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2.
The European Venus Explorer (EVE) mission described in this paper was proposed in December 2010 to ESA as an ‘M-class’ mission under the Cosmic Vision programme. It consists of a single balloon platform floating in the middle of the main convective cloud layer of Venus at an altitude of 55?km, where temperatures and pressures are benign (~25°C and ~0.5 bar). The balloon float lifetime would be at least 10 Earth days, long enough to guarantee at least one full circumnavigation of the planet. This offers an ideal platform for the two main science goals of the mission: study of the current climate through detailed characterization of cloud-level atmosphere, and investigation of the formation and evolution of Venus, through careful measurement of noble gas isotopic abundances. These investigations would provide key data for comparative planetology of terrestrial planets in our solar system and beyond.  相似文献   

3.
《New Astronomy Reviews》1999,43(2-4):243-249
The status and the astrophysical implications of the search for deviations from a Planck distribution in the spectrum of the Cosmic Microwave Background are presented.  相似文献   

4.
Cosmic ray electrons represent a background for gamma-ray observations with Cherenkov telescopes, initiating air-showers which are difficult to distinguish from photon-initiated showers. This similarity, however, and the presence of cosmic ray electrons in every field observed, makes them potentially very useful for calibration purposes. Here we study the precision with which the relative energy scale and collection area/efficiency for photons can be established using electrons for a major next generation instrument such as CTA. We find that variations in collection efficiency on hour timescales can be corrected to better than 1%. Furthermore, the break in the electron spectrum at ∼ 0.9 TeV can be used to calibrate the energy scale at the 3% level on the same timescale. For observations on the order of hours, statistical errors become negligible below a few TeV and allow for an energy scale cross-check with instruments such as CALET and AMS. Cosmic ray electrons therefore provide a powerful calibration tool, either as an alternative to intensive atmospheric monitoring and modelling efforts, or for independent verification of such procedures.  相似文献   

5.
Solar System Research - The article proposes a “tagged cosmic particle” method that uses the natural flux of high-energy particles of Galactic Cosmic Rays to study the composition of...  相似文献   

6.
《New Astronomy Reviews》1999,43(2-4):263-269
We describe a Two Channel Correlation Polarimeter built by the Milan Radio Group for searching polarization of the Cosmic Microwave Background. The system sensitivity is sufficient to detect linearly polarized signals or set firm upper limits at levels of few μK. The program of observations and some preliminary results are presented.  相似文献   

7.
ALMA will be the premier instrument for the study of galaxy evolution in the early universe—enabling studies of the gas content, dynamics and dynamical masses, and star formation with unparalleled resolution and sensitivity. Galaxy evolution and AGN growth in the early universe are believed to be strongly driven by merging and dynamical interactions. Thus, a full exploration of the environmental influence is absolutely essential. The Cosmic Evolution Survey (COSMOS) is specifically designed to probe the correlated coevolution of galaxies, star formation, active galactic nuclei (AGN) and dark matter (DM) large-scale structure (LSS) over the redshift range z>0.5 to 3. In this contribution I review the characteristics of the COSMOS survey and very exciting initial results on mapping large scale structure in galaxies and dark matter. The survey includes multi-wavelength imaging and spectroscopy from X-ray to radio wavelengths covering a 2 square degree equatorial field. Given the very high sensitivity and resolution of these datasets, COSMOS will provide unprecedented samples of objects at z>3 for followup studies wit ALMA.  相似文献   

8.
Cosmic Research NPO, Azerbaidzhan Academy of Sciences. Translated from Astrofizika, Vol. 28, No. 2, pp. 455–262, March–April, 1988.  相似文献   

9.
Institute of Cosmic Research, USSR Academy of Sciences. Translated from Astrofizika, 28, No. 2, pp. 429–442, March–April, 1988.  相似文献   

10.
Institute of Cosmic Research, USSR Academy of Sciences. Translated from Astrofizika, Vol. 29, No. 2, pp. 369–384, September–October, 1988.  相似文献   

11.
Books reviewed in this article: Afterglow of Creation: From the Fireball to the Discovery of Cosmic Ripples by Marcus Chown The Doomsday Asteroid Meteorite Craters by Kathleen Mark  相似文献   

12.
A survey is made of the present constraints on cosmological parameters from Cosmic Microwave Background Anisotropies. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

13.
Polarimetry is an area of high energy astrophysics which is still relatively unexplored, even though it is recognized that this type of measurement could drastically increase our knowledge of the physics and geometry of high energy sources. For this reason, in the context of the design of a Gamma-Ray Imager based on new hard-X and soft gamma ray focusing optics for the next ESA Cosmic Vision call for proposals (Cosmic Vision 2015-2025), it is important that this capability should be implemented in the principal on-board instrumentation. For the particular case of wide band-pass Laue optics we propose a focal plane based on a thick pixelated CdTe detector operating with high efficiency between 60–600keV. The high segmentation of this type of detector (1–2mm pixel size) and the good energy resolution (a few keV FWHM at 500keV) will allow high sensitivity polarisation measurements (a few % for a 10mCrab source in 106s) to be performed. We have evaluated the modulation Q factors and minimum detectable polarisation through the use of Monte Carlo simulations (based on the GEANT 4 toolkit) for on and off-axis sources with power law emission spectra using the point spread function of a Laue lens in a feasible configuration.  相似文献   

14.
Book Reviews     
Book reviewed in this article: Spectroscopic Characterization of Minerals and their Surfaces edited by Lelia M. Coyne, Stephen W. S. McKeever and David F. Blake. Cosmic Debris, Meteorites in History , John G. Burke  相似文献   

15.
A new detector for accurate localization of the cosmic gamma-burst sources is presented. The detector is intended for satellite applications, but balloon flights will be used in the development phase. The advantages and limitations of Arctic balloon flights are discussed based on a trial flight in August 1979.Paper presented at the Symposium on Cosmic Gamma-Ray Bursts, held at Toulouse, France, 26–29 November, 1979.  相似文献   

16.
Relative abundances for the VH group of Cosmic Radiation (20≤Z≤28) at energiesE≤600 MeV nucl?1 have been measured by means of plastic detector LEXAN. The stack was exposed to cosmic rays during a 82 hr balloon flight at Sioux Falls (South Dakota) at an average altitude equivalent to 4 g cm?2 of residual atmosphere. A total number of 1058 events have been analyzed, out of which 675 have been unambiguously identified. Two different discrimination methods have been applied in order to test their influence on final spectra. Extrapolation to the top of the atmosphere has been achieved in the frame of the regular model including an energy loss term that has led to corrections of the order of 60% in the extrapolated abundances. The relative abundances so obtained are in reasonable agreement with those reported by other authors using electronic detectors. Abnormal high abundances of manganese and cobalt can be attributed to wide temperature variations during the registration interval. In spite of the poor mass resolution, a high abundance of54Fe has been evidenced, indicating a non-stellar origin for cosmic iron.  相似文献   

17.
A54 Cosmic Ray Acceleration in Galactic Wind Shocks A71 Detection of Ultra‐High Energy Cosmic Rays and Neutrinos with LOFAR A80 Status of the gravitational‐wave detector GEO600 A87 Recent Results and Future of the MAGIC gamma‐ray telescope A92 Cosmic ray detection with the radio technique A93 Cosmic Ray Physics with IceCube A94 The resonance‐like gamma‐ray absorption processes for use in astrophysics A97 Geometry reconstruction of air shower fluorescence detectors revisited A102 Supermassive Binary Black Holes & Radio Jets A108 Muonic Component of Air Showers Measured by KASCADE‐Grande A110 Towards new frontiers: observation of photons with energies above 1018 eV A112 The IceCube Neutrino Telescope A114 The ground‐based gamma‐ray observatory CTA A116 IceCube: Recent Results and Prospects A117 Particle Physics with AMANDA and IceCube A118 Altitude dependence of fluorescence light emission by extensive air showers A120 Neutrino‐induced cascades in AMANDA & IceCube A122 Enhancement Telescopes for the Pierre Auger Southern Observatory in Argentina A123 Proton spectra from relativistic shock environments in AGN and GRBs A124 The Baikal Neutrino Telescope – Physics Results A127 Searches for point‐like sources of cosmic neutrinos with IceCube A128 The MAGIC/IceCube Target of Opportunity Programtest run A131 Supernova detection with IceCube: from low to high energy neutrinos A132 Measurement of the UHECR energy spectrum from hybrid data of the Pierre Auger Observatory A133 Extension of IceCube at Lower Energy: the Use of AMANDA as Nested Array and the Future Prospectives A135 Searching for neutrinos with the Pierre Auger Observatory A138 Search for Transient Emission of Neutrinos in IceCube A140 Acoustic Neutrino Detection in Antarctic Ice A159 AMANDA limits on the diffuse muon‐neutrino flux: physics implications A164 Investigation of the Radio Emission of Cosmic Ray Air Showers with LOPES A168 The Northern Site of the Pierre Auger Observatory A170 Shower reconstruction and size spectra with KASCADE‐Grande data A171 Neutrinos from Gamma Ray Bursts: predictions and limits from AMANDA‐II data A172 Simulation study of shower profiles from ultra‐high energy cosmic rays A174 Upper limit to the photon fraction in cosmic rays above 1019 eV from the Pierre Auger Observatory A176 Astrophysics at MeV energies A180 Study of the Cosmic Ray Composition above 0.4 EeV using the Longitudinal Profiles of Showers observed at the Pierre Auger Observatory A185 Backgrounds for UHE horizontal neutrino showers A186 The Front‐End Cards of the Pierre Auger Surface Detectors: Test Results and Performance in the Field A187 Monte Carlo Studies for MAGIC‐II A194 Measuring the proton‐air cross section from logitudinal air shower profiles A195 The UHECR energy spectrummeasured at the Pierre Auger Observatory A203 Highlights of Observations of Galactic Sources with the MAGIC telescope A207 Adesign study for a 12.5 m ∅︁ Imaging Air Cherenkov Telescope for ground‐based γ ‐ray astronomy A210 The Future of Long‐Wavelengths Radio‐Astronomy in Germany: LOFAR and GLOW A211 Online Monitoring of the Pierre Auger Observatory A216 OPTIMA‐Burst – Catching GRB Afterglows (and other Transients) with High Time Resolution A227 JEM‐EUSO mission A232 Rapid Variations in AGN: Clues on Particle Accelerators A235 Systematic search forVHEgamma‐ray emission from X‐ray bright high‐frequency peaked BL Lac objects A237 Prospects for GeV Astronomy in the Era of GLAST A241 Improvements of the energy reconstruction for the MAGIC telescope by means of analysis and Monte Carlo techniques A265 Discovery of VHE γ ‐rays from BL Lacertae with the MAGIC telescope A266 Results of two observation cycles of LS I+61°303 with the MAGIC telescope A267 Wide Range Multifrequency Observations of Northern TeV Blazars A269 Diffusive and convective cosmic ray transport in elliptical galaxies  相似文献   

18.
《New Astronomy Reviews》1999,43(2-4):289-296
We describe the BOOMERanG experiment, a stratospheric balloon telescope intended to measure the Cosmic Microwave Background anisotropy at angular scales between a few degrees and ten arcminutes. The experiment has been optimized for a long duration (7 to 14 days) flight circumnavigating Antarctica at the end of 1998. A test flight was performed on 30 August 1997 in Texas. The level of performance achieved in the test flight was satisfactory and compatible with the requirements for the long duration flight.  相似文献   

19.
Intensity variation of cosmic rays near the heliospheric current sheet   总被引:1,自引:0,他引:1  
Cosmic ray intensity variations near the heliospheric current sheet—both above and below it—have been studied during 1964–1976. Superposed epoch analysis of the cosmic ray neutron monitor data with respect to sector boundaries (i.e., heliospheric current sheet crossings) has been performed. In this analysis we have used the data from neutron monitors well distributed in latitude over the Earth's surface. First, this study has been made during the two solar activity minimum periods 1964–1965 and 1975–1976, using the data from Thule (cut-off rigidity 0 GV), Deep River (cut-off rigidity 1.02 GV), Rome (cut-off rigidity 6.32 GV) and Huancayo (cut-off rigidity 13.45 GV) neutron monitors. We have also analyzed the data from Deep River, Rome and Huancayo neutron monitors, for whom we have the data for full period (1964–1976), by dividing the periods according to the changes in solar activity, interplanetary magnetic field polarity and coronal holes. All these studies have shown a negative gradient with respect to heliomagnetic latitude (current sheet). These results have been discussed in the light of theoretical and observational evidences. Suggestions have been given to overcome the discrepancy between the observational and theoretical results. Further, possible explanations for these observational results have been suggested.  相似文献   

20.
《New Astronomy Reviews》1999,43(2-4):251-256
Selected topics in antenna design for Cosmic Microwave Background Radiation measurements are presented. Some general topics in antenna theory are introduced, from the radio wavelength point of view, and used to illustrate some examples of current experiments. The attention is focused on anisotropy measurements, outlining the principal systematic effect to be considered when designing an experiment and some recipes to reduce them.  相似文献   

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