L. C., Seranyane, S., Serylak, M., Shepherd, D. S., Siebrits, R., Sofeya, L., Spann, R., Springbok, R., Swart, P. S., Thondikulam, Venkatasubramani L., Theron, I. P., Tiplady, A., Toruvanda, O., Tshongweni, S., Heever, L. van den, van der Merwe, C., van Rooyen, R., Wakhaba, S., Walker, A. L., Welz, M., Williams, L., Wolleben, M., Woudt, P. A., Young, N. J., and Zwart, J. T. L.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The construction of the KAT-7 array in the Karoo region of the Northern Cape in South Africa was intended primarily as an engineering prototype for technologies and techniques applicable to the MeerKAT telescope. This paper looks at the main engineering and scien- tific highlights from this effort, and discusses their applicability to both MeerKAT and other next-generation radio telescopes. In particular we found that the composite dish surface works well, but it becomes complicated to fabricate for a dish lacking circular symmetry; the Stir- ling cycle cryogenic system with ion pump to achieve vacuum works but demands much higher maintenance than an equivalent Gifford-McMahon cycle system; the ROACH (Recon- figurable Open Architecture Computing Hardware)-based correlator with SPEAD (Stream- ing Protocol for Exchanging Astronomical Data) protocol data transfer works very well and KATCP (Karoo Array Telescope Control Protocol) control protocol has proven very flexible and convenient. KAT-7 has also been used for scientific observations where it has a niche in mapping low surface-brightness continuum sources, some extended HI halos and OH masers in star-forming regions. It can also be used to monitor continuum source variability, observe pulsars, and make VLBI observations

Published
2016
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15. Association of Direct Oral Anticoagulation Management Strategies With Clinical Outcomes for Adults With Atrial Fibrillation

Author

Derington, Catherine G., primary, Goodrich, Glenn K., additional, Xu, Stanley, additional, Clark, Nathan P., additional, Reynolds, Kristi, additional, An, Jaejin, additional, Witt, Daniel M., additional, Smith, David H., additional, O’Keeffe-Rosetti, Maureen, additional, Lang, Daniel T., additional, Ho, P. Michael, additional, Cheetham, T. Craig, additional, Comer, Angela C., additional, and King, Jordan B., additional

Published
2023
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22. Maternal and neonatal outcomes associated with treating hypertension in pregnancy at different thresholds

Author

Avalos, Lyndsay A., primary, Neugebauer, Romain S., additional, Nance, Nerissa, additional, Badon, Sylvia E., additional, Cheetham, T. Craig, additional, Easterling, Thomas R., additional, Reynolds, Kristi, additional, Idu, Abisola, additional, Bider‐Canfield, Zoe, additional, Holt, Victoria L., additional, and Dublin, Sascha, additional

Published
2023
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28. Identifying hypertensive disorders of pregnancy, a comparison of two epidemiologic definitions

Author

Cheetham, T. Craig, primary, Shortreed, Susan M., additional, Avalos, Lyndsay A., additional, Reynolds, Kristi, additional, Holt, Victoria L., additional, Easterling, Thomas R., additional, Portugal, Cecilia, additional, Zhou, Hui, additional, Neugebauer, Romain S., additional, Bider, Zoe, additional, Idu, Abisola, additional, and Dublin, Sascha, additional

Published
2022
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29. Obesity-associated GNAS mutations and the melanocortin pathway

Author

Mendes de Oliveira E, Keogh JM, Talbot F, Henning E, Ahmed R, Perdikari A, Bounds R, Wasiluk N, Ayinampudi V, Barroso I, Mokrosinski J, Jyothish D, Lim S, Gupta S, Kershaw M, Matei C, Partha P, Randell T, McAulay A, Wilson LC, Cheetham T, Crowne EC, Clayton P, and Farooqi IS

Subjects
General Economics, Econometrics and Finance
Published
2022

35. Maternal and neonatal outcomes of antihypertensive treatment in pregnancy: A retrospective cohort study

Author

Dublin, Sascha, primary, Idu, Abisola, additional, Avalos, Lyndsay A., additional, Cheetham, T. Craig, additional, Easterling, Thomas R., additional, Chen, Lu, additional, Holt, Victoria L., additional, Nance, Nerissa, additional, Bider-Canfield, Zoe, additional, Neugebauer, Romain S., additional, Reynolds, Kristi, additional, Badon, Sylvia E., additional, and Shortreed, Susan M., additional

Published
2022
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41. The 1.28 GHz MeerKAT Galactic Center Mosaic

Author

Heywood, I., primary, Rammala, I., additional, Camilo, F., additional, Cotton, W. D., additional, Yusef-Zadeh, F., additional, Abbott, T. D., additional, Adam, R. M., additional, Adams, G., additional, Aldera, M. A., additional, Asad, K. M. B., additional, Bauermeister, E. F., additional, Bennett, T. G. H., additional, Bester, H. L., additional, Bode, W. A., additional, Botha, D. H., additional, Botha, A. G., additional, Brederode, L. R. S., additional, Buchner, S., additional, Burger, J. P., additional, Cheetham, T., additional, de Villiers, D. I. L., additional, Dikgale-Mahlakoana, M. A., additional, du Toit, L. J., additional, Esterhuyse, S. W. P., additional, Fanaroff, B. L., additional, February, S., additional, Fourie, D. J., additional, Frank, B. S., additional, Gamatham, R. R. G., additional, Geyer, M., additional, Goedhart, S., additional, Gouws, M., additional, Gumede, S. C., additional, Hlakola, M. J., additional, Hokwana, A., additional, Hoosen, S. W., additional, Horrell, J. M. G., additional, Hugo, B., additional, Isaacson, A. I., additional, Józsa, G. I. G., additional, Jonas, J. L., additional, Joubert, A. F., additional, Julie, R. P. M., additional, Kapp, F. B., additional, Kenyon, J. S., additional, Kotzé, P. P. A., additional, Kriek, N., additional, Kriel, H., additional, Krishnan, V. K., additional, Lehmensiek, R., additional, Liebenberg, D., additional, Lord, R. T., additional, Lunsky, B. M., additional, Madisa, K., additional, Magnus, L. G., additional, Mahgoub, O., additional, Makhaba, A., additional, Makhathini, S., additional, Malan, J. A., additional, Manley, J. R., additional, Marais, S. J., additional, Martens, A., additional, Mauch, T., additional, Merry, B. C., additional, Millenaar, R. P., additional, Mnyandu, N., additional, Mokone, O. J., additional, Monama, T. E., additional, Mphego, M. C., additional, New, W. S., additional, Ngcebetsha, B., additional, Ngoasheng, K. J., additional, Ockards, M. T., additional, Oozeer, N., additional, Otto, A. J., additional, Passmoor, S. S., additional, Patel, A. A., additional, Peens-Hough, A., additional, Perkins, S. J., additional, Ramaila, A. J. T., additional, Ramanujam, N. M. R., additional, Ramudzuli, Z. R., additional, Ratcliffe, S. M., additional, Robyntjies, A., additional, Salie, S., additional, Sambu, N., additional, Schollar, C. T. G., additional, Schwardt, L. C., additional, Schwartz, R. L., additional, Serylak, M., additional, Siebrits, R., additional, Sirothia, S. K., additional, Slabber, M., additional, Smirnov, O. M., additional, Sofeya, L., additional, Taljaard, B., additional, Tasse, C., additional, Tiplady, A. J., additional, Toruvanda, O., additional, Twum, S. N., additional, van Balla, T. J., additional, van der Byl, A., additional, van der Merwe, C., additional, Van Tonder, V., additional, Van Wyk, R., additional, Venter, A. J., additional, Venter, M., additional, Wallace, B. H., additional, Welz, M. G., additional, Williams, L. P., additional, and Xaia, B., additional

Published
2022
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42. The MeerKAT Galaxy Cluster Legacy Survey

Author

Knowles, K., primary, Cotton, W. D., additional, Rudnick, L., additional, Camilo, F., additional, Goedhart, S., additional, Deane, R., additional, Ramatsoku, M., additional, Bietenholz, M. F., additional, Brüggen, M., additional, Button, C., additional, Chen, H., additional, Chibueze, J. O., additional, Clarke, T. E., additional, de Gasperin, F., additional, Ianjamasimanana, R., additional, Józsa, G. I. G., additional, Hilton, M., additional, Kesebonye, K. C., additional, Kolokythas, K., additional, Kraan-Korteweg, R. C., additional, Lawrie, G., additional, Lochner, M., additional, Loubser, S. I., additional, Marchegiani, P., additional, Mhlahlo, N., additional, Moodley, K., additional, Murphy, E., additional, Namumba, B., additional, Oozeer, N., additional, Parekh, V., additional, Pillay, D. S., additional, Passmoor, S. S., additional, Ramaila, A. J. T., additional, Ranchod, S., additional, Retana-Montenegro, E., additional, Sebokolodi, L., additional, Sikhosana, S. P., additional, Smirnov, O., additional, Thorat, K., additional, Venturi, T., additional, Abbott, T. D., additional, Adam, R. M., additional, Adams, G., additional, Aldera, M. A., additional, Bauermeister, E. F., additional, Bennett, T. G. H., additional, Bode, W. A., additional, Botha, D. H., additional, Botha, A. G., additional, Brederode, L. R. S., additional, Buchner, S., additional, Burger, J. P., additional, Cheetham, T., additional, de Villiers, D. I. L., additional, Dikgale-Mahlakoana, M. A., additional, du Toit, L. J., additional, Esterhuyse, S. W. P., additional, Fadana, G., additional, Fanaroff, B. L., additional, Fataar, S., additional, Foley, A. R., additional, Fourie, D. J., additional, Frank, B. S., additional, Gamatham, R. R. G., additional, Gatsi, T. G., additional, Geyer, M., additional, Gouws, M., additional, Gumede, S. C., additional, Heywood, I., additional, Hlakola, M. J., additional, Hokwana, A., additional, Hoosen, S. W., additional, Horn, D. M., additional, Horrell, J. M. G., additional, Hugo, B. V., additional, Isaacson, A. R., additional, Jonas, J. L., additional, Jordaan, J. D. B., additional, Joubert, A. F., additional, Julie, R. P. M., additional, Kapp, F. B., additional, Kasper, V. A., additional, Kenyon, J. S., additional, Kotzé, P. P. A., additional, Kotze, A. G., additional, Kriek, N., additional, Kriel, H., additional, Krishnan, V. K., additional, Kusel, T. W., additional, Legodi, L. S., additional, Lehmensiek, R., additional, Liebenberg, D., additional, Lord, R. T., additional, Lunsky, B. M., additional, Madisa, K., additional, Magnus, L. G., additional, Main, J. P. L., additional, Makhaba, A., additional, Makhathini, S., additional, Malan, J. A., additional, Manley, J. R., additional, Marais, S. J., additional, Maree, M. D. J., additional, Martens, A., additional, Mauch, T., additional, McAlpine, K., additional, Merry, B. C., additional, Millenaar, R. P., additional, Mokone, O. J., additional, Monama, T. E., additional, Mphego, M. C., additional, New, W. S., additional, Ngcebetsha, B., additional, Ngoasheng, K. J., additional, Ockards, M. T., additional, Otto, A. J., additional, Patel, A. A., additional, Peens-Hough, A., additional, Perkins, S. J., additional, Ramanujam, N. M., additional, Ramudzuli, Z. R., additional, Ratcliffe, S. M., additional, Renil, R., additional, Robyntjies, A., additional, Rust, A. N., additional, Salie, S., additional, Sambu, N., additional, Schollar, C. T. G., additional, Schwardt, L. C., additional, Schwartz, R. L., additional, Serylak, M., additional, Siebrits, R., additional, Sirothia, S. K., additional, Slabber, M., additional, Sofeya, L., additional, Taljaard, B., additional, Tasse, C., additional, Tiplady, A. J., additional, Toruvanda, O., additional, Twum, S. N., additional, van Balla, T. J., additional, van der Byl, A., additional, van der Merwe, C., additional, van Dyk, C. L., additional, Van Tonder, V., additional, Van Wyk, R., additional, Venter, A. J., additional, Venter, M., additional, Welz, M. G., additional, Williams, L. P., additional, and Xaia, B., additional

Published
2022
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44. Prevalence of prescription opioid use during pregnancy in eight US health plans during 2001–2014

Author

Pocobelli, Gaia, primary, Dublin, Sascha, additional, Bobb, Jennifer F., additional, Albertson‐Junkans, Ladia, additional, Andrade, Susan, additional, Cheetham, T. Craig, additional, Salgado, Gladys, additional, Griffin, Marie R., additional, Raebel, Marsha A., additional, Smith, David, additional, Li, De‐Kun, additional, Pawloski, Pamala A., additional, Toh, Sengwee, additional, Taylor, Lockwood, additional, Hua, Wei, additional, Horn, Pamela, additional, Trinidad, James P., additional, and Boudreau, Denise M., additional

Published
2021
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47. Prevalence and trends in the use of antipsychotic medications during pregnancy in the U.S., 2001–2007: a population-based study of 585,615 deliveries

Author

Toh, Sengwee, Li, Qian, Cheetham, T. Craig, Cooper, William O., Davis, Robert L., Dublin, Sascha, Hammad, Tarek A., Li, De-Kun, Pawloski, Pamala A., Pinheiro, Simone P., Raebel, Marsha A., Scott, Pamela E., Smith, David H., Bobo, William V., Lawrence, Jean M., Dashevsky, Inna, Haffenreffer, Katherine, Avalos, Lyndsay A., and Andrade, Susan E.

Published
2013
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48. Medication Exposure in Pregnancy Risk Evaluation Program

Author

Andrade, Susan E., Davis, Robert L., Cheetham, T. Craig, Cooper, William O., Li, De-Kun, Amini, Thushi, Beaton, Sarah J., Dublin, Sascha, Hammad, Tarek A., Pawloski, Pamala A., Raebel, Marsha A., Smith, David H., Staffa, Judy A., Toh, Sengwee, Dashevsky, Inna, Haffenreffer, Katherine, Lane, Kimberly, Platt, Richard, and Scott, Pamela E.

Published
2012
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