Radio polarization measurements from RRAT J1819-1458 (2009)
Karastergiou, A., Hotan, A. W, Van Straten, W., McLaughlin, M. A, Ord, S. M
We present the first polarization measurements of the radio emission from RRAT J1819$-$1458. Our observations, conducted in parallel to regular timing sessions, have yielded a small number of bright...
Phase-resolved Faraday rotation in pulsars (2009)
Noutsos, A., Karastergiou, A., Kramer, M., Johnston, S., Stappers, B. W.
We have detected significant Rotation Measure variations for 9 bright pulsars, as a function of pulse longitude. An additional sample of 10 pulsars showed a rather constant RM with phase, yet a small...
Despite some success in explaining the observed polarisation angle swing of radio pulsars within the geometric rotating vector model, many deviations from the expected S-like swing are observed. In...
Radio polarization measurements from RRAT J1819-1458 (2009)
Karastergiou, A., Hotan, A. W., Van Straten, W., McLaughlin, M. A., Ord, S. M.
We present the first polarization measurements of the radio emission from RRAT J1819-1458. Our observations, conducted in parallel to regular timing sessions, have yielded a small number of bright...
Radio polarization measurements from RRAT J1819-1458 (2009)
Karastergiou, A., Hotan, A. W., Van Straten, W., McLaughlin, M. A., Ord, S. M.
We present the first polarization measurements of the radio emission from RRAT J1819-1458. Our observations, conducted in parallel to regular timing sessions, have yielded a small number of bright...
Johnston, Simon, Kramer, M., Karastergiou, A., Hobbs, G., Ord, S., Wallman, J.
We have conducted observations of 22 pulsars at frequencies of 0.7, 1.4 and 3.1 GHz and present their polarization profiles. The observations were carried out for two main purposes. First we compare...
An empirical model for the beams of radio pulsars (2007)
Karastergiou, A., Johnston, S.
Motivated by recent results on the location of the radio emission in pulsar magnetospheres, we have developed a model which can account for the large diversity found in the average profile shapes of...
The variable radio-to-X-ray spectrum of the magnetar XTE J1810-197 (2007)
Camilo, F., Ransom, S. M., Penalver, J., Karastergiou, A., Van Kerkwijk, M. H., Durant, M., ...
We have observed the 5.54s anomalous X-ray pulsar XTE J1810-197 at radio, millimeter, and infrared (IR) wavelengths, with the aim of learning about its broad-band spectrum. At the IRAM 30m telescope,...
Bhat, N. D. R., Gupta, Y., Kramer, M., Karastergiou, A., Lyne, A. G., Johnston, S.
We revisit the phenomenon of pulse nulling using high-quality single-pulse data of PSR B1133+16 from simultaneous multifrequency observations. Observations were made at 325, 610, 1400 and 4850 MHz as...
Adapting and expanding interferometric arrays (2006)
Karastergiou, A., Neri, R., Gurwell, M. A.
We outline here a simple yet efficient method for finding optimized configurations of the elements of radio-astronomical interferometers with fixed pad locations. The method can be successfully...
An empirical model for the polarization of pulsar radio emission (2005)
Melrose, D., Miller, A., Karastergiou, A., Luo, Q.
We present an empirical model for single pulses of radio emission from pulsars based on gaussian probability distributions for relevant variables. The radiation at a specific pulse phase is...
Absolute polarisation position angle profiles of southern pulsars at 1.4 and 3.1 GHz (2005)
Karastergiou, A., Johnston, S.
We present here a direct comparison of the polarisation position angle (PA) profiles of 17 pulsars, observed at 1.4 and 3.1 GHz. Absolute PAs are obtained at each frequency, permitting a measurement...
Polarisation profiles of southern pulsars at 3.1 GHz (2005)
Karastergiou, A., Johnston, S., Manchester, R. N.
We present polarisation profiles for 48 southern pulsars observed with the new 10-cm receiver at the Parkes telescope. We have exploited the low system temperature and high bandwidth of the receiver...
|V|: New insight into the circular polarization of radio pulsars (2003)
Karastergiou, A., Johnston, S., Mitra, D., Edwards, R. T.
We present a study of single pulses from nine bright northern pulsars to investigate the behaviour of circular polarisation, V. The observations were conducted with the Effelsberg 100-m radio...
Kramer, M., Karastergiou, A., Gupta, Y., Johnston, S., Bhat, N. D. R., Lyne, A. G.
In this paper we demonstrate that a large, unexplored reservoir of information about pulsar emission exists, that is directly linked to the radiating particles and their radiation process: We present...
Karastergiou, A., Johnston, S., Kramer, M.
We investigate circular polarization in pulsar radio emission through simultaneous observations of PSR B1133+16 at two frequencies. In particular, we investigate the association of the handedness of...
Geodetic Precession in PSR B1913+16 (2003)
Kramer, M., Loehmer, O., Karastergiou, A.
We review the observational evidence for geodetic precession in PSR B1913+16 and present the latest observations and results from modelling the system geometry and beam.
Karastergiou, A., Johnston, S., Kramer, M.
We investigate circular polarization in pulsar radio emission through simultaneous observations of PSR B1133+16 at two frequencies. In particular, we investigate the association of the handedness of...
Kramer, M., Karastergiou, A., Gupta, Y., Johnston, S., Bhat, N. D. R., Lyne, A. G.
In this paper we demonstrate that a large, unexplored reservoir of information about pulsar emission exists, that is directly linked to the radiating particles and their radiation process: We present...
|V| : new insight into the circular polarization of radio pulsars (2003)
Karastergiou, A., Johnston, S., Mitra, D., Edwards, R. T.
We present a study of single pulses from nine bright northern pulsars to investigate the behaviour of circular polarization, V. The observations were conducted with the Effelsberg 100-m radio...
Karastergiou, A., Kramer, M., Johnston, S., Lyne, A. G., Bhat, N. D. R., Gupta, Y.
In this paper, we present a study of orthogonal polarization modes in the radio emission of PSR B1133+16, conducted within the frame of simultaneous, multi-frequency, single-pulse observations....
Karastergiou, A., Kramer, M., Johnston, S., Lyne, A. G., Bhat, N. D. R., Gupta, Y.
In this letter, we present a study of orthogonal polarization modes in the radio emission of PSR B1133+16, conducted within the frame of simultaneous, multi-frequency, single-pulse observations....
Karastergiou, A., Kramer, M., Johnston, S., Lyne, A. G., Bhat, N. D. R., Gupta, Y.
In this letter, we present a study of orthogonal polarization modes in the radio emission of PSR B1133+16, conducted within the frame of simultaneous, multi-frequency, single-pulse observations....
Karastergiou, A., Kramer, M., Johnston, S., Lyne, A. G., Bhat, N. D. R., Gupta, Y.
In this letter, we present a study of orthogonal polarization modes in the radio emission of PSR B1133+16, conducted within the frame of simultaneous, multi-frequency, single-pulse observations....
Karastergiou, A., Von Hoensbroech, A., Kramer, M., Lorimer, D. R., Lyne, A. G., Doroshenko, O., ...
We present the first results from a programme of multi-frequency simultaneous single pulse observations carried out as part of the European Pulsar Network. We detail the main data analysis methods...
Geodetic Precession and the Binary Pulsar B1913+16 (2000)
Karastergiou, A., Kramer, M., Wex, N., Von Hoensbroech, A.
A change of the component separation in the profiles of the binary pulsar PSR B1913+16 has been observed for the first time (Kramer 1998) as expected by geodetic precession. In this work we extend...