scholarly journals The Needs and Requirements from the Standpoint of the Ultraviolet Solar Observations

1968 ◽  
Vol 1 ◽  
pp. 538-540
Author(s):  
E.M. Reeves
Keyword(s):  
Spatial Resolution ◽  
Time Resolution ◽  
Solar Disk ◽  
Emission Lines ◽  
High Time Resolution ◽  
The Sun ◽  
X Ray ◽  
Solar Observations ◽  
Partial Success

Extending from the present to the early part of 1969 there are three Orbiting Solar Observatories to be launched, and these will all be capable of constructing spectroheliograms of the Sun in solar emission lines of the EUV and X-ray region. The recently launched and highly successful OSO-III has obtained EUV and X-ray spectra with high-time resolution, but without spatial resolution on the solar disk. The later OSO satellites will provide spatial resolution of 1′ of arc to 30″ of arc, and will provide the basis for the extension to even higher spatial resolution in the future.The comparatively short periods covered by these satellites, coupled with a real probability of only partial success, make it particularly important to obtain the fullest possible use of the data by implementing a complementary and simultaneous series of ground-based observations.

scholarly journals Recent Development of the Nobeyama 17GHz Interferometer and Some Initial Results

1980 ◽  
Vol 86 ◽  
pp. 123-126
Author(s):  
Keizo Kai
Keyword(s):  
Spatial Resolution ◽  
Time Resolution ◽  
Solar Radio ◽  
High Time Resolution ◽  
The Sun ◽  
Radio Observatory ◽  
Time Calibration ◽  
Drift Scan ◽  
Time Variations ◽  
Initial Results

We have constructed a 17GHz interferometer of a multi-correlator type at the Nobeyama Solar Radio Observatory. Novel features of the new interferometer are summarized as (i) high time-resolution up to 0.8 s and (ii) “real-time” calibration of the whole system with an accuracy of ~ 2% for amplitudes and ~ 2° for phases. With the aid of these advantages over an interferometer of a conventional drift-scan type we are able to detect and follow rapid time variations of even a faint source (say, ~ 0.5 s.f.u.) on the Sun with a spatial resolution of ~ 40″. The interferometer has been put in operation since July 1978. We have recorded hundreds of bursts at 17GHz in a year including some tens of rapidly changing sources which would not precisely be measured so far. We present here some preliminary results of observations such as polarization structures of both rapidly changing and GRF bursts.

Towards a microchannel-based X-ray detector with two-dimensional spatial and time resolution and high dynamic range

2015 ◽  
Vol 22 (5) ◽  
pp. 1202-1206 ◽  
Author(s):  
Bernhard W. Adams ◽  
Anil U. Mane ◽  
Jeffrey W. Elam ◽  
Razib Obaid ◽  
Matthew Wetstein ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Time Resolution ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
High Time Resolution ◽  
Two Dimensional ◽  
X Ray ◽  
High Dynamic ◽  
Time Gating ◽  
Better Than

X-ray detectors that combine two-dimensional spatial resolution with a high time resolution are needed in numerous applications of synchrotron radiation. Most detectors with this combination of capabilities are based on semiconductor technology and are therefore limited in size. Furthermore, the time resolution is often realised through rapid time-gating of the acquisition, followed by a slower readout. Here, a detector technology is realised based on relatively inexpensive microchannel plates that uses GHz waveform sampling for a millimeter-scale spatial resolution and better than 100 ps time resolution. The technology is capable of continuous streaming of time- and location-tagged events at rates greater than 107events per cm2. Time-gating can be used for improved dynamic range.

scholarly journals Time-Resolved Optical Spectroscopy of AM Her X-Ray Sources

1987 ◽  
Vol 93 ◽  
pp. 613-624
Author(s):  
M. Mouchet ◽  
S.F. Van Amerongen ◽  
J.M. Bonnet-Bidaud ◽  
J.P. Osborne
Keyword(s):  
Radial Velocity ◽  
Time Resolution ◽  
Emission Lines ◽  
High Time Resolution ◽  
Rapid Variability ◽  
Time Resolved ◽  
X Ray ◽  
Narrow Component ◽  
Broad Component

AbstractWe present high-time resolution spectroscopy of two AM Her sources E1405−451 and E1013−477. For E1405−451, the Balmer emission lines profiles can be divided into a narrow component and a broad one. The amplitudes of the radial velocity curves of these components are respectively 265±30 km/s and 390±50 km/s. The orientation of the column determined from polarimetry is not compatible with the broad component being formed in the lowest parts of the column. Photometric and spectroscopic results on E1013−477 do not confirm the previous reported 103 min. period. Rapid variability (<1.5h) as well as long term modulation (>3.3h) is present in these data.

scholarly journals IPS Observations of Short-Time Scale Interplanetary Activity

1996 ◽  
Vol 154 ◽  
pp. 225-228
Author(s):  
Pradeep Gothoskar ◽  
A. Pramesh Rao
Keyword(s):  
Time Scale ◽  
Solar Maximum ◽  
Component Model ◽  
Scintillation Index ◽  
Short Time Scale ◽  
High Time Resolution ◽  
The Sun ◽  
X Ray ◽  
Average Mass ◽  
Short Time

AbstractWe have carried out a program of continuous Interplanetary Scintillation (IPS) monitoring of the interplanetary activity using Ooty Radio Telescope (ORT). From May 1990 to March 1991, during the 22nd solar maximum, a few radio sources were monitored to provide long stretches of IPS data with a high-time resolution of few minutes. These observations covered 0.3 to 0.8 AU region (12° to 70° elongations) around the sun at several heliographic latitudes. During the observation, we detected 33 short-time scale IPS events which had significant variation in the scintillation index and solar wind velocity. These were considered to be due to travelling interplanetary disturbances.A multi-component model of plasma density enhancement was developed to estimate the geometry and physical properties of these IPS events. Detailed analysis of 20 of these events suggests, 1. fast IPS events were interplanetary signatures of Coronal Mass Ejections (CMEs), 2. the average mass and energy of these events was ~ 1016 gm and 1033 erg respectively, 3. 80% of IPS events were associated with X-ray flares on the sun and 50% were associated with geomagnetic activity at earth. Detailed study of the multi-component model suggests IPS observations at smaller elongations (hence at higher radio frequencies) are more suited to detect fast-moving interplanetary disturbances such as produced by CMEs.

A high time resolution x-ray diagnostic on the Madison Symmetric Torus

2015 ◽  
Vol 86 (7) ◽  
pp. 073512 ◽  
Author(s):  
Ami M. DuBois ◽  
John David Lee ◽  
Abdulgadar F. Almagri
Keyword(s):  
Time Resolution ◽  
High Time ◽  
High Time Resolution ◽  
X Ray ◽  
Madison Symmetric Torus

VI. The Sun as a Star

1988 ◽  
Vol 20 (1) ◽  
pp. 102-106
Author(s):  
L.E. Cram
Keyword(s):  
Time Scales ◽  
Spatial Extent ◽  
The Sun ◽  
Distinguishing Characteristic ◽  
X Ray ◽  
Spatially Resolved ◽  
Solar Observations ◽  
The Earth ◽  
The Subject

Studies of the global (spatially unresolved) output from the sun are important for two main reasons: (1) the global solar output directed towards the earth plays a central role in solar-terrestrial relations, and (2) global solar observations form a link between (neccessarily) global observations of stars and the more refined spatially resolved observations which are available for the sun. This report covers both aspects (insofar as they concern the sun), using the time-scales of various phenomena as a basic distinguishing characteristic. Note that certain studies of spatially unresolved solar output have not been discussed, since they are actually directed toward the investigation of phenomena of strictly limited spatial extent [e.g. radiospectrograph observations (e.g. Wiehl et al. 1985) and studies of X-ray bursts (e.g. Thomas et al. 1985)]. Collections of relevant papers may be found in De Jager and Svestka (1985) and Labonte et al. (1984), while a review of germane stellar work is available in Baliunas and Vaughan (1985) and solar-terrestrial work in Donnelly and Heath (1985). A comprehensive summary of the subject by Hudson will appear soon in Review of Geophysics and Planetary Physics.

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