Zobrazeno 1 - 10
of 238
pro vyhledávání: '"Harker G"'
Autor:
Dale, M.L., Mancini, M., Stevens, A., Brumbach, B.H., Prewitt, A., Harker, G., Silva-Batista, C., Ragothaman, A., Folmer, R.L., Quinn, J.F., Horak, F.B.
Publikováno v:
In Contemporary Clinical Trials Communications October 2023 35
Autor:
Patil, A. H., Yatawatta, S., Koopmans, L. V. E., de Bruyn, A. G., Brentjens, M. A., Zaroubi, S., Asad, K. M. B., Hatef, M., Jelic, V., Mevius, M., Offringa, A. R., Pandey, V. N., Vedantham, H., Abdalla, F. B., Brouw, W. N., Chapman, E., Ciardi, B., Gehlot, B. K., Ghosh, A., Harker, G., Iliev, I. T., Kakiichi, K., Majumdar, S., Silva, M. B., Mellema, G., Schaye, J., Vrbanec, D., Wijnholds, S. J.
We present the first limits on the Epoch of Reionization (EoR) 21-cm HI power spectra, in the redshift range $z=7.9-10.6$, using the Low-Frequency Array (LOFAR) High-Band Antenna (HBA). In total 13\,h of data were used from observations centred on th
Externí odkaz:
http://arxiv.org/abs/1702.08679
Autor:
Mevius, M., van der Tol, S., Pandey, V. N., Vedantham, H. K., Brentjens, M. A., de Bruyn, A. G., Abdalla, F. B., Asad, K. M. B., Bregman, J. D., Brouw, W. N., Bus, S., Chapman, E., Ciardi, B., Fernandez, E. R., Ghosh, A., Harker, G., Iliev, I. T., Jelić, V., Kazemi, S., Koopmans, L. V. E., Noordam, J. E., Offringa, A. R., Patil, A. H., van Weeren, R. J., Wijnholds, S., Yatawatta, S., Zaroubi, S.
Publikováno v:
Radio Sci. 51 (2016) 927-941
LOFAR is the LOw Frequency Radio interferometer ARray located at mid-latitude ($52^{\circ} 53'N$). Here, we present results on ionospheric structures derived from 29 LOFAR nighttime observations during the winters of 2012/2013 and 2013/2014. We show
Externí odkaz:
http://arxiv.org/abs/1606.04683
Autor:
Jelić, V., de Bruyn, A. G., Pandey, V. N., Mevius, M., Haverkorn, M., Brentjens, M. A., Koopmans, L. V. E., Zaroubi, S., Abdalla, F. B., Asad, K. M. B., Bus, S., Chapman, E., Ciardi, B., Fernandez, E. R., Ghosh, A., Harker, G., Iliev, I. T., Jensen, H., Kazemi, S., Mellema, G., Offringa, A. R., Patil, A. H., Vedantham, H. K., Yatawatta, S.
Publikováno v:
A&A 583, A137 (2015)
This study aims to characterize linear polarization structures in LOFAR observations of the interstellar medium (ISM) in the 3C196 field, one of the primary fields of the LOFAR-Epoch of Reionization key science project. We have used the high band ant
Externí odkaz:
http://arxiv.org/abs/1508.06650
Autor:
Ciardi, B., Inoue, S., Abdalla, F. B., Asad, K., Bernardi, G., Bolton, J. S., Brentjens, M., de Bruyn, A. G., Chapman, E., Daiboo, S., Fernandez, E. R., Ghosh, A., Graziani, L., Harker, G. J. A., Iliev, I. T., Jelic, V., Jensen, H., Kazemi, S., Koopmans, L. V. E., Martinez, O., Maselli, A., Mellema, G., Offringa, A. R., Pandey, V. N., Schaye, J., Thomas, R., Vedantham, H., Yatawatta, S., Zaroubi, S.
We investigate the feasibility of detecting 21cm absorption features in the afterglow spectra of high redshift long Gamma Ray Bursts (GRBs). This is done employing simulations of cosmic reionization, together with the instrumental characteristics of
Externí odkaz:
http://arxiv.org/abs/1504.07448
Autor:
Asad, K. M. B., Koopmans, L. V. E., Jelić, V., Pandey, V. N., Ghosh, A., Abdalla, F. B., Bernardi, G., Brentjens, M. A., de Bruyn, A. G., Bus, S., Ciardi, B., Chapman, E., Daiboo, S., Fernandez, E. R., Harker, G., Iliev, I. T., Jensen, H., Martinez-Rubi, O., Mellema, G., Mevius, M., Offringa, A. R., Patil, A. H., Schaye, J., Thomas, R. M., van der Tol, S., Vedantham, H. K., Yatawatta, S., Zaroubi, S.
Detection of the 21-cm signal coming from the epoch of reionization (EoR) is challenging especially because, even after removing the foregrounds, the residual Stokes $I$ maps contain leakage from polarized emission that can mimic the signal. Here, we
Externí odkaz:
http://arxiv.org/abs/1503.01644
Autor:
Vedantham, H. K., Koopmans, L. V. E., de Bruyn, A. G., Wijnholds, S. J., Brentjens, M., Abdalla, F. B., Asad, K. M. B., Bernardi, G., Bus, S., Chapman, E., Ciardi, B., Daiboo, S., Fernandez, E. R., Ghosh, A., Harker, G., Jelic, V., Jensen, H., Kazemi, S., Lambropoulos, P., Martinez-Rubi, O., Mellema, G., Mevius, M., Offringa, A. R., Pandey, V. N., Patil, A. H., Thomas, R. M., Veligatla, V., Yatawatta, S., Zaroubi, S., Anderson, J., Asgekar, A., Bell, M. E., Bentum, M. J., Best, P., Bonafede, A., Breitling, F., Broderick, J., Brüggen, M., Butcher, H. R., Corstanje, A., de Gasperin, F., de Geus, E., Deller, A., Duscha, S., Eislöffel, J., Engels, D., Falcke, H., Fallows, R. A., Fender, R., Ferrari, C., Frieswijk, W., Garrett, M. A., Grießmeier, J., Gunst, A. W., Hassall, T. E., Heald, G., Hoeft, M., Hörandel, J., Iacobelli, M., Juette, E., Kondratiev, V. I., Kuniyoshi, M., Kuper, G., Mann, G., Markoff, S., McFadden, R., McKay-Bukowski, D., Mulcahy, D. D., Munk, H., Nelles, A., Norden, M. J., Orru, E., Pandey-Pommier, M., Pizzo, R., Polatidis, A. G., Reich, W., Renting, A., Röttgering, H., Schwarz, D., Shulevski, A., Smirnov, O., Stappers, B. W., Steinmetz, M., Swinbank, J., Tagger, M., Tang, Y., Tasse, C., ter Veen, S., Thoudam, S., Toribio, C., vocks, C., Wise, M. W., Wucknitz, O., Zarka, P.
We present radio observations of the Moon between $35$ and $80$ MHz to demonstrate a novel technique of interferometrically measuring large-scale diffuse emission extending far beyond the primary beam (global signal) for the first time. In particular
Externí odkaz:
http://arxiv.org/abs/1407.4244
Autor:
Jelic, V., de Bruyn, A. G., Mevius, M., Abdalla, F. B., Asad, K. M. B., Bernardi, G., Brentjens, M. A., Bus, S., Chapman, E., Ciardi, B., Daiboo, S., Fernandez, E. R., Ghosh, A., Harker, G., Jensen, H., Kazemi, S., Koopmans, L. V. E., Labropoulos, P., Martinez-Rubi, O., Mellema, G., Offringa, A. R., Pandey, V. N., Patil, A. H., Thomas, R. M., Vedantham, H. K., Veligatla, V., Yatawatta, S., Zaroubi, S., Alexov, A., Anderson, J., Avruch, I. M., Beck, R., Bell, M. E., Bentum, M. J., Best, P., Bonafede, A., Bregman, J., Breitling, F., Broderick, J., Brouw, W. N., Bruggen, M., Butcher, H. R., Conway, J. E., de Gasperin, F., de Geus, E., Deller, A., Dettmar, R. -J., Duscha, S., Eisloffel, J., Engels, D., Falcke, H., Fallows, R. A., Fender, R., Ferrari, C., Frieswijk, W., Garrett, M. A., Griessmeier, J., Gunst, A. W., Hamaker, J. P., Hassall, T. E., Haverkorn, M., Heald, G., Hessels, J. W. T., Hoeft, M., Horandel, J., Horneffer, A., van der Horst, A., Iacobelli, M., Juette, E., Karastergiou, A., Kondratiev, V. I., Kramer, M., Kuniyoshi, M., Kuper, G., van Leeuwen, J., Maat, P., Mann, G., McKay-Bukowski, D., McKean, J. P., Munk, H., Nelles, A., Norden, M. J., Paas, H., Pandey-Pommier, M., Pietka, G., Pizzo, R., Polatidis, A. G., Reich, W., Rottgering, H., Rowlinson, A., Scaife, A. M. M., Schwarz, D., Serylak, M., Smirnov, O., Steinmetz, M., Stewart, A., Tagger, M., Tang, Y., Tasse, C., ter Veen, S., Thoudam, S., Toribio, C., Vermeulen, R., Vocks, C., van Weeren, R. J., Wijers, R. A. M. J., Wijnholds, S. J., Wucknitz, O., Zarka, P.
Publikováno v:
A&A 568, A101 (2014)
This study aims to characterise the polarized foreground emission in the ELAIS-N1 field and to address its possible implications for the extraction of the cosmological 21-cm signal from the Low-Frequency Array - Epoch of Reionization (LOFAR-EoR) data
Externí odkaz:
http://arxiv.org/abs/1407.2093
Autor:
Offringa, A. R., de Bruyn, A. G., Zaroubi, S., Koopmans, L. V. E., Wijnholds, S. J., Abdalla, F. B., Brouw, W. N., Ciardi, B., Iliev, I. T., Harker, G. J. A., Mellema, G., Bernardi, G., Zarka, P., Ghosh, A., Alexov, A., Anderson, J., Asgekar, A., Avruch, I. M., Beck, R., Bell, M. E., Bell, M. R., Bentum, M. J., Best, P., Bîrzan, L., Breitling, F., Broderick, J., Brüggen, M., Butcher, H. R., de Gasperin, F., de Geus, E., de Vos, M., Duscha, S., Eislöffel, J., Fallows, R. A., Ferrari, C., Frieswijk, W., Garrett, M. A., Grießmeier, J., Hassall, T. E., Horneffer, A., Iacobelli, M., Juette, E., Karastergiou, A., Klijn, W., Kondratiev, V. I., Kuniyoshi, M., Kuper, G., van Leeuwen, J., Loose, M., Maat, P., Macario, G., Mann, G., McKean, J. P., Meulman, H., Norden, M. J., Orru, E., Paas, H., Pandey-Pommier, M., Pizzo, R., Polatidis, A. G., Rafferty, D., Reich, W., van Nieuwpoort, R., Röttgering, H., Scaife, A. M. M., Sluman, J., Smirnov, O., Sobey, C., Tagger, M., Tang, Y., Tasse, C., ter Veen, S., Toribio, C., Vermeulen, R., Vocks, C., van Weeren, R. J., Wise, M. W., Wucknitz, O.
Faint undetected sources of radio-frequency interference (RFI) might become visible in long radio observations when they are consistently present over time. Thereby, they might obstruct the detection of the weak astronomical signals of interest. This
Externí odkaz:
http://arxiv.org/abs/1307.5580
Autor:
Jensen, Hannes, Datta, Kanan K., Mellema, Garrelt, Chapman, Emma, Abdalla, Filipe B., Iliev, Ilian T., Mao, Yi, Santos, Mario G., Shapiro, Paul R., Zaroubi, Saleem, Bernardi, G., Brentjens, M. A., de Bruyn, A. G., Ciardi, B., Harker, G. J. A., Jelić, V., Kazemi, S., Koopmans, L. V. E., Labropoulos, P., Martinez, O., Offringa, A. R., Pandey, V. N., Schaye, J., Thomas, R. M., Veligatla, V., Vedantham, H., Yatawatta, S.
One of the most promising ways to study the epoch of reionization (EoR) is through radio observations of the redshifted 21-cm line emission from neutral hydrogen. These observations are complicated by the fact that the mapping of redshifts to line-of
Externí odkaz:
http://arxiv.org/abs/1303.5627