860 research outputs found
Impact of Laser Guide Star facilities on neighbouring telescopes: the case of GTC, TMT, VLT, and ELT lasers and the Cherenkov Telescope Array
No full textReflecting on Cherenkov reflections
No full textMagic Telescope may observe and reveal at horizons lights from air-shower Cherenkov reflections. The ground, the sea, the cloudy sky (below the mountain) may reflect PeVs-EeV UHECR Cherenkov lights observable by MAGIC telescopes. Even rarest UHE neutrino skimming the atmosphere or skimming the Earth may induce upward-horizontal airshowers: a new Neutrino Astronomy. These fluorescence signals or the Cherenkov reflections in upper cloudy sky may flash in correlated BL-Lac or GRB shining at opposite edges. Geomagnetic splitting of Horizontal Air-showers may offer a new spectroscopy of UHECR from the knee up to GZK energy edges
Preliminary optical design of a polychromator for a Raman LIDAR for atmospheric calibration of the Cherenkov Telescope Array
No full textThe preliminary design of a polychromator unit for a Raman lidar (Light Detection And Ranging) for atmospheric calibration in the framework of the Cherenkov Telescope Array (CTA) project is presented. To obtain high quality data from CTA, a precise monitoring of the atmospheric transmission is needed. Remote-sensing instruments, like elastic/Raman lidars, have already been proven a powerful tool in environmental studies, and a lidar installed and operated at the CTA site is foreseen for correcting systematic biases on the energy and flux. The lidar we discuss here consists of a powerful laser that emits light pulses into the atmosphere, a mirror of 1.8 m diameter that collects the backscattered light and a polychromator unit where the light is analyzed. The laser is a pulsed Nd:YAG with the first two harmonics available at 355 and 532 nm and the polychromator has 4 read-out channels: two to analyze the elastic backscattering at 355 and 532 nm and two for the Raman Nitrogen back-scattered light, at 387 and 607 nm, respectively. The polychromator module needs to collect the majority of the light coming from the telescope, to split the different wavelengths and to focus the beams onto photomultiplier detectors. The collection and focalization of the beams are done by means of simple lens-couples and the separation with custom-made dichroic mirrors and narrow-band filters. The performance of the conceived optical design, the adopted design choices for the glass, surface figure and size of the lenses, and the expected throughput for the different channels are hereafter described. © 2012 SPIE
Strategy implementation for the CTA Atmospheric monitoring program
No full textThe Cherenkov Telescope Array (CTA) is the next generation facility of Imaging Atmospheric Cherenkov Telescopes. It reaches unprecedented sensitivity and energy resolution in very-high-energy gamma-ray astronomy. CTA detects Cherenkov light emitted within an atmospheric shower of particles initiated by cosmic-gamma rays or cosmic rays entering the Earth's atmosphere. From the combination of images the Cherenkov light produces in the telescopes, one is able to infer the primary particle energy and direction. A correct energy estimation can be thus performed only if the local atmosphere is well characterized. The atmosphere not only affects the shower development itself, but also the Cherenkov photon transmission from the emission point in the particle shower, at about 10-20 km above the ground, to the detector. Cherenkov light on the ground is peaked in the UV-blue region, and therefore molecular and aerosol extinction phenomena are important. The goal of CTA is to control systematics in energy reconstruction to better than 10%. For this reason, a careful and continuous monitoring and characterization of the atmosphere is required. In addition, CTA will be operated as an observatory, with data made public along with appropriate analysis tools. High-level data quality can only be ensured if the atmospheric properties are consistently and continuously taken into account. In this contribution, we concentrate on discussing the implementation strategy for the various atmospheric monitoring instruments currently under discussion in CTA. These includes Raman lidars and ceilometers, stellar photometers and others available both from commercial providers and public research centers
Upper limits on GeV--TeV gamma-ray emission for follow-up observations with the MAGIC telescope
No full textDuring the first observation cycle of the MAGIC telescope, 9 successful GRB follow-up observations were performed. For 2 bursts, the obser- vation started even while the prompt emission was still ongoing. In none of these observations a significant excess over background could be detected. We present a direct determination of the MAGIC sensitivity in GRB observation mode from the Crab Nebula and the obtained upper limits for the 9 observations. At energies around 100 GeV, MAGIC is currently the fastest and most sensitive GRB detector in the world
Analysis techniques and performance of the Domino Ring Sampler version 4 based readout for the MAGIC telescopes
No full textRecently the readout of the MAGIC telescopes has been upgraded to a new system based on the Domino Ring Sampler version 4 chip. We present the analysis techniques and the signal extraction performance studies of this system. We study the behavior of the baseline, the noise, the cross-talk, the linearity and the time resolution. We investigate also the optimal signal extraction. In addition we show some of the analysis techniques specific to the readout based on the Domino Ring Sampler version 2 chip, previously used in the MAGIC II telescope. (C) 2013 Elsevier B.V. All rights reserved
The MAGIC Telescope and the Observation of Gamma Ray Bursts
No full textThe MAGIC Telescope, now taking data with an energy threshold well below 100 GeV, will soon be able to take full advantage of the fast slewing capability of its altazimuthal mount. Exploiting the link with the GCN network, the MAGIC Telescope could be one of the first ground-based experiments able to see the prompt emission of Gamma Ray Bursts in the few tens of GeV region
Upper limits on GeV-TeV gamma-ray emission for follow-up observations with the MAGIC telescope
No full textMAGIC upper limits on the Very High Energy emission from GRBs
No full textSince the beginning of its operation in April 2005, the MAGIC telescope was able to observe ten different GRB events since their early beginning, even while the prompt emission was still ongoing. Observations, with energy thresholds spanning between 80 and 300 GeV, did not reveal any γ‐ray emission. We present a direct determination of the MAGIC sensitivity in GRB mode and the upper limits for the ten follow‐up observations. At energies around 100 GeV, MAGIC is currently the fastest and most sensitive operational GRB detector in the world
Birmingham News sleeve BN0021572
No full textWoman's Club Directory / Mrs. Cecil Buck / [Mrs.] Major F. M. Gaug
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