scholarly journals An observational study of the interaction of impulsive and periodic perturbations in the solar atmosphere

1997 ◽  
Vol 181 ◽  
pp. 307-314
Author(s):  
F.-L. Deubner ◽  
R. Kleineisel
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Observational Study ◽  
Solar Atmosphere ◽  
White Light ◽  
Mechanical Energy ◽  
List Type ◽  
Type Number ◽  
Photospheric Layer ◽  
Frequency Regime

Time series of simultaneous high resolution filtergram observations in white light and in CaK2 have been employed to study the dynamical interdependence of the ‘low’ and the ‘high’ layers of the solar atmosphere, the 3-D propagation of perturbations in the stratification, and the excitation of p-mode and other oscillations. Impulsive and oscillatory perturbations have been isolated in the wavenumber and frequency regime, and their mutual interaction was also studied.Several of our findings challenge interpretation and deserve further study. •The occurrence of a granule can be clearly recognized in the upper chromosphere.•A granule induces low brightness and low oscillation amplitudes at the CaK2 level, whereas the opposite happens at the intergranular border.•It is not always evident that the ‘source’ of the perturbation is located at the lower, i.e. the photospheric layer.•It is far from being clear which components of the various perturbations contribute to a net outward mechanical energy flux.

The LDE-Type Flare Occurrence (1969-1993)

1994 ◽  
Vol 144 ◽  
pp. 279-282
Author(s):  
A. Antalová
Keyword(s):  
Time Series ◽  
Fourier Analysis ◽  
Sunspot Cycle ◽  
List Type ◽  
Type Number ◽  
Solar Cycles ◽  
Type Iv ◽  
Long Duration ◽  
Cycle Maximum ◽  
Flare Index

AbstractThe occurrence of LDE-type flares in the last three cycles has been investigated. The Fourier analysis spectrum was calculated for the time series of the LDE-type flare occurrence during the 20-th, the 21-st and the rising part of the 22-nd cycle. LDE-type flares (Long Duration Events in SXR) are associated with the interplanetary protons (SEP and STIP as well), energized coronal archs and radio type IV emission. Generally, in all the cycles considered, LDE-type flares mainly originated during a 6-year interval of the respective cycle (2 years before and 4 years after the sunspot cycle maximum). The following significant periodicities were found:• in the 20-th cycle: 1.4, 2.1, 2.9, 4.0, 10.7 and 54.2 of month,• in the 21-st cycle: 1.2, 1.6, 2.8, 4.9, 7.8 and 44.5 of month,• in the 22-nd cycle, till March 1992: 1.4, 1.8, 2.4, 7.2, 8.7, 11.8 and 29.1 of month,• in all interval (1969-1992):a)the longer periodicities: 232.1, 121.1 (the dominant at 10.1 of year), 80.7, 61.9 and 25.6 of month,b)the shorter periodicities: 4.7, 5.0, 6.8, 7.9, 9.1, 15.8 and 20.4 of month.Fourier analysis of the LDE-type flare index (FI) yields significant peaks at 2.3 - 2.9 months and 4.2 - 4.9 months. These short periodicities correspond remarkably in the all three last solar cycles. The larger periodicities are different in respective cycles.

scholarly journals Acceleration, Containment and Emission of High Energy Flare Particles: Radio Evidence

1974 ◽  
Vol 57 ◽  
pp. 423-435 ◽  
Author(s):  
A. Boischot
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Solar Atmosphere ◽  
Impulsive Phase ◽  
High Energy ◽  
Continuous Phase ◽  
List Type ◽  
Radio Bursts ◽  
Type Ii ◽  
Type Number

The existence of non thermal radio bursts provide evidences for the acceleration of electrons in the solar atmosphere.It is shown, from the characteristics of the bursts, that the electrons are accelerated in at least four different phases: (1)An impulsive phase which gives μib and III bursts.(2)A gradual phase which gives μIV and S1IV bursts.(3)A quasi-continuous phase which gives S2IV bursts and noise storms.(4)An acceleration by shock waves gives type II bursts.(5)Eventually, another shock-wave acceleration giving the moIV burst.

scholarly journals Introduction to the session

1979 ◽  
Vol 84 ◽  
pp. 323-323
Keyword(s):  
High Resolution ◽  
Observational Data ◽  
Far Infrared ◽  
List Type ◽  
Type Number ◽  
Ionized Gas ◽  
The Past ◽  
Hydrogen Recombination ◽  
Great Development

There has been a great development in the past few years of observational data of various kinds: (a)HI observations of high resolution and sensitivity (Cohen and Davies, Burton et al., Kerr et al.)(b)Observations of molecules, in particular high-resolution observations of CO (Burton, Gordon, Bania, Liszt, Solomon et al.)(c)Infrared and far-infrared(d)Ionized gas: hydrogen recombination lines, and in particular Nell (with 4″ beam) (Mezger et al., Townes, Wollman et al.)

scholarly journals Use of Kodak Tech-Pan Film at the Ukstu

1994 ◽  
Vol 161 ◽  
pp. 129-139 ◽  
Author(s):  
Q.A. Parker ◽  
S. Phillipps ◽  
D.H. Morgan ◽  
D.F. Malin ◽  
K.S. Russell ◽  
...  
Keyword(s):  
High Resolution ◽  
Great Success ◽  
List Type ◽  
Type Number ◽  
Schmidt Telescope ◽  
Fine Grained ◽  
Focal Surface ◽  
Flexible Film ◽  
The Uk ◽  
Reciprocity Failure

Kodak Technical Pan (Tech Pan) emulsion is an extremely fine grained, high resolution, panchromatic negative film with extended red sensitivity. It has been produced under this name since about 1980 (Kodak P–255, 1981) and is available on Kodak's Estar base in a number of thicknesses and sizes. The thick ∗∗base Tech Pan is designated 4415 and has been used with great success by the amateur astronomical community for many years (e.g. Martys 1991). Its astronomical potential was recognised early by Everhart (1981). However, tests at professional telescopes (e.g. West et al. 1981) and early sensitometer tests at the UK Schmidt Telescope (UKST) in 1981 and 1987 were discontinued when the glass and film samples did not respond well to normal hypersensitisation techniques. These and other difficulties led to a lack of interest among the professional astronomical community until quite recently (Russell et al. 1992; Parker & Malin 1992). The first successful use of 14 × 14 inch hypered Tech-Pan 4415 film in the UKST was in March 1991. Films were obtained which exhibited excellent image quality and resolution. Furthermore, in good seeing these appeared to be about 1 magnitude deeper than the equivalent IIIa-F emulsion on glass but with considerably lower grain noise. This result was achieved because two main problems associated with Tech-Pan and film use in the UKST have been resolved. These were: 1) obtaining Tech-Pan film with long exposure speed sufficient for deep astronomical photography (i.e. reduction of low intenstiy reciprocity failure); 2) overcoming the practical difficulties of mounting large-format flexible film at the UKST's curved focal surface.

scholarly journals Absorption Line Systems at z > 3 in the QSO 2000-330

1987 ◽  
Vol 124 ◽  
pp. 799-802
Author(s):  
R.W. Hunstead ◽  
M. Pettini ◽  
J.C. Blades ◽  
H.S. Murdoch
Keyword(s):  
High Resolution ◽  
Absorption Line ◽  
Heavy Element ◽  
Absorption Lines ◽  
List Type ◽  
Type Number ◽  
Element Abundances ◽  
Preliminary Results ◽  
Forest Region ◽  
Velocity Dispersions

This paper presents some preliminary results from analysis of our high-resolution (30–35 km/s FWHM) spectra of the Lyman α forest region in the z = 3.78 QSO 2000-330. These spectra were obtained at the Anglo-Australian Telescope over several observing seasons and have been analysed by fitting multiple-cloud Voigt profiles to Lyman series and heavy-element absorption lines. Two specific issues are addressed here: (i)The distribution of column densities, N(H I), and velocity dispersions, b, for hydrogen clouds in the interval zabs = 3.43–3.78;(ii)Heavy-element abundances in a system at zabs = 3.1723.

scholarly journals Mounting and Storage Specimens

1996 ◽  
Vol 4 (10) ◽  
pp. 14-15
Author(s):  
Peter J. Goodhew
Keyword(s):  
High Resolution ◽  
List Type ◽  
Type Number ◽  
Very Old ◽  
X Ray ◽  
And Storage ◽  
Vast Range

Specimen support grids are now almost universally 3.05 mm in diameter, except for a few high resolution stages and some very old instruments. They are available in a vast range of materials and designs. One catalogue lists 86 types in a total of 10 materials. The reason for this proliferation is to enable one to control the following:(a)the amount of support the specimen needs (unsupported areas range from 20 pm to 1 mm in extent);(b)the material of the grid, so that it neither interferes with X-ray analysis nor reacts with the specimen;(c)the labeling of specific regions of a specimen (many grids have identification marks for relocation of interesting fields).The cheapest most widely used supports are copper grids at a spacing of 100 bars in"1. Most grids have a shiny side and a dull side. Opinions differ as to the best side on which to mount the specimen but if a consistent practice is adopted it is always known which way up in the microscope the specimen was mounted.

Liaison psychiatry: pathology medical-psychiatric concomitant to the cognitive impairment

2011 ◽  
Vol 26 (S2) ◽  
pp. 384-384
Author(s):  
A.I. Ledo ◽  
J. Coullaut-Valera ◽  
I.M. Sanchez ◽  
A. Soto ◽  
I. Lopez
Keyword(s):  
Internal Medicine ◽  
Cognitive Impairment ◽  
Informed Consent ◽  
Observational Study ◽  
Neuropsychiatric Symptoms ◽  
Specific Treatment ◽  
List Type ◽  
Type Number ◽  
Liaison Psychiatry ◽  
Dsm Iv

Objectives1Determine the prevalence of cognitive impairment in the population to study.2Determine treatment antidemential more prescribed in the population to study.3Determine the drugs more associated with the treatment antidemential.4Determine what is the pathology psychiatric more associated with cognitive impairment.5Determine the profile patient with cognitive impairment.MethodA retrospective and observational study. Sample size of 2628 patients. The criterions for inclusion were: persons admitted to the HCUV in 2006–2010, assisted by the service of liaison psychiatry hospitalized and that gave the informed consent. Was carried out valuation neuropsychological (MMS and CDR). Diagnostic as DSM-IV-TR.ResultsThe prevalence of cognitive impairment was 15.2%.The specialties that most requested the service of psychiatry at link were: internal medicine: 31.6%; Traumatology: 11.9%; 83.6% had been hospitalized for somatic reasons 9,6% for psychiatric reasons. The most common psychiatric pathology was Delirium 32.9%; Adaptive Disorder 30.7%, Cognitive Impairment 15.2%. Out of the 15.2% of patients with dementia, 85% receives specific treatment with at least a drug antidemential. The most used was Citicoline85,3%. In 71% observed concomitantly neuropsychiatric symptoms:Agitation(63,2%), anxiety(6,7%). The main associated treatments were Tiapride(70,1%) and Quetiapina and (21,9%).ConclusionsThe prevalence of cognitive impairment in patients of liaison psychiatry hospitalized in the HCUV is high, 15%. The frequency grows up with age increases as well as the related medical pathology. In the specific treatment have been used mainly:Donepezilo, Rivastigmine [3] Memantine. The evolution of the patients was favorable in 88,9%.

scholarly journals Arops : The ASIAGO Red Objective-Prism Survey

1998 ◽  
Vol 179 ◽  
pp. 142-143
Author(s):  
U. Munari ◽  
R. Passuello
Keyword(s):  
High Resolution ◽  
List Type ◽  
Type Number ◽  
Schmidt Telescope ◽  
Technical Data ◽  
Objective Prism

AROPS is an objective-prism survey conducted at high galactic latitudes with the 67/92 cm (f=205 cm) Schmidt telescope of the Asiago Astrophysical Observatory (Italy). The basic technical data are: – TP4415 high resolution plates, 20×20 cm, treated in forming gas (H2+N2) and covering 24 deg2 on sky– 4° UBK7 objective prism, for a dispersion of 1490 Åmm−1 at NaI D– blue side cut-off at 4980 Å using a 2mm GG14 filter, for a recorded λ range 5000–7000 Å– untrailed spectra to record V ∼ 16.5 mag stars with 40 min exposures

scholarly journals High Resolution Spectroscopy of the Disk Chromosphere. III: Evidence for the Propagation and Dissipation of Mechanical Energy in the Chromosphere

1974 ◽  
Vol 56 ◽  
pp. 51-53
Author(s):  
L. Cram
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Shock Waves ◽  
Acoustic Wave ◽  
Mechanical Energy ◽  
Local Heating ◽  
High Resolution Spectroscopy ◽  
Small Scale ◽  
Velocity Pulse ◽  
Flow Parameters

We describe time-series observations of small-scale Can emission features located outside the network in the quiet chromosphere. Simultaneous spectra in K and λ8542 show unambiguously that the evolutionary behaviour of the K-line profile is due to an outwardly propagating velocity pulse. Assuming that this pulse is a progressive acoustic wave, as suggested by the inferred flow parameters, we show that the wave loses mechanical energy in traversing the chromosphere. This implies that the bright Can features (K grains) are the manifestation of local heating in the chromosphere, possibly by shock waves.

scholarly journals Data for Probing the Sun

1998 ◽  
Vol 185 ◽  
pp. 1-12
Author(s):  
Yvonne Elsworth
Keyword(s):  
Solar Atmosphere ◽  
Doppler Shift ◽  
Solar Surface ◽  
Solar Interior ◽  
Doppler Velocity ◽  
List Type ◽  
The Sun ◽  
Type Number ◽  
Solar Oscillations ◽  
Restoring Force

The observations of solar oscillations provide an unrivalled, precise way of probing the solar interior. In this paper, I consider the observations and their interpretation in terms of the physics of the Sun. The oscillations that we are concerned with here are the so-called p modes, i.e. oscillations for which pressure is the restoring force. The modes for which gravity is the restoring force have yet to be unambiguously detected on the Sun. The observations are made either as Doppler velocity or as intensity and are, in general, very small effects. To get an impression of the precision required, consider that in integrated velocity the total signal is ~ 1 m s−1 with the strongest individual modes being about 15-20 cm s−1. The weakest, detected modes are of order a few mm s−1. When this signal is measured as a Doppler shift, v/c is a few parts in 1011. The observations are made by a variety of instruments on Earth or in Space which can be simply divided into those which observe the Sun as a star and those which image the solar surface into many pixels Although there are many different observers using many different techniques, in all cases one is analysing light emitted from a region relatively high in the atmosphere of the Sun. When one considers how these measurements can be interpreted in terms of the solar oscillations, two issues arise: 1.Roughly where in the solar atmosphere are the lines formed?2.How different are the heights of formation for different lines?

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