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This is the concluding article in a series of 3 studies that investigate the anatomical determinants of thalamocortical (TC) input to excitatory neurons in a cortical column of rat primary somatosensory cortex (S1). We used viral synaptophysin-enhanced green fluorescent protein expression in thalamic neurons and reconstructions of biocytin-labeled cortical(More)
During the several months of the outburst of Mkn 501 in 1997 the source has been monitored in TeV γ-rays with the HEGRA stereoscopic system of imaging atmospheric Cherenkov telescopes. Quite remarkably it turned out that the shapes of the daily γ-ray energy spectra remained essentially stable throughout the entire state of high activity despite dramatic(More)
Čerenkov images of air showers can also be classified using multifractal and wavelet parameters, as compared to the conventional Hillas image parameters. This new technique was applied to the images recorded by the cameras of the stereoscopic imaging aiř Cerenkov-telescopes operated by the HEGRA collaboration. With respect to the identification of(More)
During 1997, the BL Lac Object Mkn 501 was the brightest known object in the TeV γ-ray sky. The emission was characterized by dramatic variations in intensity with a mean flux exceeding by a factor of three the steady γ-ray flux of the Crab Nebula. The stereoscopic HEGRA system of 4 Imaging Atmospheric Cherenkov Telescopes, with an energy threshold of about(More)
Preprint The time profiles of Cherenkov images of cosmic-ray showers and of γ-ray showers are investigated, using data gathered with the HEGRA system of imaging atmospheric Cherenkov telescopes during the 1997 outbursts of Mrk 501. Photon arrival times are shown to vary across the shower images. The dominant feature is a time gradient along the major axis(More)
A detection of TeV γ-rays from Mkn 501 is reported , based on observations made between March and August 1996 with the first HEGRA Cherenkov telescope (CT1). From the image analysis, 351 excess candidate γ-ray events are obtained from the 147 h dataset. The statistical significance of the excess is 5.2 σ. The average excess rate is 2.4 ± 0.5 h −1 above the(More)
Based on the Monte Carlo simulations we have studied the performance of the HEGRA system of imaging aiř Cerenkov telescopes (IACTs) in its present configuration of 4 IACTs as well as in its future final configuration of 5 IACTs. Here we present the results on the basic characteristics of the IACT system which are used in the standard data analysis(More)
Since its commissioning in fall 1996, the stereo-scopic system of Imaging Atmospheric Cherenkov Telescopes (IACTs) of HEGRA, with an energy flux sensitivity ν F ν at 1 TeV of 10 −11 erg cm −2 s −1 for one hour of observation time, has been used to monitor the BL Lac object Mkn 421 on a regular basis. In this paper, we report detailed temporal and spectral(More)