The Active Mirror Control of the MAGIC Telescope

One of the main design goals of the MAGIC telescopes is the very fast repositioning in case of Gamma Ray Burst (GRB) alarms, implying a low weight of the telescope dish. This is accomplished by using a space frame made of carbon fiber epoxy tubes, resulting in a strong but not very rigid support structure. Therefore it is necessary to readjust the individual mirror tiles to correct for deformations of the dish under varying gravitational load while tracking an object. We present the concept of the Active Mirror Control (AMC) as implemented in the MAGIC telescopes and the actual performance reached. Additionally we show that also telescopes using a stiff structure can benefit from using an AMC.Comment: Contribution to the 30th ICRC, Merida, Mexico, July 2007 on behalf of the MAGIC Collaboratio

Эндоскопическая диагностика и лечение ятрогенных разрывов трахеи

Abstract Respiratory tract trauma is not only the result of injuries to the chest and neck, but may be iatrogenic as well. Diagnosis of iatrogenic damage to the trachea is based on data from clinical and instrumental studies. Among the instrumental diagnostic measures, preference is given to early fibrobronchoscopy.The aim of the study is to assess the possibilities of fiberoptic bronchoscopy in the diagnosis of iatrogenic tracheal injuries. Materials and methods. This study analyzed the use of fiberoptic bronchoscopy in 51 patients with suspected iatrogenic damage to the trachea. For iatrogenic ruptures of the trachea, the location on the posterior (membranous) wall and the longitudinal direction (100%), as well as location in the lower and middle thoracic sections of the trachea (71.4%), are typical.Conclusion Bronchoscopy is a direct method for diagnosing this type of damage, which allows the location, size of the defect and tactics to be accurately determined.РЕЗЮМЕ Повреждения дыхательных путей являются не только следствием травмы груди и шеи, но и носят ятрогенный характер. Диагностика ятрогенных повреждений трахеи основывается на данных клинических и инструментальных исследований. Среди инструментальных диагностических мероприятий предпочтение отдается ранней фибробронхоскопии.ЦЕЛЬ Оценка возможностей фибробронхоскопии в диагностике ятрогенных повреждений трахеи.МАТЕРИАЛ И МЕТОДЫ В данном исследовании проведен анализ использования фибробронхоскопии у 51 пациента с подозрением на ятрогенное повреждение трахеи. Для ятрогенных разрывов трахеи типичными являются расположение на задней (мембранозной) стенке и продольное направление (100%), а также локализация в нижне- и среднегрудном отделах трахеи (71,4%).ЗАКЛЮЧЕНИЕ Бронхоскопия является прямым методом диагностики этого вида повреждения, которая позволяет точно установить локализацию, размеры дефекта и определить тактику ведения данной категории больных

Комбинированная бронхоскопия в удалении длительно стоящего инородного тела левого нижнедолевого бронха

The authors report a clinical observation of the removal of a large foreign body (a dental prosthesis with a sharp metal pin) of the left inferior bronchus with combined use of rigid and flexible bronchoscopy. A foreign body was detected two years later by chance during examination for complications. It is noted that the combination of rigid and flexible bronchoscopy allows good visualization of the surgical intervention to be performed and additional damage to the bronchi and trachea to be avoided while removing a foreign body.Авторы представляют клиническое наблюдение удаления крупного инородного тела (зубной протез с острым металлическим штифтом) левого нижнедолевого бронха при одновременном использовании ригидной и гибкой бронхоскопии. Инородное тело обнаружено через два года случайно при обследовании по поводу осложнений. Отмечено, что комбинация ригидной и гибкой бронхоскопии позволяет добиться хорошего визуального обеспечения оперативного вмешательства и предотвратить дополнительные повреждения бронхов и трахеи при удалении инородного тела повышенной травматичности

Спонтанный разрыв аневризмы желудочно-сальниковой артерии

We report a rare clinical case of spontaneous rupture of the aneurysm left gastroepiploic artery with life-threatening intra-abdominal haemorrhage.Authors declare lack of the conflicts of interests. Представлено редкое клиническое наблюдение спонтанного разрыва аневризмы левой желудочно-сальниковой артерии с жизнеугрожающим внутрибрюшным кровотечением.Авторы заявляют об отсутствии конфликта интересов

First bounds on the very high energy gamma-ray emission from Arp 220

Using the Major Atmospheric Gamma Imaging Cherenkov Telescope (MAGIC), we have observed the nearest ultra-luminous infrared galaxy Arp 220 for about 15 hours. No significant signal was detected within the dedicated amount of observation time. The first upper limits to the very high energy $\gamma$-ray flux of Arp 220 are herein reported and compared with theoretical expectations.Comment: Accepted for publication in Ap

Implementation of the Random Forest Method for the Imaging Atmospheric Cherenkov Telescope MAGIC

The paper describes an application of the tree classification method Random Forest (RF), as used in the analysis of data from the ground-based gamma telescope MAGIC. In such telescopes, cosmic gamma-rays are observed and have to be discriminated against a dominating background of hadronic cosmic-ray particles. We describe the application of RF for this gamma/hadron separation. The RF method often shows superior performance in comparison with traditional semi-empirical techniques. Critical issues of the method and its implementation are discussed. An application of the RF method for estimation of a continuous parameter from related variables, rather than discrete classes, is also discussed.Comment: 16 pages, 8 figure

Unfolding of differential energy spectra in the MAGIC experiment

The paper describes the different methods, used in the MAGIC experiment, to unfold experimental energy distributions of cosmic ray particles (gamma-rays). Questions and problems related to the unfolding are discussed. Various procedures are proposed which can help to make the unfolding robust and reliable. The different methods and procedures are implemented in the MAGIC software and are used in most of the analyses.Comment: Submitted to NIM

Discovery of VHE Gamma Radiation from IC443 with the MAGIC Telescope

We report the detection of a new source of very high energy (VHE, E_gamma >= 100GeV) gamma-ray emission located close to the Galactic Plane, MAGIC J0616+225, which is spatially coincident with SNR IC443. The observations were carried out with the MAGIC telescope in the periods December 2005 - January 2006 and December 2006 - January 2007. Here we present results from this source, leading to a VHE gamma-ray signal with a statistical significance of 5.7 sigma in the 2006/7 data and a measured differential gamma-ray flux consistent with a power law, described as dN_gamma/(dA dt dE) = (1.0 +/- 0.2)*10^(-11)(E/0.4 TeV)^(-3.1 +/- 0.3) cm^(-2)s^(-1)TeV^(-1). We briefly discuss the observational technique used and the procedure implemented for the data analysis. The results are put in the perspective of the multiwavelength emission and the molecular environment found in the region of IC443.Comment: Accepted by ApJ Letter

Systematic search for VHE gamma-ray emission from X-ray bright high-frequency BL Lac objects

All but three (M87, BL Lac and 3C 279) extragalactic sources detected so far at very high energy (VHE) gamma-rays belong to the class of high-frequency peaked BL Lac (HBL) objects. This suggested to us a systematic scan of candidate sources with the MAGIC telescope, based on the compilation of X-ray blazars by Donato et al. (2001). The observations took place from December 2004 to March 2006 and cover sources on the northern sky visible under small zenith distances zd < 30 degrees at culmination. The sensitivity of the search was planned for detecting X-ray bright F(1 keV) > 2 uJy) sources emitting at least the same energy flux at 200 GeV as at 1 keV. In order to avoid strong gamma-ray attenuation close to the energy threshold, the redshift of the sources was constrained to values z<0.3. Of the fourteen sources observed, 1ES 1218+304 and 1ES 2344+514 have been detected in addition to the known bright TeV blazars Mrk 421 and Mrk 501. A marginal excess of 3.5 sigma from the position of 1ES 1011+496 was observed and has been confirmed as a source of VHE gamma-rays by a second MAGIC observation triggered by a high optical state (Albert et al. 2007). For the remaining sources, we present here the 99% confidence level upper limits on the integral flux above ~200 GeV. We characterize the sample of HBLs (including all HBLs detected at VHE so far) by looking for correlations between their multi-frequency spectral indices determined from simultaneous optical, archival X-ray, and radio luminosities, finding that the VHE emitting HBLs do not seem to constitute a unique subclass. The absorption corrected gamma-ray luminosities at 200 GeV of the HBLs are generally not higher than their X-ray luminosities at 1 keV.Comment: 15 pages, 7 figures, 5 tables, submitted to ApJ (revised version

Upper limit for gamma-ray emission above 140 GeV from the dwarf spheroidal galaxy Draco

The nearby dwarf spheroidal galaxy Draco with its high mass to light ratio is one of the most auspicious targets for indirect dark matter searches. Annihilation of hypothetical DM particles can result in high-energy gamma-rays, e.g. from neutralino annihilation in the supersymmetric framework. With the MAGIC telescope a search for a possible DM signal originating from Draco was performed during 2007. The analysis of the data results in a flux upper limit of 1.1x10^-11 photons cm^-2 sec^-1 for photon energies above 140 GeV, assuming a point like source. Furthermore, a comparison with predictions from supersymmetric models is given. While our results do not constrain the mSUGRA phase parameter space, a very high flux enhancement can be ruled out.Comment: Accepted for publication by Astrophysical Journa