scholarly journals High Time Resolution Spectroscopy of Short Period Variable Objects

2004 ◽  
Vol 194 ◽  
pp. 263-263
Author(s):  
R. Michel ◽  
J. L. A. Fordham
Keyword(s):  
Time Resolution ◽  
Photon Counting ◽  
Cataclysmic Variables ◽  
High Time ◽  
High Time Resolution ◽  
Photon Counting Detector ◽  
San Pedro ◽  
Short Period ◽  
Period Variable ◽  
Detector Technology

Photon counting detector technology allows high time resolution spectroscopy on sources such as pulsars and cataclysmic variables. Here we report on first observing trials on Cvs in a high time resolution mode undertaken with the MIC photon counting detector (Fordham et al. 2000) on the 2.1m telescope at San Pedro Martir Observatory.

scholarly journals High time resolution measurements of the thermosphere from Fabry-Perot Interferometer measurements of atomic oxygen

2007 ◽  
Vol 25 (6) ◽  
pp. 1269-1278 ◽  
Author(s):  
E. A. K. Ford ◽  
A. L. Aruliah ◽  
E. M. Griffin ◽  
I. McWhirter
Keyword(s):  
Gravity Waves ◽  
Time Resolution ◽  
Lower Thermosphere ◽  
Line Emission ◽  
Auroral Oval ◽  
High Time ◽  
High Time Resolution ◽  
Short Period ◽  
Fabry Perot ◽  
Thermospheric Winds

Abstract. Recent advances in the performance of CCD detectors have enabled a high time resolution study of the high latitude upper thermosphere with Fabry-Perot Interferometers (FPIs) to be performed. 10-s integration times were used during a campaign in April 2004 on an FPI located in northern Sweden in the auroral oval. The FPI is used to study the thermosphere by measuring the oxygen red line emission at 630.0 nm, which emits at an altitude of approximately 240 km. Previous time resolutions have been 4 min at best, due to the cycle of look directions normally observed. By using 10 s rather than 40 s integration times, and by limiting the number of full cycles in a night, high resolution measurements down to 15 s were achievable. This has allowed the maximum variability of the thermospheric winds and temperatures, and 630.0 nm emission intensities, at approximately 240 km, to be determined as a few minutes. This is a significantly greater variability than the often assumed value of 1 h or more. A Lomb-Scargle analysis of this data has shown evidence of gravity wave activity with waves with short periods. Gravity waves are an important feature of mesosphere-lower thermosphere (MLT) dynamics, observed using many techniques and providing an important mechanism for energy transfer between atmospheric regions. At high latitudes gravity waves may be generated in-situ by localised auroral activity. Short period waves were detected in all four clear nights when this experiment was performed, in 630.0 nm intensities and thermospheric winds and temperatures. Waves with many periodicities were observed, from periods of several hours, down to 14 min. These waves were seen in all parameters over several nights, implying that this variability is a typical property of the thermosphere.

scholarly journals Eclipsing AM Herculis Binaries

1997 ◽  
Vol 163 ◽  
pp. 391-395
Author(s):  
Jeremy Bailey
Keyword(s):  
Magnetic Field ◽  
Strong Magnetic Field ◽  
Time Resolution ◽  
White Dwarf ◽  
Cataclysmic Variables ◽  
High Time ◽  
High Time Resolution ◽  
Companion Star ◽  
Fundamental Properties ◽  
Cyclotron Radiation

AbstractAM Herculis Binaries (or Polars) are a subclass of the Cataclysmic Variables in which the accreting white dwarf has a strong magnetic field giving rise to highly polarized cyclotron radiation from the shock heated accretion region. A number of AM Herculis binaries are now known in which the white dwarf is eclipsed by the companion star. High time resolution observations of these eclipses allow a particularly detailed study of the process of accretion onto the magnetic white dwarf. Results on a number of systems will be presented and used to derive information on the accretion structure as well as on the fundamental properties of the binaries.

High time resolution observations of Cataclysmic Variables with OPTIMA

2008 ◽  
Author(s):  
Gottfried Kanbach ◽  
Alexander Stefanescu ◽  
Sven Duscha ◽  
Helmut Steinle ◽  
Vadim Burwitz ◽  
...  
Keyword(s):  
Time Resolution ◽  
Cataclysmic Variables ◽  
High Time ◽  
High Time Resolution

scholarly journals Review of the ultrafast time resolution photopolarimeters based on SPADs

2013 ◽  
Vol 9 (S301) ◽  
pp. 487-488
Author(s):  
Aga Słowikowska ◽  
Gottfried Kanbach ◽  
Krzysztof Goździewski ◽  
Krzysztof Krzeszowski ◽  
Arne Rau
Keyword(s):  
Time Resolution ◽  
Single Photon ◽  
Cataclysmic Variables ◽  
High Time ◽  
High Time Resolution ◽  
Time Of Arrival ◽  
Crab Pulsar ◽  
Periodic Oscillations ◽  
Avalanche Diodes ◽  
Optical Photons

AbstractWe review photopolarimeters that are based on the Single Photon Avalanche Diodes (SPADs) and were designed, built, developed, and extensively used for high time resolution studies of astrophysical sources. Examples of such detectors are OPTIMA, GASP, AquEYE, and IquEYE which can measure the time of arrival of single optical photons with an accuracy of down to 50 picoseconds. We describe the most exciting results obtained with the SPADs detectors starting from the best existing optical polarimetric measurements of the Crab pulsar, the discovery of the first optical magnetar and its quasi-periodic oscillations, as well as a verification of exoplanets around eclipsing cataclysmic variables. Additionally, we discuss possible applications of such detectors for asteroseismology.

scholarly journals High Time Resolution Observations of the Crab Pulsar with the UCL MIC Detector

2000 ◽  
Vol 177 ◽  
pp. 85-86 ◽  
Author(s):  
R. Much ◽  
A. Carramiñana ◽  
J.L.A. Fordham ◽  
H. Kawakami ◽  
R. Michel
Keyword(s):  
Light Curve ◽  
Time Resolution ◽  
Main Pulse ◽  
High Time ◽  
High Time Resolution ◽  
Crab Pulsar ◽  
San Pedro

AbstractHigh time resolution (41.4μs) observations of the Crab Pulsar have been undertaken on the 2.1m telescopes at San Pedro Martir and the Observatorio Astrofisico Guillermo Haro (MX) in January/February 1999. In our prelimenary analysis of the Crab Pulsar’s light curve we obtained a slightly narrow widths on the seondary pulse than that reported by Percival et al. Our data indicate the presence of substructures in the pulsar’s main pulse, though not statistically convincing.

scholarly journals BVIT: A Visible Imaging, Photon Counting Instrument on the Southern African Large Telescope for High Time Resolution Astronomy

2012 ◽  
Vol 37 ◽  
pp. 1453-1460 ◽  
Author(s):  
Jason B. McPhate ◽  
Oswald H.W. Siegmund ◽  
Barry Y. Welsh ◽  
John V. Vallerga ◽  
David A.H. Buckley ◽  
...  
Keyword(s):  
Time Resolution ◽  
Photon Counting ◽  
High Time ◽  
High Time Resolution ◽  
Large Telescope ◽  
Visible Imaging

scholarly journals Astronomical Performances of the Mepsicron, A New Large Area Imaging Photon Counter

1984 ◽  
Vol 78 ◽  
pp. 177-180
Author(s):  
C. Firmani ◽  
L. Gutiérrez ◽  
E. Ruíz ◽  
L. Salas ◽  
G.F. Bisiacchi ◽  
...  
Keyword(s):  
High Resolution ◽  
Time Resolution ◽  
Photon Counting ◽  
High Time ◽  
High Time Resolution ◽  
Spectroscopic Techniques ◽  
Position Sensor ◽  
Large Area ◽  
Photon Counter ◽  
Fabry Perot

The new detector MEPSICRON (microchannel electron position sensor with time resolution) is an image photomultiplier sensor for high spatial and time resolution, working in a photon counting regime. It has been especially designed for deep sky photometric pictures, for high resolution spectrophotometry with single or crossed dispersion spectrographs for long slit spectroscopic techniques, for high time resolution pictures and spectrophotometry especially related with speckles techniques and very fast varying sources as pulsars, and for Fabry-Pérot interferometry.

scholarly journals Aqueye and Iqueye, Very-High-Time-Resolution Photon-Counting Photometers

2011 ◽  
Vol 7 (S285) ◽  
pp. 280-282
Author(s):  
Cesare Barbieri ◽  
Giampiero Naletto ◽  
Luca Zampieri ◽  
Enrico Verroi ◽  
Serena Gradari ◽  
...  
Keyword(s):  
Time Resolution ◽  
Arrival Time ◽  
Dynamic Range ◽  
Crab Nebula ◽  
Photon Counting ◽  
High Time ◽  
High Time Resolution ◽  
Definition Of ◽  
The Crab Nebula ◽  
Very High

AbstractWe describe very high-time-resolution photometers capable of tagging the arrival time of each photon with a resolution and accuracy of few hundred picoseconds, for hours of continuous acquisition, and with a dynamic range of more than 6 orders of magnitude. The final goal is the conceptual definition of a “quantum” photometer for the E-ELT, capable of detecting and measuring second-order correlation effects in photon streams from celestial sources. Two prototype units have been built and operated, one for the Asiago 1.8-m telescope (AquEYE) and one for the 3.5-m NTT (IquEYE).Here we will present results obtained by IquEYE on the Crab Nebula pulsar in simultaneous radio observations with Jodrell Bank in December 2009.

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