Open principle for large high-resolution solar telescopes

NARCIS (Netherlands)

Hammerschlag, R.H.; Bettonvil, F.C.M.; Jägers, A.P.L.; Sliepen, G.

2009-01-01

Vacuum solar telescopes solve the problem of image deterioration inside the telescope due to refractive index fluctuations of the air heated by the solar light. However, such telescopes have a practical diameter limit somewhat over 1 m. The Dutch Open Telescope (DOT) was the pioneering demonstrator

Chinese large solar telescopes site survey

Science.gov (United States)

Liu, Yu

2017-04-01

In order to observe the solar surface with unprecedentedly higher resolution, Chinse solar physics society decided to launch their solar site survey project in 2010 as the first step to look for the best candidate sites for the Chinese next-generation large-aperture solar telescopes, i.e., the 5-8 meter Chinese Giant Solar Telescope, and the 1 meter level coronagraph. We have built two long-term monitoring sites in Daocheng, with altitudes of around 4800 meters above the sea level located in the large Shangri-La mountain area, and we have collected systematic site data since 2014. Clear evidence, including the key parameters of seeing factor, sky brightness and water vapor content, has indicated that the large Shangri-La area owns the potential conditions of excellent seeing level and sufficient amount of clear-sky hours suitable for developing large solar telescopes. We will review the site survey progress and present the preliminary statistical results in this talk.

Construction of the Advanced Technology Solar Telescope

Science.gov (United States)

Rimmele, T. R.; Keil, S.; McMullin, J.; Knölker, M.; Kuhn, J. R.; Goode, P. R.; Rosner, R.; Casini, R.; Lin, H.; Tritschler, A.; Wöger, F.; ATST Team

2012-12-01

The 4m Advance Technology Solar Telescope (ATST) will be the most powerful solar telescope and the world's leading ground-based resource for studying solar magnetism that controls the solar wind, flares, coronal mass ejections and variability in the Sun's output. The project has entered its construction phase. Major subsystems have been contracted. As its highest priority science driver ATST shall provide high resolution and high sensitivity observations of the dynamic solar magnetic fields throughout the solar atmosphere, including the corona at infrared wavelengths. With its 4m aperture, ATST will resolve features at 0.″03 at visible wavelengths and obtain 0.″1 resolution at the magnetically highly sensitive near infrared wavelengths. A high order adaptive optics system delivers a corrected beam to the initial set of state-of-the-art, facility class instrumentation located in the Coudé laboratory facility. The initial set of first generation instruments consists of five facility class instruments, including imagers and spectro-polarimeters. The high polarimetric sensitivity and accuracy required for measurements of the illusive solar magnetic fields place strong constraints on the polarization analysis and calibration. Development and construction of a four-meter solar telescope presents many technical challenges, including thermal control of the enclosure, telescope structure and optics and wavefront control. A brief overview of the science goals and observational requirements of the ATST will be given, followed by a summary of the design status of the telescope and its instrumentation, including design status of major subsystems, such as the telescope mount assembly, enclosure, mirror assemblies, and wavefront correction

Prospects for γ-ray imaging telescopes

International Nuclear Information System (INIS)

Carter, J.N.; Dean, A.J.; Ramsden, D.

1981-01-01

Apart from the requirement for a new, high angular-resolution gamma-ray telescope for the more precise location of known COS-B gamma-ray sources, there is also a need for another instrument that can be used in a search for the gamma-ray emission from specific X-ray-emitting objects. If there is to be any hope of relating gamma ray emission to specific candidate X-ray objects, then an angular resolution of typically a few minutes of arc is required to resolve adjacent sources in crowded regions of the sky such as the galactic centre. Efforts to improve the angular resolution of track-chamber telescopes are compared. For energies close to 1 MeV telescopes have either used collimators to restrict the field of view or have made use of the kinematics of the Compton scattering process to determine the direction of the incident photon. The use of coded aperture techniques in high angular resolution X-ray astronomy telescopes is reviewed. A practical telescope for astronomy at high energies described by Carter is mentioned. At low energies an imaging telescope could be constructed by making use of position-sensitive detectors initially developed for use in medical physics. Such a telescope is outlined in general terms and its benefits and uses given. (U.K.)

A Cosmic Ray Telescope For Educational Purposes

International Nuclear Information System (INIS)

Voulgaris, G.; Kazanas, S.; Chamilothoris, I.

2010-01-01

Cosmic ray detectors are widely used, for educational purposes, in order to motivate students to the physics of elementary particles and astrophysics. Using a 'telescope' of scintillation counters, the directional characteristics, diurnal variation, correlation with solar activity, can be determined, and conclusions about the composition, origin and interaction of elementary particles with the magnetic field of earth can be inferred. A telescope was built from two rectangular scintillator panels with dimensions: 91.6x1.9x3.7 cm 3 . The scintillators are placed on top of each other, separated by a fixed distance of 34.6 cm. They are supported by a wooden frame which can be rotated around a horizontal axis. Direction is determined by the coincidence of the signals of the two PMTs. Standard NIM modules are used for readout. This device is to be used in the undergraduate nuclear and particle physics laboratory. The design and construction of the telescope as well as some preliminary results are presented.

Hartman Testing of X-Ray Telescopes

Science.gov (United States)

Saha, Timo T.; Biskasch, Michael; Zhang, William W.

2013-01-01

Hartmann testing of x-ray telescopes is a simple test method to retrieve and analyze alignment errors and low-order circumferential errors of x-ray telescopes and their components. A narrow slit is scanned along the circumference of the telescope in front of the mirror and the centroids of the images are calculated. From the centroid data, alignment errors, radius variation errors, and cone-angle variation errors can be calculated. Mean cone angle, mean radial height (average radius), and the focal length of the telescope can also be estimated if the centroid data is measured at multiple focal plane locations. In this paper we present the basic equations that are used in the analysis process. These equations can be applied to full circumference or segmented x-ray telescopes. We use the Optical Surface Analysis Code (OSAC) to model a segmented x-ray telescope and show that the derived equations and accompanying analysis retrieves the alignment errors and low order circumferential errors accurately.

Active control of the Chinese Giant Solar Telescope

Science.gov (United States)

Dai, Yichun; Yang, Dehua; Jin, Zhenyu; Liu, Zhong; Qin, Wei

2014-07-01

The Chinese Giant Solar Telescope (CGST) is the next generation solar telescope of China with diameter of 8 meter. The unique feature of CGST is that its primary is a ring, which facilitates the polarization detection and thermal control. In its present design and development phase, two primary mirror patterns are considered. For one thing, the primary mirror is expected to construct with mosaic mirror with 24 trapezoidal (or petal) segments, for another thing, a monolithic mirror is also a candidate for its primary mirror. Both of them depend on active control technique to maintain the optical quality of the ring mirror. As a solar telescope, the working conditions of the CGST are quite different from those of the stellar telescopes. To avoid the image deterioration due to the mirror seeing and dome seeing, especially in the case of the concentration of flux in a solar telescope, large aperture solar projects prefer to adopt open telescopes and open domes. In this circumstance, higher wind loads act on the primary mirror directly, which will cause position errors and figure errors of the primary with matters worse than those of the current 10-meter stellar telescopes with dome protect. Therefore, it gives new challenges to the active control capability, telescope structure design, and wind shielding design. In this paper, the study progress of active control of CGST for its mosaic and monolithic mirror are presented, and the wind effects on such two primary mirrors are also investigated.

Signatures of cosmic-ray interactions on the solar surface

Science.gov (United States)

Seckel, D.; Stanev, Todor; Gaisser, T. K.

1991-01-01

The fluxes of neutrinos, gamma rays, antiprotons, neutrons, and antineutrons that result from collisions of high-energy Galactic cosmic rays with the solar atmosphere are estimated. The results are sensitive to assumptions about cosmic-ray transport in the magnetic fields of the inner solar system. The high-energy photon flux should be observable by the Gamma Ray Observatory. The neutrino flux should produce less than one event per year in the next generation of neutrino telescopes. The antiproton flux is unobservable against the Galactic background. The neutron and antineutron fluxes are detectable only if neutrons produced in terrestrial cosmic-ray events may be discriminated against.

An application of space technology to the terrestrial search for axions: the X-ray mirror telescope at CAST

Energy Technology Data Exchange (ETDEWEB)

Lutz, Gerhard E-mail: gerhard.lutz@cern.ch; Braeuninger, H.; Englhauser, J.; Hartmann, R.; Kang, D.; Kotthaus, R.; Kuster, M.; Serber, W.; Strueder, L

2004-02-01

An X-ray mirror telescope consisting of a Wolter I type mirror assembly as used in X-ray astronomy and a new type X-ray CCD has been added to the CERN Axion Solar Telescope experiment. It will strongly improve the sensitivity in the search for axions, a so far elusive particle. The axion is predicted in order to explain the observed CP conservation in strong interaction which is not expected within the generally accepted 'standard model'. Construction and performance of the X-ray telescope are described. An improvement by two orders of magnitude in the signal over background S/B event ratio is estimated.

An application of space technology to the terrestrial search for axions The X-ray mirror telescope at CAST

CERN Document Server

Lutz, Gerhard; Englhauser, J; Hartmann, R; Kang, D; Kotthaus, R; Kuster, M; Serber, W; Strüder, L

2004-01-01

An X-ray mirror telescope consisting of a Wolter I type mirror assembly as used in X-ray astronomy and a new type X-ray CCD has been added to the CERN Axion Solar Telescope experiment. It will strongly improve the sensitivity in the search for axions, a so far elusive particle. The axion is predicted in order to explain the observed CP conservation in strong interaction which is not expected within the generally accepted "standard model". Construction and performance of the X-ray telescope are described. An improvement by two orders of magnitude in the signal over background S/B event ratio is estimated.

Use of graphite epoxy composites in the Solar-A Soft X-Ray Telescope

Science.gov (United States)

Jurcevich, B. K.; Bruner, M. E.

1990-01-01

This paper describes the use of composite materials in the Soft X-Ray Telescope (SXT). One of the primary structural members of the telescope is a graphite epoxy metering tube. The metering tube maintains the structural stability of the telescope during launch as well as the focal length through various environmental conditions. The graphite epoxy metering tube is designed to have a negative coefficient of thermal expansion to compensate for the positive expansion of titanium structural supports. The focus is maintained to + or - 0.001 inch by matching the CTE of the composite tube to the remaining structural elements.

GISOT: a giant solar telescope

Science.gov (United States)

Hammerschlag, Robert H.; von der Lühe, Oskar F.; Bettonvil, Felix C.; Jägers, Aswin P.; Snik, Frans

2004-10-01

A concept is presented for an extremely large high-resolution solar telescope with an aperture of 11 m and diffraction limited for visual wavelengths. The structure of GISOT will be transparent to wind and placed on a transparent stiff tower. For efficient wind flushing, all optics, including the primary mirror, will be located above the elevation axis. The aperture will be of the order of 11 m, not rotatively symmetrical, but of an elongated shape with dimensions 11 x 4 m. It consists of a central on-axis 4 m mirror with on both sides 3 pieces of 2 m mirrors. The optical layout will be kept simple to guarantee quality and minimize stray light. A Coudé room for instruments is planned below the telescope. The telescope will not be housed in a dome-like construction, which interferes with the open principle. Instead the telescope will be protected by a foldable tent construction with a diameter of the order of 30 m, which doesn"t form any obstruction during observations, but can withstand the severe weather circumstances on mountain sites. Because of the nature of the solar scene, extremely high resolution in only one dimension is sufficient to solve many exciting problems in solar physics and in this respect the concept of GISOT is very promising.

Soft x-ray spectrographs for solar observations

International Nuclear Information System (INIS)

Bruner, M.E.

1988-01-01

This paper surveys some of the recent advances in the state of the art of soft X-ray spectrometers, particularly as they might be applied to Solar Observations. The discussions center on the windowless region from roughly 1 to 100 A, and covers both grating and crystal instruments. The author begins with a short discussion of the solar soft X-ray spectrum and its interpretation, followed by a few general comments on problems peculiar to soft X-ray instruments. The paper reviews of recent developments in spectrometer optical design, which has been a lively field during the last dozen years. This is particularly true in the case of grating spectrometers. The paper concludes with a short section on telescope considerations, and some remarks on future flight opportunities

The Sun's X-ray Emission During the Recent Solar Minimum

Science.gov (United States)

Sylwester, Janusz; Kowalinski, Mirek; Gburek, Szymon; Siarkowski, Marek; Kuzin, Sergey; Farnik, Frantisek; Reale, Fabio; Phillips, Kenneth J. H.

2010-02-01

The Sun recently underwent a period of a remarkable lack of major activity such as large flares and sunspots, without equal since the advent of the space age a half century ago. A widely used measure of solar activity is the amount of solar soft X-ray emission, but until recently this has been below the threshold of the X-ray-monitoring Geostationary Operational Environmental Satellites (GOES). There is thus an urgent need for more sensitive instrumentation to record solar X-ray emission in this range. Anticipating this need, a highly sensitive spectrophotometer called Solar Photometer in X-rays (SphinX) was included in the solar telescope/spectrometer TESIS instrument package on the third spacecraft in Russia's Complex Orbital Observations Near-Earth of Activity of the Sun (CORONAS-PHOTON) program, launched 30 January 2009 into a near-polar orbit. SphinX measures X-rays in a band similar to the GOES longer-wavelength channel.

LOBSTER - New Space X-Ray telescopes

International Nuclear Information System (INIS)

Hudec, R.; Pina, L.; Simon, V.; Sveda, L.; Inneman, A.; Semencova, V.; Skulinova, M.

2007-01-01

We discuss the technological and scientific aspects of fully innovative very wide-field X-ray telescopes with high sensitivity. The prototypes of Lobster telescopes designed, developed and tested are very promising, allowing the proposals for space projects with very wide-field Lobster Eye X-ray optics to be considered for the first time. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study of various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc. For example, the Lobster optics based X-ray All Sky Monitor is capable to detect around 20 GRBs and 8 XRFs yearly and this will surely significantly contribute to the related science

Science with the solar optical telescope

Science.gov (United States)

Jordan, S. D.; Hogan, G. D.

1984-01-01

The Solar Optical Telescope (SOT) is designed to provide the solar physics community with the data necessary for solving several fundamental problems in the energetics and dynamics of the solar atmosphere. Among these problems are questions on the origin and evolution of the sun's magnetic field, heating of the outer solar atmosphere, and sources of the solar wind in the lower lying regions of the outer atmosphere. The SOT will be built under the management of NASA's Goddard Space Flight Center, with science instruments provided by teams led by Principal Investigators. The telescope will be built by the Perkin-Elmer Corporation, and the science instruments selected for the first flight will be provided by the Lockheed Palo Alto Research Laboratory (LPARL) and the California Institute of Technology, with actual construction of a combined science instrument taking place at the LPARL. The SOT has a 1.3-meter-diameter primary mirror that will be capable of achieving diffraction-limited viewing in the visible of 0.1 arc-second. This dimension is less than a hydrodynamic scale-height or a mean-free-path of a continuum photon in the solar atmosphere. Image stability will be achieved by a control system in the telescope, which moves both the primary and tertiary mirrors in tandem, and will be further enhanced by a correlation tracker in the combined science instrument. The SOT Facility is currently scheduled for its first flight on Spacelab at the beginning of the 1990's.

Advanced X-Ray Telescope Mirrors Provide Sharpest Focus Ever

Science.gov (United States)

1997-03-01

Performing beyond expectations, the high- resolution mirrors for NASA's most powerful orbiting X-ray telescope have successfully completed initial testing at Marshall Space Flight Center's X-ray Calibration Facility, Huntsville, AL. "We have the first ground test images ever generated by the telescope's mirror assembly, and they are as good as -- or better than -- expected," said Dr. Martin Weisskopf, Marshall's chief scientist for NASA's Advanced X-ray Astrophysics Facility (AXAF). The mirror assembly, four pairs of precisely shaped and aligned cylindrical mirrors, will form the heart of NASA's third great observatory. The X-ray telescope produces an image by directing incoming X-rays to detectors at a focal point some 30 feet beyond the telescope's mirrors. The greater the percentage of X-rays brought to focus and the smaller the size of the focal spot, the sharper the image. Tests show that on orbit, the mirror assembly of the Advanced X-ray Astrophysics Facility will be able to focus approximately 70 percent of X-rays from a source to a spot less than one-half arc second in radius. The telescope's resolution is equivalent to being able to read the text of a newspaper from half a mile away. "The telescope's focus is very clear, very sharp," said Weisskopf. "It will be able to show us details of very distant sources that we know are out there, but haven't been able to see clearly." In comparison, previous X-ray telescopes -- Einstein and Rosat -- were only capable of focusing X- rays to five arc seconds. The Advanced X-ray Telescope's resolving power is ten times greater. "Images from the new telescope will allow us to make major advances toward understanding how exploding stars create and disperse many of the elements necessary for new solar systems and for life itself," said Dr. Harvey Tananbaum, director of the Advanced X- ray Astrophysics Facility Science Center at the Smithsonian Astrophysical Observatory, in Cambridge, MA -- responsible for the telescope

X-ray observations of solar flares with the Einstein Observatory

International Nuclear Information System (INIS)

Schmitt, J.H.M.M.; Fink, H.; Harnden, F.R. Jr.; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA)

1987-01-01

The first Einstein Observatory Imaging Proportional Counter (IPC) observations of solar flares are presented. These flares were detected in scattered X-ray light when the X-ray telescope was pointed at the sunlit earth. The propagation and scattering of solar X-rays in the earth's atmosphere are discussed in order to be able to deduce the solar X-ray flux incident on top of the atmosphere from scattered X-ray intensity measurements. After this correction, the scattered X-ray data are interpreted as full-disk observations of the sun obtained with the same instrumentation used for observations of flares on other stars. Employing the same data analysis and interpretation techniques, extremely good agreement is found between the physical flare parameters deduced from IPC observations and known properties of compact loop flares. This agreement demonstrates that flare observations with the IPC can reveal physical parameters such as temperature and density quite accurately in the solar case and therefore suggests that the interpretations of stellar X-ray flare observations are on a physically sound basis. 26 references

VizieR Online Data Catalog: WATCH Solar X-Ray Burst Catalogue (Crosby+ 1998)

Science.gov (United States)

Crosby, N.; Lund, N.; Vilmer, N.; Sunyaev, R.

1998-01-01

Catalogue containing solar X-ray bursts measured by the Danish Wide Angle Telescope for Cosmic Hard X-Rays (WATCH) experiment aboard the Russian satellite GRANAT in the deca-keV energy range. Table 1 lists the periods during which solar observations with WATCH are available (WATCH ON-TIME) and where the bursts listed in the catalogue have been observed. (2 data files).

Design progress of the solar UV-Vis-IR telescope (SUVIT) aboard SOLAR-C

Science.gov (United States)

Katsukawa, Y.; Ichimoto, K.; Suematsu, Y.; Hara, H.; Kano, R.; Shimizu, T.; Matsuzaki, K.

2013-09-01

We present a design progress of the Solar UV-Vis-IR Telescope (SUVIT) aboard the next Japanese solar mission SOLAR-C. SUVIT has an aperture diameter of ~1.4 m for achieving spectro-polarimetric observations with spatial and temporal resolution exceeding the Hinode Solar Optical Telescope (SOT). We have studied structural and thermal designs of the optical telescope as well as the optical interface between the telescope and the focal plane instruments. The focal plane instruments are installed into two packages, filtergraph and spectrograph packages. The spectropolarimeter is the instrument dedicated to accurate polarimetry in the three spectrum windows at 525 nm, 854 nm, and 1083 nm for observing magnetic fields at both the photospheric and chromospheric layers. We made optical design of the spectrograph accommodating the conventional slit spectrograph and the integral field unit (IFU) for two-dimensional coverage. We are running feasibility study of the IFU using fiber arrays consisting of rectangular cores.

CubeX: The CubeSAT X-ray Telescope for Elemental Abundance Mapping of Airless Bodies and X-ray Pulsar Navigation

Science.gov (United States)

Nittler, L. R.; Hong, J.; Kenter, A.; Romaine, S.; Allen, B.; Kraft, R.; Masterson, R.; Elvis, M.; Gendreau, K.; Crawford, I.; Binzel, R.; Boynton, W. V.; Grindlay, J.; Ramsey, B.

2017-12-01

The surface elemental composition of a planetary body provides crucial information about its origin, geological evolution, and surface processing, all of which can in turn provide information about solar system evolution as a whole. Remote sensing X-ray fluorescence (XRF) spectroscopy has been used successfully to probe the major-element compositions of airless bodies in the inner solar system, including the Moon, near-Earth asteroids, and Mercury. The CubeSAT X-ray Telescope (CubeX) is a concept for a 6U planetary X-ray telescope (36U with S/C), which utilizes Miniature Wolter-I X-ray optics (MiXO), monolithic CMOS and SDD X-ray sensors for the focal plane, and a Solar X-ray Monitor (heritage from the REXIS XRF instrument on NASA's OSIRIS-REx mission). CubeX will map the surface elemental composition of diverse airless bodies by spectral measurement of XRF excited by solar X-rays. The lightweight ( 1 kg) MiXO optics provide sub-arcminute resolution with low background, while the inherently rad-hard CMOS detectors provide improved spectral resolution ( 150 eV) at 0 °C. CubeX will also demonstrate X-ray pulsar timing based deep space navigation (XNAV). Successful XNAV will enable autonomous deep navigation with little to no support from the Deep Space Network, hence lowering the operation cost for many more planetary missions. Recently selected by NASA Planetary Science Deep Space SmallSat Studies, the first CubeX concept, designed to rideshare to the Moon as a secondary spacecraft on a primary mission, is under study in collaboration with the Mission Design Center at NASA Ames Research Center. From high altitude ( 6,000 km) frozen polar circular orbits, CubeX will study > 8 regions ( 110 km) of geological interest on the Moon over one year to produce a high resolution ( 2-3 km) elemental abundance map of each region. The novel focal plane design of CubeX also allows us to evaluate the performance of absolute navigation by sequential observations of several

Solar cosmic ray events at large radial distances from the sun

International Nuclear Information System (INIS)

Zwickl, R.; Webber, W.R.; McDonald, F.B.; Teegarden, B.; Trainor, J.

1975-01-01

Using the GSFC-UNH cosmic ray telescope on Pioneer 10 and 11 we have examined solar cosmic ray events out to a distance approximately 5 AU from the sun. Here we consider two aspects of this work, both related to our anisotropy studies. First, a detailed error analysis of the cosine fit to the anisotropy is presented. Second, we look at the anisotropy and intensity time characteristics during solar events as a function of radial distance. (orig.) [de

Assembly of NASA's Most Powerful X-Ray Telescope Completed

Science.gov (United States)

1998-03-01

Assembly of the world's most powerful X-ray telescope, NASA's Advanced X-ray Astrophysics Facility, was completed last week with the installation of its power-generating twin solar panels. The observatory is scheduled for launch aboard Space Shuttle mission STS-93, in December 1998. The last major components of the observatory were bolted and pinned into place March 4 at TRW Space & Electronics Group in Redondo Beach, Calif., and pre-launch testing of the fully assembled observatory began March 7. "Completion of the observatory's assembly process is a big step forward toward launch scheduled for the end of this year," said Fred Wojtalik, manager of the Observatory Projects Office at NASA's Marshall Space Flight Center in Huntsville, Ala. "With all the major components in place, we are now concentrating on a thorough pre-launch checkout of the observatory." "We're delighted to reach this major milestone for the program," said Craig Staresinich, TRW's Advanced X-ray Astrophysics Facility program manager. "The entire observatory team has worked hard to get to this point and will continue an exhaustive test program to ensure mission success. We're looking forward to delivering a truly magnificent new space capability to NASA later this summer." The first pre-launch test of the Advanced X-ray Astrophysics Facility was an acoustic test, which simulated the sound pressure environment inside the Space Shuttle cargo bay during launch. A thorough electrical checkout before and after the acoustic test verifies that the observatory and its science instruments can withstand the extreme sound levels and vibrations that accompany launch. "With 10 times the resolution and 50-100 times the sensitivity of any previous X-ray telescope, this observatory will provide us with a new perspective of our universe," said the project's chief scientist, Dr. Martin Weisskopf of Marshall Center. "We'll be able to study sources of X-rays throughout the universe, like colliding galaxies and black

On the co-alignment of solar telescopes. A new approach to solar pointing

International Nuclear Information System (INIS)

Staiger, J

2013-01-01

Helioseismological measurements require long observing times and thus may be adversely affected by lateral image drifts as caused by pointing instabilities. At the Vacuum Tower Telescope VTT, Tenerife we have recorded drift values of up to 5'' per hour under unstable thermal conditions (dome opening, strong day-to-day thermal gradients). Typically drifts of 0.5'' – 1.0'' per hour may be encountered under more favorable conditions. Past experience has shown that most high-resolution solar telescopes may be affected by this problem to some degree. This inherent shortcoming of solar pointing is caused by the fact that the guiding loop can be closed only within the guiding beam but not within the telescope's main beam. We have developed a new approach to this problem. We correlate continuum brightness patterns observed from within the telescope main beam with patterns originating from a full disk telescope. We show that brightness patterns of sufficient size are unique with respect to solar location at any instant of time and may serve as a location identifier. We make use of the fact that averaged location information of solar structures is invariant with respect to telescope resolution. We have carried out tests at the VTT together with SDO. We have used SDO as a full disk reference. We were able to reduce lateral image drifts by an order of magnitude.

Commissioning and First Operation of the Cryogenics for the CERN Axion Solar Telescope (CAST)

CERN Document Server

Barth, K; Passardi, Giorgio; Pezzetti, M; Pirotte, O; Stewart, L; Vullierme, B; Walckiers, L; Zioutas, Konstantin

2004-01-01

A new experiment, the CERN Axion Solar Telescope (CAST) was installed and commissioned in 2002. Its aim is to experimentally prove the existence of an as yet hypothetical particle predicted by theory as a solution of the strong CP problem and possible candidate for galactic dark matter. The heart of the detector consists of a decommissioned 10-m long LHC superconducting dipole prototype magnet, providing a magnetic field of up to 9.5 T. The whole telescope assembly is aligned with high precision to the core of the sun. If they exist, axions could be copiously produced in the core of the sun and converted into photons within the transverse magnetic field of the telescope. The converted low-energy solar axion spectrum, peaked around a mean energy of 4.4 keV, can then be focused by a special x-ray mirror system and detected by low-background photon detectors, installed on each end of the telescopes twin beam pipes. This paper describes the external and proximity cryogenic system and magnet commissioning as well ...

Search for solar axions with the X-ray telescope of the CAST experiment (phase II); Suche nach solaren Axionen mit dem Roentgenteleskop des CAST-Experiments (Phase II)

Energy Technology Data Exchange (ETDEWEB)

Nordt, Annika

2009-10-14

The CAST (CERN Solar Axion Telescope) experiment is searching for solar axions by their conversion into photons inside a transverse magnetic field. So far, no solar axionsignal has been detected, but a new upper limit could be given (CAST Phase I). Since 2005, CAST entered in its second phase where it operates with a buffer gas ({sup 4}He) in the conversion region to extend the sensitivity of the experiment to higher axionmasses. For the first time it is possible to enter the theoretically favored axion massrange and to give an upper limit for this solar axion mass-range (>0.02 eV). This thesis is about the analysis of the X-ray telescope data Phase II with {sup 4}He inside the magnet. The result for the coupling constant of axions to photons is: g{sub {alpha}}{sub {gamma}}{sub {gamma}}<1.6-6.0 x 10{sup -10} GeV{sup -1} (95%C.L.) for m{sub a}=0.02-0.4 eV. (2) This result is better than any result that has been given before in this mass range for solar axions. (orig.)

Secondary mirror system for the European Solar Telescope (EST)

Science.gov (United States)

Cavaller, L.; Siegel, B.; Prieto, G.; Hernandez, E.; Casalta, J. M.; Mercader, J.; Barriga, J.

2010-07-01

The European Solar Telescope (EST) is a European collaborative project to build a 4m class solar telescope in the Canary Islands, which is now in its design study phase. The telescope will provide diffraction limited performance for several instruments observing simultaneously at the Coudé focus at different wavelengths. A multi-conjugated adaptive optics system composed of a tip-tilt mirror and several deformable mirrors will be integrated in the telescope optical path. The secondary mirror system is composed of the mirror itself (Ø800mm), the alignment drives and the cooling system needed to remove the solar heat load from the mirror. During the design study the feasibility to provide fast tip-tilt capabilities at the secondary mirror to work as the adaptive optics tip-tilt mirror is also being evaluated.

Cross-Calibrating Sunspot Magnetic Field Strength Measurements from the McMath-Pierce Solar Telescope and the Dunn Solar Telescope

Science.gov (United States)

Watson, Fraser T.; Beck, Christian; Penn, Matthew J.; Tritschler, Alexandra; Pillet, Valentín Martinez; Livingston, William C.

2015-11-01

In this article we describe a recent effort to cross-calibrate data from an infrared detector at the McMath-Pierce Solar Telescope and the Facility InfraRed Spectropolarimeter (FIRS) at the Dunn Solar Telescope. A synoptic observation program at the McMath-Pierce has measured umbral magnetic field strengths since 1998, and this data set has recently been compared with umbral magnetic field observations from SOHO/MDI and SDO/HMI. To further improve on the data from McMath-Pierce, we compared the data with measurements taken at the Dunn Solar Telescope with far greater spectral resolution than has been possible with space instrumentation. To minimise potential disruption to the study, concurrent umbral measurements were made so that the relationship between the two datasets can be most accurately characterised. We find that there is a strong agreement between the umbral magnetic field strengths recorded by each instrument, and we reduced the FIRS data in two different ways to successfully test this correlation further.

Hard x-ray telescope mission

DEFF Research Database (Denmark)

Gorenstein, P.; Worrall, D.; Joensen, K.D.

1996-01-01

The Hard X-Ray Telescope was selected for study as a possible new intermediate size mission for the early 21st century. Its principal attributes are: (1) multiwavelength observing with a system of focussing telescopes that collectively observe from the UV to over 1 MeV, (2) much higher sensitivity...

A satellite born charged particles telescope for the study of cosmic ray nuclei

Energy Technology Data Exchange (ETDEWEB)

De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy)]|[INFN, Rome (Italy); Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy); Bellotti, R.; Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy)

1995-09-01

The description of the high energy particle telescope NINA for the study of cosmic ray nuclei is presented. The instrument will be installed on board of the Resource 01 satellite and will fly on a polar orbit at 690 Km. The telescope consists on a pile of 16 detecting planes each of them is composed by two silicon strip detectors with perpendicular strips and has a total area of 60x60mm{sup 2}. The experiment goals are the study of cosmic ray protons and nuclei in the energy range 12-100 MeV/amu. It will be sensitive to the anomalous component and will also make the observation of the large solar flare events and geophysical phenomena as well. This experiment is the first step of the program RIM whose goal is the satellite study of anti particles in primary cosmic rays.

Toward Adaptive X-Ray Telescopes

Science.gov (United States)

O'Dell, Stephen L.; Atkins, Carolyn; Button, Tim W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peer; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffrey J.;

Optical Design for a Survey X-Ray Telescope

Science.gov (United States)

Saha, Timo T.; Zhang, William W.; McClelland, Ryan S.

2014-01-01

Optical design trades are underway at the Goddard Space Flight Center to define a telescope for an x-ray survey mission. Top-level science objectives of the mission include the study of x-ray transients, surveying and long-term monitoring of compact objects in nearby galaxies, as well as both deep and wide-field x-ray surveys. In this paper we consider Wolter, Wolter-Schwarzschild, and modified Wolter-Schwarzschild telescope designs as basic building blocks for the tightly nested survey telescope. Design principles and dominating aberrations of individual telescopes and nested telescopes are discussed and we compare the off-axis optical performance at 1.0 KeV and 4.0 KeV across a 1.0-degree full field-of-view.

The 1.5 meter solar telescope GREGOR

Science.gov (United States)

Schmidt, W.; von der Lühe, O.; Volkmer, R.; Denker, C.; Solanki, S. K.; Balthasar, H.; Bello Gonzalez, N.; Berkefeld, Th.; Collados, M.; Fischer, A.; Halbgewachs, C.; Heidecke, F.; Hofmann, A.; Kneer, F.; Lagg, A.; Nicklas, H.; Popow, E.; Puschmann, K. G.; Schmidt, D.; Sigwarth, M.; Sobotka, M.; Soltau, D.; Staude, J.; Strassmeier, K. G.; Waldmann , T. A.

2012-11-01

The 1.5 m telescope GREGOR opens a new window to the understanding of solar small-scale magnetism. The first light instrumentation includes the Gregor Fabry Pérot Interferometer (GFPI), a filter spectro-polarimeter for the visible wavelength range, the GRating Infrared Spectro-polarimeter (GRIS) and the Broad-Band Imager (BBI). The excellent performance of the first two instruments has already been demonstrated at the Vacuum Tower Telescope. GREGOR is Europe's largest solar telescope and number 3 in the world. Its all-reflective Gregory design provides a large wavelength coverage from the near UV up to at least 5 microns. The field of view has a diameter of 150 arcsec. GREGOR is equipped with a high-order adaptive optics system, with a subaperture size of 10 cm, and a deformable mirror with 256 actuators. The science goals are focused on, but not limited to, solar magnetism. GREGOR allows us to measure the emergence and disappearance of magnetic flux at the solar surface at spatial scales well below 100 km. Thanks to its spectro-polarimetric capabilities, GREGOR will measure the interaction between the plasma flows, different kinds of waves, and the magnetic field. This will foster our understanding of the processes that heat the chromosphere and the outer layers of the solar atmosphere. Observations of the surface magnetic field at very small spatial scales will shed light on the variability of the solar brightness.

Proposed National Large Solar Telescope Jagdev Singh

Indian Academy of Sciences (India)

proposed to design, fabricate and install a 2-meter class solar telescope at a suitable site in India to ... which can facilitate simultaneous measurements of the solar atmospheric parameters and of the vector ... Intensity variation of. 1% or less.

Millimeter and X-Ray Emission from the 5 July 2012 Solar Flare

Science.gov (United States)

Tsap, Y. T.; Smirnova, V. V.; Motorina, G. G.; Morgachev, A. S.; Kuznetsov, S. A.; Nagnibeda, V. G.; Ryzhov, V. S.

2018-03-01

The 5 July 2012 solar flare SOL2012-07-05T11:44 (11:39 - 11:49 UT) with an increasing millimeter spectrum between 93 and 140 GHz is considered. We use space and ground-based observations in X-ray, extreme ultraviolet, microwave, and millimeter wave ranges obtained with the Reuven Ramaty High-Energy Solar Spectroscopic Imager, Solar Dynamics Observatory (SDO), Geostationary Operational Environmental Satellite, Radio Solar Telescope Network, and Bauman Moscow State Technical University millimeter radio telescope RT-7.5. The main parameters of thermal and accelerated electrons were determined through X-ray spectral fitting assuming the homogeneous thermal source and thick-target model. From the data of the Atmospheric Imaging Assembly/SDO and differential-emission-measure calculations it is shown that the thermal coronal plasma gives a negligible contribution to the millimeter flare emission. Model calculations suggest that the observed increase of millimeter spectral flux with frequency is determined by gyrosynchrotron emission of high-energy (≳ 300 keV) electrons in the chromosphere. The consequences of the results are discussed in the light of the flare-energy-release mechanisms.

NST: Thermal Modeling for a Large Aperture Solar Telescope

Science.gov (United States)

Coulter, Roy

2011-05-01

Late in the 1990s the Dutch Open Telescope demonstrated that internal seeing in open, large aperture solar telescopes can be controlled by flushing air across the primary mirror and other telescope structures exposed to sunlight. In that system natural wind provides a uniform air temperature throughout the imaging volume, while efficiently sweeping heated air away from the optics and mechanical structure. Big Bear Solar Observatory's New Solar Telescope (NST) was designed to realize that same performance in an enclosed system by using both natural wind through the dome and forced air circulation around the primary mirror to provide the uniform air temperatures required within the telescope volume. The NST is housed in a conventional, ventilated dome with a circular opening, in place of the standard dome slit, that allows sunlight to fall only on an aperture stop and the primary mirror. The primary mirror is housed deep inside a cylindrical cell with only minimal openings in the side at the level of the mirror. To date, the forced air and cooling systems designed for the NST primary mirror have not been implemented, yet the telescope regularly produces solar images indicative of the absence of mirror seeing. Computational Fluid Dynamics (CFD) analysis of the NST primary mirror system along with measurements of air flows within the dome, around the telescope structure, and internal to the mirror cell are used to explain the origin of this seemingly incongruent result. The CFD analysis is also extended to hypothetical systems of various scales. We will discuss the results of these investigations.

The first X-ray imaging spectroscopy of quiescent solar active regions with NuSTAR

DEFF Research Database (Denmark)

Hannah, Iain G.; Grefenstette, Brian W.; Smith, David M.

2016-01-01

We present the first observations of quiescent active regions (ARs) using the Nuclear Spectroscopic Telescope Array (NuSTAR), a focusing hard X-ray telescope capable of studying faint solar emission from high-temperature and non-thermal sources. We analyze the first directly imaged and spectrally...... resolved X-rays above 2 keV from non-flaring ARs, observed near the west limb on 2014 November 1. The NuSTAR X-ray images match bright features seen in extreme ultraviolet and soft X-rays. The NuSTAR imaging spectroscopy is consistent with isothermal emission of temperatures 3.1-4.4 MK and emission...

Physics and astrophysics with gamma-ray telescopes

Energy Technology Data Exchange (ETDEWEB)

Vandenbroucke, J. [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)

2012-08-15

In the past few years gamma-ray astronomy has entered a golden age. A modern suite of telescopes is now scanning the sky over both hemispheres and over six orders of magnitude in energy. At {approx}TeV energies, only a handful of sources were known a decade ago, but the current generation of ground-based imaging atmospheric Cherenkov telescopes (H.E.S.S., MAGIC, and VERITAS) has increased this number to nearly one hundred. With a large field of view and duty cycle, the Tibet and Milagro air shower detectors have demonstrated the promise of the direct particle detection technique for TeV gamma rays. At {approx}GeV energies, the Fermi Gamma-ray Space Telescope has increased the number of known sources by nearly an order of magnitude in its first year of operation. New classes of sources that were previously theorized to be gamma-ray emitters have now been confirmed observationally. Moreover, there have been surprise discoveries of GeV gamma-ray emission from source classes for which no theory predicted it was possible. In addition to elucidating the processes of high-energy astrophysics, gamma-ray telescopes are making essential contributions to fundamental physics topics including quantum gravity, gravitational waves, and dark matter. I summarize the current census of astrophysical gamma-ray sources, highlight some recent discoveries relevant to fundamental physics, and describe the synergetic connections between gamma-ray and neutrino astronomy. This is a brief overview intended in particular for particle physicists and neutrino astronomers, based on a presentation at the Neutrino 2010 conference in Athens, Greece. I focus in particular on results from Fermi (which was launched soon after Neutrino 2008), and conclude with a description of the next generation of instruments, namely HAWC and the Cherenkov Telescope Array.

The X-ray mirror telescope and the pn-CCD detector of CAST

CERN Document Server

Kuster, M; Englhauser, J; Franz, J; Friedrich, P; Hartmann, R; Kang, D; Kotthaus, R; Lutz, Gerhard; Moralez, J; Serber, W; Strüder, L

2004-01-01

The Cern Axion Solar Telescope - CAST - uses a prototype 9 Tesla LHC superconducting dipole magnet to search for a hypothetical pseudoscalar particle, the axion, which was proposed by theory in the 1980s to solve the strong CP problem and which could be a dark matter candidate. In CAST a strong magnetic field is used to convert the solar axions to detectable photons via inverse Primakoff effect. The resulting X-rays are thermally distributed in the energy range of 1-7 keV and can be observed with conventional X-ray detectors. The most sensitive detector system of CAST is a pn-CCD detector originally developed for XMM-Newton combined with a Wolter I type X-ray mirror system. The combination of a focusing X-ray optics and a state of the art pn-CCD detector which combines high quantum efficiency, good spacial and energy resolution, and low background improves the sensitivity of the CAST experiment such that for the first time the axion photon coupling constant can be probed beyond the best astrophysical constrai...

Novel X-ray telescopes for wide-field X-ray monitoring

International Nuclear Information System (INIS)

Hudec, R.; Inneman, A.; Pina, L.; Sveda, L.

2005-01-01

We report on fully innovative very wide-field of view X-ray telescopes with high sensitivity as well as large field of view. The prototypes are very promising, allowing the proposals for space projects with very wide-field Lobster-eye X-ray optics to be considered. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study and to understand various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc. The Lobster optics based X-ray All Sky Monitor is capable to detect around 20 GRBs and 8 XRFs yearly and this will surely significantly contribute to the related science

Operating performance of the gamma-ray Cherenkov telescope: An end-to-end Schwarzschild–Couder telescope prototype for the Cherenkov Telescope Array

Energy Technology Data Exchange (ETDEWEB)

Dournaux, J.L., E-mail: jean-laurent.dournaux@obspm.fr [GEPI, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Paris Cité, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); De Franco, A. [Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Laporte, P. [GEPI, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Paris Cité, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); White, R. [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Greenshaw, T. [University of Liverpool, Oliver Lodge Laboratory, P.O. Box 147, Oxford Street, Liverpool L69 3BX (United Kingdom); Sol, H. [LUTH, Observatoire de Paris, PSL Research University, CNRS, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); Abchiche, A. [CNRS, Division technique DT-INSU, 1 Place Aristide Briand, 92190 Meudon (France); Allan, D. [Department of Physics and Centre for Advanced Instrumentation, Durham University, South Road, Durham DH1 3LE (United Kingdom); Amans, J.P. [GEPI, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Paris Cité, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); Armstrong, T.P. [Department of Physics and Centre for Advanced Instrumentation, Durham University, South Road, Durham DH1 3LE (United Kingdom); Balzer, A.; Berge, D. [GRAPPA, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Boisson, C. [LUTH, Observatoire de Paris, PSL Research University, CNRS, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); and others

2017-02-11

The Cherenkov Telescope Array (CTA) consortium aims to build the next-generation ground-based very-high-energy gamma-ray observatory. The array will feature different sizes of telescopes allowing it to cover a wide gamma-ray energy band from about 20 GeV to above 100 TeV. The highest energies, above 5 TeV, will be covered by a large number of Small-Sized Telescopes (SSTs) with a field-of-view of around 9°. The Gamma-ray Cherenkov Telescope (GCT), based on Schwarzschild–Couder dual-mirror optics, is one of the three proposed SST designs. The GCT is described in this contribution and the first images of Cherenkov showers obtained using the telescope and its camera are presented. These were obtained in November 2015 in Meudon, France.

SphinX: The Solar Photometer in X-Rays

Science.gov (United States)

Gburek, Szymon; Sylwester, Janusz; Kowalinski, Miroslaw; Bakala, Jaroslaw; Kordylewski, Zbigniew; Podgorski, Piotr; Plocieniak, Stefan; Siarkowski, Marek; Sylwester, Barbara; Trzebinski, Witold; Kuzin, Sergey V.; Pertsov, Andrey A.; Kotov, Yurij D.; Farnik, Frantisek; Reale, Fabio; Phillips, Kenneth J. H.

2013-04-01

Solar Photometer in X-rays (SphinX) was a spectrophotometer developed to observe the Sun in soft X-rays. The instrument observed in the energy range ≈ 1 - 15 keV with resolution ≈ 0.4 keV. SphinX was flown on the Russian CORONAS-PHOTON satellite placed inside the TESIS EUV and X telescope assembly. The spacecraft launch took place on 30 January 2009 at 13:30 UT at the Plesetsk Cosmodrome in Russia. The SphinX experiment mission began a couple of weeks later on 20 February 2009 when the first telemetry dumps were received. The mission ended nine months later on 29 November 2009 when data transmission was terminated. SphinX provided an excellent set of observations during very low solar activity. This was indeed the period in which solar activity dropped to the lowest level observed in X-rays ever. The SphinX instrument design, construction, and operation principle are described. Information on SphinX data repositories, dissemination methods, format, and calibration is given together with general recommendations for data users. Scientific research areas in which SphinX data find application are reviewed.

Variable X-ray sky with Lobster Eye Telescopes

International Nuclear Information System (INIS)

Hudec, R.; Pina, L.; Inneman, A.; Sveda, L.

2004-01-01

The variable X-ray sky requires wide-field monitoring with high sensitivity. We refer on novel X-ray telescopes with high sensitivity as well as large field of view. The results are very promising, allowing the proposals for space projects with very wide-field Lobster-eye X-ray optics to be considered. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study and to understand various astrophysical objects such as AGN, SNe, GRBs, X-ray flashes, galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc

Hard X-ray imaging with a slat collimated telescope

International Nuclear Information System (INIS)

Lu Zhuguo; Kotov, Yu.D.; Suslov, A.Yu.

1995-01-01

Imaging experiments with a slat collimated hard X-ray telescope are described in this paper demonstrating the feasibility of the direct demodulation imaging method used in hard X-ray scanning modulation experiments. On 25 September 1993 an X-ray raster scan observation of Cyg X-1 was performed in a balloon flight with the hard X-ray telescope HAPI-4. An experiment to image radioactive X-ray sources was performed in the laboratory before. In both experiments the expected X-ray images were obtained, confirming the imaging capability of this method. (orig.)

A retrospective of the GREGOR solar telescope in scientific literature

Science.gov (United States)

Denker, C.; von der Lühe, O.; Feller, A.; Arlt, K.; Balthasar, H.; Bauer, S.-M.; Bello González, N.; Berkefeld, Th.; Caligari, P.; Collados, M.; Fischer, A.; Granzer, T.; Hahn, T.; Halbgewachs, C.; Heidecke, F.; Hofmann, A.; Kentischer, T.; Klva{ňa, M.; Kneer, F.; Lagg, A.; Nicklas, H.; Popow, E.; Puschmann, K. G.; Rendtel, J.; Schmidt, D.; Schmidt, W.; Sobotka, M.; Solanki, S. K.; Soltau, D.; Staude, J.; Strassmeier, K. G.; Volkmer, R.; Waldmann, T.; Wiehr, E.; Wittmann, A. D.; Woche, M.

2012-11-01

In this review, we look back upon the literature, which had the GREGOR solar telescope project as its subject including science cases, telescope subsystems, and post-focus instruments. The articles date back to the year 2000, when the initial concepts for a new solar telescope on Tenerife were first presented at scientific meetings. This comprehensive bibliography contains literature until the year 2012, i.e., the final stages of commissioning and science verification. Taking stock of the various publications in peer-reviewed journals and conference proceedings also provides the ``historical'' context for the reference articles in this special issue of Astronomische Nachrichten/Astronomical Notes.

LOBSTER: new space x-ray telescopes

Science.gov (United States)

Hudec, R.; Sveda, L.; Pína, L.; Inneman, A.; Semencova, V.; Skulinova, M.

2017-11-01

The LOBSTER telescopes are based on the optical arrangement of the lobster eye. The main difference from classical X-ray space telescopes in wide use is the very large field of view while the use of optics results in higher efficiency if compared with detectors without optics. Recent innovative technologies have enabled to design, to develop and to test first prototypes. They will provide deep sensitive survey of the sky in X-rays for the first time which is essential for both long-term monitoring of celestial high-energy sources as well as in understanding transient phenomena. The technology is now ready for applications in space.

X-ray astronomy 2000: Wide field X-ray monitoring with lobster-eye telescopes

International Nuclear Information System (INIS)

Inneman, A.; Hudec, R.; Pina, L.; Gorenstein, P.

2001-01-01

The recently available first prototypes of innovative very wide field X-ray telescopes of Lobster-Eye type confirm the feasibility to develop such flight instruments in a near future. These devices are expected to allow very wide field (more than 1000 square degrees) monitoring of the sky in X-rays (up to 10 keV and perhaps even more) with faint limits. We will discuss the recent status of the development of very wide field X-ray telescopes as well as related scientific questions including expected major contributions such as monitoring and study of X-ray afterglows of Gamma Ray Bursts

Optical telescope BIRT in ORIGIN for gamma ray burst observing

DEFF Research Database (Denmark)

Content, Robert; Content, Robert; Sharples, Ray

2012-01-01

The ORIGIN concept is a space mission with a gamma ray, an X-ray and an optical telescope to observe the gamma ray bursts at large Z to determine the composition and density of the intergalactic matter in the line of sight. It was an answer to the ESA M3 call for proposal. The optical telescope i...... length. All 3 instruments use the same 2k x 2k detector simultaneously so that telescope pointing and tip-tilt control of a fold mirror permit to place the gamma ray burst on the desired instrument without any other mechanism. © 2012 SPIE....

Solar cooker effect test and temperature field simulation of radio telescope subreflector

International Nuclear Information System (INIS)

Chen, Deshen; Wang, Huajie; Qian, Hongliang; Zhang, Gang; Shen, Shizhao

2016-01-01

Highlights: • Solar cooker effect test of a telescope subreflector is conducted for the first time. • The cause and temperature distribution regularities are analyzed contrastively. • Simulation methods are proposed using light beam segmentation and tracking methods. • The validity of simulation methods is evaluated using the test results. - Abstract: The solar cooker effect can cause a local high temperature of the subreflector and can directly affect the working performance of the radio telescope. To study the daily temperature field and solar cooker effect of a subreflector, experimental studies are carried out with a 3-m-diameter radio telescope model for the first time. Initially, the solar temperature distribution rules, especially the solar cooker effect, are summarized according to the field test results under the most unfavorable conditions. Then, a numerical simulation for the solar temperature field of the subreflector is studied by light beam segmentation and tracking methods. Finally, the validity of the simulation methods is evaluated using the test results. The experimental studies prove that the solar cooker effect really exists and should not be overlooked. In addition, simulation methods for the subreflector temperature field proposed in this paper are effective. The research methods and conclusions can provide valuable references for thermal design, monitoring and control of similar high-precision radio telescopes.

Prospects for the CERN Axion Solar Telescope Sensitivity to 14.4 keV Axions

CERN Document Server

Jakovcic, K; Aune, S; Avignone, F T; Barth, K; Belov, A; Beltrn, B; Bruninger, H; Carmona, J M; Cebrin, S; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Eleftheriadis, C; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Ioanis; Gninenko, S; Hasinoff, M D; Heinsius, F H; Hoffmann, Dieter H H; Irastorza, I G; Jacoby, J; Kang, D; Knigsmann, K; Kotthaus, R; Krcmar, M; Kousouris, a K; Kuster, M; Laki, B; Lasseur, C; Liolios, A; Ljubici, A; Lutz, G; Luzn, G; Miller, D W; Morales, A; Morales, J; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Ruz, J; Riege, H; Semertzidis, Y K; Serpico, Pasquale Dario; Stewart, o L; Vieira, J D; Villar, J; Vogel, J; Walckiers, L; Zioutas, K; Jakovcic, Kresimir

2007-01-01

The CERN Axion Solar Telescope (CAST) is searching for solar axions using the 9.0 T strong and 9.26 m long transverse magnetic field of a twin aperture LHC test magnet, where axions could be converted into X-rays via reverse Primakoff process. Here we explore the potential of CAST to search for 14.4 keV axions that could be emitted from the Sun in M1 nuclear transition between the first, thermally excited state, and the ground state of 57Fe nuclide. Calculations of the expected signals, with respect to the axion-photon coupling, axion-nucleon coupling and axion mass, are presented in comparison with the experimental sensitivity.

Search for Solar Axions by the CERN Axion Solar Telescope with 3 He Buffer Gas: Closing the Hot Dark Matter Gap

CERN Document Server

Arik, M.; Barth, K.; Belov, A.; Borghi, S.; Bräuninger, H.; Cantatore, G.; Carmona, J.M.; Cetin, S.A.; Collar, J.I.; Da Riva, E.; Dafni, T.; Davenport, M.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Friedrich, P.; Galán, J.; García, J.A.; Gardikiotis, A.; Garza, J.G.; Gazis, E.N.; Geralis, T.; Georgiopoulou, E.; Giomataris, I.; Gninenko, S.; Gómez, H.; Gómez Marzoa, M.; Gruber, E.; Guthörl, T.; Hartmann, R.; Hauf, S.; Haug, F.; Hasinoff, M.D.; Hoffmann, D.H.H.; Iguaz, F.J.; Irastorza, I.G.; Jacoby, J.; Jakovčić, K.; Karuza, M.; Königsmann, K.; Kotthaus, R.; Krčmar, M.; Kuster, M.; Lakić, B.; Lang, P.M.; Laurent, J.M.; Liolios, A.; Ljubičić, A.; Lozza, V.; Luzón, G.; Neff, S.; Niinikoski, T.; Nordt, A.; Papaevangelou, T.; Pivovaroff, M.J.; Raffelt, G.; Riege, H.; Rodríguez, A.; Rosu, M.; Ruz, J.; Savvidis, I.; Shilon, I.; Silva, P.S.; Solanki, S.K.; Stewart, L.; Tomás, A.; Tsagri, M.; van Bibber, K.; Vafeiadis, T.; Villar, J.; Vogel, J.K.; Yildiz, S.C.; Zioutas, K.

2014-01-01

The CERN Axion Solar Telescope (CAST) has finished its search for solar axions with 3^He buffer gas, covering the search range 0.64 eV < m_a <1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess X-rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g_ag < 3.3 x 10^{-10} GeV^{-1} at 95% CL, with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of g_a, for example by the currently discussed next generation helioscope IAXO.

Search for Solar Axions by the CERN Axion Solar Telescope with He3 Buffer Gas: Closing the Hot Dark Matter Gap

Science.gov (United States)

Arik, M.; Aune, S.; Barth, K.; Belov, A.; Borghi, S.; Bräuninger, H.; Cantatore, G.; Carmona, J. M.; Cetin, S. A.; Collar, J. I.; Da Riva, E.; Dafni, T.; Davenport, M.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Friedrich, P.; Galán, J.; García, J. A.; Gardikiotis, A.; Garza, J. G.; Gazis, E. N.; Geralis, T.; Georgiopoulou, E.; Giomataris, I.; Gninenko, S.; Gómez, H.; Gómez Marzoa, M.; Gruber, E.; Guthörl, T.; Hartmann, R.; Hauf, S.; Haug, F.; Hasinoff, M. D.; Hoffmann, D. H. H.; Iguaz, F. J.; Irastorza, I. G.; Jacoby, J.; Jakovčić, K.; Karuza, M.; Königsmann, K.; Kotthaus, R.; Krčmar, M.; Kuster, M.; Lakić, B.; Lang, P. M.; Laurent, J. M.; Liolios, A.; Ljubičić, A.; Luzón, G.; Neff, S.; Niinikoski, T.; Nordt, A.; Papaevangelou, T.; Pivovaroff, M. J.; Raffelt, G.; Riege, H.; Rodríguez, A.; Rosu, M.; Ruz, J.; Savvidis, I.; Shilon, I.; Silva, P. S.; Solanki, S. K.; Stewart, L.; Tomás, A.; Tsagri, M.; van Bibber, K.; Vafeiadis, T.; Villar, J.; Vogel, J. K.; Yildiz, S. C.; Zioutas, K.; CAST Collaboration

2014-03-01

The CERN Axion Solar Telescope has finished its search for solar axions with He3 buffer gas, covering the search range 0.64 eV≲ma≲1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of gaγ≲3.3×10-10 GeV-1 at 95% C.L., with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of gaγ, for example by the currently discussed next generation helioscope International AXion Observatory.

The Animated Gamma-ray Sky Revealed by the Fermi Gamma-ray Space Telescope

International Nuclear Information System (INIS)

Grenier, Isabelle

2009-01-01

The Fermi Gamma-ray Space Telescope has been observing the sky in gamma-rays since August 2008. In addition to breakthrough capabilities in energy coverage (20 MeV-300 GeV) and angular resolution, the wide field of view of the Large Area Telescope enables observations of 20% of the sky at any instant, and of the whole sky every three hours. It has revealed a very animated sky with bright gamma-ray bursts flashing and vanishing in minutes, powerful active galactic nuclei flaring over hours and days, many pulsars twinkling in the Milky Way, and X-ray binaries shimmering along their orbit. Most of these variable sources had not been seen by the Fermi predecessor, EGRET, and the wealth of new data already brings important clues to the origin of the high-energy emission and particles powered by the compact objects. The telescope also brings crisp images of the bright gamma-ray emission produced by cosmic-ray interactions in the interstellar medium, thus allowing to measure the cosmic nuclei and electron spectra across the Galaxy, to weigh interstellar clouds, in particular in the dark-gas phase. The telescope sensitivity at high energy will soon provide useful constraints on dark-matter annihilations in a variety of environments. I will review the current results and future prospects of the Fermi mission.

Imaging capabilities of SXT for Solar-A

Science.gov (United States)

Lemen, J. R.; Acton, L. W.; Brown, W. A.; Bruner, M. E.; Catura, R. C.

1991-01-01

The present study characterizes the Soft X-ray Telescope (SXT), a grazing-incidence solar X-ray telescope which will be flown on the Japanese Solar-A satellite. X-ray tests showed that the SXT mirror meets or exceeds design requirements. SXT advantages over Skylab are: improved time resolution (not less than 0.5 s), greatly decreased mirror scatter, coaligned aspect telescope to intersperse images of sunspots and magnetic plage, and digital data readout.

Progress of site survey for large solar telescopes in western China

Science.gov (United States)

Liu, Yu; Song, Tengfei; Zhang, Xuefei; Liu, Shunqing; Zhao, Mingyu; Tian, Zhanjun; Miao, Yuhu; Li, Hongbo; Huang, Jing; Su, Baoyu; Lu, Yongyin; Li, Xiaobo; Song, Qiwu

Excellent sites are necessary for developing and installing ground-based large telescopes. For very-high-resolution solar observations, it had been unclear whether there exist good candidate sites in the west areas in China, including the Tibetan Plateau and the Pamirs Plateau. The project of solar site survey for the next-generation large solar telescopes, i.e., the Chinese Giant Solar Telescope (CGST) and the large coronagraph, has been launched since 2011. Based on the close collaboration among Chinese solar society and the scientists from NSO, HAO and other institutes, we have successfully developed the standard instruments for solar site survey and applied them to more than 50 different sites distributed in Xinjiang, Tibet, Qinghai, Sichuan, Yunnan and Ningxia provinces. We have built two long-term monitoring sites in Tibet and the large Shangri-La to take systematic site data. Clear evidence, including the key parameters of seeing factor, sky brightness and water vapor content, has indicated that a few potential sites in the large Tibetan areas should obtain the excellent astronomical conditions for our purpose to develop CGST and large coronagraph. We introduce the fresh site survey results in this report.

Soft X-ray focusing Telescope aboard AstroSat

DEFF Research Database (Denmark)

Singh, K. P.; Dewangan, G. C.; Chandra, S.

2017-01-01

The Soft X-ray focusing Telescope (SXT) is a moderateresolution X-ray imaging spectrometer supplementing the ultraviolet and hard X-ray payloads for broadband studies of cosmic sources with AstroSat. Well suited for observing bright X-ray sources, SXT observations of nearby active galactic nuclei...

SphinX MEASUREMENTS OF THE 2009 SOLAR MINIMUM X-RAY EMISSION

International Nuclear Information System (INIS)

Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Bakała, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B.; Kuzin, S.; Farnik, F.; Reale, F.; Phillips, K. J. H.

2012-01-01

The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 × 10 47 cm –3 and 1.1 × 10 48 cm –3 . Comparing SphinX emission with that from the Hinode X-ray Telescope, we deduce that most of the emission is from general coronal structures rather than confined features like bright points. For one of 27 intervals of exceptionally low activity identified in the SphinX data, the Sun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT (0.1-2.4 keV) was less than most nearby K and M dwarfs.

SphinX Measurements of the 2009 Solar Minimum X-Ray Emission

Science.gov (United States)

Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Kuzin, S.; Farnik, F.; Reale, F.; Phillips, K. J. H.; Bakała, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B.

2012-06-01

The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 × 1047 cm-3 and 1.1 × 1048 cm-3. Comparing SphinX emission with that from the Hinode X-ray Telescope, we deduce that most of the emission is from general coronal structures rather than confined features like bright points. For one of 27 intervals of exceptionally low activity identified in the SphinX data, the Sun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT (0.1-2.4 keV) was less than most nearby K and M dwarfs.

SphinX MEASUREMENTS OF THE 2009 SOLAR MINIMUM X-RAY EMISSION

Energy Technology Data Exchange (ETDEWEB)

Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Bakala, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B. [Space Research Centre, Polish Academy of Sciences, 51-622, Kopernika 11, Wroclaw (Poland); Kuzin, S. [P. N. Lebedev Physical Institute (FIAN), Russian Academy of Sciences, Leninsky Prospect 53, Moscow 119991 (Russian Federation); Farnik, F. [Astronomical Institute, Ondrejov Observatory (Czech Republic); Reale, F. [Dipartimento di Fisica, Universita di Palermo, Palermo, Italy, and INAF, Osservatorio Astronomico di Palermo, Palermo (Italy); Phillips, K. J. H., E-mail: js@cbk.pan.wroc.pl [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom)

2012-06-01

The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 Multiplication-Sign 10{sup 47} cm{sup -3} and 1.1 Multiplication-Sign 10{sup 48} cm{sup -3}. Comparing SphinX emission with that from the Hinode X-ray Telescope, we deduce that most of the emission is from general coronal structures rather than confined features like bright points. For one of 27 intervals of exceptionally low activity identified in the SphinX data, the Sun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT (0.1-2.4 keV) was less than most nearby K and M dwarfs.

Search for solar axions by the CERN axion solar telescope with 3He buffer gas: closing the hot dark matter gap.

Science.gov (United States)

Arik, M; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Da Riva, E; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Garza, J G; Gazis, E N; Geralis, T; Georgiopoulou, E; Giomataris, I; Gninenko, S; Gómez, H; Gómez Marzoa, M; Gruber, E; Guthörl, T; Hartmann, R; Hauf, S; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovčić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Lang, P M; Laurent, J M; Liolios, A; Ljubičić, A; Luzón, G; Neff, S; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, I; Shilon, I; Silva, P S; Solanki, S K; Stewart, L; Tomás, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J; Vogel, J K; Yildiz, S C; Zioutas, K

2014-03-07

The CERN Axion Solar Telescope has finished its search for solar axions with (3)He buffer gas, covering the search range 0.64 eV ≲ ma ≲ 1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of gaγ ≲ 3.3 × 10(-10)  GeV(-1) at 95% C.L., with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of gaγ, for example by the currently discussed next generation helioscope International AXion Observatory.

FERMI/LARGE AREA TELESCOPE BRIGHT GAMMA-RAY SOURCE LIST

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Atwood, W. B.; Axelsson, M.; Battelino, M.; Baldini, L.; Bellazzini, R.; Ballet, J.; Band, D. L.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bignami, G. F.; Bonamente, E.

2009-01-01

Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope (Fermi) began a sky survey in August. The Large Area Telescope (LAT) on Fermi in three months produced a deeper and better resolved map of the γ-ray sky than any previous space mission. We present here initial results for energies above 100 MeV for the 205 most significant (statistical significance greater than ∼10σ) γ-ray sources in these data. These are the best characterized and best localized point-like (i.e., spatially unresolved) γ-ray sources in the early mission data.

Fermi Large Area Telescope Bright Gamma-ray Source List

Energy Technology Data Exchange (ETDEWEB)

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /KIPAC, Menlo Park /SLAC; Ajello, M.; /KIPAC, Menlo Park /SLAC; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Band, D.L.; /NASA, Goddard /NASA, Goddard; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Bechtol, K.; /KIPAC, Menlo Park /SLAC; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /KIPAC, Menlo Park /SLAC; Bignami, G.F.; /Pavia U.; Bloom, Elliott D.; /KIPAC, Menlo Park /SLAC; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /KIPAC, Menlo Park /SLAC; Bregeon, J.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle /Bari U. /INFN, Bari /KIPAC, Menlo Park /SLAC /IASF, Milan /IASF, Milan /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /KIPAC, Menlo Park /SLAC /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /KIPAC, Menlo Park /SLAC /INFN, Perugia /Perugia U. /KIPAC, Menlo Park /SLAC /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /KIPAC, Menlo Park /SLAC /ASDC, Frascati /NASA, Goddard /Maryland U. /Naval Research Lab, Wash., D.C. /INFN, Trieste /Pavia U. /Bari U. /INFN, Bari /KIPAC, Menlo Park /SLAC /UC, Santa Cruz /KIPAC, Menlo Park /SLAC /KIPAC, Menlo Park /SLAC /KIPAC, Menlo Park /SLAC /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /NASA, Goddard; /more authors..

2009-05-15

Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope (Fermi) began a sky survey in August. The Large Area Telescope (LAT) on Fermi in three months produced a deeper and better resolved map of the {gamma}-ray sky than any previous space mission. We present here initial results for energies above 100 MeV for the 205 most significant (statistical significance greater than {approx}10{sigma}) {gamma}-ray sources in these data. These are the best characterized and best localized point-like (i.e., spatially unresolved) {gamma}-ray sources in the early mission data.

CRaTER: The Cosmic Ray Telescope for the Effects of Radiation Experiment on the Lunar Reconnaissance Orbiter Mission

OpenAIRE

Spence, H. E.; Case, A. W.; Golightly, M. J.; Heine, T.; Larsen, B. A.; Blake, J. B.; Caranza, P.; Crain, W. R.; George, J.; Lalic, M.; Lin, A.; Looper, M. D.; Mazur, J. E.; Salvaggio, D.; Kasper, J. C.

2009-01-01

The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO) characterizes the radiation environment to be experienced by humans during future lunar missions. CRaTER measures the effects of ionizing energy loss in matter due to penetrating solar energetic protons (SEP) and galactic cosmic rays (GCR), specifically in silicon solid-state detectors and after interactions with tissue-equivalent plastic (TEP), a synthetic analog of human tissue. The CRaT...

Soft X-ray variability over the present minimum of solar activity as observed by SphinX

Science.gov (United States)

Gburek, S.; Siarkowski, M.; Kepa, A.; Sylwester, J.; Kowalinski, M.; Bakala, J.; Podgorski, P.; Kordylewski, Z.; Plocieniak, S.; Sylwester, B.; Trzebinski, W.; Kuzin, S.

2011-04-01

Solar Photometer in X-rays (SphinX) is an instrument designed to observe the Sun in X-rays in the energy range 0.85-15.00 keV. SphinX is incorporated within the Russian TESIS X and EUV telescope complex aboard the CORONAS-Photon satellite which was launched on January 30, 2009 at 13:30 UT from the Plesetsk Cosmodrome, northern Russia. Since February, 2009 SphinX has been measuring solar X-ray radiation nearly continuously. The principle of SphinX operation and the content of the instrument data archives is studied. Issues related to dissemination of SphinX calibration, data, repository mirrors locations, types of data and metadata are discussed. Variability of soft X-ray solar flux is studied using data collected by SphinX over entire mission duration.

Characteristics of hard X-ray double sources in impulsive solar flares

Science.gov (United States)

Sakao, T.; Kosugi, T.; Masuda, S.; Yaji, K.; Inda-Koide, M.; Makishima, K.

1996-01-01

Imaging observations of solar flare hard X-ray sources with the Hard X-ray Telescope (HXT) aboard the Yohkoh satellite have revealed that hard X-ray emissions (greater than 30 ke V) originate most frequently from double sources. The double sources are located on both sides of the magnetic neutral line, suggesting that the bulk of hard X-rays is emitted from footpoints of flaring magnetic loops. We also found that hard X-rays from the double sources are emitted simultaneously within a fraction of second and that the weaker source tends to be located in the stronger magnetic field region, showing a softer spectrum. Physcial implications on the observed characteristics of the hard X-ray double sources are discussed.

Correlation tracking study for meter-class solar telescope on space shuttle. [solar granulation

Science.gov (United States)

Smithson, R. C.; Tarbell, T. D.

1977-01-01

The theory and expected performance level of correlation trackers used to control the pointing of a solar telescope in space using white light granulation as a target were studied. Three specific trackers were modeled and their performance levels predicted for telescopes of various apertures. The performance of the computer model trackers on computer enhanced granulation photographs was evaluated. Parametric equations for predicting tracker performance are presented.

Trends in NOAA Solar X-ray Imager Performance

Science.gov (United States)

Hill, Steven M.; Darnell, John A.; Seaton, Daniel B.

2016-05-01

NOAA has provided operational soft X-ray imaging of the sun since the early 2000’s. After 15 years of observations by four different telescopes, it is appropriate to examine the data in terms of providing consistent context for scientific missions. In particular, this presentation examines over 7 million GOES Solar X-ray Imager (SXI) images for trends in performance parameters including dark current, response degradation, and inter-calibration. Because observations from the instrument have overlapped not only with each other, but also with research observations like Yohkoh SXT and Hinode XRT, relative performance comparisons can be made. The first GOES Solar X-ray Imager was launched in 2001 and entered operations in 2003. The current SXIs will remain in operations until approximately 2020, when a new series of Solar (extreme-)Ultraviolet Imagers (SUVIs) will replace them as the current satellites reach their end of life. In the sense that the SXIs are similar to Yokoh’s SXT and Hinode’s XRT, the SUVI instruments will be similar to SOHO’s EIT and SDO’s AIA. The move to narrowband EUV imagers will better support eventual operational estimation of plasma conditions. While NOAA’s principal use of these observations is real-time space weather forecasting, they will continue to provide a reliable context measurement for researchers for decades to come.

A Micromegas-based low-background x-ray detector coupled to a slumped-glass telescope for axion research

CERN Document Server

Aznar, F; Christensen, F E; Dafni, T; Decker, T A; Ferrer-Ribas, E; Garcia, J A; Giomataris, I; Gracia, J G; Hailey, C J; Hill, R M; Iguaz, F J; Irastorza, I G; Jakobsen, A C; Luzon, G; Mirallas, H; Papaevangelou, T; Pivovaroff, M J; Ruz, J; Vafeiadis, T; Vogel, J K

2015-01-01

We report on the design, construction and operation of a low background x-ray detection line composed of a shielded Micromegas (micromesh gaseous structure) detector of the microbulk technique. The detector is made from radiopure materials and is placed at the focal point of a $\\sim$~5 cm diameter, 1.3 m focal-length, cone-approximation Wolter I x-ray telescope (XRT) comprised of thermally-formed (or "slumped") glass substrates deposited with multilayer coatings. The system has been conceived as a technological pathfinder for the future International Axion Observatory (IAXO), as it combines two of the techniques (optic and detector) proposed in the conceptual design of the project. It is innovative for two reasons: it is the first time an x-ray optic has been designed and fabricated specifically for axion research, and the first time a Micromegas detector has been operated with an x-ray optic. The line has been installed at one end of the CERN Axion Solar Telescope (CAST) magnet and is currently looking for s...

Adaptive optics system application for solar telescope

Science.gov (United States)

Lukin, V. P.; Grigor'ev, V. M.; Antoshkin, L. V.; Botugina, N. N.; Emaleev, O. N.; Konyaev, P. A.; Kovadlo, P. G.; Krivolutskiy, N. P.; Lavrionova, L. N.; Skomorovski, V. I.

2008-07-01

The possibility of applying adaptive correction to ground-based solar astronomy is considered. Several experimental systems for image stabilization are described along with the results of their tests. Using our work along several years and world experience in solar adaptive optics (AO) we are assuming to obtain first light to the end of 2008 for the first Russian low order ANGARA solar AO system on the Big Solar Vacuum Telescope (BSVT) with 37 subapertures Shack-Hartmann wavefront sensor based of our modified correlation tracker algorithm, DALSTAR video camera, 37 elements deformable bimorph mirror, home made fast tip-tip mirror with separate correlation tracker. Too strong daytime turbulence is on the BSVT site and we are planning to obtain a partial correction for part of Sun surface image.

Modeling the electron-proton telescope on Solar Orbiter

Energy Technology Data Exchange (ETDEWEB)

Boden, Sebastian; Steinhagen, Jan; Kulkarni, S.R.; Tammen, Jan; Elftmann, Robert; Martin, Cesar; Ravanbakhsh, Ali; Boettcher, Stephan; Seimetz, Lars; Wimmer-Schweingruber, Robert F. [Christian-Albrechts-Universitaet, Kiel (Germany)

2014-07-01

The Electron Proton Telescope (EPT) is one of four sensors in the Energetic Particle Detector suite for Solar Orbiter. It investigates low energy electrons and protons of solar events in an energy range from 20 - 400 keV for electrons and 20 keV - 7 MeV for protons. It distinguishes electrons from protons using a magnet/foil technique with silicon detectors. There will be two EPT units, each with double-barreled telescopes, one looking sunwards/antisunwards and the other north/south. We set up a Monte Carlo model of EPT using the GEANT4 framework, which we can use to simulate interactions of energetic particles in the sensor. Here we present simulation results of the energy coverage for different ion species, and we study how it is possible to distinguish between them.

The MAGIC gamma-ray telescope: status and first results

International Nuclear Information System (INIS)

Fernandez, Enrique

2006-01-01

MAGIC, a 17 m diameter Cherenkov telescope for gamma ray astronomy, has recently been commissioned at the Roque de los Muchachos site in the Island of La Palma, of the Canary Islands. The telescope was proposed in 1998 with the goal of lowering the threshold of observation of gamma rays by ground detectors to 20-30 GeV energies. This paper describes its main design features, its physics objectives and its first operations

Focal plane instrument for the Solar UV-Vis-IR Telescope aboard SOLAR-C

Science.gov (United States)

Katsukawa, Yukio; Suematsu, Yoshinori; Shimizu, Toshifumi; Ichimoto, Kiyoshi; Takeyama, Norihide

2011-10-01

It is presented the conceptual design of a focal plane instrument for the Solar UV-Vis-IR Telescope (SUVIT) aboard the next Japanese solar mission SOLAR-C. A primary purpose of the telescope is to achieve precise as well as high resolution spectroscopic and polarimetric measurements of the solar chromosphere with a big aperture of 1.5 m, which is expected to make a significant progress in understanding basic MHD processes in the solar atmosphere. The focal plane instrument consists of two packages: A filtergraph package is to get not only monochromatic images but also Dopplergrams and magnetograms using a tunable narrow-band filter and interference filters. A spectrograph package is to perform accurate spectro-polarimetric observations for measuring chromospheric magnetic fields, and is employing a Littrow-type spectrograph. The most challenging aspect in the instrument design is wide wavelength coverage from 280 nm to 1.1 μm to observe multiple chromospheric lines, which is to be realized with a lens unit including fluoride glasses. A high-speed camera for correlation tracking of granular motion is also implemented in one of the packages for an image stabilization system, which is essential to achieve high spatial resolution and high polarimetric accuracy.

The STAR-X X-Ray Telescope Assembly (XTA)

Science.gov (United States)

McClelland, Ryan S.; Bautz, Mark W.; Bonafede, Joseph A.; Miller, Eric D.; Saha, Timo T.; Solly, Peter M.; Zhang, William W.

2017-01-01

The Survey and Time-domain Astrophysical Research eXplorer (STAR-X) science goals are to discover what powers the most violent explosions in the Universe, understand how black holes grow across cosmic time and mass scale, and measure how structure formation heats the majority of baryons in the Universe. To achieve these goals, STAR-X requires a powerful X-ray telescope with a large field of view, large collecting area, and excellent point spread function. The STAR-X instrument, the X-Ray Telescope Assembly (XTA), meets these requirements using a powerful X-ray mirror technology based on precision-polished single crystal silicon and a mature CCD detector technology. The XTA is composed of three major subsystems: an X-ray Mirror Assembly (MA) of high resolution, lightweight mirror segments fabricated out of single crystal silicon; a Focal Plane Assembly (FPA) made of back-illuminated CCD's capable of detecting X-rays with excellent quantum efficiency; and a composite Telescope Tube that structurally links the MA and FPA. The MA consists of 5,972 silicon mirror segments mounted into five subassemblies called meta-shells. A meta-shell is constructed from an annular central structural shell covered with interlocking layers of mirror segments. This paper describes the requirements, design, and analysis of the XTA subsystems with particular focus on the MA.

Harnessing solar pressure to slew and point large infrared space telescopes

Science.gov (United States)

Errico, Simona; Angel, Roger P.; Calvert, Paul D.; Woof, Neville

2003-03-01

Large astronomical Gossamer telescopes in space will need to employ large solar shields to safeguard the optics from solar radiation. These types of telescopes demand accurate controls to maintain telescope pointing over long integration periods. We propose an active solar shield system that harnesses radiation pressure to accurately slew and acquire new targets without the need for reaction wheels or thrusters. To provide the required torques, the solar shield is configured as an inverted, 4-sided pyramidal roof. The sloped roof interior surfaces are covered with hinged “tiles” made from piezoelectric film bimorphs with specular metallized surfaces. Nominally, the tiles lie flat against the roof and the sunlight is reflected outward equally from all sloped surfaces. However, when the tiles on one roof pitch are raised, the pressure balance is upset and the sunshade is pushed to one side. By judicious selection of the tiles and control of their lift angle, the solar pressure can be harvested to stabilize the spacecraft orientation or to change its angular momentum. A first order conceptual design performance analysis and the results from the experimental design, fabrication and testing of piezoelectric bimorph hinge elements will be presented. Next phase challenges in engineering design, materials technology, and systems testing will be discussed.

The spectrometer/telescope for imaging X-rays on board the ESA Solar Orbiter spacecraft

International Nuclear Information System (INIS)

Krucker, S.; Benz, A.O.; Hurford, G.J.; Arnold, N.G.; Orleański, P.; Gröbelbauer, H.-P.; Casadei, D.; Kobler, S.; Iseli, L.; Wiehl, H.J.; Csillaghy, A.; Etesi, L.; Hochmuth, N.; Battaglia, M.; Bednarzik, M.; Resanovic, R.; Grimm, O.; Viertel, G.; Commichau, V.; Howard, A.

2013-01-01

Solar Orbiter is a Sun-observing mission led by the European Space Agency, addressing the interaction between the Sun and the heliosphere. It will carry ten instruments, among them the X-ray imaging spectrometer STIX. STIX will determine the intensity, spectrum, timing, and location of thermal and accelerated electrons near the Sun through their bremsstrahlung X-ray emission. This report gives a brief overview of the STIX scientific goals and covers in more detail the instrument design and challenges

Solar Hα and white light telescope at Hvar Observatory

Czech Academy of Sciences Publication Activity Database

Čalogovic, J.; Dumbovic, M.; Novak, S.; Vršnak, B.; Brajša, R.; Pötzi, W.; Hirtenfellner-Polanec, W.; Veronig, A.; Hanslmeier, A.; Klvaňa, Miroslav; Ambrož, Pavel

2012-01-01

Roč. 36, č. 2012 (2012), s. 83-88 ISSN 1845-8319 Institutional support: RVO:67985815 Keywords : solar observations * telescope * photosphere Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

Ground-based gamma-ray astronomy with Cherenkov telescopes

International Nuclear Information System (INIS)

Hinton, Jim

2009-01-01

Very high-energy (>100 GeV) γ-ray astronomy is emerging as an important discipline in both high-energy astrophysics and astro-particle physics. This field is currently dominated by imaging atmospheric-Cherenkov telescopes (IACTs) and arrays of these telescopes. Such arrays have achieved the best angular resolution and energy flux sensitivity in the γ-ray domain and are still far from the fundamental limits of the technique. Here, I will summarize some key aspects of this technique and go on to review the current status of the major instruments and to highlight selected recent results.

Application of an EMCCD Camera for Calibration of Hard X-Ray Telescopes

DEFF Research Database (Denmark)

Vogel, Julia K.; Pivovaroff, M. J.; Nagarkar, V. V.

2012-01-01

has seen focusing optics developed for balloon experiments [1] and they will soon be implemented in approved space missions such as the Nuclear Spectroscopic Telescope Array (NuSTAR) [2] and ASTRO-H [3]. The full characterization of x-ray optics for astrophysical and solar imaging missions, including...... measurement of the point spread function (PSF) as well as scattering and reflectivity properties of substrate coatings, requires a very high spatial resolution, high sensitivity, photon counting and energy discriminating, large area detector. Novel back-thinned Electron Multiplying Charge-Coupled Devices...... high frame rates due to its controllable internal gain. Additionally, thick CsI(Tl) yields high detection efficiency for x-rays [6]. This type of detector has already proven to be a unique device very suitable for calibrations in astrophysics: such a camera was used to support the characterization...

Design review of the Brazilian Experimental Solar Telescope

Science.gov (United States)

Dal Lago, A.; Vieira, L. E. A.; Albuquerque, B.; Castilho, B.; Guarnieri, F. L.; Cardoso, F. R.; Guerrero, G.; Rodríguez, J. M.; Santos, J.; Costa, J. E. R.; Palacios, J.; da Silva, L.; Alves, L. R.; Costa, L. L.; Sampaio, M.; Dias Silveira, M. V.; Domingues, M. O.; Rockenbach, M.; Aquino, M. C. O.; Soares, M. C. R.; Barbosa, M. J.; Mendes, O., Jr.; Jauer, P. R.; Branco, R.; Dallaqua, R.; Stekel, T. R. C.; Pinto, T. S. N.; Menconi, V. E.; Souza, V. M. C. E. S.; Gonzalez, W.; Rigozo, N.

2015-12-01

The Brazilian's National Institute for Space Research (INPE), in collaboration with the Engineering School of Lorena/University of São Paulo (EEL/USP), the Federal University of Minas Gerais (UFMG), and the Brazilian's National Laboratory for Astrophysics (LNA), is developing a solar vector magnetograph and visible-light imager to study solar processes through observations of the solar surface magnetic field. The Brazilian Experimental Solar Telescope is designed to obtain full disk magnetic field and line-of-sight velocity observations in the photosphere. Here we discuss the system requirements and the first design review of the instrument. The instrument is composed by a Ritchey-Chrétien telescope with a 500 mm aperture and 4000 mm focal length. LCD polarization modulators will be employed for the polarization analysis and a tuning Fabry-Perot filter for the wavelength scanning near the Fe II 630.25 nm line. Two large field-of-view, high-resolution 5.5 megapixel sCMOS cameras will be employed as sensors. Additionally, we describe the project management and system engineering approaches employed in this project. As the magnetic field anchored at the solar surface produces most of the structures and energetic events in the upper solar atmosphere and significantly influences the heliosphere, the development of this instrument plays an important role in advancing scientific knowledge in this field. In particular, the Brazilian's Space Weather program will benefit most from the development of this technology. We expect that this project will be the starting point to establish a strong research program on Solar Physics in Brazil. Our main aim is to progressively acquire the know-how to build state-of-art solar vector magnetograph and visible-light imagers for space-based platforms.

X-ray spectrometer spectrograph telescope system. [for solar corona study

Science.gov (United States)

Bruner, E. C., Jr.; Acton, L. W.; Brown, W. A.; Salat, S. W.; Franks, A.; Schmidtke, G.; Schweizer, W.; Speer, R. J.

1979-01-01

A new sounding rocket payload that has been developed for X-ray spectroscopic studies of the solar corona is described. The instrument incorporates a grazing incidence Rowland mounted grating spectrograph and an extreme off-axis paraboloic sector feed system to isolate regions of the sun of order 1 x 10 arc seconds in size. The focal surface of the spectrograph is shared by photographic and photoelectric detection systems, with the latter serving as a part of the rocket pointing system control loop. Fabrication and alignment of the optical system is based on high precision machining and mechanical metrology techniques. The spectrograph has a resolution of 16 milliangstroms and modifications planned for future flights will improve the resolution to 5 milliangstroms, permitting line widths to be measured.

Method of incident low-energy gamma-ray direction reconstruction in the GAMMA-400 gamma-ray space telescope

International Nuclear Information System (INIS)

Kheymits, M D; Leonov, A A; Zverev, V G; Galper, A M; Arkhangelskaya, I V; Arkhangelskiy, A I; Yurkin, Yu T; Bakaldin, A V; Suchkov, S I; Topchiev, N P; Dalkarov, O D

2016-01-01

The GAMMA-400 gamma-ray space-based telescope has as its main goals to measure cosmic γ-ray fluxes and the electron-positron cosmic-ray component produced, theoretically, in dark-matter-particles decay or annihilation processes, to search for discrete γ-ray sources and study them in detail, to examine the energy spectra of diffuse γ-rays — both galactic and extragalactic — and to study gamma-ray bursts (GRBs) and γ-rays from the active Sun. Scientific goals of GAMMA-400 telescope require fine angular resolution. The telescope is of a pair-production type. In the converter-tracker, the incident gamma-ray photon converts into electron-positron pair in the tungsten layer and then the tracks are detected by silicon- strip position-sensitive detectors. Multiple scattering processes become a significant obstacle in the incident-gamma direction reconstruction for energies below several gigaelectronvolts. The method of utilising this process to improve the resolution is proposed in the presented work. (paper)

HOT PLASMA FROM SOLAR ACTIVE-REGION CORES: CONSTRAINTS FROM THE HINODE X-RAY TELESCOPE

Energy Technology Data Exchange (ETDEWEB)

Schmelz, J. T. [USRA, 7178 Columbia Gateway Drive, Columbia, MD 21046 (United States); Christian, G. M.; Matheny, P. O., E-mail: jschmelz@usra.edu [Physics Department, University of Memphis, Memphis, TN 38152 (United States)

2016-12-20

Mechanisms invoked to heat the solar corona to millions of degrees kelvin involve either magnetic waves or magnetic reconnections. Turbulence in the convection zone produces MHD waves, which travel upward and dissipate. Photospheric motions continuously build up magnetic energy, which is released through magnetic reconnection. In this paper, we concentrate on hot non-flaring plasma with temperatures of 5 MK <  T  < 10 MK because it is one of the few observables for which wave and reconnection models make different predictions. Wave models predict no (or little) hot plasma, whereas reconnection models predict it, although in amounts that are challenging to detect with current instrumentation. We used data from the X-ray Telescope (XRT) and the Atmospheric Imaging Assembly (AIA). We requested a special XRT observing sequence, which cycled through the thickest XRT filter several times per hour so we could average these images and improve the signal-to-noise. We did differential emission measure (DEM) analysis using the time-averaged thick-filter data as well as all available channels from both the XRT and AIA for regions observed on 2014 December 11. Whereas our earlier work was only able to determine that plasma with a temperature greater than 5 MK was present , we are now able to find a well-constrained DEM distribution. We have therefore added a strong observational constraint that must be explained by any viable coronal heating model. Comparing state-of-the-art wave and reconnection model predictions, we can conclude that reconnection is heating the hot plasma in these active regions.

Solar coronal non-thermal processes (Solar Maximum Mission). Final report

International Nuclear Information System (INIS)

Hudson, H.S.

1983-02-01

The Solar Maximum Mission was used to study solar coronal phenomena in hard X-radiation, since its instrument complement included the first solar hard X-ray telescope. Phenomena related to those discovered from OSO-5 and OSO-7 observations were emphasized

DynamiX, numerical tool for design of next-generation x-ray telescopes.

Science.gov (United States)

Chauvin, Maxime; Roques, Jean-Pierre

2010-07-20

We present a new code aimed at the simulation of grazing-incidence x-ray telescopes subject to deformations and demonstrate its ability with two test cases: the Simbol-X and the International X-ray Observatory (IXO) missions. The code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, accounting for the x-ray interactions and for the telescope motion and deformation. The simulation produces images and spectra for any telescope configuration using Wolter I mirrors and semiconductor detectors. This numerical tool allows us to study the telescope performance in terms of angular resolution, effective area, and detector efficiency, accounting for the telescope behavior. We have implemented an image reconstruction method based on the measurement of the detector drifts by an optical sensor metrology. Using an accurate metrology, this method allows us to recover the loss of angular resolution induced by the telescope instability. In the framework of the Simbol-X mission, this code was used to study the impacts of the parameters on the telescope performance. In this paper we present detailed performance analysis of Simbol-X, taking into account the satellite motions and the image reconstruction. To illustrate the versatility of the code, we present an additional performance analysis with a particular configuration of IXO.

DynamiX, numerical tool for design of next-generation x-ray telescopes

International Nuclear Information System (INIS)

Chauvin, Maxime; Roques, Jean-Pierre

2010-01-01

We present a new code aimed at the simulation of grazing-incidence x-ray telescopes subject to deformations and demonstrate its ability with two test cases: the Simbol-X and the International X-ray Observatory (IXO) missions. The code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, accounting for the x-ray interactions and for the telescope motion and deformation. The simulation produces images and spectra for any telescope configuration using Wolter I mirrors and semiconductor detectors. This numerical tool allows us to study the telescope performance in terms of angular resolution, effective area, and detector efficiency, accounting for the telescope behavior. We have implemented an image reconstruction method based on the measurement of the detector drifts by an optical sensor metrology. Using an accurate metrology, this method allows us to recover the loss of angular resolution induced by the telescope instability. In the framework of the Simbol-X mission, this code was used to study the impacts of the parameters on the telescope performance. In this paper we present detailed performance analysis of Simbol-X, taking into account the satellite motions and the image reconstruction. To illustrate the versatility of the code, we present an additional performance analysis with a particular configuration of IXO.

DynamiX, numerical tool for design of next-generation x-ray telescopes

Energy Technology Data Exchange (ETDEWEB)

Chauvin, Maxime; Roques, Jean-Pierre

2010-07-20

We present a new code aimed at the simulation of grazing-incidence x-ray telescopes subject to deformations and demonstrate its ability with two test cases: the Simbol-X and the International X-ray Observatory (IXO) missions. The code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, accounting for the x-ray interactions and for the telescope motion and deformation. The simulation produces images and spectra for any telescope configuration using Wolter I mirrors and semiconductor detectors. This numerical tool allows us to study the telescope performance in terms of angular resolution, effective area, and detector efficiency, accounting for the telescope behavior. We have implemented an image reconstruction method based on the measurement of the detector drifts by an optical sensor metrology. Using an accurate metrology, this method allows us to recover the loss of angular resolution induced by the telescope instability. In the framework of the Simbol-X mission, this code was used to study the impacts of the parameters on the telescope performance. In this paper we present detailed performance analysis of Simbol-X, taking into account the satellite motions and the image reconstruction. To illustrate the versatility of the code, we present an additional performance analysis with a particular configuration of IXO.

Hard X-ray/soft gamma-ray telescope designs for future astrophysics missions

DEFF Research Database (Denmark)

Ferreira, Desiree Della Monica; Christensen, Finn Erland; Pivovaroff, Michael J.

2013-01-01

We present several concept designs of hard X-ray/soft λ-ray focusing telescopes for future astrophysics missions. The designs are based on depth graded multilayer coatings. These have been successfully employed on the NuSTAR mission for energies up to 80 keV. Recent advances in demonstrating...

Upsurge of X-ray astronomy 230-

International Nuclear Information System (INIS)

Hudec, D.R.

1978-01-01

Instruments are described used for X-ray astronomy, namely X-ray detectors and X-ray telescopes. Unlike telescopes, the detectors do not comprise X-ray optics. A survey is given of the results obtained in solar and stellar X-ray astronomy and hypotheses are submitted on the origin of X radiation in the interstellar space. (J.B.)

Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance

DEFF Research Database (Denmark)

Singh, K; Stewart, G.; Westergaard, Niels Jørgen Stenfeldt

2017-01-01

The Soft X-ray focusing Telescope (SXT), India’s first X-ray telescope based on the principle of grazing incidence, was launched aboard the AstroSat and made operational on October 26, 2015. X-rays in the energy band of 0.3–8.0 keV are focussed on to a cooled charge coupled device thus providing ...

Optical and thermal design of 1.5-m aperture solar UV visible and IR observing telescope for Solar-C mission

Science.gov (United States)

Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.; Horiuchi, T.; Matsumoto, Y.; Takeyama, N.

2017-11-01

The next Japanese solar mission, SOLAR-C, which has been envisaged after successful science operation of Hinode (SOLAR-B) mission, is perusing two plans: plan-A and plan-B, and under extensive study from science objectives as well as engineering point of view. The plan-A aims at performing out-of-ecliptic observations for investigating, with helioseismic approach, internal structure and dynamo mechanisms of the Sun. It also explores polar regions where fast solar wind is believed to originate. A baseline orbit for plan-A is a circular orbit of 1 AU distance from the Sun with its inclination at around or greater than 40 degrees. The plan-B aims to study small-scale plasma processes and structures in the solar atmosphere which attract researchers' growing interest, followed by many Hinode discoveries [1], for understanding fully dynamism and magnetic nature of the atmosphere. With plan-B, high-angular-resolution investigation of the entire solar atmosphere (from the photosphere to the corona, including their interface layers, i.e., chromosphere and transition region) is to be performed with enhanced spectroscopic and spectro-polarimetric capability as compared with Hinode, together with enhanced sensitivity towards ultra-violet wavelengths. The orbit of plan-B is either a solar synchronous polar orbit of altitude around 600 km or a geosynchronous orbit to ensure continuous solar observations. After the decision of any one of the two plans, the SOLAR-C will be proposed for launch in mid-2010s. In this paper, we will present a basic design of one of major planned instrumental payload for the plan-B: the Solar Ultra-violet Visible and near IR observing Telescope (hereafter referred to as SUVIT). The basic concept in designing the SUVIT is to utilize as much as possible a heritage of successful telescope of the Solar Optical Telescope (SOT) aboard Hinode [2]. Major differences of SUVIT from SOT are the three times larger aperture of 1.5 m, which enables to collect one

Observations of VHE γ-Ray Sources with the MAGIC Telescope

Science.gov (United States)

Bartko, H.

2008-10-01

The MAGIC telescope with its 17m diameter mirror is today the largest operating single-dish Imaging Air Cherenkov Telescope (IACT). It is located on the Canary Island La Palma, at an altitude of 2200m above sea level, as part of the Roque de los Muchachos European Northern Observatory. The MAGIC telescope detects celestial very high energy γ-radiation in the energy band between about 50 GeV and 10 TeV. Since Autumn of 2004 MAGIC has been taking data routinely, observing various objects like supernova remnants (SNRs), γ-ray binaries, Pulsars, Active Galactic Nuclei (AGN) and Gamma-ray Bursts (GRB). We briefly describe the observational strategy, the procedure implemented for the data analysis, and discuss the results for individual sources. An outlook to the construction of the second MAGIC telescope is given.

X-ray Emission from Solar Flares

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Solar flares; X-ray detectors; X-ray line emission and continuum; break energy; microflares. Abstract. Solar X-ray Spectrometer (SOXS), the first space-borne solar astronomy experiment of India was designed to improve our current understanding of X-ray emission from the Sun in general and solar flares in ...

Caliste-SO, a CdTe based spectrometer for bright solar event observations in hard X-rays

Energy Technology Data Exchange (ETDEWEB)

Meuris, A., E-mail: aline.meuris@cea.fr [CEA-Irfu – CEA Saclay, F-91191 Gif-sur-Yvette Cedex (France); Limousin, O.; Gevin, O.; Blondel, C.; Martignac, J. [CEA-Irfu – CEA Saclay, F-91191 Gif-sur-Yvette Cedex (France); Vassal, M.-C.; Soufflet, F.; Fiant, N. [3D Plus – 408 rue Hélène Boucher, F-78532 Buc Cedex (France); Bednarzik, M.; Stutz, S. [Paul Scherrer Institute (PSI), Laboratory for Micro- and Nanotechnology, 5232 Villigen (Switzerland); Grimm, O.; Commichau, V. [ETH Zurich, Institute for Particle Physics, Schafmattstrasse 20, 8093 Zurich (Switzerland)

2015-07-01

Caliste-SO is a CdTe hybrid detector designed to be used as a spectrometer for a hard X-ray Fourier telescope. The imaging technique was implemented in the Yohkoh satellite in 1991 and the RHESSI satellite in 2002 to achieve arc-second angular resolution images of solar flares with spectroscopic capabilities. The next generation of such instruments will be the Spectrometer Telescope Imaging X-rays (STIX) on-board the Solar Orbiter mission adopted by the European Space Agency in 2011 for launch in 2017. The design and performance of Caliste-SO allows both high spectral resolution and high count rate measurements from 4 to 150 keV with limited demands on spacecraft resources such as mass, power and volume (critical for interplanetary missions). The paper reports on the flight production of the Caliste-SO devices for STIX, describing the test facilities built-up in Switzerland and France. It illustrates some results obtained with the first production samples that will be mounted in the STIX engineering model.

Measurement of the high-energy gamma-ray emission from the Moon with the Fermi Large Area Telescope

CERN Document Server

Ackermann, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bonino, R.; Bottacini, E.; Bregeon, J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P.A.; Cavazzuti, E.; Cecchi, C.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Costanza, F.; Cuoco, A.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S.W.; Di Venere, L.; Drell, P.S.; Favuzzi, C.; Fegan, S.J.; Focke, W.B.; Franckowiak, A.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J.E.; Guiriec, S.; Harding, A. K.; Hewitt, J. W.; Horan, D.; Hou, X.; Iafrate, G.; Jóhannesson, G.; Kamae, T.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M.N.; Lubrano, P.; Magill, J.; Maldera, S.; Manfreda, A.; Mayer, M.; Mazziotta, M.N.; Michelson, P.F.; Mitthumsiri, W.; Mizuno, T.; Monzani, M.E.; Morselli, A.; Murgia, S.; Nuss, E.; Omodei, N.; Orlando, E.; Ormes, J.F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Pivato, G.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Sgrò, C.; Reposeur, T.; Siskind, E.J.; Spada, F.; Spandre, G.; Spinelli, P.; Takahashi, H.; Thayer, J.B.; Thompson, D.J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Vianello, G.; Winer, B. L.; Wood, K. S.; Yassine, M.; Cerutti, F.; Ferrari, A.; Sala, P.R.

2016-01-01

We have measured the gamma-ray emission spectrum of the Moon using the data collected by the Large Area Telescope onboard the Fermi satellite during its first 7 years of operation, in the energy range from 30 MeV up to a few GeV. We have also studied the time evolution of the flux, finding a correlation with the solar activity. We have developed a full Monte Carlo simulation describing the interactions of cosmic rays with the lunar surface. The results of the present analysis can be explained in the framework of this model, where the production of gamma rays is due to the interactions of cosmic-ray proton and helium nuclei with the surface of the Moon. Finally, we have used our simulation to derive the cosmic-ray proton and helium spectra near Earth from the Moon gamma-ray data.

Cosmic ray effect on the X-ray Trigger Telescope of UFFO/Lomonosov using YSO scintillation crystal array in space

DEFF Research Database (Denmark)

Kim, M. B.; Jeong, S.; Jeong, H. M.

2017-01-01

UFFO Burst Alert and Trigger telescope (UBAT) is the X-ray trigger telescope of UFFO/Lomonosov to localize X-ray source with coded mask method and X-ray detector. Its X-ray detector is made up of 36 8×8 pixels Yttrium OxyorthoSilicate (Y2SiO5:Ce, YSO) scintillation crystal arrays and 36 64-channe...

Search for sub-eV mass solar axions by the CERN Axion Solar Telescope with 3He buffer gas.

Science.gov (United States)

Arik, M; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gómez, H; Gruber, E; Guthörl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovčić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Lozza, V; Lutz, G; Luzón, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S K; Stewart, L; Tomás, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K

2011-12-23

The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using (3)He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with (4)He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV≲m(a)≲0.64 eV. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g(aγ)≲2.3×10(-10) GeV(-1) at 95% C.L., the exact value depending on the pressure setting. Kim-Shifman-Vainshtein-Zakharov axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In the future we will extend our search to m(a)≲1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.

Solar System Observations with the James Webb Space Telescope

OpenAIRE

Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael; Ferruit, Pierre

2014-01-01

The James Webb Space Telescope will enable a wealth of new scientific investigations in the near- and mid-infrared, with sensitivity and spatial/spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar...

Soft X-ray images of the solar corona using normal incidence optics

Science.gov (United States)

Bruner, M. E.; Haisch, B. M.; Brown, W. A.; Acton, L. W.; Underwood, J. H.

1988-01-01

A solar coronal loop system has been photographed in soft X-rays using a normal incidence telescope based on multilayer mirror technology. The telescope consisted of a spherical objective mirror of 4 cm aperture and 1 m focal length, a film cassette, and a focal plane shutter. A metallized thin plastic film filter was used to exclude visible light. The objective mirror was covered with a multilayer coating consisting of alternating layers of tungsten and carbon whose combined thicknesses satisfied the Bragg diffraction condition for 44 A radiation. The image was recorded during a rocket flight on October 25, 1985 and was dominated by emission lines arising from the Si XII spectrum. The rocket also carried a high resolution soft X-ray spectrograph that confirmed the presence of Si XII line radiation in the source. This image represents the first successful use of multilayer technology for astrophysical observations.

MuSICa image slicer prototype at 1.5-m GREGOR solar telescope

Science.gov (United States)

Calcines, A.; López, R. L.; Collados, M.; Vega Reyes, N.

2014-07-01

Integral Field Spectroscopy is an innovative technique that is being implemented in the state-of-the-art instruments of the largest night-time telescopes, however, it is still a novelty for solar instrumentation. A new concept of image slicer, called MuSICa (Multi-Slit Image slicer based on collimator-Camera), has been designed for the integral field spectrograph of the 4-m European Solar Telescope. This communication presents an image slicer prototype of MuSICa for GRIS, the spectrograph of the 1.5-m GREGOR solar telescope located at the Observatory of El Teide. MuSICa at GRIS reorganizes a 2-D field of view of 24.5 arcsec into a slit of 0.367 arcsec width by 66.76 arcsec length distributed horizontally. It will operate together with the TIP-II polarimeter to offer high resolution integral field spectropolarimetry. It will also have a bidimensional field of view scanning system to cover a field of view up to 1 by 1 arcmin.

Evolution of cosmic ray fluxes during the rising phase of solar cycle 23: ULYSSES EPAC and COSPIN/KET observations

International Nuclear Information System (INIS)

Heber, B.; Keppler, E.; Blake, J.B.; Fraenz, M.; Kunow, H.

2000-01-01

Galactic cosmic rays are entering the heliosphere from the interstellar medium, while anomalous cosmic rays are believed to be pickup ions accelerated at the heliospheric termination shock. Both particle species are modulated by the solar wind and the heliospheric magnetic field. Since 1997 solar activity increased and as a consequence the flux of galactic and anomalous cosmic ray decreased. In this paper we will discuss the variation of low energy anomalous cosmic rays as measured by the Ulysses Energetic Particle Composition Experiment (EPAC) and the Kiel Electron Telescope (KET) on board Ulysses. Specifically we are addressing the question: Are there differences in the modulation of galactic and anomalous cosmic rays and what are possible implication for the modulation of cosmic rays in the heliosphere?

The spectrometer/telescope for imaging X-rays on board the ESA Solar Orbiter spacecraft

Czech Academy of Sciences Publication Activity Database

Krucker, S.; Benz, A. O.; Hurford, G.J.; Arnold, N.G.; Orleanski, P.; Groebelbauer, H.-P.; Casadei, D.; Kobler, S.; Iseli, L.; Wiehl, H.J.; Fárník, František

2013-01-01

Roč. 732, December (2013), s. 295-298 ISSN 0168-9002. [Vienna Conference on Instrumentation /13./. Vienna, 11.02.2013-15.02.2013] Institutional support: RVO:67985815 Keywords : Fourier optics * X-ray imaging * solar flares Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 1.316, year: 2013

The SOLAR-C Mission: Plan B Payload Concept

Science.gov (United States)

Shimizu, T.; Sakao, T.; Katsukawa, Y.; Group, J. S. W.

2012-08-01

The telescope concepts for the SOLAR-C Plan B mission as of the time of the Hinode-3 meeting were briefly presented for having comments from the international solar physics community. The telescope candidates are 1) near IR-visible-UV telescope with 1.5m aperture and enhanced spectro-polarimetric capability, 2) UV/EUV high throughput spectrometer, and 3) next generation X-ray telescope.

Deposition and characterization of multilayers on thin foil x-ray mirrors for high-throughput x-ray telescopes

DEFF Research Database (Denmark)

Hussain, Ahsen M.; Joensen, Karsten D.; Hoeghoej, P.

1996-01-01

W/Si and Co/C multilayers have been deposited on epoxy- replicated Au mirrors from the ASTRO-E telescope project, SPectrum Roentgen Gamma (SRG) flight mirrors, DURAN glass substrates and Si witness wafers. A characterization of the multilayers with both hard x-rays and soft x-rays is presented....... This clearly indicates the effectiveness of the epoxy-replication process for the production of smooth substrates for multilayer deposition to be used in future x-ray telescopes....

Aplanatic telescopes based on Schwarzschild optical configuration: from grazing incidence Wolter-like x-ray optics to Cherenkov two-mirror normal incidence telescopes

Science.gov (United States)

Sironi, Giorgia

2017-09-01

At the beginning of XX century Karl Schwarzschild defined a method to design large-field aplanatic telescopes based on the use of two aspheric mirrors. The approach was then refined by Couder (1926) who, in order to correct for the astigmatic aberration, introduced a curvature of the focal plane. By the way, the realization of normal-incidence telescopes implementing the Schwarzschild aplanatic configuration has been historically limited by the lack of technological solutions to manufacture and test aspheric mirrors. On the other hand, the Schwarzschild solution was recovered for the realization of coma-free X-ray grazing incidence optics. Wolter-like grazing incidence systems are indeed free of spherical aberration, but still suffer from coma and higher order aberrations degrading the imaging capability for off-axis sources. The application of the Schwarzschild's solution to X-ray optics allowed Wolter to define an optical system that exactly obeys the Abbe sine condition, eliminating coma completely. Therefore these systems are named Wolter-Schwarzschild telescopes and have been used to implement wide-field X-ray telescopes like the ROSAT WFC and the SOHO X-ray telescope. Starting from this approach, a new class of X-ray optical system was proposed by Burrows, Burg and Giacconi assuming polynomials numerically optimized to get a flat field of view response and applied by Conconi to the wide field x-ray telescope (WFXT) design. The Schwarzschild-Couder solution has been recently re-discovered for the application to normal-incidence Cherenkov telescopes, thanks to the suggestion by Vassiliev and collaborators. The Italian Institute for Astrophysics (INAF) realized the first Cherenkov telescope based on the polynomial variation of the Schwarzschild configuration (the so-called ASTRI telescope). Its optical qualification was successfully completed in 2016, demonstrating the suitability of the Schwarzschild-like configuration for the Cherenkov astronomy requirements

The nuclear spectroscopic telescope array (NuSTAR) high-energy X-ray mission

DEFF Research Database (Denmark)

Madsen, Kristin K.; Harrison, Fiona A.; Hongjun An

2014-01-01

The Nuclear Spectroscopic Telescope Array (NuSTAR) mission was launched on 2012 June 13 and is the first focusing high-energy X-ray telescope in orbit operating above ~10 keV. NuSTAR flies two co-aligned Wolter-I conical approximation X-ray optics, coated with Pt/C and W/Si multilayers...

Silicon pore optics for future x-ray telescopes

Science.gov (United States)

Wille, Eric; Bavdaz, Marcos; Wallace, Kotska; Shortt, Brian; Collon, Maximilien; Ackermann, Marcelo; Günther, Ramses; Olde Riekerink, Mark; Koelewijn, Arenda; Haneveld, Jeroen; van Baren, Coen; Erhard, Markus; Kampf, Dirk; Christensen, Finn; Krumrey, Michael; Freyberg, Michael; Burwitz, Vadim

2017-11-01

Lightweight X-ray Wolter optics with a high angular resolution will enable the next generation of X-ray telescopes in space. The candidate mission ATHENA (Advanced Telescope for High Energy Astrophysics) required a mirror assembly of 1 m2 effective area (at 1 keV) and an angular resolution of 10 arcsec or better. These specifications can only be achieved with a novel technology like Silicon Pore Optics, which is being developed by ESA together with a consortium of European industry. Silicon Pore Optics are made of commercial Si wafers using process technology adapted from the semiconductor industry. We present the recent upgrades made to the manufacturing processes and equipment, ranging from the manufacture of single mirror plates towards complete focusing mirror modules mounted in flight configuration, and results from first vibration tests. The performance of the mirror modules is tested at X-ray facilities that were recently extended to measure optics at a focal distance up to 20 m.

The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission

Energy Technology Data Exchange (ETDEWEB)

Atwood, W.B.; /UC, Santa Cruz; Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Anderson, B. /UC, Santa Cruz; Axelsson, M.; /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Band, D.L.; /NASA, Goddard /NASA, Goddard; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bartelt, J.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bastieri, Denis; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bederede, D.; /DAPNIA, Saclay; Bellardi, F.; /INFN, Pisa; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bignami, G.F.; /Pavia U.; Bisello, D.; /INFN, Padua /Padua U.; Bissaldi, E.; /Garching, Max Planck Inst., MPE; Blandford, R.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Pisa /INFN, Pisa /Bari U. /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /INFN, Padua /Padua U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /Kalmar U. /Royal Inst. Tech., Stockholm /DAPNIA, Saclay /ASI, Rome /INFN, Pisa /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /DAPNIA, Saclay /NASA, Goddard /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

2009-05-15

The Large Area Telescope (Fermi/LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view (FoV), high-energy {gamma}-ray telescope, covering the energy range from below 20 MeV to more than 300 GeV. The LAT was built by an international collaboration with contributions from space agencies, high-energy particle physics institutes, and universities in France, Italy, Japan, Sweden, and the United States. This paper describes the LAT, its preflight expected performance, and summarizes the key science objectives that will be addressed. On-orbit performance will be presented in detail in a subsequent paper. The LAT is a pair-conversion telescope with a precision tracker and calorimeter, each consisting of a 4 x 4 array of 16 modules, a segmented anticoincidence detector that covers the tracker array, and a programmable trigger and data acquisition system. Each tracker module has a vertical stack of 18 (x, y) tracking planes, including two layers (x and y) of single-sided silicon strip detectors and high-Z converter material (tungsten) per tray. Every calorimeter module has 96 CsI(Tl) crystals, arranged in an eight-layer hodoscopic configuration with a total depth of 8.6 radiation lengths, giving both longitudinal and transverse information about the energy deposition pattern. The calorimeter's depth and segmentation enable the high-energy reach of the LAT and contribute significantly to background rejection. The aspect ratio of the tracker (height/width) is 0.4, allowing a large FoV (2.4 sr) and ensuring that most pair-conversion showers initiated in the tracker will pass into the calorimeter for energy measurement. Data obtained with the LAT are intended to (1) permit rapid notification of high-energy {gamma}-ray bursts and transients and facilitate monitoring of variable sources, (2) yield an extensive catalog of several thousand high-energy sources obtained from an all-sky survey, (3

MT_RAYOR: a versatile raytracing tool for x-ray telescopes

DEFF Research Database (Denmark)

Westergaard, Niels Jørgen Stenfeldt

2011-01-01

The prediction of the properties of X-ray telescopes is important for the planning of observations and the interpretation of data. The mirror quality in terms of micro-roughness scattering and deformations relative to the idealized shape plays a crucial role for the sensitivity of the telescope...

X-ray telescope mirrors made of slumped glass sheets

Science.gov (United States)

Winter, A.; Breunig, E.; Friedrich, P.; Proserpio, L.

2017-11-01

For several decades, the field of X-ray astronomy has been playing a major role in understanding the processes in our universe. From binary stars and black holes up to galaxy clusters and dark matter, high energetic events have been observed and analysed using powerful X-ray telescopes like e.g. Rosat, Chandra, and XMM-Newton [1,2,3], giving us detailed and unprecedented views of the high-energy universe. In November 2013, the theme of "The Hot and Energetic Universe" was rated as of highest importance for future exploration and in June 2014 the ATHENA Advanced Telescope for High Energy Astrophysics was selected by ESA for the second large science mission (L2) in the ESA Cosmic Vision program, with launch foreseen in 2028 [4]. By combining a large X-ray telescope with state-of-the-art scientific instruments, ATHENA will address key questions in astrophysics, including: How and why does ordinary matter assemble into the galaxies and galactic clusters that we see today? How do black holes grow and influence their surroundings? In order to answer these questions, ATHENA needs a powerful mirror system which exceed the capabilities of current missions, especially in terms of collecting area. However, current technologies have reached the mass limits of the launching rocket, creating the need for more light-weight mirror systems in order to enhance the effective area without increasing the telescope mass. Hence new mirror technologies are being developed which aim for low-weight systems with large collecting areas. Light material like glass can be used, which are shaped to form an X-ray reflecting system via the method of thermal glass slumping.

Frontier of solar observation. Solar activity observed by 'HINODE' mission

International Nuclear Information System (INIS)

Watanabe, Tetsuya

2008-01-01

After launched in September 2006, solar observation satellite 'HINODE' has been a solar observatory on orbit with the scientific instruments well operated and its continuous observation was conducted steadily on almost all solar atmospheres from photosphere to corona. 'HINODE' was equipped with the solar optical telescope, extreme-ultraviolet imaging spectrometer and x-ray telescope and aimed at clarifying the mystery of solar physics related with coronal heating and magnetic reconnection. Present state of 'HINODE' was described from observations made in initial observation results, which have made several discoveries, such as Alfven waves in the corona, unexpected dynamics in the chromosphere and photosphere, continuous outflowing plasma as a possible source of solar wind, and fine structures of magnetic field in sunspots and solar surface. (T. Tanaka)

Precollimator Manufacturing for X-ray Telescopes, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Space-based x-ray telescopes currently involve the use of a precollimator (PC) to shield the optics from stray light. Each PC consists of cylindrical aluminum ribs...

Spectrum of the isotropic diffuse gamma-ray emission derived from first-year Fermi Large Area Telescope data.

Science.gov (United States)

Abdo, A A; Ackermann, M; Ajello, M; Atwood, W B; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cavazzuti, E; Cecchi, C; Celik, O; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L R; Conrad, J; Cutini, S; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; Di Bernardo, G; do Couto e Silva, E; Drell, P S; Drlica-Wagner, A; Dubois, R; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Frailis, M; Fukazawa, Y; Funk, S; Fusco, P; Gaggero, D; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giommi, P; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guillemot, L; Guiriec, S; Gustafsson, M; Hanabata, Y; Harding, A K; Hayashida, M; Hughes, R E; Itoh, R; Jackson, M S; Jóhannesson, G; Johnson, A S; Johnson, R P; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Kuehn, F; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Mazziotta, M N; McConville, W; McEnery, J E; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Panetta, J H; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piron, F; Porter, T A; Rainò, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, L S; Rodriguez, A Y; Roth, M; Ryde, F; Sadrozinski, H F-W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Sellerholm, A; Sgrò, C; Shaw, M S; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Starck, J-L; Strickman, M S; Strong, A W; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J B; Thayer, J G; Thompson, D J; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Vasileiou, V; Vilchez, N; Vitale, V; Waite, A P; Wang, P; Winer, B L; Wood, K S; Ylinen, T; Ziegler, M

2010-03-12

We report on the first Fermi Large Area Telescope (LAT) measurements of the so-called "extragalactic" diffuse gamma-ray emission (EGB). This component of the diffuse gamma-ray emission is generally considered to have an isotropic or nearly isotropic distribution on the sky with diverse contributions discussed in the literature. The derivation of the EGB is based on detailed modeling of the bright foreground diffuse Galactic gamma-ray emission, the detected LAT sources, and the solar gamma-ray emission. We find the spectrum of the EGB is consistent with a power law with a differential spectral index gamma = 2.41 +/- 0.05 and intensity I(>100 MeV) = (1.03 +/- 0.17) x 10(-5) cm(-2) s(-1) sr(-1), where the error is systematics dominated. Our EGB spectrum is featureless, less intense, and softer than that derived from EGRET data.

Suche nach solaren Axionen mit dem CCD-Detektor in CAST (CERN Axion Solar Telescope)

CERN Document Server

Kang, Donghwa

2007-01-01

The CERN Axion Solar Telescope (CAST) experiment at CERN searches for solar axions with energies in the keV range. Axions could be produced in the Sun's core by the interaction of thermal photons with virtual photons of the strong electromagnetic field. In this experiment, the solar axions can be converted to photons in the field of a 9 Tesla superconducting magnet. At both ends of the 10 m long dipole magnet, three different X-ray detectors were installed, which are sensitive in the interesting photon energy range. This thesis is devoted to the determination of an upper limit on the axion-photon coupling constant g$_{a\\gamma}$. The analysis is based on the data taken by the CCD detector in the CAST experiment during the years 2003 and 2004. First results of the 2003 data taking were published showing no significant signal above background. However, these results constrain the upper limit of the axion-photon coupling constant by a factor 5 compared to previous axion search experiments. Moreover, the result of...

Observing the Sun with Coronado telescopes telescopes

CERN Document Server

Pugh, Philip

2007-01-01

The Sun provides amateur astronomers with one of the few opportunities for daytime astronomy. In order to see the major features of our nearest star, special telescopes that have a very narrow visible bandwidth are essential. The bandwidth has to be as narrow as 1 A- 10-10 m (1 Angstrom) and centred on the absorption line of neutral hydrogen. This makes many major features of the Suna (TM)s chromosphere visible to the observer. Such narrow-band "Fabry-Perot etalon filters" are high technology, and until the introduction of the Coronado range of solar telescopes, were too expensive for amateur use. The entry-level Coronado telescope, the PST (Personal Solar Telescope) costs under 500. Solar prominences (vast columns of plasma, best seen at the edge of the solar disk), filaments, flares, sunspots, plage and active regions are all visible and can be imaged to produce spectacular solar photographs. Philip Pugh has assembled a team of contributors who show just how much solar work can be done with Coronado telesco...

Measured reflectance of graded multilayer mirrors designed for astronomical hard X-ray telescopes

DEFF Research Database (Denmark)

Christensen, Finn Erland; Craig, W.W.; Windt, D.L.

2000-01-01

Future astronomical X-ray telescopes, including the balloon-borne High-Energy Focusing Telescope (HEFT) and the Constellation-X Hard X-ray Telescope (Con-X HXT) plan to incorporate depth-graded multilayer coatings in order to extend sensitivity into the hard X-ray (10 less than or similar to E less......-graded W/Si multilayers optimized for broadband performance up to 69.5 keV (WK-edge). These designs are ideal for both the HEFT and Con-X HXT applications. We compare the measurements to model calculations to demonstrate that the reflectivity can be well described by the intended power law distribution...

Set of instruments for solar EUV and soft X-ray monitoring onboard satellite Coronas-Photon

Science.gov (United States)

Kotov, Yury; Kochemasov, Alexey; Kuzin, Sergey; Kuznetsov, Vladimir; Sylwester, Janusz; Yurov, Vitaly

Coronas-Photon mission is the third satellite of the Russian Coronas program on solar activity observation. The main goal of the "Coronas-Photon" is the study of solar hard electromagnetic radiation in the wide energy range from UV up to high energy gamma-radiation (2000MeV). Scientific payload for solar radiation observation consists of three types of instruments: Monitors (Natalya-2M, Konus-RF, RT-2, Penguin-M, BRM, PHOKA, Sphin-X, SOKOL spectral and timing measurements of full solar disk radiation have timing in flare/burst mode up to one msec. Instruments Natalya-2M, Konus-RF, RT-2 will cover the wide energy range of hard X-rays and soft gamma-rays (15keV to 2000MeV) and will together constitute the largest area detectors ever used for solar observations. Detectors of gamma-ray monitors are based on structured inorganic scintillators. For X-ray and EUV monitors the scintillation phoswich detectors, gas proportional counter, CdZnTe assembly and filter-covered Si-diodes are used. Telescope-spectrometer TESIS for imaging solar spectroscopy in X-rays has angular resolution up to 1arcsec in three spectral lines. Satellite platform and scientific payload is under construction to be launched in autumn 2008. Satellite orbit is circular with initial height 550km and inclination 82.5degrees. Accuracy of the spacecraft orientation to the Sun is better 3arcmin. In the report the capability of PHOKA, SphinX, SOKOL and TESIS as well as the observation program are described and discussed.

Simulation of the Simbol-X telescope: imaging performance of a deformable x-ray telescope

Science.gov (United States)

Chauvin, Maxime; Roques, Jean-Pierre

2009-08-01

We have developed a simulation tool for a Wolter I telescope subject to deformations. The aim is to understand and predict the behavior of Simbol-X and other future missions (NuSTAR, Astro-H, IXO, ...). Our code, based on Monte-Carlo ray-tracing, computes the full photon trajectories up to the detector plane, along with the deformations. The degradation of the imaging system is corrected using metrology. This tool allows to perform many analyzes in order to optimize the configuration of any of these telescopes.

Simulation results of the electron-proton telescope for Solar Orbiter

Energy Technology Data Exchange (ETDEWEB)

Boden, Sebastian; Steinhagen, Jan; Kulkarni, Shrinivasrao; Grunau, Jan; Paspirgilis, Rolf; Martin, Cesar; Boettcher, Stephan; Seimetz, Lars; Schuster, Bjoern; Kulemzin, Alexander; Wimmer-Schweingruber, Robert F. [Christian-Albrechts-Universitaet Kiel (Germany)

2013-07-01

The Electron Proton Telescope (EPT) is one of five instruments in the Energetic Particle Detector suite for Solar Orbiter. It investigates low energy electrons and protons of solar events. EPT covers an energy range from 20400 keV for electrons and 20 keV-7 MeV for protons and distinguishes electrons from protons using a magnet/foil technique with silicon detectors. There will be two EPT units, each with double-barreled telescopes, one looking sunwards/antisunwards and the other north/south. EPT is designed using the GEometry ANd Tracking (GEANT) simulation toolkit developed by CERN for Monte Carlo calculations. Here we present the details of our simulations and the simulation results with respect to energy coverage and the geometrical factor of the EPT instrument. We also look at the far-field of the EPT magnets, which is important for electromagnetic cleanliness considerations.

Effects of Contamination Upon the Performance of X-Ray Telescopes

Science.gov (United States)

O'Dell, Stephen L.; Elsner, Ronald F.; Oosterbroek, Tim

2010-01-01

Particulate and molecular contamination can each impact the performance of x-ray telescope systems. Furthermore, any changes in the level of contamination between on-ground calibration and in-space operation can compromise the validity of the calibration. Thus, it is important to understand the sensitivity of telescope performance, especially the net effective area and the wings of the point spread function to contamination. Here, we quantify this sensitivity and discuss the flow-down of science requirements to contamination-control requirements. As an example, we apply this methodology to the International X-ray Observatory (IXO), currently under joint study by ESA, JAXA, and NASA.

Optimization of graded multilayer designs for astronomical x-ray telescopes

DEFF Research Database (Denmark)

Mao, P.H.; Harrison, F.A.; Windt, D.L.

1999-01-01

We developed a systematic method for optimizing the design of depth-graded multilayers for astronomical hard-x-ray and soft-gamma-ray telescopes based on the instrument's bandpass and the field of view. We apply these methods to the design of the conical-approximation Wolter I optics employed...... by the balloon-borne High Energy Focusing Telescope, using W/Si as the multilayer materials. In addition, we present optimized performance calculations of mirrors, using other material pairs that are capable of extending performance to photon energies above the W K-absorption edge (69.5 keV), including Pt/C, Ni...

Solar System Observations with the James Webb Space Telescope

Science.gov (United States)

Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael;

Potential of the McMath-Pierce 1.6-Meter Solar Telescope for Speckle Interferometry

Science.gov (United States)

Harshaw, Richard; Jones, Gregory; Wiley, Edward; Boyce, Patrick; Branston, Detrick; Rowe, David; Genet, Russell

2015-09-01

We explored the aiming and tracking accuracy of the McMath-Pierce 1.6 m solar telescope at Kitt Peak National Observatory as part of an investigation of using this telescope for speckle interferometry of close visual double stars. Several slews of various lengths looked for hysteresis in the positioning system (we found none of significance) and concluded that the 1.6 m telescope would make a useful telescope for speckle interferometry.

Background study for the pn-CCD detector of CERN Axion Solar Telescope

CERN Document Server

Cebrián, S; Kuster, M.; Beltran, B.; Gomez, H.; Hartmann, R.; Irastorza, I. G.; Kotthaus, R.; Luzon, G.; Morales, J.; Ruz, J.; Struder, L.; Villar, J. A.

2007-01-01

The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into photons with energies up to around 10 keV via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) prototype magnet. A backside illuminated pn-CCD detector in conjunction with an X-ray mirror optics is one of the three detectors used in CAST to register the expected photon signal. Since this signal is very rare and different background components (environmental gamma radiation, cosmic rays, intrinsic radioactive impurities in the set-up, ...) entangle it, a detailed study of the detector background has been undertaken with the aim to understand and further reduce the background level of the detector. The analysis is based on measured data taken during the Phase I of CAST and on Monte Carlo simulations of different background components. This study will show that the observed background level (at a rate of (8.00+-0.07)10^-5 counts/cm^2/s/keV between 1 and 7 keV) s...

UBAT of UFFO/ Lomonosov: The X-Ray Space Telescope to Observe Early Photons from Gamma-Ray Bursts

Science.gov (United States)

Jeong, S.; Panasyuk, M. I.; Reglero, V.; Connell, P.; Kim, M. B.; Lee, J.; Rodrigo, J. M.; Ripa, J.; Eyles, C.; Lim, H.; Gaikov, G.; Jeong, H.; Leonov, V.; Chen, P.; Castro-Tirado, A. J.; Nam, J. W.; Svertilov, S.; Yashin, I.; Garipov, G.; Huang, M.-H. A.; Huang, J.-J.; Kim, J. E.; Liu, T.-C.; Petrov, V.; Bogomolov, V.; Budtz-Jørgensen, C.; Brandt, S.; Park, I. H.

2018-02-01

The Ultra-Fast Flash Observatory (UFFO) Burst Alert and Trigger Telescope (UBAT) has been designed and built for the localization of transient X-ray sources such as Gamma Ray Bursts (GRBs). As one of main instruments in the UFFO payload onboard the Lomonosov satellite (hereafter UFFO/ Lomonosov), the UBAT's roles are to monitor the X-ray sky, to rapidly locate and track transient sources, and to trigger the slewing of a UV/optical telescope, namely Slewing Mirror Telescope (SMT). The SMT, a pioneering application of rapid slewing mirror technology has a line of sight parallel to the UBAT, allowing us to measure the early UV/optical GRB counterpart and study the extremely early moments of GRB evolution. To detect X-rays, the UBAT utilizes a 191.1 cm2 scintillation detector composed of Yttrium Oxyorthosilicate (YSO) crystals, Multi-Anode Photomultiplier Tubes (MAPMTs), and associated electronics. To estimate a direction vector of a GRB source in its field of view, it employs the well-known coded aperture mask technique. All functions are written for implementation on a field programmable gate array to enable fast triggering and to run the device's imaging algorithms. The UFFO/ Lomonosov satellite was launched on April 28, 2016, and is now collecting GRB observation data. In this study, we describe the UBAT's design, fabrication, integration, and performance as a GRB X-ray trigger and localization telescope, both on the ground and in space.

The Focusing Optics X-ray Solar Imager (FOXSI) SMEX Mission

Science.gov (United States)

Christe, S.; Shih, A. Y.; Krucker, S.; Glesener, L.; Saint-Hilaire, P.; Caspi, A.; Allred, J. C.; Battaglia, M.; Chen, B.; Drake, J. F.; Gary, D. E.; Goetz, K.; Gburek, S.; Grefenstette, B.; Hannah, I. G.; Holman, G.; Hudson, H. S.; Inglis, A. R.; Ireland, J.; Ishikawa, S. N.; Klimchuk, J. A.; Kontar, E.; Kowalski, A. F.; Massone, A. M.; Piana, M.; Ramsey, B.; Schwartz, R.; Steslicki, M.; Turin, P.; Ryan, D.; Warmuth, A.; Veronig, A.; Vilmer, N.; White, S. M.; Woods, T. N.

2017-12-01

We present FOXSI (Focusing Optics X-ray Solar Imager), a Small Explorer (SMEX) Heliophysics mission that is currently undergoing a Phase A concept study. FOXSI will provide a revolutionary new perspective on energy release and particle acceleration on the Sun. FOXSI is a direct imaging X-ray spectrometer with higher dynamic range and better than 10x the sensitivity of previous instruments. Flown on a 3-axis-stabilized spacecraft in low-Earth orbit, FOXSI uses high-angular-resolution grazing-incidence focusing optics combined with state-of-the-art pixelated solid-state detectors to provide direct imaging of solar hard X-rays for the first time. FOXSI is composed of a pair of x-ray telescopes with a 14-meter focal length enabled by a deployable boom. Making use of a filter-wheel and high-rate-capable solid-state detectors, FOXSI will be able to observe the largest flares without saturation while still maintaining the sensitivity to detect x-ray emission from weak flares, escaping electrons, and hot active regions. This mission concept is made possible by past experience with similar instruments on two FOXSI sounding rocket flights, in 2012 and 2014, and on the HEROES balloon flight in 2013. FOXSI's hard X-ray imager has a field of view of 9 arcminutes and an angular resolution of better than 8 arcsec; it will cover the energy range from 3 up to 50-70 keV with a spectral resolution of better than 1 keV; and it will have sub-second temporal resolution.

Adaptive Lobster-Eye Hard X-Ray Telescope, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — To address NASA needs for hard X-ray telescopes for starlight detection and wavefront analysis, Physical Optics Corporation (POC) proposes to develop an Adjustable...

The MAGIC telescope for gamma-ray astronomy above 30 GeV

Science.gov (United States)

Moralejo, A.; MAGIC Collaboration

The MAGIC telescope is presently at its commissioning phase at the Roque de los Muchachos Observatory (ORM) on the island of La Palma. MAGIC will become the largest ground-based gamma ray telescope in the world, being sensitive to photons of energies as low as 30 GeV. The spectral range between 10 and 300 GeV remains to date mostly unexplored. Observations in this region of the spectrum are expected to provide key data for the understanding of a wide variety of astrophysical phenomena belonging to the so-called ``non thermal Universe'', like the processes in the nuclei of active galaxies, the radiation mechanisms of pulsars and supernova remnants, and the enigmatic gamma-ray bursts. And overview of the telescope and its Physics goals is presented.

Exploring the Extreme Universe with the Fermi Gamma-Ray Space Telescope

Science.gov (United States)

Thompson, David J.; Digel, Seth W.; Racusin, Judith L.

2012-01-01

In ways similar to experiments in nuclear and particle physics, high-energy astrophysics usesgamma rays and energetic charged particles toprobe processes that involve large energy transfers.Since its launch in 2008, the international Fermi Gamma-Ray Space Telescope has been exploringnatural particle accelerators and the interactionsof high-energy particles in the universe. Withsources ranging from thunderstorms on Earth to galaxies and exploding stars in distant parts of the cosmos, the telescopes subjects of study are almostas diverse as were those of the scientist whose name it bears.

Wide field X-ray telescopes: Detecting X-ray transients/afterglows related to gamma ray bursts

International Nuclear Information System (INIS)

Hudec, Rene; Pina, Ladislav; Inneman, Adolf; Gorenstein, Paul; Rezek, Tomas

1999-01-01

The recent discovery of X-ray afterglows of GRBs opens the possibility of analyses of GRBs by their X-ray detections. However, imaging X-ray telescopes in current use mostly have limited field of view. Alternative X-ray optics geometries achieving very large fields of view have been theoretically suggested in the 70ies but not constructed and used so far. We review the geometries and basic properties of the wide-field X-ray optical systems based on one- and two-dimensional lobster-eye geometry and suggest technologies for their development and construction. First results of the development of double replicated X-ray reflecting flats for use in one-dimensional X-ray optics of lobster eye type are presented and discussed. Optimum strategy for locating GRBs upon their X-ray counterparts is also presented and discussed

The CERN axion solar telescope (CAST)

International Nuclear Information System (INIS)

Aalseth, C.E.; Arik, E.; Autiero, D.; Avignone, F.T.; Barth, K.; Bowyer, S.M.; Brauninger, H.; Brodzinski, R.L.; Carmona, J.M.; Cebrian, S.; Celebi, G.; Cetin, S.; Collar, J.I.; Creswick, R.; Delbart, A.; Delattre, M.; DiLella, L.; De Oliveira, R.; Eleftheriadis, Ch.; Erdutan, N.; Fanourakis, G.; Farach, H.A.; Fiorini, C.; Geralis, Th.; Giomataris, I.; Girard, T.A.; Gninenko, S.N.; Golubev, N.A.; Hasinoff, M.; Hoffmann, D.; Irastorza, I.G.; Jacoby, J.; Jeanneau, F.; Knopf, M.A.; Kovzelev, A.V.; Kotthaus, R.; Krcmar, M.; Krecak, Z.; Lakic, B.; Liolios, A.; Ljubicic, A.; Lutz, G.; Longoni, A.; Luzon, G.; Mailov, A.; Matveev, V.A.; Miley, H.S.; Morales, A.; Morales, J.; Mutterer, M.; Nikolaidis, A.; Nussinov, S.; Ortiz, A.; Pitts, W.K.; Placci, A.; Postoev, V.E.; Raffelt, G.G.; Riege, H.; Sampieto, M.; Sarsa, M.; Savvidis, I.; Stipcevic, M.; Thomas, C.W.; Thompson, R.C.; Valco, P.; Villar, J.A.; Villierme, B.; Walckiers, L.; Wilcox, W.; Zachariadou, K.; Zioutas, K.

2002-01-01

A decommissioned LHC test magnet is being prepared as the CERN Axion Solar Telescope (CAST) experiment. The magnet has a field of 9.6 Tesla and length of 10 meters. It is being mounted on a platform to track the sun over ±8 deg. vertically and ±45 deg. , horizontally. A sensitivity in axion-photon coupling gαγγ -11 GeV -1 can be reached for m α ≤ 10 -2 eV, and with a gas filled tube-can reach gαγγ ≤ 10 -10 GeV -1 for axion masses m α < 2eV

Gamma ray astronomy with atmospheric Cherenkov telescopes: the future

International Nuclear Information System (INIS)

Krennrich, Frank

2009-01-01

Atmospheric Cherenkov telescopes have been key to the recent discoveries in teraelectronvolt (TeV) γ-ray astronomy. The detection of TeV γ rays from more than 90 galactic and extragalactic sources provides a wealth of data for probing physical phenomena that pertain to some of the big questions in astrophysics. These include the understanding of the origin of cosmic rays, unveiling the connection between relativistic jets and black holes, shedding light on dark matter and its relation to supersymmetric particles and estimating the brightness of cosmological diffuse radiation fields in the optical/infrared waveband. While these recent advances were made with instruments designed in the 1990s, the present paper is concerned with a next generation of imaging atmospheric Cherenkov telescopes (IACTs) that are currently in the conceptual planning stage. We discuss the basic ideas, the required technology and expected performance of a ≥1 square-kilometer array, which is poised to yield the most dramatic step yet to come in TeV astronomy.

The Focusing Optics X-ray Solar Imager Small Explorer Concept Mission

Science.gov (United States)

Christe, Steven; Shih, Albert Y.; Dennis, Brian R.; Glesener, Lindsay; Krucker, Sam; Saint-Hilaire, Pascal; Gubarev, Mikhail; Ramsey, Brian

2016-05-01

We present the FOXSI (Focusing Optics X-ray Solar Imager) small explorer (SMEX) concept, a mission dedicated to studying particle acceleration and energy release on the Sun. FOXSI is designed as a 3-axis stabilized spacecraft in low-Earth orbit making use of state-of-the-art grazing incidence focusing optics combined withpixelated solid-state detectors, allowing for direct imaging of solar X-rays. The current design being studied features multiple telescopes with a 14 meter focal length enabled by a deployable boom.FOXSI will observe the Sun in the 3-100 keV energy range. The FOXSI imaging concept has already been tested on two sounding rocket flights, in 2012 and 2014 and on the HEROES balloon payload flight in 2013. FOXSI will image the Sun with an angular resolution of 5'', a spectral resolution of 0.5 keV, and sub-second temporal resolution. FOXSI is a direct imaging spectrometer with high dynamic range and sensitivity and will provide a brand-new perspective on energy release on the Sun. We describe the mission and its science objectives.

The X-ray Telescope for the SWIFT Gamma-Ray Burst Mission

International Nuclear Information System (INIS)

Wells, A.; Abbey, A.F.; Beardmore, A.; Mukerjee, K.; Osborne, J.P.; Watson, D.J.; Willingale, R.; Burrows, D. N.; Hill, J. E.; Nousek, J.A.; Miles, B.J.; Mori, K.; Morris, D.C.; Zugger, M.; Chincarini, G.; Campana, S.; Citterio, O.; Moretti, A.; Tagliaferri, G.; Bosworth, J.

2004-01-01

The X-ray Telescope (XRT) for the SWIFT mission, built by the international consortium from Pennsylvania State University (United States), University of Leicester (UK) and Osservatorio Astronomico di Brera (Italy), is already installed on the SWIFT spacecraft. The XRT has two key functions on SWIFT; to determine locations of GRBs to better than 5 arc seconds within 100 seconds of initial detection of a burst and to measure spectra and light curves of the X-ray afterglow over around four orders of magnitude of decay in the afterglow intensity. This paper summarises the XRT performance, operating modes and sensitivity for the detection of prompt and extended X-ray afterglows from gamma-ray bursts. The performance characteristics have been determined from data taken during the ground calibration campaign at MPE's Panter facility in September 2002

Solar flares and the cosmic ray intensity

International Nuclear Information System (INIS)

Hatton, C.J.

1980-01-01

The relationship between the cosmic ray intensity and solar activity during solar cycle 20 is discussed. A model is developed whereby it is possible to simulate the observed cosmic ray intensity from the observed number of solar flares of importance >= 1. This model leads to a radius for the modulation region of 60-70 AU. It is suggested that high speed solar streams also made a small contribution to the modulation of cosmic rays during solar cycle 20. (orig.)

Neutron-induced 2.2 MeV background in gamma ray telescopes

International Nuclear Information System (INIS)

Zanrosso, E.M.; Long, J.L.; Zych, A.D.; White, R.S.; Hughes Aircraft Co., Los Angeles, CA)

1985-01-01

Neutron-induced gamma ray production is an important source of background in Compton scatter gamma ray telescopes where organic scintillator material is used. Most important is deuteron formation when atmospheric albedo and locally produced neutrons are thermalized and subsequently absorbed in the hydrogenous material. The resulting 2.2 MeV gamma line essentially represents a continuous isotropic source within the scintillator itself. Interestingly, using a scintillator material with a high hydrogen-to-carbon ratio to minimize the neutron-induced 4.4 MeV carbon line favors the np reaction. The full problem of neutron-induced background in Compton scatter telescopes has been previously discussed. Results are presented of observations with the University of California balloon-borne Compton scatter telescope where the 2.2 MeV induced line emission is prominently seen

New solar telescope in Big Bear: evidence for super-diffusivity and small-scale solar dynamos?

International Nuclear Information System (INIS)

Goode, Philip R; Abramenko, Valentyna; Yurchyshyn, Vasyl

2012-01-01

The 1.6 m clear aperture New Solar Telescope (NST) in Big Bear Solar Observatory (BBSO) is now providing the highest resolution solar data ever. These data have revealed surprises about the Sun on small-scales including the observation that bright points (BPs), which can be used as proxies for the intense, compact magnetic elements that are apparent in photospheric intergranular lanes. The BPs are ever more numerous on ever smaller spatial scales as though there were no limit to how small the BPs can be. Here we discuss high resolution NST data on BPs that provide support for the ideas that a turbulent regime of super-diffusivity dominates in the quiet Sun, and there are local dynamos operating near the solar surface. (comment)

The Advanced Gamma-ray Imaging System (AGIS): Telescope Mechanical Designs

Science.gov (United States)

Guarino, V.; Buckley, J.; Byrum, K.; Falcone, A.; Fegan, S.; Finley, J.; Hanna, D.; Horan, D.; Kaaret, P.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Wagner, R.; Woods, M.; Vassiliev, V.

2008-04-01

The concept of a future ground-based gamma-ray observatory, AGIS, in the energy range 40 GeV-100 TeV is based on an array of sim 100 imaging atmospheric Cherenkov telescopes (IACTs). The anticipated improvements of AGIS sensitivity, angular resolution and reliability of operation impose demanding technological and cost requirements on the design of IACTs. The relatively inexpensive Davies-Cotton telescope design has been used in ground-based gamma-ray astronomy for almost fifty years and is an excellent option. We are also exploring alternative designs and in this submission we focus on the recent mechanical design of a two-mirror telescope with a Schwarzschild-Couder (SC) optical system. The mechanical structure provides support points for mirrors and camera. The design was driven by the requirement of minimizing the deflections of the mirror support structures. The structure is also designed to be able to slew in elevation and azimuth at 10 degrees/sec.

Using frequency response functions to manage image degradation from equipment vibration in the Daniel K. Inouye Solar Telescope

Science.gov (United States)

McBride, William R.; McBride, Daniel R.

2016-08-01

The Daniel K Inouye Solar Telescope (DKIST) will be the largest solar telescope in the world, providing a significant increase in the resolution of solar data available to the scientific community. Vibration mitigation is critical in long focal-length telescopes such as the Inouye Solar Telescope, especially when adaptive optics are employed to correct for atmospheric seeing. For this reason, a vibration error budget has been implemented. Initially, the FRFs for the various mounting points of ancillary equipment were estimated using the finite element analysis (FEA) of the telescope structures. FEA analysis is well documented and understood; the focus of this paper is on the methods involved in estimating a set of experimental (measured) transfer functions of the as-built telescope structure for the purpose of vibration management. Techniques to measure low-frequency single-input-single-output (SISO) frequency response functions (FRF) between vibration source locations and image motion on the focal plane are described. The measurement equipment includes an instrumented inertial-mass shaker capable of operation down to 4 Hz along with seismic accelerometers. The measurement of vibration at frequencies below 10 Hz with good signal-to-noise ratio (SNR) requires several noise reduction techniques including high-performance windows, noise-averaging, tracking filters, and spectral estimation. These signal-processing techniques are described in detail.

Pointing stability of Hinode and requirements for the next Solar mission Solar-C

Science.gov (United States)

Katsukawa, Y.; Masada, Y.; Shimizu, T.; Sakai, S.; Ichimoto, K.

2017-11-01

It is essential to achieve fine pointing stability in a space mission aiming for high resolutional observations. In a future Japanese solar mission SOLAR-C, which is a successor of the HINODE (SOLAR-B) mission, we set targets of angular resolution better than 0.1 arcsec in the visible light and better than 0.2 - 0.5 arcsec in EUV and X-rays. These resolutions are twice to five times better than those of corresponding instruments onboard HINODE. To identify critical items to achieve the requirements of the pointing stability in SOLAR-C, we assessed in-flight performance of the pointing stability of HINODE that achieved the highest pointing stability in Japanese space missions. We realized that one of the critical items that have to be improved in SOLAR-C is performance of the attitude stability near the upper limit of the frequency range of the attitude control system. The stability of 0.1 arcsec (3σ) is required in the EUV and X-ray telescopes of SOLAR-C while the HINODE performance is slightly worse than the requirement. The visible light telescope of HINODE is equipped with an image stabilization system inside the telescope, which achieved the stability of 0.03 arcsec (3σ) by suppressing the attitude jitter in the frequency range lower than 10 Hz. For further improvement, it is expected to suppress disturbances induced by resonance between the telescope structures and disturbances of momentum wheels and mechanical gyros in the frequency range higher than 100 Hz.

Wide field x-ray telescopes: Detecting x-ray transients/afterglows related to GRBs

International Nuclear Information System (INIS)

Hudec, Rene; Pina, Ladislav; Inneman, Adolf; Gorenstein, Paul

1998-01-01

The recent discovery of X-ray afterglows of GRBs opens the possibility of analyses of GRBs by their X-ray detections. However, imaging X-ray telescopes in current use mostly have limited fields of view. Alternative X-ray optics geometries achieving very large fields of view have been theoretically suggested in the 70's but not constructed and used so far. We review the geometries and basic properties of the wide-field X-ray optical systems based on one- and two-dimensional lobster-eye geometry and suggest technologies for their development and construction. First results of the development of double replicated X-ray reflecting flats for use in one-dimensional X-ray optics of lobster-eye type are presented and discussed. The optimum strategy for locating GRBs upon their X-ray counterparts is also presented and discussed

The Spectrometer/Telescope for Imaging X-rays on Solar Orbiter: Flight design, challenges and trade-offs

International Nuclear Information System (INIS)

Krucker, S.; Bednarzik, M.; Grimm, O.; Hurford, G.J.; Limousin, O.; Meuris, A.; Orleański, P.; Seweryn, K.; Skup, K.R.

2016-01-01

STIX is the X-ray spectral imaging instrument on-board the Solar Orbiter space mission of the European Space Agency, and together with nine other instruments will address questions of the interaction between the Sun and the heliosphere. STIX will study the properties of thermal and accelerated electrons near the Sun through their Bremsstrahlung X-ray emission, addressing in particular the emission from flaring regions on the Sun. The design phase of STIX has been concluded. This paper reports the final flight design of the instrument, focusing on design challenges that were faced recently and how they were addressed.

The 2016 Transit of Mercury Observed from Major Solar Telescopes and Satellites

Science.gov (United States)

Pasachoff, Jay M.; Schneider, Glenn; Gary, Dale; Chen, Bin; Sterling, Alphonse C.; Reardon, Kevin P.; Dantowitz, Ronald; Kopp, Greg A.

2016-10-01

We report observations from the ground and space of the 9 May 2016 transit of Mercury. We build on our explanation of the black-drop effect in transits of Venus based on spacecraft observations of the 1999 transit of Mercury (Schneider, Pasachoff, and Golub, Icarus 168, 249, 2004). In 2016, we used the 1.6-m New Solar Telescope at the Big Bear Solar Observatory with active optics to observe Mercury's transit at high spatial resolution. We again saw a small black-drop effect as 3rd contact neared, confirming the data that led to our earlier explanation as a confluence of the point-spread function and the extreme solar limb darkening (Pasachoff, Schneider, and Golub, in IAU Colloq. 196, 2004). We again used IBIS on the Dunn Solar Telescope of the Sacramento Peak Observatory, as A. Potter continued his observations, previously made at the 2006 transit of Mercury, at both telescopes of the sodium exosphere of Mercury (Potter, Killen, Reardon, and Bida, Icarus 226, 172, 2013). We imaged the transit with IBIS as well as with two RED Epic IMAX-quality cameras alongside it, one with a narrow passband. We show animations of our high-resolution ground-based observations along with observations from XRT on JAXA's Hinode and from NASA's Solar Dynamics Observatory. Further, we report on the limit of the transit change in the Total Solar Irradiance, continuing our interest from the transit of Venus TSI (Schneider, Pasachoff, and Willson, ApJ 641, 565, 2006; Pasachoff, Schneider, and Willson, AAS 2005), using NASA's SORCE/TIM and the Air Force's TCTE/TIM. See http://transitofvenus.info and http://nicmosis.as.arizona.edu.Acknowledgments: We were glad for the collaboration at Big Bear of Claude Plymate and his colleagues of the staff of the Big Bear Solar Observatory. We also appreciate the collaboration on the transit studies of Robert Lucas (Sydney, Australia) and Evan Zucker (San Diego, California). JMP appreciates the sabbatical hospitality of the Division of Geosciences and

Searching for Axions from Celestial Objects with the X-Ray Telescope at CAST

CERN Document Server

Guthörl, T

2009-01-01

The CAST (CERN Solar Axion Telescope) experiment is designed to detect axions from the sun by making use of the inverse Primakoff effekt i.e. reconversion of axions into X-ray photons under the influence of a strong magnetic field. In order to track the sun the magnet used is mounted to a moveable device. This movability can also be used to track celestial objects of interest such as the galactic centre or Scorpio X-1, which is the brightest X-ray source besides the sun. The data gained with the CCD detector during trackings of these objects are analysed in this work. Since no signal above background can be observed an upper limit on the free parameter flux times axion-photon coupling constant^2 is determined. This upper limit in turn can be used to calculate a maximum energy loss due to axion emission for both the galactic centre and Sco X-1. The results presented in this work imply that e.g. the galactic centre can emit axions with up to 10^42 W without being detected by CAST.

The Relation Between Magnetic Fields and X-ray Emission for Solar Microflares and Active Regions

Science.gov (United States)

Kirichenko, A. S.; Bogachev, S. A.

2017-09-01

We present the result of a comparison between magnetic field parameters and the intensity of X-ray emission for solar microflares with Geosynchronous Operational Environmental Satellites (GOES) classes from A0.02 to B5.1. For our study, we used the monochromatic MgXII Imaging Spectroheliometer (MISH), the Full-disk EUV Telescope (FET), and the Solar PHotometer in X-rays (SphinX) instruments onboard the Complex Orbital Observations Near-Earth of Activity of the Sun-Photon CORONAS- Photon spacecraft because of their high sensitivity in soft X-rays. The peak flare flux (PFF) for solar microflares was found to depend on the strength of the magnetic field and on the total unsigned magnetic flux as a power-law function. In the spectral range 2.8 - 36.6 Å, which shows very little increase related to microflares, the power-law index of the relation between the X-ray flux and magnetic flux for active regions is 1.48 ±0.86, which is close to the value obtained previously by Pevtsov et al. ( Astrophys. J. 598, 1387, 2003) for different types of solar and stellar objects. In the spectral range 1 - 8 Å, the power-law indices for PFF(B) and PFF(Φ) for microflares are 3.87 ±2.16 and 3 ±1.6, respectively. We also make suggestions on the heating mechanisms in active regions and microflares under the assumption of loops with constant pressure and heating using the Rosner-Tucker-Vaiana scaling laws.

The Miniature X-ray Solar Spectrometer (MinXSS) CubeSats: instrument capabilities and early science analysis on the quiet Sun, active regions, and flares.

Science.gov (United States)

Moore, Christopher S.; Woods, Tom; Caspi, Amir; Dennis, Brian R.; MinXSS Instrument Team, NIST-SURF Measurement Team

2018-01-01

Detection of soft X-rays (sxr) from the Sun provide direct information on coronal plasma at temperatures in excess of ~1 MK, but there have been relatively few solar spectrally resolved measurements from 0.5 – 10. keV. The Miniature X-ray Solar Spectrometer (MinXSS) CubeSat is the first solar science oriented CubeSat mission flown for the NASA Science Mission Directorate, and has provided measurements from 0.8 -12 keV, with resolving power ~40 at 5.9 keV, at a nominal ~10 second time cadence. MinXSS design and development has involved over 40 graduate students supervised by professors and professionals at the University of Colorado at Boulder. Instrument radiometric calibration was performed at the National Institute for Standard and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF) and spectral resolution determined from radioactive X-ray sources. The MinXSS spectra allow for determining coronal abundance variations for Fe, Mg, Ni, Ca, Si, S, and Ar in active regions and during flares. Measurements from the first of the twin CubeSats, MinXSS-1, have proven to be consistent with the Geostationary Operational Environmental Satellite (GOES) 0.1 – 0.8 nm energy flux. Simultaneous MinXSS-1 and Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observations have provided the most complete sxr spectral coverage of flares in recent years. These combined measurements are vital in estimating the heating flare loops by non-thermal accelerated electrons. MinXSS-1 measurements have been combined with the Hinode X-ray Telescope (XRT) and Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO-AIA) to further constrain the coronal temperature distribution during quiescent times. The structure of the temperature distribution (especially for T > 5 MK) is important for deducing heating processes in the solar atmosphere. MinXSS-1 observations yield some of the tightest constraints on the high temperature component of the coronal plasma, in the

Diffractive X-Ray Telescopes

International Nuclear Information System (INIS)

Skinner, G.K.; Skinner, G.K

2010-01-01

Diffractive X-ray telescopes using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution several orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro arc seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the supermassive black holes in the center of active galaxies What then is precluding their immediate adoption Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed atmospheric absorption

EIT: Solar corona synoptic observations from SOHO with an Extreme-ultraviolet Imaging Telescope

Science.gov (United States)

Delaboudiniere, J. P.; Gabriel, A. H.; Artzner, G. E.; Michels, D. J.; Dere, K. P.; Howard, R. A.; Catura, R.; Stern, R.; Lemen, J.; Neupert, W.

1988-01-01

The Extreme-ultraviolet Imaging Telescope (EIT) of SOHO (solar and heliospheric observatory) will provide full disk images in emission lines formed at temperatures that map solar structures ranging from the chromospheric network to the hot magnetically confined plasma in the corona. Images in four narrow bandpasses will be obtained using normal incidence multilayered optics deposited on quadrants of a Ritchey-Chretien telescope. The EIT is capable of providing a uniform one arc second resolution over its entire 50 by 50 arc min field of view. Data from the EIT will be extremely valuable for identifying and interpreting the spatial and temperature fine structures of the solar atmosphere. Temporal analysis will provide information on the stability of these structures and identify dynamical processes. EIT images, issued daily, will provide the global corona context for aid in unifying the investigations and in forming the observing plans for SOHO coronal instruments.

Instrument Design of the Large Aperture Solar UV Visible and IR Observing Telescope (SUVIT) for the SOLAR-C Mission

Science.gov (United States)

Suematsu, Y.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.; Takeyama, N.

2012-12-01

We present an instrumental design of one major solar observation payload planned for the SOLAR-C mission: the Solar Ultra-violet Visible and near IR observing Telescope (SUVIT). The SUVIT is designed to provide high-angular-resolution investigation of the lower solar atmosphere, from the photosphere to the uppermost chromosphere, with enhanced spectroscopic and spectro-polarimetric capability in wide wavelength regions from 280 nm (Mg II h&k lines) to 1100 nm (He I 1083 nm line) with 1.5 m class aperture and filtergraphic and spectrographic instruments.

The challenge of developing thin mirror shells for future x-ray telescopes

Science.gov (United States)

Döhring, Thorsten; Stollenwerk, Manfred; Gong, Qingqing; Proserpio, Laura; Winter, Anita; Friedrich, Peter

2015-09-01

Previously used mirror technologies are not able to fulfil the requirements of future X-ray telescopes due to challenging requests from the scientific community. Consequently new technical approaches for X-ray mirror production are under development. In Europe the technical baseline for the planned X-ray observatory ATHENA is the radical new approach of silicon pore optics. NASÁs recently launched NuSTAR mission uses segmented mirrors shells made from thin bended glasses, successfully demonstrating the feasibility of the glass forming technology for X-ray mirrors. For risk mitigation also in Europe the hot slumping of thin glasses is being developed as an alternative technology for lightweight X-ray telescopes. The high precision mirror manufacturing requires challenging technical developments; several design trades and trend-setting decisions need to be made and are discussed within this paper. Some new technical and economic aspects of the intended glass mirror serial production are also studied within the recently started interdisciplinary project INTRAAST, an acronym for "industry transfer of astronomical mirror technologies". The goal of the project, embedded in a cooperation of the Max-Planck-Institute for extraterrestrial Physics and the University of Applied Sciences Aschaffenburg, is to master the challenge of producing thin mirror shells for future X-ray telescopes. As a first project task the development of low stress coatings for thin glass mirror substrates have been started, the corresponding technical approach and first results are presented.

The Advanced Gamma-ray Imaging System (AGIS): Telescope Optical System Designs

Science.gov (United States)

Vassiliev, Vladimir; Buckley, Jim; Falcone, Abe; Fegan, Steven; Finley, John; Gaurino, Victor; Hanna, David; Kaaret, Philip; Konopelko, Alex; Krawczynski, Henric; Romani, Roger; Weekes, Trevor

2008-04-01

AGIS is a conceptual design for a future ground-based gamma-ray observatory based on an array of ˜100 imaging atmospheric Cherenkov telescopes (IACTs) with a sensitivity to gamma-rays in the energy range 40 GeV-100 TeV. The anticipated improvement of AGIS sensitivity, angular resolution, and reliability of operation imposes demanding technological and cost requirements on the design of the IACTs. In this submission we focus on the optical system (OS) of the AGIS telescopes and consider options which include traditional Davies-Cotton and the other prime- focus telescope designs, as well as a novel two-mirror aplanatic OS originally proposed by Schwarzschild. Emerging new mirror production technologies based on replication processes such as cold and hot glass slumping, cured CFRP, and electroforming provide new opportunities for cost effective solutions for the design of the OS. We evaluate the capabilities of these mirror fabrication methods for the AGIS project.

Adaptation of Dunn Solar Telescope for Jovian Doppler spectro imaging

Science.gov (United States)

Underwood, Thomas A.; Voelz, David; Schmider, François-Xavier; Jackiewicz, Jason; Dejonghe, Julien; Bresson, Yves; Hull, Robert; Goncalves, Ivan; Gualme, Patrick; Morand, Frédéric; Preis, Olivier

2017-09-01

This paper describes instrumentation used to adapt the Dunn Solar Telescope (DST) located on Sacramento Peak in Sunspot, NM for observations using the Doppler Spectro Imager (DSI). The DSI is based on a Mach-Zehnder interferometer and measures the Doppler shift of solar lines allowing for the study of atmospheric dynamics of giant planets and the detection of their acoustic oscillations. The instrumentation is being designed and built through a collaborative effort between a French team from the Observatoire de la Cote d'Azur (OCA) that designed the DSI and a US team at New Mexico State University (NMSU). There are four major components that couple the DSI to the DST: a guider/tracker, fast steering mirror (FSM), pupil stabilizer and transfer optics. The guider/tracker processes digital video to centroid-track the planet and outputs voltages to the DST's heliostat controls. The FSM removes wavefront tip/tilt components primarily due to turbulence and the pupil stabilizer removes any slow pupil "wander" introduced by the telescope's heliostat/turret arrangement. The light received at a science port of the DST is sent through the correction and stabilization components and into the DSI. The FSM and transfer optics designs are being provided by the OCA team and serve much the same functions as they do for other telescopes at which DSI observations have been conducted. The pupil stabilization and guider are new and are required to address characteristics of the DST.

The nuclear spectroscopic telescope array (NuSTAR) high-energy X-ray mission

DEFF Research Database (Denmark)

Harrison, Fiona A.; Craig, William W.; Christensen, Finn Erland

2013-01-01

The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing far beyond the ~10 keV high-energy cutoff achieved by all previous X...

Telescope Array Radar (TARA) observatory for Ultra-High Energy Cosmic Rays

Energy Technology Data Exchange (ETDEWEB)

Abbasi, R.; Othman, M. Abou Bakr [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Allen, C. [University of Kansas, Lawrence, KS 66045 (United States); Beard, L. [Purdue University, West Lafayette, IN 47907 (United States); Belz, J. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Besson, D. [University of Kansas, Lawrence, KS 66045 (United States); Moscow Engineering and Physics Institute, 31 Kashirskaya Shosse, Moscow 115409 (Russian Federation); Byrne, M.; Farhang-Boroujeny, B.; Gardner, A. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Gillman, W.H. [Gillman and Associates, Salt Lake City, UT 84106 (United States); Hanlon, W. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Hanson, J. [University of Kansas, Lawrence, KS 66045 (United States); Jayanthmurthy, C. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Kunwar, S. [University of Kansas, Lawrence, KS 66045 (United States); Larson, S.L. [Utah State University, Logan, Utah 84322 (United States); Myers, I., E-mail: isaac@cosmic.utah.edu [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Prohira, S.; Ratzlaff, K. [University of Kansas, Lawrence, KS 66045 (United States); Sokolsky, P. [University of Utah, 115 S 1400 E #201 JFB, Salt Lake City, UT 84112 (United States); Takai, H. [Brookhaven National Laboratory, Upton, NY 11973 (United States); and others

2014-12-11

Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest “conventional” cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems.

Telescope Array Radar (TARA) observatory for Ultra-High Energy Cosmic Rays

International Nuclear Information System (INIS)

Abbasi, R.; Othman, M. Abou Bakr; Allen, C.; Beard, L.; Belz, J.; Besson, D.; Byrne, M.; Farhang-Boroujeny, B.; Gardner, A.; Gillman, W.H.; Hanlon, W.; Hanson, J.; Jayanthmurthy, C.; Kunwar, S.; Larson, S.L.; Myers, I.; Prohira, S.; Ratzlaff, K.; Sokolsky, P.; Takai, H.

2014-01-01

Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest “conventional” cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems

Telescope Array Radar (TARA) observatory for Ultra-High Energy Cosmic Rays

Science.gov (United States)

Abbasi, R.; Othman, M. Abou Bakr; Allen, C.; Beard, L.; Belz, J.; Besson, D.; Byrne, M.; Farhang-Boroujeny, B.; Gardner, A.; Gillman, W. H.; Hanlon, W.; Hanson, J.; Jayanthmurthy, C.; Kunwar, S.; Larson, S. L.; Myers, I.; Prohira, S.; Ratzlaff, K.; Sokolsky, P.; Takai, H.; Thomson, G. B.; Von Maluski, D.

2014-12-01

Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest "conventional" cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems.

Observations of Pulsars with the Fermi Gamma-ray Space Telescope

International Nuclear Information System (INIS)

Parent, D.

2009-11-01

The Large Area Telescope (LAT) on Fermi, launched on 2008 June 11, is a space telescope to explore the high energy γ-ray universe. The instrument covers the energy range from 20 MeV to 300 GeV with greatly improved sensitivity and ability to localize γ-ray point sources. It detects γ-rays through conversion to electron-positron pairs and measurement of their direction in a tracker and their energy in a calorimeter. This thesis presents the γ-ray light curves and the phase-resolved spectral measurements of radio-loud gamma-ray pulsars detected by the LAT. The measurement of pulsar spectral parameters (i.e. integrated flux, spectral index, and energy cut-off) depends on the instrument response functions (IRFs). A method developed for the on-orbit validation of the effective area is presented using the Vela pulsar. The cut efficiencies between the real data and the simulated data are compared at each stage of the background rejection. The results are then propagated to the IRFs, allowing the systematic uncertainties of the spectral parameters to be estimated. The last part of this thesis presents the discoveries, using both the LAT observations and the radio and X ephemeris, of new individual γ-ray pulsars such as PSR J0205+6449, and the Vela-like pulsars J2229+6114 and J1048-5832. Timing and spectral analysis are investigated in order to constrain the γ-ray emission model. In addition, we discuss the properties of a large population of γ-ray pulsars detected by the LAT, including normal pulsars, and millisecond pulsars. (author)

Discoveries by the Fermi Gamma Ray Space Telescope

Science.gov (United States)

Gehrels, Neil

2011-01-01

Fermi is a large space gamma-ray mission developed by NASA and the DOE with major contributions from France, Germany, Italy, Japan and Sweden. It was launched in June 2008 and has been performing flawlessly since then. The main instrument is the Large Area Telescope (LAT) operating in the 20 MeV to 300 GeV range and a smaller monitor instrument is the Gamma-ray Burst Monitor (GBM) operating in the 8 keV to 40 MeV range. New findings are occurring every week. Some of the key discoveries are: 1) Discovery of many new gamma-ray pulsars, including gamma-ray only and millisecond pulsars. 2) Detection of high energy gamma-ray emission from globular clusters, most likely due to summed emission from msec pulsars. 3) Discovery of delayed and extended high energy gamma-ray emission from short and long gamma-ray busts. 4) Detection of approximately 250 gamma-ray bursts per year with the GBM instrument. 5) Most accurate measurement of the cosmic ray electron spectrum between 30 GeV and 1 TeV, showing some excess above the conventional diffusion model. The talk will present the new discoveries and their implications.

THERMAL PROPERTIES OF A SOLAR CORONAL CAVITY OBSERVED WITH THE X-RAY TELESCOPE ON HINODE

Energy Technology Data Exchange (ETDEWEB)

Reeves, Katharine K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St. MS 58, Cambridge, MA 02138 (United States); Gibson, Sarah E. [HAO/NCAR, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Kucera, Therese A. [NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States); Hudson, Hugh S. [Space Sciences Laboratories, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Kano, Ryouhei, E-mail: kreeves@cfa.harvard.edu [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

2012-02-20

Coronal cavities are voids in coronal emission often observed above high latitude filament channels. Sometimes, these cavities have areas of bright X-ray emission in their centers. In this study, we use data from the X-ray Telescope (XRT) on the Hinode satellite to examine the thermal emission properties of a cavity observed during 2008 July that contains bright X-ray emission in its center. Using ratios of XRT filters, we find evidence for elevated temperatures in the cavity center. The area of elevated temperature evolves from a ring-shaped structure at the beginning of the observation, to an elongated structure two days later, finally appearing as a compact round source four days after the initial observation. We use a morphological model to fit the cavity emission, and find that a uniform structure running through the cavity does not fit the observations well. Instead, the observations are reproduced by modeling several short cylindrical cavity 'cores' with different parameters on different days. These changing core parameters may be due to some observed activity heating different parts of the cavity core at different times. We find that core temperatures of 1.75 MK, 1.7 MK, and 2.0 MK (for July 19, July 21, and July 23, respectively) in the model lead to structures that are consistent with the data, and that line-of-sight effects serve to lower the effective temperature derived from the filter ratio.

Off-limb EUV observations of the solar corona and transients with the CORONAS-F/SPIRIT telescope-coronagraph

Directory of Open Access Journals (Sweden)

V. Slemzin

2008-10-01

Full Text Available The SPIRIT telescope aboard the CORONAS-F satellite (in orbit from 26 July 2001 to 5 December 2005, observed the off-limb solar corona in the 175 Å (Fe IX, X and XI lines and 304 Å (He II and Si XI lines bands. In the coronagraphic mode the mirror was tilted to image the corona at the distance of 1.1...5 R_sun from the solar center, the outer occulter blocked the disk radiation and the detector sensitivity was enhanced. This intermediate region between the fields of view of ordinary extreme-ultraviolet (EUV telescopes and most of the white-light (WL coronagraphs is responsible for forming the streamer belt, acceleration of ejected matter and emergence of slow and fast solar wind. We present here the results of continuous coronagraphic EUV observations of the solar corona carried out during two weeks in June and December 2002. The images showed a "diffuse" (unresolved component of the corona seen in both bands, and non-radial, ray-like structures seen only in the 175 Å band, which can be associated with a streamer base. The correlations between latitudinal distributions of the EUV brightness in the corona and at the limb were found to be high in 304 Å at all distances and in 175 Å only below 1.5 R_sun. The temporal correlation of the coronal brightness along the west radial line, with the brightness at the underlying limb region was significant in both bands, independent of the distance. On 2 February 2003 SPIRIT observed an expansion of a transient associated with a prominence eruption seen only in the 304 Å band. The SPIRIT data have been compared with the corresponding data of the SOHO LASCO, EIT and UVCS instruments.

A study of the sensitivity of an imaging telescope (GRITS) for high energy gamma-ray astronomy. Final report

International Nuclear Information System (INIS)

Yearian, M.R.

1990-08-01

When a gamma-ray telescope is placed in Earth orbit, it is bombarded by a flux of cosmic protons much greater than the flux of interesting gammas. These protons can interact in the telescope's thermal shielding to produce detectable gamma rays, most of which are vetoed. Since the proton flux is so high, the unvetoed gamma rays constitute a significant background relative to some weak sources. This background increases the observing time required to pinpoint some sources and entirely obscures other sources. Although recent telescopes have been designed to minimize this background, its strength and spectral characteristics were not previously calculated in detail. Monte Carlo calculations are presented which characterize the strength, spectrum and other features of the cosmic proton background using FLUKA, a hadronic cascade program. Several gamma-ray telescopes, including SAS-2, EGRET and the Gamma Ray Imaging Telescope System (GRITS), are analyzed, and their proton-induced backgrounds are characterized. In all cases, the backgrounds are either shown to be low relative to interesting signals or suggestions are made which would reduce the background sufficiently to leave the telescope unimpaired. In addition, several limiting cases are examined for comparison to previous estimates and calibration measurements

ATST telescope mount: telescope of machine tool

Science.gov (United States)

Jeffers, Paul; Stolz, Günter; Bonomi, Giovanni; Dreyer, Oliver; Kärcher, Hans

2012-09-01

The Advanced Technology Solar Telescope (ATST) will be the largest solar telescope in the world, and will be able to provide the sharpest views ever taken of the solar surface. The telescope has a 4m aperture primary mirror, however due to the off axis nature of the optical layout, the telescope mount has proportions similar to an 8 meter class telescope. The technology normally used in this class of telescope is well understood in the telescope community and has been successfully implemented in numerous projects. The world of large machine tools has developed in a separate realm with similar levels of performance requirement but different boundary conditions. In addition the competitive nature of private industry has encouraged development and usage of more cost effective solutions both in initial capital cost and thru-life operating cost. Telescope mounts move relatively slowly with requirements for high stability under external environmental influences such as wind buffeting. Large machine tools operate under high speed requirements coupled with high application of force through the machine but with little or no external environmental influences. The benefits of these parallel development paths and the ATST system requirements are being combined in the ATST Telescope Mount Assembly (TMA). The process of balancing the system requirements with new technologies is based on the experience of the ATST project team, Ingersoll Machine Tools who are the main contractor for the TMA and MT Mechatronics who are their design subcontractors. This paper highlights a number of these proven technologies from the commercially driven machine tool world that are being introduced to the TMA design. Also the challenges of integrating and ensuring that the differences in application requirements are accounted for in the design are discussed.

Tests of lobster eye optics for small space X-ray telescope

Czech Academy of Sciences Publication Activity Database

Tichý, V.; Barbera, M.; Collura, A.; Hromčík, M.; Hudec, René; Inneman, A.; Jakůbek, J.; Maršík, J.; Maršíková, V.; Pína, L.; Varisco, S.

2011-01-01

Roč. 633, č. 1 (2011), S169-S171 ISSN 0168-9002. [International Workshop on Radiation Imaging Detectors /11./. Praha, 29.06.2009-03.07.2009] Institutional research plan: CEZ:AV0Z10030501 Keywords : X-ray optics * X-ray telescope * all-sky monitor Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.207, year: 2011

Solar-cosmic-ray variability

International Nuclear Information System (INIS)

Reedy, R.C.

1976-01-01

The maximum flux of particles from solar events that should be considered in designing the shielding for a space habitation is discussed. The activities of various radionuclides measured in the top few centimeters of lunar rocks are used to examine the variability of solar cosmic ray fluxes over the last five million years. 10 references

Gamma Ray Large Area Space Telescope (GLAST) Balloon Flight Engineering Model: Overview

Science.gov (United States)

Thompson, D. J.; Godfrey, G.; Williams, S. M.; Grove, J. E.; Mizuno, T.; Sadrozinski, H. F.-W.; Kamae, T.; Ampe, J.; Briber, Stuart; Dann, James;

Impulsive and long duration high-energy gamma-ray emission from the very bright 2012 March 7 solar flares

Energy Technology Data Exchange (ETDEWEB)

Ajello, M. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Albert, A.; Allafort, A.; Caliandro, G. A.; Cameron, R. A.; Charles, E. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L. [Università di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa I-56127 Pisa (Italy); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D.; Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bissaldi, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, and Università di Trieste, I-34127 Trieste (Italy); Bonamente, E.; Cecchi, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Brigida, M. [Dipartimento di Fisica " M. Merlin" dell' Università e del Politecnico di Bari, I-70126 Bari (Italy); Bruel, P. [Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, Palaiseau (France); Buehler, R. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Caraveo, P. A., E-mail: nicola.omodei@stanford.edu, E-mail: vahep@stanford.edu, E-mail: melissa.pesce.rollins@pi.infn.it [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, I-20133 Milano (Italy); and others

2014-07-01

The Fermi Large Area Telescope (LAT) detected gamma-rays up to 4 GeV from two bright X-class solar flares on 2012 March 7, showing both an impulsive and temporally extended emission phases. The gamma-rays appear to originate from the same active region as the X-rays associated with these flares. The >100 MeV gamma-ray flux decreases monotonically during the first hour (impulsive phase) followed by a slower decrease for the next 20 hr. A power law with a high-energy exponential cutoff can adequately describe the photon spectrum. Assuming that the gamma rays result from the decay of pions produced by accelerated protons and ions with a power-law spectrum, we find that the index of that spectrum is ∼3, with minor variations during the impulsive phase. During the extended phase the photon spectrum softens monotonically, requiring the proton index varying from ∼4 to >5. The >30 MeV proton flux observed by the GOES satellites also shows a flux decrease and spectral softening, but with a harder spectrum (index ∼2-3). Based on these observations, we explore the relative merits of prompt or continuous acceleration scenarios, hadronic or leptonic emission processes, and acceleration at the solar corona or by the fast coronal mass ejections. We conclude that the most likely scenario is continuous acceleration of protons in the solar corona that penetrate the lower solar atmosphere and produce pions that decay into gamma rays. However, acceleration in the downstream of the shock cannot be definitely ruled out.

Estimating the sky map in gamma-ray astronomy with a Compton telescope

International Nuclear Information System (INIS)

Herbert, T.J.

1991-01-01

Compton telescopes represent an effective design for γ-ray astronomy in the 1-30 MeV range. However, the complexity of the system response to incident γ-rays has restricted the formulation of optimal methods for processing the data. Since data is only acquired at considerable expense and difficulty a significant investment in both algorithm development and computer processing time are warranted. Current methods for processing low level data form the sky map as either the sum or product of the probabilities that each recorded γ-ray originated from within an area of the sky map. Instead, we model the unknown sky map itself as the means of a Poisson process generating the γ-ray recorded by the telescope. In this paper the authors formulate the probability density function of the data conditioned upon the sky map and derive an iterative algorithm for estimating the sky map by the method of maximum likelihood

Solar X-ray bursts

International Nuclear Information System (INIS)

Urnov, A.M.

1980-01-01

In the popular form the consideration is given to the modern state tasks and results of X-ray spectrometry of solar bursts. The operation of X-ray spectroheliograph is described. Results of spectral and polarization measurings of X-ray radiation of one powerful solar burst are presented. The conclusion has been drawn that in the process of burst development three characteristic stages may be distingwished: 1) the initial phase; just in this period processes which lead to observed consequences-electromagnetic and corpuscular radiation are born; 2) the impulse phase, or the phase of maximum, is characterised by sharp increase of radiation flux. During this phase the main energy content emanates and some volumes of plasma warm up to high temperatures; 3) the phase of burst damping, during which plasma cools and reverts to the initial condition

Thin Mirror Shaping Technology for High-Throughput X-ray Telescopes

Science.gov (United States)

Schattenburg, Mark

This proposal is submitted to the NASA Research Opportunities in Space and Earth Sciences program (ROSES-2012) in response to NASA Research Announcement NNH12ZDA001N- APRA. It is targeted to the Astronomy and Astrophysics Research and Analysis (APRA) program element under the Supporting Technology category. Powerful x-ray telescope mirrors are critical components of a raft of small-to-large mission concepts under consideration by NASA. The science questions addressed by these missions have certainly never been more compelling and the need to fulfill NASA s core missions of exploring the universe and strengthening our nation s technology base has never been greater. Unfortunately, budgetary constraints are driving NASA to consider the cost/benefit and risk factors of new missions more carefully than ever. New technology for producing x-ray telescopes with increased resolution and collecting area, while holding down cost, are key to meeting these goals and sustaining a thriving high-energy astrophysics enterprise in the US. We propose to develop advanced technology which will lead to thin-shell x-ray telescope mirrors rivaling the Chandra x-ray telescope in spatial resolution but with 10-100X larger area all at significantly reduced weight, risk and cost. The proposed effort builds on previous research at MIT and complements NASA-supported research at other institutions. We are currently pursuing two thin-mirror technology development tracks which we propose to extend and accelerate with NASA support. The first research track utilizes rapidly-maturing thermal glass slumping technology which uses porous ceramic air-bearing mandrels to shape glass mirrors without touching, thus avoiding surface-induced mid-range spatial frequency ripples. A second research track seeks to remove any remaining mid- to long-range errors in mirrors by using scanning ion-beam implant to impart small, highly deterministic and very stable amounts of stress into thin glass, utilizing local

The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

Energy Technology Data Exchange (ETDEWEB)

Alvarez-Muñiz, J. [Universidad de Santiago de Compostela, Departamento de Física de Partículas, Campus Sur, Universidad, E-15782 Santiago de Compostela (Spain); Amaral Soares, E. [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Berlin, A.; Bogdan, M. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Boháčová, M. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Institute of Physics of the Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic); Bonifazi, C. [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Carvalho, W.R. [Universidad de Santiago de Compostela, Departamento de Física de Partículas, Campus Sur, Universidad, E-15782 Santiago de Compostela (Spain); Mello Neto, J.R.T. de [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Facal San Luis, P., E-mail: facal@kicp.uchicago.edu [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Genat, J.F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); and others

2013-08-11

We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4–4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope – to validate the telescope design, and to demonstrate a large detector duty cycle – were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory. -- Highlights: • The MIDAS objective is to detect ultra high energy cosmic rays using microwaves. • GHz radiation could provide a powerful alternative to current detection methods. • The MIDAS prototype explores the potential of the microwave technique.

The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

International Nuclear Information System (INIS)

Alvarez-Muñiz, J.; Amaral Soares, E.; Berlin, A.; Bogdan, M.; Boháčová, M.; Bonifazi, C.; Carvalho, W.R.; Mello Neto, J.R.T. de; Facal San Luis, P.; Genat, J.F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P.

2013-01-01

We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4–4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope – to validate the telescope design, and to demonstrate a large detector duty cycle – were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory. -- Highlights: • The MIDAS objective is to detect ultra high energy cosmic rays using microwaves. • GHz radiation could provide a powerful alternative to current detection methods. • The MIDAS prototype explores the potential of the microwave technique

Development of thermally formed glass optics for astronomical hard X-ray telescopes

DEFF Research Database (Denmark)

Craig, W.W.; Hailey, C.J.; Jimenez-Garate, M.

2000-01-01

The next major observational advance in hard X-ray/soft gamma-ray astrophysics will come with the implementation of telescopes capable of focusing 10-200 keV radiation. Focusing allows high signal-to-noise imaging and spectroscopic observations of many sources in this band for the first time...

Construction Status and Early Science with the Daniel K. Inouye Solar Telescope

Science.gov (United States)

McMullin, Joseph P.; Rimmele, Thomas R.; Warner, Mark; Martinez Pillet, Valentin; Craig, Simon; Woeger, Friedrich; Tritschler, Alexandra; Berukoff, Steven J.; Casini, Roberto; Goode, Philip R.; Knoelker, Michael; Kuhn, Jeffrey Richard; Lin, Haosheng; Mathioudakis, Mihalis; Reardon, Kevin P.; Rosner, Robert; Schmidt, Wolfgang

2016-05-01

The 4-m Daniel K. Inouye Solar Telescope (DKIST) is in its seventh year of overall development and its fourth year of site construction on the summit of Haleakala, Maui. The Site Facilities (Utility Building and Support & Operations Building) are in place with ongoing construction of the Telescope Mount Assembly within. Off-site the fabrication of the component systems is completing with early integration testing and verification starting.Once complete this facility will provide the highest sensitivity and resolution for study of solar magnetism and the drivers of key processes impacting Earth (solar wind, flares, coronal mass ejections, and variability in solar output). The DKIST will be equipped initially with a battery of first light instruments which cover a spectral range from the UV (380 nm) to the near IR (5000 nm), and capable of providing both imaging and spectro-polarimetric measurements throughout the solar atmosphere (photosphere, chromosphere, and corona); these instruments are being developed by the National Solar Observatory (Visible Broadband Imager), High Altitude Observatory (Visible Spectro-Polarimeter), Kiepenheuer Institute (Visible Tunable Filter) and the University of Hawaii (Cryogenic Near-Infrared Spectro-Polarimeter and the Diffraction-Limited Near-Infrared Spectro-Polarimeter). Further, a United Kingdom consortium led by Queen's University Belfast is driving the development of high speed cameras essential for capturing the highly dynamic processes measured by these instruments. Finally, a state-of-the-art adaptive optics system will support diffraction limited imaging capable of resolving features approximately 20 km in scale on the Sun.We present the overall status of the construction phase along with the current challenges as well as a review of the planned science testing and the transition into early science operations.

Design of an x-ray telescope optics for XEUS

Science.gov (United States)

Graue, Roland; Kampf, Dirk; Wallace, Kotska; Lumb, David; Bavdaz, Marcos; Freyberg, Michael

2017-11-01

The X-ray telescope concept for XEUS is based on an innovative high performance and light weight Silicon Pore Optics technology. The XEUS telescope is segmented into 16 radial, thermostable petals providing the rigid optical bench structure of the stand alone XRay High Precision Tandem Optics. A fully representative Form Fit Function (FFF) Model of one petal is currently under development to demonstrate the outstanding lightweight telescope capabilities with high optically effective area. Starting from the envisaged system performance the related tolerance budgets were derived. These petals are made from ceramics, i.e. CeSiC. The structural and thermal performance of the petal shall be reported. The stepwise alignment and integration procedure on petal level shall be described. The functional performance and environmental test verification plan of the Form Fit Function Model and the test set ups are described in this paper. In parallel to the running development activities the programmatic and technical issues wrt. the FM telescope MAIT with currently 1488 Tandem Optics are under investigation. Remote controlled robot supported assembly, simultaneous active alignment and verification testing and decentralised time effective integration procedures shall be illustrated.

New solar axion search using the CERN Axion Solar Telescope with 4He filling

Science.gov (United States)

Arik, M.; Aune, S.; Barth, K.; Belov, A.; Bräuninger, H.; Bremer, J.; Burwitz, V.; Cantatore, G.; Carmona, J. M.; Cetin, S. A.; Collar, J. I.; Da Riva, E.; Dafni, T.; Davenport, M.; Dermenev, A.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Galán, J.; García, J. A.; Gardikiotis, A.; Garza, J. G.; Gazis, E. N.; Geralis, T.; Georgiopoulou, E.; Giomataris, I.; Gninenko, S.; Gómez Marzoa, M.; Hasinoff, M. D.; Hoffmann, D. H. H.; Iguaz, F. J.; Irastorza, I. G.; Jacoby, J.; Jakovčić, K.; Karuza, M.; Kavuk, M.; Krčmar, M.; Kuster, M.; Lakić, B.; Laurent, J. M.; Liolios, A.; Ljubičić, A.; Luzón, G.; Neff, S.; Niinikoski, T.; Nordt, A.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M. J.; Raffelt, G.; Rodríguez, A.; Rosu, M.; Ruz, J.; Savvidis, I.; Shilon, I.; Solanki, S. K.; Stewart, L.; Tomás, A.; Vafeiadis, T.; Villar, J.; Vogel, J. K.; Yildiz, S. C.; Zioutas, K.; CAST Collaboration

2015-07-01

The CERN Axion Solar Telescope (CAST) searches for a →γ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward the Sun. Two parallel magnet bores can be filled with helium of adjustable pressure to match the x-ray refractive mass mγ to the axion search mass ma. After the vacuum phase (2003-2004), which is optimal for ma≲0.02 eV , we used 4He in 2005-2007 to cover the mass range of 0.02-0.39 eV and 3He in 2009-2011 to scan from 0.39 to 1.17 eV. After improving the detectors and shielding, we returned to 4He in 2012 to investigate a narrow ma range around 0.2 eV ("candidate setting" of our earlier search) and 0.39-0.42 eV, the upper axion mass range reachable with 4He, to "cross the axion line" for the KSVZ model. We have improved the limit on the axion-photon coupling to ga γ<1.47 ×10-10 GeV-1 (95% C.L.), depending on the pressure settings. Since 2013, we have returned to the vacuum and aim for a significant increase in sensitivity.

Probing a Possible Vacuum Refractive Index with Gamma-Ray Telescopes

CERN Document Server

Ellis, John; Nanopoulos, D V; PH-TH

2009-01-01

We have used a stringy model of quantum space-time foam to suggest that the vacuum may exhibit a non-trivial refractive index depending linearly on gamma-ray energy: eta -1 ~ E_gamma/M_QG1, where M_QG1 is some mass scale typical of quantum gravity that may be ~ 10^18 GeV: see Phys. Lett. B 665, 412 (2008) and references therein. The MAGIC, HESS and Fermi gamma-ray telescopes have recently probed the possible existence of such an energy-dependent vacuum refractive index. All find indications of time-lags for higher-energy photons, but cannot exclude the possibility that they are due to intrinsic delays at the sources. However, the MAGIC and HESS observations of time-lags in emissions from AGNs Mkn 501 and PKS 2155-304 are compatible with each other and a refractive index depending linearly on the gamma-ray energy, with M_QG1 ~ 10^18 GeV. We combine their results to estimate the time-lag Delta t to be expected for the highest-energy photon from GRB 080916c measured by the Fermi telescope, which has an energy ~ ...

Future prospects for γ-ray astronomy

International Nuclear Information System (INIS)

Fichtel, C.

1981-01-01

As γ-ray astronomy moves from the discovery to the exploratory phase, the promise of γ-ray astrophysics noted by theorists in the late 1940s and 1950s is beginning to be realized. In the future, satellites should carry instruments that will have over an order of magnitude greater sensitivity than those flown thus far, and, for at least some portions of the γ-ray energy range, these detectors will also have substantially improved energy and angular resolution. The information to be obtained from these experiments should greatly enhance our knowledge of several astrophysical phenomena including the very energetic and nuclear processes associated with compact objects, astrophysical nucleosynthesis, solar particle acceleration, the chemical composition of the planets and other bodies of the Solar System, the structure of our Galaxy, the origin and dynamic pressure effects of the cosmic rays, high energy particles and energetic processes in other galaxies especially active ones, and the degree of matter-antimatter symmetry of the Universe. The γ-ray results of the forthcoming programs such as Gamma-I, the Gamma Ray Observatory, the γ-ray burst network, Solar Polar, and very high energy γ-ray telescopes on the ground will almost certainly provide justification for more sophisticated telescopes. These advanced instruments might be placed on the Space Platform currently under study by N.A.S.A. (author)

Future prospects for. gamma. -ray astronomy

Energy Technology Data Exchange (ETDEWEB)

Fichtel, C [National Aeronautics and Space Administration, Greenbelt, MD (USA). Goddard Space Flight Center

1981-06-30

As ..gamma..-ray astronomy moves from the discovery to the exploratory phase, the promise of ..gamma..-ray astrophysics noted by theorists in the late 1940s and 1950s is beginning to be realized. In the future, satellites should carry instruments that will have over an order of magnitude greater sensitivity than those flown thus far, and, for at least some portions of the ..gamma..-ray energy range, these detectors will also have substantially improved energy and angular resolution. The information to be obtained from these experiments should greatly enhance our knowledge of several astrophysical phenomena including the very energetic and nuclear processes associated with compact objects, astrophysical nucleosynthesis, solar particle acceleration, the chemical composition of the planets and other bodies of the Solar System, the structure of our Galaxy, the origin and dynamic pressure effects of the cosmic rays, high energy particles and energetic processes in other galaxies especially active ones, and the degree of matter-antimatter symmetry of the Universe. The ..gamma..-ray results of the forthcoming programs such as Gamma-I, the Gamma Ray Observatory, the ..gamma..-ray burst network, Solar Polar, and very high energy ..gamma..-ray telescopes on the ground will almost certainly provide justification for more sophisticated telescopes. These advanced instruments might be placed on the Space Platform currently under study by N.A.S.A.

Observation of Galactic Sources of Very High Energy γ-RAYS with the Magic Telescope

Science.gov (United States)

Bartko, H.

The MAGIC telescope with its 17m diameter mirror is today the largest operating single-dish Imaging Air Cherenkov Telescope (IACT). It is located on the Canary Island La Palma, at an altitude of 2200 m above sea level, as part of the Roque de los Muchachos European Northern Observatory. The MAGIC telescope detects celestial very high energy γ-radiation in the energy band between about 50 GeV and 10 TeV. Since the autumn of 2004 MAGIC has been taking data routinely, observing various objects, like supernova remnants (SNRs), γ-ray binaries, Pulsars, Active Galactic Nuclei (AGN) and Gamma-ray Bursts (GRB). We briefly describe the observational strategy, the procedure implemented for the data analysis, and discuss the results of observations of Galactic Sources.

Multilayer coating facility for the HEFT hard x-ray telescope

DEFF Research Database (Denmark)

Cooper-Jensen, Carsten P.; Christensen, Finn Erland; Chen, Hubert

2001-01-01

A planar magnetron sputtering facility has been established at the Danish Space Research Institute (DSRI) for the production coating of depth graded multilayers on the thermally slumped glass segments which form the basis for the hard X-ray telescope on the HEFT balloon project. The facility...

Highlights of GeV Gamma-Ray Astronomy

Science.gov (United States)

Thompson, David J.

2010-01-01

Because high-energy gamma rays are primarily produced by high-energy particle interactions, the gamma-ray survey of the sky by the Fermi Gamma-ray Space Telescope offers a view of sites of cosmic ray production and interactions. Gamma-ray bursts, pulsars, pulsar wind nebulae, binary sources, and Active Galactic Nuclei are all phenomena that reveal particle acceleration through their gamma-ray emission. Diffuse Galactic gamma radiation, Solar System gamma-ray sources, and energetic radiation from supernova remnants are likely tracers of high-energy particle interactions with matter and photon fields. This paper will present a broad overview of the constantly changing sky seen with the Large Area Telescope (LAT) on the Fermi spacecraft.

WILL THE LARGE SYNOPTIC SURVEY TELESCOPE DETECT EXTRA-SOLAR PLANETESIMALS ENTERING THE SOLAR SYSTEM?

International Nuclear Information System (INIS)

Moro-Martin, Amaya; Turner, Edwin L.; Loeb, Abraham

2009-01-01

Planetesimal formation is a common by-product of the star formation process. Taking the dynamical history of the solar system as a guideline-in which the planetesimal belts were heavily depleted due to gravitational perturbation with the giant planets-and assuming similar processes have taken place in other planetary systems, one would expect the interstellar space to be filled with extra-solar planetesimals. However, not a single one of these objects has been detected so far entering the solar system, even though it would clearly be distinguishable from a solar system comet due to its highly hyperbolic orbit. The Large Synoptic Survey Telescope (LSST) will provide wide coverage maps of the sky to a very high sensitivity, ideal to detect moving objects like comets, both active and inactive. In anticipation of these observations, we estimate how many inactive 'interstellar comets' might be detected during the duration of the survey. The calculation takes into account estimates (from observations and models) of the number density of stars, the amount of solids available to form planetesimals, the frequency of planet and planetesimal formation, the efficiency of planetesimal ejection, and the possible size distribution of these small bodies.

Solar cycle variation of cosmic ray intensity along with interplanetary and solar wind plasma parameters

International Nuclear Information System (INIS)

Mishra, R.K.; Tiwari, S.; Agarwal, R.

2008-01-01

Galactic cosmic rays are modulated at their propagation in the heliosphere by the effect of the large-scale structure of the interplanetary medium. A comparison of the variations in the cosmic ray intensity data obtained by neutron monitoring stations with those in geomagnetic disturbance, solar wind velocity (V), interplanetary magnetic field (B), and their product (V , B) near the Earth for the period 1964-2004 has been presented so as to establish a possible correlation between them. We used the hourly averaged cosmic ray counts observed with the neutron monitor in Moscow. It is noteworthy that a significant negative correlation has been observed between the interplanetary magnetic field, product (V , B) and cosmic ray intensity during the solar cycles 21 and 22. The solar wind velocity has a good positive correlation with cosmic ray intensity during solar cycle 21, whereas it shows a weak correlation during cycles 20, 22 and 23. The interplanetary magnetic field shows a weak negative correlation with cosmic rays for solar cycle 20, and a good anti-correlation for solar cycles 21-23 with the cosmic ray intensity, which, in turn, shows a good positive correlation with disturbance time index (Dst) during solar cycles 21 and 22, and a weak correlation for cycles 20 and 23. (Authors)

Multilayer X-ray imaging systems

Science.gov (United States)

Shealy, D. L.; Hoover, R. B.; Gabardi, D. R.

1986-01-01

An assessment of the imaging properties of multilayer X-ray imaging systems with spherical surfaces has been made. A ray trace analysis was performed to investigate the effects of using spherical substrates (rather than the conventional paraboloidal/hyperboloidal contours) for doubly reflecting Cassegrain telescopes. These investigations were carried out for mirrors designed to operate at selected soft X-ray/XUV wavelengths that are of significance for studies of the solar corona/transition region from the Stanford/MSFC Rocket X-Ray Telescope. The effects of changes in separation of the primary and secondary elements were also investigated. These theoretical results are presented as well as the results of ray trace studies to establish the resolution and vignetting effects as a function of field angle and system parameters.

Prospects for Gamma-Ray Burst detection by the Cherenkov Telescope Array

Directory of Open Access Journals (Sweden)

Bissaldi E.

2017-01-01

Full Text Available The Large Area Telescope (LAT on the Fermi satellite is expected to publish a catalogue with more than 100 Gamma-Ray Bursts (GRBs detected above 100 MeV thanks to a new detection algorithm and a new event reconstruction. This work aims at revising the prospects for GRB alerts with the Cherenkov Telescope Array (CTA based on the new LAT results. We start considering the simulation of the observations with the full CTA of two extremely bright events, the long GRB 130427A and the short GRB 090510, then we investigate how these GRBs would be observed by a particular configuration of the array with the telescopes pointing to different directions in what is called the “coupled divergent mode”.

Preliminary Feasibility Study of the Solar Observation Payloads for STSAT-CLASS Satellites

Directory of Open Access Journals (Sweden)

Yong-Jae Moon

2004-12-01

Full Text Available In this paper, we present preliminary feasibility studies on three types of solar observation payloads for future Korean Science and Technology Satellite (STSAT programs. The three candidates are (1 an UV imaging telescope, (2 an UV spectrograph, and (3 an X-ray spectrometer. In the case of UV imaging telescope, the most important constraint seems to be the control stability of a satellite in order to obtain a reasonably good spatial resolution. Considering that the current pointing stability estimated from the data of the Far ultraviolet Imaging Spectrograph (FIMS onboard the Korean STSAT-1, is around 1 arc minutes/sec, we think that it is hard to obtain a spatial resolution sufficient for scientific research by such an UV Imaging Telescope. For solar imaging missions, we realize that an image stabilization system, which is composed of a small guide telescope with limb sensor and a servo controller of secondary mirror, is quite essential for a very good pointing stability of about 0.1 arcsec. An UV spectrograph covering the solar full disk seems to be a good choice in that there is no risk due to poor pointing stability as well as that it can provide us with valuable UV spectral irradiance data valuable for studying their effects on the Earth's atmosphere and satellites. The heritage of the FIMS can be a great advantage of developing the UV spectrograph. Its main disadvantage is that two major missions are in operation or scheduled. Our preliminary investigations show that an X-ray spectrometer for the full disk Sun seems to be the best choice among the three candidates. The reasons are : (1 high temporal and spectral X-ray data are very essential for studying the acceleration process of energetic particles associated with solar flares, (2 we have a good heritage of X-ray detectors including a rocket-borne X-ray detector, (3 in the case of developing countries such as India and Czech, solar X-ray spectrometers were selected as their early stage

Characteristic studies on solar x-ray flares and solar radio bursts during descending phases of solar cycles 22 and 23

International Nuclear Information System (INIS)

Bhattacharya, J.; De, B.K.; Guha, A.

2014-01-01

In this paper, a comparative study between the solar X-ray flares and solar radio bursts in terms of their duration and energy has been done. This has been done by analyzing the data in a statistical way covering the descending phase of the 22nd and 23rd solar cycles. It has been observed that the most probable value of duration of both solar X-ray flares and solar radio bursts remain same for a particular cycle. There is a slight variation in the most probable value of duration in going from 22nd cycle to 23rd cycle in the case of both kinds of events. This small variation may be due to the variation of polar field. A low correlation has been observed between energy fluxes in solar X-ray flares and in solar radio bursts. This has been attributed to the non symmetric contribution of energy to the solar radio and X-ray band controlled by solar magnetic field

X-ray Optics Development at MSFC

Science.gov (United States)

Sharma, Dharma P.

2017-01-01

Development of high resolution focusing telescopes has led to a tremendous leap in sensitivity, revolutionizing observational X-ray astronomy. High sensitivity and high spatial resolution X-ray observations have been possible due to use of grazing incidence optics (paraboloid/hyperboloid) coupled with high spatial resolution and high efficiency detectors/imagers. The best X-ray telescope flown so far is mounted onboard Chandra observatory launched on July 23,1999. The telescope has a spatial resolution of 0.5 arc seconds with compatible imaging instruments in the energy range of 0.1 to 10 keV. The Chandra observatory has been responsible for a large number of discoveries and has provided X-ray insights on a large number of celestial objects including stars, supernova remnants, pulsars, magnetars, black holes, active galactic nuclei, galaxies, clusters and our own solar system.

Using Deep Learning for Gamma Ray Source Detection at the First G-APD Cherenkov Telescope (FACT)

Science.gov (United States)

Bieker, Jacob

2018-06-01

Finding gamma-ray sources is of paramount importance for Imaging Air Cherenkov Telescopes (IACT). This study looks at using deep neural networks on data from the First G-APD Cherenkov Telescope (FACT) as a proof-of-concept of finding gamma-ray sources with deep learning for the upcoming Cherenkov Telescope Array (CTA). In this study, FACT’s individual photon level observation data from the last 5 years was used with convolutional neural networks to determine if one or more sources were present. The neural networks used various architectures to determine which architectures were most successful in finding sources. Neural networks offer a promising method for finding faint and extended gamma-ray sources for IACTs. With further improvement and modifications, they offer a compelling method for source detection for the next generation of IACTs.

Digital optical correlator x-ray telescope alignment monitoring system

Science.gov (United States)

Lis, Tomasz; Gaskin, Jessica; Jasper, John; Gregory, Don A.

2018-01-01

The High-Energy Replicated Optics to Explore the Sun (HEROES) program is a balloon-borne x-ray telescope mission to observe hard x-rays (˜20 to 70 keV) from the sun and multiple astrophysical targets. The payload consists of eight mirror modules with a total of 114 optics that are mounted on a 6-m-long optical bench. Each mirror module is complemented by a high-pressure xenon gas scintillation proportional counter. Attached to the payload is a camera that acquires star fields and then matches the acquired field to star maps to determine the pointing of the optical bench. Slight misalignments between the star camera, the optical bench, and the telescope elements attached to the optical bench may occur during flight due to mechanical shifts, thermal gradients, and gravitational effects. These misalignments can result in diminished imaging and reduced photon collection efficiency. To monitor these misalignments during flight, a supplementary Bench Alignment Monitoring System (BAMS) was added to the payload. BAMS hardware comprises two cameras mounted directly to the optical bench and rings of light-emitting diodes (LEDs) mounted onto the telescope components. The LEDs in these rings are mounted in a predefined, asymmetric pattern, and their positions are tracked using an optical/digital correlator. The BAMS analysis software is a digital adaption of an optical joint transform correlator. The aim is to enhance the observational proficiency of HEROES while providing insight into the magnitude of mechanically and thermally induced misalignments during flight. Results from a preflight test of the system are reported.

The First ALMA Observation of a Solar Plasmoid Ejection from an X-Ray Bright Point

Science.gov (United States)

Shimojo, M.; Hudson, H. S.; White, S. M.; Bastian, T.; Iwai, K.

2017-12-01

Eruptive phenomena are important features of energy releases events, such solar flares, and have the potential to improve our understanding of the dynamics of the solar atmosphere. The 304 A EUV line of helium, formed at around 10^5 K, is found to be a reliable tracer of such phenomena, but the determination of physical parameters from such observations is not straightforward. We have observed a plasmoid ejection from an X-ray bright point simultaneously with ALMA, SDO/AIA, and Hinode/XRT. This paper reports the physical parameters of the plasmoid obtained by combining the radio, EUV, and X-ray data. As a result, we conclude that the plasmoid can consist either of (approximately) isothermal ˜10^5 K plasma that is optically thin at 100 GHz, or a ˜10^4 K core with a hot envelope. The analysis demonstrates the value of the additional temperature and density constraints that ALMA provides, and future science observations with ALMA will be able to match the spatial resolution of space-borne and other high-resolution telescopes.

The Nuclear Spectroscopic Telescope Array (NuSTAR) High-Energy X-ray Mission

Science.gov (United States)

Harrison, Fiona A.; Craig, Willliam W.; Christensen, Finn E.; Hailey, Charles J.; Zhang, William W.; Boggs, Steven E.; Stern, Daniel; Cook, W. Rick; Forster, Karl; Giommi, Paolo;

FERMI/LARGE AREA TELESCOPE DISCOVERY OF GAMMA-RAY EMISSION FROM THE FLAT-SPECTRUM RADIO QUASAR PKS 1454-354

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bogaert, G.; Bonamente, E.; Brigida, M.

2009-01-01

We report the discovery by the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope of high-energy γ-ray (GeV) emission from the flat-spectrum radio quasar PKS 1454-354 (z = 1.424). On 2008 September 4, the source rose to a peak flux of (3.5 ± 0.7) x 10 -6 ph cm -2 s -1 (E > 100 MeV) on a timescale of hours and then slowly dropped over the following 2 days. No significant spectral changes occurred during the flare. Fermi/LAT observations also showed that PKS 1454-354 is the most probable counterpart of the unidentified EGRET source 3EG J1500-3509. Multiwavelength measurements performed during the following days (7 September with Swift; 6-7 September with the ground-based optical telescope Automated Telescope for Optical Monitoring; 13 September with the Australia Telescope Compact Array) resulted in radio, optical, UV, and X-ray fluxes greater than archival data, confirming the activity of PKS 1454-354.

GLASS AND SILICON FOILS FOR X-RAY SPACE TELESCOPE MIRRORS

Directory of Open Access Journals (Sweden)

M. MIKA

2011-12-01

Full Text Available Unique observations delivered by space X-ray imaging telescopes have been significantly contributing to important discoveries of current astrophysics. The telescopes’ most crucial part is a high throughput, heavily nested mirror array reflecting X-rays and focusing them to a detector. Future astronomical projects on large X-ray telescopes require novel materials and technologies for the construction of the reflecting mirrors. The future mirrors must be lightweight and precisely shaped to achieve large collecting area with high angular resolution of a few arc sec. The new materials and technologies must be cost-effective as well. Currently, the most promising materials are glass or silicon foils which are commercially produced on a large scale. A thermal forming process was used for the precise shaping of these foils. The forced and free slumping of the foils was studied in the temperature range of hot plastic deformation and the shapes obtained by the different slumping processes were compared. The shapes and the surface quality of the foils were measured by a Taylor Hobson contact profilemeter, a ZYGO interferometer and Atomic Forced Microscopy. In the experiments, both heat-treatment temperature and time were varied following our experiment design. The obtained data and relations can be used for modelling and optimizing the thermal forming procedure.

Imaging Plasma Density Structures in the Soft X-Rays Generated by Solar Wind Charge Exchange with Neutrals

Science.gov (United States)

Sibeck, David G.; Allen, R.; Aryan, H.; Bodewits, D.; Brandt, P.; Branduardi-Raymont, G.; Brown, G.; Carter, J. A.; Collado-Vega, Y. M.; Collier, M. R.; Connor, H. K.; Cravens, T. E.; Ezoe, Y.; Fok, M.-C.; Galeazzi, M.; Gutynska, O.; Holmström, M.; Hsieh, S.-Y.; Ishikawa, K.; Koutroumpa, D.; Kuntz, K. D.; Leutenegger, M.; Miyoshi, Y.; Porter, F. S.; Purucker, M. E.; Read, A. M.; Raeder, J.; Robertson, I. P.; Samsonov, A. A.; Sembay, S.; Snowden, S. L.; Thomas, N. E.; von Steiger, R.; Walsh, B. M.; Wing, S.

2018-06-01

measurements rarely suffice to determine the global extent of these density structures or their global variation as a function of solar wind conditions, except in the form of empirical studies based on observations from many different times and solar wind conditions. Remote sensing observations provide global information about auroral ovals (FUV and hard X-ray), the terrestrial plasmasphere (EUV), and the terrestrial ring current (ENA). ENA instruments with low energy thresholds (˜1 keV) have recently been used to obtain important information concerning the magnetosheaths of Venus, Mars, and the Earth. Recent technological developments make these magnetosheaths valuable potential targets for high-cadence wide-field-of-view soft X-ray imagers. Section 2 describes proposed dayside interaction mechanisms, including reconnection, the Kelvin-Helmholtz instability, and other processes in greater detail with an emphasis on the plasma density structures that they generate. It focuses upon the questions that remain as yet unanswered, such as the significance of each proposed interaction mode, which can be determined from its occurrence pattern as a function of location and solar wind conditions. Section 3 outlines the physics underlying the charge exchange generation of soft X-rays. Section 4 lists the background sources (helium focusing cone, planetary, and cosmic) of soft X-rays from which the charge exchange emissions generated by solar wind exchange must be distinguished. With the help of simulations employing state-of-the-art magnetohydrodynamic models for the solar wind-magnetosphere interaction, models for Earth's exosphere, and knowledge concerning these background emissions, Sect. 5 demonstrates that boundaries and regions such as the bow shock, magnetosheath, magnetopause, and cusps can readily be identified in images of charge exchange emissions. Section 6 reviews observations by (generally narrow) field of view (FOV) astrophysical telescopes that confirm the presence of

EARLY OPTICAL OBSERVATIONS OF GAMMA-RAY BURSTS BY THE TAROT TELESCOPES: PERIOD 2001-2008

International Nuclear Information System (INIS)

Klotz, A.; Boer, M.; Atteia, J. L.; Gendre, B.

2009-01-01

The Telescopes a Action Rapide pour les Objets Transitoires telescopes are two robotic observatories designed to observe the prompt optical emission counterpart and the early afterglow of gamma-ray bursts (GRBs). We present data acquired between 2001 and 2008 and discuss the properties of the optical emission of GRBs, noting various interesting results. The optical emission observed during the prompt GRB phase is rarely very bright: we estimate that 5%-20% of GRBs exhibit a bright optical flash (R < 14) during the prompt gamma-ray emission, and that more than 50% of the GRBs have an optical emission fainter than R = 15.5 when the gamma-ray emission is active. We study the apparent optical brightness distribution of GRBs at 1000 s showing that our observations confirm the distribution derived by other groups. The combination of these results with those obtained by other rapid slewing telescopes allows us to better characterize the early optical emission of GRBs and to emphasize the importance of very early multiwavelength GRB studies for the understanding of the physics of the ejecta.

Silicon telescope for prototype sensor characterisation using particle beam and cosmic rays

CERN Multimedia

Fu, Jinlin

2016-01-01

We present the design and the performance of a silicon strip telescope that we have built and recently used as reference tracking system for prototype sensor characterisation. The telescope was operated on beam at the CERN SPS and also using cosmic rays in the laboratory. We will describe the data acquisition system, based on a custom electronic board that we have developed, and the online monitoring system to control the quality of the data in real time.

The current status of development of the electron and proton telescope for Solar Orbiter

Energy Technology Data Exchange (ETDEWEB)

Steinhagen, Jan; Kulkarni, Shrinivasrao; Boden, Sebastian; Martin-Garcia, Cesar; Boettcher, Stephan; Schuster, Bjoern; Seimetz, Lars; Wimmer-Schweingruber, Robert F. [IEAP, Christian-Albrechts-Universitaet zu Kiel (Germany)

2013-07-01

ESA's Solar Orbiter mission, scheduled for launch in January 2017, will study how the sun creates the inner heliosphere. Therefore, the spacecraft will perform in situ and remote sensing measurements of the sun on a high inclination orbit with a perihelion of about 60 solar radii, making it possible to observe the poles of the sun from nearby. The Energetic Particle Detector suite on-board of Solar Orbiter will measure particles of a wide energy range and from multiple directions. One of the important sensors of the EPD suite is the Electron and Proton Telescope. It consists of two antiparallel telescopes with two silicon detectors respectively and is designed to detect electrons between 20 - 400 keV and protons from 20 keV to 7 MeV. EPT relies on a magnet/foil technique to discriminate between electrons and protons. Its design is driven by mass allocation, the thermal environment, power consumption and electronic noise; especially the magnet system must guarantee stray fields low enough to be compliant with the Solar Orbiter EMC requirements. Here, we present the current status of the Structural/Thermal Model and Engineering Model assembly as well as the integration and testing of the prototype.

The magnetic connectivity of coronal shocks from behind-the-limb flares to the visible solar surface during γ-ray events

Science.gov (United States)

Plotnikov, I.; Rouillard, A. P.; Share, G. H.

2017-12-01

Context. The observation of >100 MeV γ-rays in the minutes to hours following solar flares suggests that high-energy particles interacting in the solar atmosphere can be stored and/or accelerated for long time periods. The occasions when γ-rays are detected even when the solar eruptions occurred beyond the solar limb as viewed from Earth provide favorable viewing conditions for studying the role of coronal shocks driven by coronal mass ejections (CMEs) in the acceleration of these particles. Aims: In this paper, we investigate the spatial and temporal evolution of the coronal shocks inferred from stereoscopic observations of behind-the-limb flares to determine if they could be the source of the particles producing the γ-rays. Methods: We analyzed the CMEs and early formation of coronal shocks associated with γ-ray events measured by the Fermi-Large Area Telescope (LAT) from three eruptions behind the solar limb as viewed from Earth on 2013 Oct. 11, 2014 Jan. 06 and Sep. 01. We used a 3D triangulation technique, based on remote-sensing observations to model the expansion of the CME shocks from above the solar surface to the upper corona. Coupling the expansion model to various models of the coronal magnetic field allowed us to derive the time-dependent distribution of shock Mach numbers and the magnetic connection of particles produced by the shock to the solar surface visible from Earth. Results: The reconstructed shock fronts for the three events became magnetically connected to the visible solar surface after the start of the flare and just before the onset of the >100 MeV γ-ray emission. The shock surface at these connections also exhibited supercritical Mach numbers required for significant particle energization. The strongest γ-ray emissions occurred when the flanks of the shocks were connected in a quasi-perpendicular geometry to the field lines reaching the visible surface. Multipoint, in situ, measurements of solar energetic particles (SEPs) were

Galactic cosmic ray spectra during solar cycle 23 and 24. Measurement capabilities of the electron proton helium telescope on board SOHO

Energy Technology Data Exchange (ETDEWEB)

Kuehl, Patrick; Dresing, Nina; Gieseler, Jan; Heber, Bernd; Klassen, Andreas [Christian-Albrechts Universitaet zu Kiel (Germany)

2016-07-01

The solar modulation of galactic cosmic rays (GCR) can be studied in detail by long term variations of the GCR energy spectrum (e.g. on the scales of a solar cycle). With almost 20 years of data, the Electron Proton Helium INstrument (EPHIN) aboard SOHO is well suited for these kind of investigations. Although the design of the instrument is optimized to measure proton and helium isotope spectra up to 50 MeV/nucleon the capability exist that allow to determine energy spectra above 1.5 GeV/nucleon. Therefore we developed a sophisticated inversion method to calculate such proton spectra. The method relies on a GEANT4 Monte Carlo simulation of the instrument and a simplified spacecraft model that calculates the energy response function of EPHIN for electrons, protons and heavier ions. As a result we present galactic cosmic ray spectra from 1995 to 2015. For validation, the derived spectra are compared to AMS, BESS and PAMELA data. Furthermore we discuss the spectra with respect to the solar modulation.

FRAM telescope - monitoring of atmospheric extinction and variable star photometry

Science.gov (United States)

Jurysek, J.; Honkova, K.; Masek, M.

2015-02-01

The FRAM (F/(Ph)otometric Robotic Atmospheric Monitor) telescope is a part of the Pierre Auger Observatory (PAO) located near town Malargüe in Argentina. The main task of the FRAM telescope is the continuous night - time monitoring of the atmospheric extinction and its wavelength dependence. The current methodology of the measurement of a atmospheric extinction and for instrumentation properties also allows simultaneous observation of other interesting astronomical targets. The current observations of the FRAM telescope are focused on the photometry of eclipsing binaries, positional refinement of minor bodies of the Solar system and observations of optical counterparts of gamma ray bursts. In this contribution, we briefly describe the main purpose of the FRAM telescope for the PAO and we also present its current astrono mical observing program.

Development of the Advanced Energetic Pair Telescope (AdEPT) for Medium-Energy Gamma-Ray Astronomy

Science.gov (United States)

Hunter, Stanley D.; Bloser, Peter F.; Dion, Michael P.; McConnell, Mark L.; deNolfo, Georgia A.; Son, Seunghee; Ryan, James M.; Stecker, Floyd W.

2011-01-01

Progress in high-energy gamma-ray science has been dramatic since the launch of INTEGRAL, AGILE and FERMI. These instruments, however, are not optimized for observations in the medium-energy (approx.0.3< E(sub gamma)< approx.200 MeV) regime where many astrophysical objects exhibit unique, transitory behavior, such as spectral breaks, bursts, and flares. We outline some of the major science goals of a medium-energy mission. These science goals are best achieved with a combination of two telescopes, a Compton telescope and a pair telescope, optimized to provide significant improvements in angular resolution and sensitivity. In this paper we describe the design of the Advanced Energetic Pair Telescope (AdEPT) based on the Three-Dimensional Track Imager (3-DTI) detector. This technology achieves excellent, medium-energy sensitivity, angular resolution near the kinematic limit, and gamma-ray polarization sensitivity, by high resolution 3-D electron tracking. We describe the performance of a 30x30x30 cm3 prototype of the AdEPT instrument.

The First ALMA Observation of a Solar Plasmoid Ejection from an X-Ray Bright Point

Energy Technology Data Exchange (ETDEWEB)

Shimojo, Masumi [National Astronomical Observatory of Japan, Tokyo, 181-8588 (Japan); Hudson, Hugh S. [School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ (United Kingdom); White, Stephen M. [Space Vehicles Directorate, Air Force Research Laboratory, Kirtland AFB, NM 87117-5776 (United States); Bastian, Timothy S. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Iwai, Kazumasa, E-mail: masumi.shimojo@nao.ac.jp [Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, 464-8601 (Japan)

2017-05-20

Eruptive phenomena such as plasmoid ejections or jets are important features of solar activity and have the potential to improve our understanding of the dynamics of the solar atmosphere. Such ejections are often thought to be signatures of the outflows expected in regions of fast magnetic reconnection. The 304 Å EUV line of helium, formed at around 10{sup 5} K, is found to be a reliable tracer of such phenomena, but the determination of physical parameters from such observations is not straightforward. We have observed a plasmoid ejection from an X-ray bright point simultaneously at millimeter wavelengths with ALMA, at EUV wavelengths with SDO /AIA, and in soft X-rays with Hinode /XRT. This paper reports the physical parameters of the plasmoid obtained by combining the radio, EUV, and X-ray data. As a result, we conclude that the plasmoid can consist either of (approximately) isothermal ∼10{sup 5} K plasma that is optically thin at 100 GHz, or a ∼10{sup 4} K core with a hot envelope. The analysis demonstrates the value of the additional temperature and density constraints that ALMA provides, and future science observations with ALMA will be able to match the spatial resolution of space-borne and other high-resolution telescopes.

Close Binary Star Speckle Interferometry on the McMath-Pierce 0.8-Meter Solar Telescope

Science.gov (United States)

Wiley, Edward; Harshaw, Richard; Jones, Gregory; Branston, Detrick; Boyce, Patrick; Rowe, David; Ridgely, John; Estrada, Reed; Genet, Russell

2015-09-01

Observations were made in April 2014 to assess the utility of the 0.8-meter solar telescope at the McMath-Pierce Solar Observatory at Kitt Peak National Observatory for performing speckle interferometry observations of close binary stars. Several configurations using science cameras, acquisition cameras, eyepieces, and flip mirrors were evaluated. Speckle images were obtained and recommendations for further improvement of the acquisition system are presented.

Telescoping Solar Array Concept for Achieving High Packaging Efficiency

Science.gov (United States)

Mikulas, Martin; Pappa, Richard; Warren, Jay; Rose, Geoff

2015-01-01

Lightweight, high-efficiency solar arrays are required for future deep space missions using high-power Solar Electric Propulsion (SEP). Structural performance metrics for state-of-the art 30-50 kW flexible blanket arrays recently demonstrated in ground tests are approximately 40 kW/cu m packaging efficiency, 150 W/kg specific power, 0.1 Hz deployed stiffness, and 0.2 g deployed strength. Much larger arrays with up to a megawatt or more of power and improved packaging and specific power are of interest to mission planners for minimizing launch and life cycle costs of Mars exploration. A new concept referred to as the Compact Telescoping Array (CTA) with 60 kW/cu m packaging efficiency at 1 MW of power is described herein. Performance metrics as a function of array size and corresponding power level are derived analytically and validated by finite element analysis. Feasible CTA packaging and deployment approaches are also described. The CTA was developed, in part, to serve as a NASA reference solar array concept against which other proposed designs of 50-1000 kW arrays for future high-power SEP missions could be compared.

NuSTAR Hard X-Ray Observation of a Sub-A Class Solar Flare

Energy Technology Data Exchange (ETDEWEB)

Glesener, Lindsay [School of Physics and Astronomy, University of Minnesota, Minneapolis (United States); Krucker, Säm; Hudson, Hugh [Space Sciences Laboratory, University of California at Berkeley, Berkeley (United States); Hannah, Iain G. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow (United Kingdom); Grefenstette, Brian W. [Cahill Center for Astrophysics, California Institute of Technology, Pasadena (United States); White, Stephen M. [Air Force Research Laboratory, Albuquerque (United States); Smith, David M.; Marsh, Andrew J. [Santa Cruz Institute of Particle Physics and Department of Physics, University of California at Santa Cruz, Santa Cruz (United States)

2017-08-20

We report a Nuclear Spectroscopic Telescope Array ( NuSTAR ) observation of a solar microflare, SOL2015-09-01T04. Although it was too faint to be observed by the GOES X-ray Sensor, we estimate the event to be an A0.1 class flare in brightness. This microflare, with only ∼5 counts s{sup −1} detector{sup −1} observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager ( RHESSI ), is fainter than any hard X-ray (HXR) flare in the existing literature. The microflare occurred during a solar pointing by the highly sensitive NuSTAR astrophysical observatory, which used its direct focusing optics to produce detailed HXR microflare spectra and images. The microflare exhibits HXR properties commonly observed in larger flares, including a fast rise and more gradual decay, earlier peak time with higher energy, spatial dimensions similar to the RHESSI microflares, and a high-energy excess beyond an isothermal spectral component during the impulsive phase. The microflare is small in emission measure, temperature, and energy, though not in physical size; observations are consistent with an origin via the interaction of at least two magnetic loops. We estimate the increase in thermal energy at the time of the microflare to be 2.4 × 10{sup 27} erg. The observation suggests that flares do indeed scale down to extremely small energies and retain what we customarily think of as “flare-like” properties.

The Fermi Large Area Telescope as a cosmic-ray detector

International Nuclear Information System (INIS)

Sgrò, Carmelo

2013-01-01

The Fermi Large Area Telescope is an international observatory conceived to study high energy gamma-rays from the universe. It is designed to identify and reconstruct electromagnetic showers and it can collect cosmic-ray electrons and positrons thanks to its triggering and filtering capabilities. The Fermi LAT collaboration has published several results on charged cosmic rays. We measured the inclusive spectrum of electrons and positrons from 7 GeV to 1 TeV and searched for anisotropies in the electron incoming direction. We have recently published a measurement of cosmic-ray positron-only and electron-only spectra for energies between 20 GeV and 200 GeV exploiting the Earth's magnetic field as a charge separator. In this work we describe the techniques and capabilities of the LAT as a cosmic-ray detector and review the recent results and their interpretations. Prospects for future studies and observations will also be discussed

A Population of Gamma-Ray Millisecond Pulsars Seen with the Fermi Large Area Telescope

International Nuclear Information System (INIS)

Dumora, D.; Grondin, M.H.; Guillemot, L.; Lemoine-Goumard, M.; Lovellette, M.N.; Parent, D.; Smith, D.A.; Abdo, A.A.; Chekhtman, A.; Dermer, C.D.; Grove, J.E.; Johnson, W.N.; Makeev, A.; Ray, P.S.; Strickman, M.S.; Wood, K.S.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Blandford, R.D.; Bloom, E.D.; Borgland, A.W.; Cameron, R.A.; Charles, E.; Chiang, J.; Claus, R.; Digel, S.W.; Silva, E.D.E.; Drell, P.S.; Dubois, R.; Edmonds, Y.; Focke, W.B.; Funk, S.; Glanzman, T.; Godfrey, G.; Hayashida, M.; Johannesson, G.; Kocian, M.L.; Lande, J.; Madejski, G.M.; Michelson, P.F.; Mitthumsiri, W.; Monzani, M.E.; Moskalenko, I.V.; Murgia, S.; Nolan, P.L.; Paneque, D.; Panetta, J.H.; Reimer, A.; Reimer, O.; Rochester, L.S.; Romani, R.W.; Tajima, H.; Tanaka, T.; Thayer, J.B.; Thayer, J.G.; Tramacere, A.; Uchiyama, Y.; Usher, T.L.; Van Etten, A.; Waite, A.P.; Wang, P.; Watters, K.; Atwood, W.B.; Dormody, M.; Johnson, R.P.; Porter, T.A.; Sadrozinski, H.F.W.; Schalk, T.L.; Thorsett, S.E.; Ziegler, M.; Axelsson, M.; Carlson, P.; Conrad, J.; Meurer, C.; Ryde, F.; Ylinen, T.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Kuss, M.; Latronico, L.; Omodei, N.; Pesce-Rollins, M.; Razzano, M.; Sgro, C.; Spandre, G.; Ballet, J.; Casandjian, J.M.; Grenier, I.A.; Starck, J.L.

2009-01-01

Pulsars are born with sub-second spin periods and slow by electromagnetic braking for several tens of millions of years, when detectable radiation ceases. A second life can occur for neutron stars in binary systems. They can acquire mass and angular momentum from their companions, to be spun up to millisecond periods and begin radiating again. We searched Fermi Large Area Telescope data for pulsations from all known millisecond pulsars (MSPs) outside of globular clusters, using rotation parameters from radio telescopes. Strong gamma-ray pulsations were detected for eight MSPs. The gamma-ray pulse profiles and spectral properties resemble those of young gamma-ray pulsars. The basic emission mechanism seems to be the same for MSPs and young pulsars, with the emission originating in regions far from the neutron star surface. (authors)

Caliste-SO X-ray micro-camera for the STIX instrument on-board Solar Orbiter space mission

International Nuclear Information System (INIS)

Meuris, A.; Hurford, G.; Bednarzik, M.; Limousin, O.; Gevin, O.; Le Mer, I.; Martignac, J.; Horeau, B.; Grimm, O.; Resanovic, R.; Krucker, S.; Orleański, P.

2012-01-01

The Spectrometer Telescope for Imaging X-rays (STIX) is an instrument on the Solar-Orbiter space mission that performs hard X-ray imaging spectroscopy of solar flares. It consists of 32 collimators with grids and 32 spectrometer units called Caliste-SO for indirect Fourier-transform imaging. Each Caliste-SO device integrates a 1 cm 2 CdTe pixel sensor with a low-noise low-power analog front-end ASIC and circuits for supply regulation and filtering. The ASIC named IDeF-X HD is designed by CEA/Irfu (France) whereas CdTe-based semiconductor detectors are provided by the Laboratory for Micro- and Nanotechnology, Paul Scherrer Institute (Switzerland). The design of the hybrid, based on 3D Plus technology (France), is well suited for STIX spectroscopic requirements (1 keV FWHM at 6 keV, 4 keV low-level threshold) and system constraints (4 W power and 5 kg mass). The performance of the sub-assemblies and the design of the first Caliste-SO prototype are presented.

Crystal diffraction lens telescope for focusing nuclear gamma rays

International Nuclear Information System (INIS)

Smither, R.K.; Fernandez, P.B.; Graber, T.; Faiz, M.

1996-08-01

A crystal diffraction lens was constructed at Argonne National Laboratory for use as a telescope to focus nuclear gamma rays. It consisted of 600 single crystals of germanium arranged in 8 concentric rings. The mounted angle of each crystal was adjusted to intercept and diffract the incoming gamma rays with an accuracy of a few arc sec. The performance of the lens was tested in two ways. In one case, the gamma rays were focused on a single medium size germanium detector. In the second case, the gamma rays were focused on the central germanium detector of a 3 x 3 matrix of small germanium detectors. The efficiency, image concentration and image quality, and shape were measured. The tests performed with the 3 x 3 matrix detector system were particularly interesting. The wanted radiation was concentrated in the central detector. The 8 other detectors were used to detect the Compton scattered radiation, and their energy was summed with coincident events in the central detector. This resulted in a detector with the efficiency of a large detector (all 9 elements) and the background of a small detector (only the central element). The use of the 3 x 3 detector matrix makes it possible to tell if the source is off axis and, if so, to tell in which direction. The crystal lens acts very much like a simple convex lens for visible light. Thus if the source is off to the left then the image will focus off to the right illuminating the detector on the right side: telling one in which direction to point the telescope. Possible applications of this type of crystal lens to balloon and satellite experiments will be discussed

Characteristics of the telescope for high energy gamma-ray astronomy selected for definition studies on the Gamma Ray Observatory

Science.gov (United States)

Hughes, E. B.; Hofstadter, R.; Rolfe, J.; Johansson, A.; Bertsch, D. L.; Cruickshank, W. J.; Ehrmann, C. H.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.

1980-01-01

The high energy gamma-ray telescope selected for definition studies on the Gamma Ray Observatory provides a substantial improvement in observational capability over earlier instruments. It will have about 20 times more sensitivity, cover a much broader energy range, have considerably better energy resolution and provide a significantly improved angular resolution. The design and performance are described.

X-ray polarimetry with the Polarization Spectroscopic Telescope Array (PolSTAR)

DEFF Research Database (Denmark)

Krawczynski, Henric S.; Stern, Daniel; Harrison, Fiona A.

2016-01-01

This paper describes the Polarization Spectroscopic Telescope Array (PolSTAR), a mission proposed to NASA's 2014 Small Explorer (SMEX) announcement of opportunity. PolSTAR measures the linear polarization of 3-50 keV (requirement; goal: 2.5-70 keV) X-rays probing the behavior of matter,radiation ...

The current status of model development of the electron and proton telescope for Solar Orbiter

Energy Technology Data Exchange (ETDEWEB)

Steinhagen, Jan; Kulkarni, S.R.; Tammen, Jan; Boden, Sebastian; Elftmann, Robert; Martin, Cesar; Ravanbakhsh, Ali; Boettcher, Stephan I.; Seimetz, Lars; Schuster, Bjoern; Wimmer-Schweingruber, Robert [Institute for Experimental and Applied Physics, University of Kiel (Germany)

2014-07-01

ESA's Solar Orbiter mission, scheduled for launch in January 2017, will study how the sun creates the inner heliosphere. Therefore, the spacecraft will perform in situ and remote sensing measurements of the sun on a high inclination orbit with a perihelion of about 60 solar radii, making it possible to observe the poles of the sun from nearby. The Energetic Particle Detector suite on-board of Solar Orbiter will measure particles of a wide energy range and from multiple directions. One of the important sensors of the EPD suite is the Electron Proton Telescope. It consists of two antiparallel telescopes with two silicon detectors respectively and is designed to detect electrons between 20 - 400 keV and protons from 20 keV to 7 MeV. EPT relies on a magnet/foil technique to discriminate between electrons and protons. Here, we present the testing of the Structural and Thermal Model, which has already been delivered to ASTRIUM for spacecraft level tests as well as the integration and testing of the Engineering Model, which already provides full electrical functionality.

The X-ray signature of solar coronal mass

Science.gov (United States)

Harrison, R. A.; Waggett, P. W.; Bentley, R. D.; Phillips, K. J. H.; Bruner, M.

1985-01-01

The coronal response to six solar X-ray flares has been investigated. At a time coincident with the projected onset of the white-light coronal mass ejection associated with each flare, there is a small, discrete soft X-ray enhancement. These enhancements (precursors) precede by typically about 20 m the impulsive phase of the solar flare which is dominant by the time the coronal mass ejection has reached an altitude above 0.5 solar radii. Motions of hot X-ray emitting plasma, during the precursors, which may well be a signature of the mass ejection onsets, are identified. Further investigations have also revealed a second class of X-ray coronal transient, during the main phase of the flare. These appear to be associated with magnetic reconnection above post-flare loop systems.

A Pair Production Telescope for Medium-Energy Gamma-Ray Polarimetry

Science.gov (United States)

Hunter, Stanley D.; Bloser, Peter F.; Depaola, Gerardo; Dion, Michael P.; DeNolfo, Georgia A.; Hanu, Andrei; Iparraguirre, Marcos; Legere, Jason; Longo, Francesco; McConnell, Mark L.;

The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

Science.gov (United States)

Alvarez-Muñiz, J.; Amaral Soares, E.; Berlin, A.; Bogdan, M.; Boháčová, M.; Bonifazi, C.; Carvalho, W. R.; de Mello Neto, J. R. T.; Facal San Luis, P.; Genat, J. F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P.; Ramos de Castro, A.; Reyes, L. C.; Richardson, M.; Rouille d'Orfeuil, B.; Santos, E. M.; Wayne, S.; Williams, C.; Zas, E.; Zhou, J.

2013-08-01

We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4-4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope - to validate the telescope design, and to demonstrate a large detector duty cycle - were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory.

Reflectivity around the gold L-edges of X-ray reector of the soft X-ray telescope onboard ASTRO-H

DEFF Research Database (Denmark)

Maeda, Yoshitomo; Kikuchi, Naomichi; Kurashima, Sho

2017-01-01

We report the atomic scattering factor in the 11.2-15.4 keV for the ASTRO-H Soft X-ray Telescope (SXT)9 obtained in the ground based measurements. The large effective area of the SXT covers above 10 keV. In fact, the flight data show the spectra of the celestical objects in the hard X-ray band. I...

Solar modulation of galactic cosmic rays: techniques and applications

International Nuclear Information System (INIS)

Perko, J.S.

1984-01-01

This thesis covers four topics in the theory of interplanetary cosmic-ray propagation: the first part involves the time-dependent, spherically-symmetric, solar modulation of galactic cosmic rays. A numerical technique was introduced for the solution of this problem. A model for the solar cycle variation in cosmic-ray intensity illustrated this method using enhanced particle scattering regions. The second section contains an attempt to explain recent observations which show that cosmic-ray electrons are returning to higher intensities, characteristic of solar minimum, faster than cosmic-ray protons of about the same energy, the reverse of the previous eleven-year cycle. The third section involves the solar modulation of galactic antiprotons. Using a steady-state, spherically-symmetric, numerical modulation code, a solution that reasonably fits the observed 1980 galactic proton spectrum at 1 AU implied that the modulation used for the data interpretation has been significantly underestimated. The final section contains a spherically-symmetric steady-state calculation of the effects of a strong termination shock in the heliosphere. In the end, high-energy particles cooling down in the upstream solar wind overwhelmed any accelerated low-energy particles

Solar tri-diurnal variation of cosmic rays in a wide range of rigidity

Science.gov (United States)

Mori, S.; Ueno, H.; Fujii, Z.; Morishita, I.; Nagashima, K.

1985-01-01

Solar tri-diurnal variations of cosmic rays have been analyzed in a wide range of rigidity, using data from neutron monitors, and the surface and underground muon telescopes for the period 1978-1983. The rigidity spectrum of the anisotropy in space is assumed to be of power-exponential type as (P/gamma P sub o) to the gamma exp (gamma-P/P sub o). By means of the best-fit method between the observed and the expected variations, it is obtained that the spectrum has a peak at P (=gamma P sub o) approx = 90 GV, where gamma=approx 3.0 and P sub o approx. 30 GV. The phase in space of the tri-diurnal variation is also obtained as 7.0 hr (15 hr and 23 hr LT), which is quite different from that of approx. 1 hr. arising from the axisymmetric distribution of cosmic rays with respect to the IMF.

Toward a next-generation high-energy gamma-ray telescope. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Bloom, E.D.; Evans, L.L. [eds.

1997-03-01

It has been some time between the time of the first Gamma-ray Large Area Space Telescope (GLAST) workshop, Towards a Next Generation High-Energy Gamma-Ray Telescope, in late August 1994, and the publication of a partial proceedings of that meeting. Since then there has been considerable progress in both the technical and project development of GLAST. From its origins at SLAC/Stanford in early 1992, the collaboration has currently grown to more than 20 institutions from France, Germany, Italy, Japan, and the US, and is still growing. About half of these are astrophysics/astronomy institutions; the other half are high-energy physics institutions. About 100 astronomers, astrophysicists, and particle physicists are currently spending some fraction of their time on the GLAST R and D program. The late publication date of this proceedings has resulted in some additions to the original content of the meeting. The first paper is actually a brochure prepared for NASA by Peter Michelson in early 1996. Except for the appendix, the other papers in the proceedings were presented at the conference, and written up over the following two years. Some presentations were never written up.

Towards a next-generation high-energy gamma-ray telescope. Proceedings

International Nuclear Information System (INIS)

Bloom, E.D.; Evans, L.L.

1997-03-01

It has been some time between the time of the first Gamma-ray Large Area Space Telescope (GLAST) workshop, Towards a Next Generation High-Energy Gamma-Ray Telescope, in late August 1994, and the publication of a partial proceedings of that meeting. Since then there has been considerable progress in both the technical and project development of GLAST. From its origins at SLAC/Stanford in early 1992, the collaboration has currently grown to more than 20 institutions from France, Germany, Italy, Japan, and the US, and is still growing. About half of these are astrophysics/astronomy institutions; the other half are high-energy physics institutions. About 100 astronomers, astrophysicists, and particle physicists are currently spending some fraction of their time on the GLAST R and D program. The late publication date of this proceedings has resulted in some additions to the original content of the meeting. The first paper is actually a brochure prepared for NASA by Peter Michelson in early 1996. Except for the appendix, the other papers in the proceedings were presented at the conference, and written up over the following two years. Some presentations were never written up

Enabling Telescopes of the Future: Long-Range Technology Investing

Science.gov (United States)

Thronson, Harley

2004-01-01

The Office of Space Science at NASA Headquarters has a current staff of about 60 professionals (aka, scientists, engineers, budget analysts) and an annual budget of $2.5 B out of NASA s $15.0 B. About 35 missions or programs in various stages of development or operation are managed by OSS, notable among them are Hubble Space Telescope, Mars Global Surveyor, Mars 2001 Odyssey, Chandra X-ray Observatory, TRACE (solar observatory), Cassini (mission to Saturn), Galileo (mission at Jupiter), and Next Generation Space Telescope. OSS has an annual technology budget of several hundred million dollars. So, what is it that we are doing?

The structure, logic of operation and distinctive features of the system of triggers and counting signals formation for gamma-telescope GAMMA-400

Science.gov (United States)

Topchiev, N. P.; Galper, A. M.; Arkhangelskiy, A. I.; Arkhangelskaja, I. V.; Kheymits, M. D.; Suchkov, S. I.; Yurkin, Y. T.

2017-01-01

Scientific project GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) relates to the new generation of space observatories intended to perform an indirect search for signatures of dark matter in the cosmic-ray fluxes, measurements of characteristics of diffuse gamma-ray emission and gamma-rays from the Sun during periods of solar activity, gamma-ray bursts, extended and point gamma-ray sources, electron/positron and cosmic-ray nuclei fluxes up to TeV energy region by means of the GAMMA-400 gamma-ray telescope represents the core of the scientific complex. The system of triggers and counting signals formation of the GAMMA-400 gamma-ray telescope constitutes the pipelined processor structure which collects data from the gamma-ray telescope subsystems and produces summary information used in forming the trigger decision for each event. The system design is based on the use of state-of-the-art reconfigurable logic devices and fast data links. The basic structure, logic of operation and distinctive features of the system are presented.

Vibration measurements of the Daniel K. Inouye Solar Telescope mount, Coudé rotator, and enclosure assemblies

Science.gov (United States)

McBride, William R.; McBride, Daniel R.

2016-08-01

The Daniel K. Inouye Solar Telescope (DKIST) will be the largest solar telescope in the world, with a 4-meter off-axis primary mirror and 16 meter rotating Coudé laboratory within the telescope pier. The off-axis design requires a mount similar to an 8-meter on-axis telescope. Both the telescope mount and the Coudé laboratory utilize a roller bearing technology in place of the more commonly used hydrostatic bearings. The telescope enclosure utilizes a crawler mechanism for the altitude axis. As these mechanisms have not previously been used in a telescope, understanding the vibration characteristics and the potential impact on the telescope image is important. This paper presents the methodology used to perform jitter measurements of the enclosure and the mount bearings and servo system in a high-noise environment utilizing seismic accelerometers and high dynamic-range data acquisition equipment, along with digital signal processing (DSP) techniques. Data acquisition and signal processing were implemented in MATLAB. In the factory acceptance testing of the telescope mount, multiple accelerometers were strategically located to capture the six axes-of-motion of the primary and secondary mirror dummies. The optical sensitivity analysis was used to map these mirror mount displacements and rotations into units of image motion on the focal plane. Similarly, tests were done with the Coudé rotator, treating the entire rotating instrument lab as a rigid body. Testing was performed by recording accelerometer data while the telescope control system performed tracking operations typical of various observing scenarios. The analysis of the accelerometer data utilized noise-averaging fast Fourier transform (FFT) routines, spectrograms, and periodograms. To achieve adequate dynamic range at frequencies as low as 3Hz, the use of special filters and advanced windowing functions were necessary. Numerous identical automated tests were compared to identify and select the data sets

Development of a Telescope for Medium-Energy Gamma-ray Astronomy

Science.gov (United States)

Sunter, Stan

2012-01-01

Since the launch of AGILE and FERMI, the scientific progress in high-energy (Eg greater than approximately 200 MeV) gamma-ray science has been, and will continue to be dramatic. Both of these telescopes cover a broad energy range from approximately 20 MeV to greater than 10 GeV. However, neither instrument is optimized for observations below approximately 200 MeV where many astrophysical objects exhibit unique, transitory behavior, such as spectral breaks, bursts, and flares. Hence, while significant progress from current observations is expected, there will nonetheless remain a significant sensitivity gap in the medium-energy (approximately 0.1-200 MeV) regime; the lower end of this range remains largely unexplored whereas the upper end will allow comparison with FERMI data. Tapping into this unexplored regime requires significant improvements in sensitivity. A major emphasis of modern detector development, with the goal of providing significant improvements in sensitivity in the medium-energy regime, focuses on high-resolution electron tracking. The Three-Dimensional Track Imager (3-DTI) technology being developed at GSFC provides high resolution tracking of the electron-positron pair from gamma-ray interactions from 5 to 200 MeV. The 3-DTI consists of a time projection chamber (TPC) and 2-D cross-strip microwell detector (MWD). The low-density and homogeneous design of the 3-DTI, offers unprecedented sensitivity by providing angular resolution near the kinematic limit. Electron tracking also enables measurement of gamma-ray polarization, a new tool to study astrophysical phenomenon. We describe the design, fabrication, and performance of a 30x30x30 cm3 3-DTI detector prototype of a medium-energy gamma-ray telescope.

Multi-spacecraft observations of solar hard X-ray bursts

International Nuclear Information System (INIS)

Kane, S.R.

1981-01-01

The role of multi-spacecraft observations in solar flare research is examined from the point of view of solar hard X-ray bursts and their implications with respect to models of the impulsive phase. Multi-spacecraft measurements provide a stereoscopic view of the flare region, and hence represent the only direct method of measuring directivity of X-rays. In absence of hard X-ray imaging instruments with high spatial and temporal resolution, multi-spacecraft measurements provide the only means of determining the radial (vertical) structure of the hard X-ray source. This potential of the multi-spacecraft observations is illustrated with an analysis of the presently available observations of solar hard X-ray bursts made simultaneously by two or more of the following spacecraft: International Sun Earth Explorer-3 (ISEE-3), Pioneer Venus Orbiter (PVO), Helios-B and High Energy Astrophysical Observatory-A (HEAO-A). In particular, some conclusions have been drawn about the spatial structure and directivity of 50-100 keV X-rays from impulsive flares. Desirable features of future multi-spacecraft missions are briefly discussed followed by a short description of the hard X-ray experiment on the International Solar Polar Mission which has been planned specifically for multi-spacecraft observations of the Sun. (orig.)

Development of the focal plane PNCCD camera system for the X-ray space telescope eROSITA

International Nuclear Information System (INIS)

Meidinger, Norbert; Andritschke, Robert; Ebermayer, Stefanie; Elbs, Johannes; Haelker, Olaf; Hartmann, Robert; Herrmann, Sven; Kimmel, Nils; Schaechner, Gabriele; Schopper, Florian; Soltau, Heike; Strueder, Lothar; Weidenspointner, Georg

2010-01-01

A so-called PNCCD, a special type of CCD, was developed twenty years ago as focal plane detector for the XMM-Newton X-ray astronomy mission of the European Space Agency ESA. Based on this detector concept and taking into account the experience of almost ten years of operation in space, a new X-ray CCD type was designed by the 'MPI semiconductor laboratory' for an upcoming X-ray space telescope, called eROSITA (extended Roentgen survey with an imaging telescope array). This space telescope will be equipped with seven X-ray mirror systems of Wolter-I type and seven CCD cameras, placed in their foci. The instrumentation permits the exploration of the X-ray universe in the energy band from 0.3 up to 10 keV by spectroscopic measurements with a time resolution of 50 ms for a full image comprising 384x384 pixels. Main scientific goals are an all-sky survey and investigation of the mysterious 'Dark Energy'. The eROSITA space telescope, which is developed under the responsibility of the 'Max-Planck-Institute for extraterrestrial physics', is a scientific payload on the new Russian satellite 'Spectrum-Roentgen-Gamma' (SRG). The mission is already approved by the responsible Russian and German space agencies. After launch in 2012 the destination of the satellite is Lagrange point L2. The planned observational program takes about seven years. We describe the design of the eROSITA camera system and present important test results achieved recently with the eROSITA prototype PNCCD detector. This includes a comparison of the eROSITA detector with the XMM-Newton detector.

A comparison of solar wind streams and coronal structure near solar minimum

Science.gov (United States)

Nolte, J. T.; Davis, J. M.; Gerassimenko, M.; Lazarus, A. J.; Sullivan, J. D.

1977-01-01

Solar wind data from the MIT detectors on the IMP 7 and 8 satellites and the SOLRAD 11B satellite for the solar-minimum period September-December, 1976, were compared with X-ray images of the solar corona taken by rocket-borne telescopes on September 16 and November 17, 1976. There was no compelling evidence that a coronal hole was the source of any high speed stream. Thus it is possible that either coronal holes were not the sources of all recurrent high-speed solar wind streams during the declining phase of the solar cycle, as might be inferred from the Skylab period, or there was a change in the appearance of some magnetic field regions near the time of solar minimum.

Optimum design of a coded mask X-ray telescope for rocket applications

International Nuclear Information System (INIS)

Gunson, J.; Polychronopulos, B.

1976-01-01

A review of the principles of current X-ray telescopes is made with particular emphasis on two-step imaging techniques involving coding masks. The merits and limitations of the various types of coding masks in use are examined in detail. The limitations are shown to arise from the finite nature of practical masks. By postulating periodicity, 'optimum masks' can be constructed with ideal imaging qualities. The theory for the design of such masks and the practical considerations involved in the design of a rocket-borne X-ray telescope system are discussed in full, with particular attention paid to resolution, field of view and image noise. The main emphasis throughout the paper is on one-dimensional masks but two-dimensional masks are also studied. It is concluded that optimum masks could prove very valuable in astronomical applications and also in other fields such as radiography, where high imaging quality coupled with high sensitivity and low cost are of utmost importance. (author)

Extra Solar Planetary Imaging Coronagraph and Science Requirements for the James Webb Telescope Observatory

Science.gov (United States)

Clampin, Mark

2004-01-01

1) Extra solar planetary imaging coronagraph. Direct detection and characterization of Jovian planets, and other gas giants, in orbit around nearby stars is a necessary precursor to Terrestrial Planet Finder 0 in order to estimate the probability of Terrestrial planets in our stellar neighborhood. Ground based indirect methods are biased towards large close in Jovian planets in solar systems unlikely io harbor Earthlike planets. Thus to estimate the relative abundances of terrestrial planets and to determine optimal observing strategies for TPF a pathfinder mission would be desired. The Extra-Solar Planetary Imaging Coronagraph (EPIC) is such a pathfinder mission. Upto 83 stellar systems are accessible with a 1.5 meter unobscured telescope and coronagraph combination located at the Earth-Sun L2 point. Incorporating radiometric and angular resolution considerations show that Jovians could be directly detected (5 sigma) in the 0.5 - 1.0 micron band outside of an inner working distance of 5/D with integration times of -10 - 100 hours per observation. The primary considerations for a planet imager are optical wavefront quality due to manufacturing, alignment, structural and thermal considerations. pointing stability and control, and manufacturability of coronagraphic masks and stops to increase the planetary-to- stellar contrast and mitigate against straylight. Previously proposed coronagraphic concepts are driven to extreme tolerances. however. we have developed and studied a mission, telescope and coronagraphic detection concept, which is achievable in the time frame of a Discovery class NASA mission. 2) Science requirements for the James Webb Space Telescope observatory. The James Webb Space Observatory (JWST) is an infrared observatory, which will be launched in 201 1 to an orbit at L2. JWST is a segmented, 18 mirror segment telescope with a diameter of 6.5 meters, and a clear aperture of 25 mA2. The telescope is designed to conduct imaging and spectroscopic

The thermal environment of the fiber glass dome for the new solar telescope at Big Bear Solar Observatory

Science.gov (United States)

Verdoni, A. P.; Denker, C.; Varsik, J. R.; Shumko, S.; Nenow, J.; Coulter, R.

2007-09-01

The New Solar Telescope (NST) is a 1.6-meter off-axis Gregory-type telescope with an equatorial mount and an open optical support structure. To mitigate the temperature fluctuations along the exposed optical path, the effects of local/dome-related seeing have to be minimized. To accomplish this, NST will be housed in a 5/8-sphere fiberglass dome that is outfitted with 14 active vents evenly spaced around its perimeter. The 14 vents house louvers that open and close independently of one another to regulate and direct the passage of air through the dome. In January 2006, 16 thermal probes were installed throughout the dome and the temperature distribution was measured. The measurements confirmed the existence of a strong thermal gradient on the order of 5° Celsius inside the dome. In December 2006, a second set of temperature measurements were made using different louver configurations. In this study, we present the results of these measurements along with their integration into the thermal control system (ThCS) and the overall telescope control system (TCS).

Pierre Auger Observatory and Telescope Array: Joint Contributions to the 33rd International Cosmic Ray Conference (ICRC 2013)

NARCIS (Netherlands)

Telescope Array, The; Pierre Auger Collaborations,; Abu-Zayyad, T.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, K.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, K.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nanpei, H.; Nonaka, T.; Nozato, A.; Ogio, S.; Oh, S.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Shirahama, T.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Takamura, M.; Takeda, M.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wada, Y.; Wong, T.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.; Aab, A.; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antivcic, T.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bardenet, R.; Baeuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Belletoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blumer, H.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Burton, R. E.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Diaz, J. C.; Diaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipcic, A.; Foerster, N.; Fox, B. D.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Frohlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; Garcia, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Gitto, J.; Glaser, C.; Glass, H.; Gomez Albarracin, F.; Gomez Berisso, M.; Gomez Vitale, P. F.; Goncalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Homola, P.; Hoerandel, J. R.; Horvath, P.; Hrabovsky, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kadija, K.; Kambeitz, O.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; Kegl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Krause, R.; Krohm, N.; Kroemer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leao, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopez, R.; Lopez Aguera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martinez, H.; Martinez Bravo, O.; Martraire, D.; Masias Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Micanovic, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Mostafa, M.; Moura, C. A.; Muller, M. A.; Muller, G.; Munchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novzka, L.; Oehlschlager, J.; Olinto, A.; Oliveira, M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrolini, A.; Petrov, Y.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Pontz, M.; Porcelli, A.; Preda, T.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Frias, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouille-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Ruhle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sanchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovanek, P.; Schroeder, F. G.; Schulz, A.; Schulz, J.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Smialkowski, A.; Smida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Straub, M.; Stutz, A.; Suarez, F.; Suomijarvi, T.; Supanitsky, A. D.; Susa, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tapia, A.; Tartare, M.; Tacscuau, O.; Tcaciuc, R.; Thao, N. T.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tome, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Tridapalli, D. B.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Valdes Galicia, J. F.; Valino, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cardenas, B.; Varner, G.; Vazquez, J. R.; Vazquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villasenor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Will, M.; Williams, C.; Winchen, T.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Martin, L.

2013-01-01

Joint contributions of the Pierre Auger and Telescope Array Collaborations to the 33rd International Cosmic Ray Conference, Rio de Janeiro, Brazil, July 2013: cross-calibration of the fluorescence telescopes, large scale anisotropies and mass composition.

Pierre Auger Observatory and Telescope Array: Joint Contributions to the 33rd International Cosmic Ray Conference (ICRC 2013)

Energy Technology Data Exchange (ETDEWEB)

Abu-Zayyad, T.; et al.

2013-10-02

Joint contributions of the Pierre Auger and Telescope Array Collaborations to the 33rd International Cosmic Ray Conference, Rio de Janeiro, Brazil, July 2013: cross-calibration of the fluorescence telescopes, large scale anisotropies and mass composition.

Solar Adaptive Optics

Directory of Open Access Journals (Sweden)

Thomas R. Rimmele

2011-06-01

Full Text Available Adaptive optics (AO has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO and Ground-Layer AO (GLAO will be given.

The Fermi Gamma-Ray Space Telescope, Exploding Stars, Neutron Stars, and Black Holes

Science.gov (United States)

Thompson, David J.

2010-01-01

Since August, 2008, the Fermi Gamma-ray Space Telescope has been scanning the sky, producing a full-sky image every three hours. These cosmic gamma-rays come from extreme astrophysical phenomena, many related to exploding stars (supernovae) or what these explosions leave behind: supernova remnants, neutron stars, and black holes. This talk uses sample Fermi results, plus simple demonstrations, to illustrate the exotic properties of these endpoints of stellar evolution.

RESOLVING THE FAN-SPINE RECONNECTION GEOMETRY OF A SMALL-SCALE CHROMOSPHERIC JET EVENT WITH THE NEW SOLAR TELESCOPE

Energy Technology Data Exchange (ETDEWEB)

Zeng, Zhicheng; Chen, Bin; Goode, Philip R.; Cao, Wenda [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Boulevard, Newark, NJ 07102 (United States); Ji, Haisheng [Big Bear Solar Observatory, 40386 North Shore Lane, Big Bear City, CA 92314 (United States)

2016-03-01

Jets are ubiquitously present in both quiet and active regions on the Sun. They are widely believed to be driven by magnetic reconnection. A fan-spine structure has been frequently reported in some coronal jets and flares, and has been regarded as a signature of ongoing magnetic reconnection in a topology consisting of a magnetic null connected by a fan-like separatrix surface and a spine. However, for small-scale chromospheric jets, clear evidence of such structures is rather rare, although it has been implied in earlier works that showed an inverted-Y-shaped feature. Here we report high-resolution (0.″16) observations of a small-scale chromospheric jet obtained by the New Solar Telescope (NST) using 10830 Å filtergrams. Bi-directional flows were observed across the separatrix regions in the 10830 Å images, suggesting that the jet was produced due to magnetic reconnection. At the base of the jet, a fan-spine structure was clearly resolved by the NST, including the spine and the fan-like surface, as well as the loops before and after the reconnection. A major part of this fan-spine structure, with the exception of its bright footpoints and part of the base arc, was invisible in the extreme ultraviolet and soft X-ray images (observed by the Atmosphere Imaging Assembly and the X-Ray Telescope, respectively), indicating that the reconnection occurred in the upper chromosphere. Our observations suggest that the evolution of this chromospheric jet is consistent with a two-step reconnection scenario proposed by Török et al.

RESOLVING THE FAN-SPINE RECONNECTION GEOMETRY OF A SMALL-SCALE CHROMOSPHERIC JET EVENT WITH THE NEW SOLAR TELESCOPE

International Nuclear Information System (INIS)

Zeng, Zhicheng; Chen, Bin; Goode, Philip R.; Cao, Wenda; Ji, Haisheng

2016-01-01

Jets are ubiquitously present in both quiet and active regions on the Sun. They are widely believed to be driven by magnetic reconnection. A fan-spine structure has been frequently reported in some coronal jets and flares, and has been regarded as a signature of ongoing magnetic reconnection in a topology consisting of a magnetic null connected by a fan-like separatrix surface and a spine. However, for small-scale chromospheric jets, clear evidence of such structures is rather rare, although it has been implied in earlier works that showed an inverted-Y-shaped feature. Here we report high-resolution (0.″16) observations of a small-scale chromospheric jet obtained by the New Solar Telescope (NST) using 10830 Å filtergrams. Bi-directional flows were observed across the separatrix regions in the 10830 Å images, suggesting that the jet was produced due to magnetic reconnection. At the base of the jet, a fan-spine structure was clearly resolved by the NST, including the spine and the fan-like surface, as well as the loops before and after the reconnection. A major part of this fan-spine structure, with the exception of its bright footpoints and part of the base arc, was invisible in the extreme ultraviolet and soft X-ray images (observed by the Atmosphere Imaging Assembly and the X-Ray Telescope, respectively), indicating that the reconnection occurred in the upper chromosphere. Our observations suggest that the evolution of this chromospheric jet is consistent with a two-step reconnection scenario proposed by Török et al

XMM-Newton detects X-ray 'solar cycle' in distant star

Science.gov (United States)

2004-05-01

whether the Sun's X-ray cycle is common among other solar-type stars, and in particular among those hosting potential rocky planets, can give scientists much needed clues on whether and where other forms of life might exist outside the Solar System. At the same time, understanding how typical and long-lasting is the solar behaviour will tell us more about the evolution of the climate on Earth. Further observations of HD 81809 and other similar stars are already planned with XMM-Newton. They will allow astronomers to study whether the large modulations in X-ray brightness observed in the Sun are indeed the norm for stars of its type. Understanding how other solar-like stars behave in general will give scientists better insight into the past and future of our own Sun. Note to editors The results described here were published in the April issue of the scientific journal Astronomy and Astrophysics (Vol. 418, p. L13). The authors of the paper are F. Favata, G. Micela, S. Baliunas, J. Schmitt, M. Guedel, F. Harnden Jr., S. Sciortino and R. Stern. A reprint of the paper can be found at: http://arxiv.org/abs/astro-ph/0403142 More about XMM-Newton XMM-Newton can detect more X-ray sources than any previous satellite and is helping to solve many cosmic mysteries of the violent Universe, from black holes to the formation of galaxies. It was launched on 10 December 1999, using an Ariane-5 rocket from French Guiana. It is expected to return data for a decade. XMM-Newton's high-tech design uses over 170 wafer-thin cylindrical mirrors spread over three telescopes. Its orbit takes it almost a third of the way to the Moon, so that astronomers can enjoy long, uninterrupted views of celestial objects. More information on XMM-Newton can be found at: http://www.esa.int/esaSC/SEMM8IGHZTD_1_spk.html More about SOHO SOHO is a project of international cooperation between ESA and NASA to study the Sun, from its deep core to the outer corona, and the solar wind. Fourteen European countries, led by

Status of the Daniel K. Inouye Solar Telescope: unraveling the mysteries the Sun.

Science.gov (United States)

Rimmele, Thomas R.; Pillet, Valentin; Goode, Philip R.; Knoelker, Michael; Kuhn, Jeffrey Richard; Rosner, Robert; Casini, Roberto; Lin, Haosheng; von der Luehe, Oskar; Woeger, Friedrich; Tritschler, Alexandra; Fehlmann, Andre; Jaeggli, Sarah A.; Schmidt, Wolfgang; De Wijn, Alfred; Rast, Mark; Harrington, David M.; Sueoka, Stacey R.; Beck, Christian; Schad, Thomas A.; Warner, Mark; McMullin, Joseph P.; Berukoff, Steven J.; Mathioudakis, Mihalis; DKIST Team

2018-06-01

The 4m Daniel K. Inouye Solar Telescope (DKIST) currently under construction on Haleakala, Maui will be the world’s largest solar telescope. Designed to meet the needs of critical high resolution and high sensitivity spectral and polarimetric observations of the sun, this facility will perform key observations of our nearest star that matters most to humankind. DKIST’s superb resolution and sensitivity will enable astronomers to address many of the fundamental problems in solar and stellar astrophysics, including the origin of stellar magnetism, the mechanisms of coronal heating and drivers of the solar wind, flares, coronal mass ejections and variability in solar and stellar output. DKIST will also address basic research aspects of Space Weather and help improve predictive capabilities. In combination with synoptic observations and theoretical modeling DKIST will unravel the many remaining mysteries of the Sun.The construction of DKIST is progressing on schedule with 80% of the facility complete. Operations are scheduled to begin early 2020. DKIST will replace the NSO facilities on Kitt Peak and Sac Peak with a national facility with worldwide unique capabilities. The design allows DKIST to operate as a coronagraph. Taking advantage of its large aperture and infrared polarimeters DKIST will be capable to routinely measure the currently illusive coronal magnetic fields. The state-of-the-art adaptive optics system provides diffraction limited imaging and the ability to resolve features approximately 20 km on the Sun. Achieving this resolution is critical for the ability to observe magnetic structures at their intrinsic, fundamental scales. Five instruments will be available at the start of operations, four of which will provide highly sensitive measurements of solar magnetic fields throughout the solar atmosphere – from the photosphere to the corona. The data from these instruments will be distributed to the world wide community via the NSO/DKIST data center

GRB 090926A AND BRIGHT LATE-TIME FERMI LARGE AREA TELESCOPE GAMMA-RAY BURST AFTERGLOWS

International Nuclear Information System (INIS)

Swenson, C. A.; Roming, P. W. A.; Vetere, L.; Kennea, J. A.; Maxham, A.; Zhang, B. B.; Zhang, B.; Schady, P.; Holland, S. T.; Kuin, N. P. M.; Oates, S. R.; De Pasquale, M.; Page, K. L.

2010-01-01

GRB 090926A was detected by both the Gamma-ray Burst Monitor and Large Area Telescope (LAT) instruments on board the Fermi Gamma-ray Space Telescope. Swift follow-up observations began ∼13 hr after the initial trigger. The optical afterglow was detected for nearly 23 days post trigger, placing it in the long-lived category. The afterglow is of particular interest due to its brightness at late times, as well as the presence of optical flares at T0+10 5 s and later, which may indicate late-time central engine activity. The LAT has detected a total of 16 gamma-ray bursts; nine of these bursts, including GRB 090926A, also have been observed by Swift. Of the nine Swift-observed LAT bursts, six were detected by UVOT, with five of the bursts having bright, long-lived optical afterglows. In comparison, Swift has been operating for five years and has detected nearly 500 bursts, but has only seen ∼30% of bursts with optical afterglows that live longer than 10 5 s. We have calculated the predicted gamma-ray fluence, as would have been seen by the Burst Alert Telescope (BAT) on board Swift, of the LAT bursts to determine whether this high percentage of long-lived optical afterglows is unique, when compared to BAT-triggered bursts. We find that, with the exception of the short burst GRB 090510A, the predicted BAT fluences indicate that the LAT bursts are more energetic than 88% of all Swift bursts and also have brighter than average X-ray and optical afterglows.

Multiple Etalon Systems for the Advanced Technology Solar Telescope

Science.gov (United States)

Gary, G. Allen; Balasubramaniam, K. S.; Sigwarth, Michael; Six, N. Frank (Technical Monitor)

2002-01-01

Multiple etalons systems are discussed that meet the 4-meter NSO/Advance Technology Solar Telescope (http://www.nso.edu/ATST/index.html) instrument and science requirements for a narrow bandpass imaging system. A multiple etalon system can provide an imaging interferometer working in four distinct modes: as a spectro-polarimeter, a filter-vector magnetograph, and a wide-band and broad-band high-resolution imager. Specific dual and triple etalon configurations will be described that provides spectrographic passband of 2.0-3.5nm and reduces parasitic light levels to 1/10000 as required by precise polarization measurement, e.g., Zeeman measurements of magnetic sensitive lines. A TESOS-like triple etalon system provides for spectral purity of 100 thousandths. The triple designs have the advantage of reducing the finesse requirement on each etalon, allowing much more stable blocking filters, and can have very high spectral purity. A dual-etalon double-pass Cavallini-like configuration can provide a competing configuration. This design can provide high contrast with only a double etalon. The selection of the final focal plan instrument will depend on a trade-off of the ideal instrument versus reality, the number of etalons, the aperture of etalons, the number of blocking filters the electronic control system and computer interfaces, the temperature control and controllers for the etalons and the electronics. The use of existing experience should provide significant cost savings. The heritage of use of etalons and multiple etalon systems in solar physics come from a number of observatories, which includes MSFC Solar Observatory (NASA), Sac Peak Observatory (NSO), and Kiepenheuer Institute for Solar Physics (Germany), Mees Solar Observatory (University of Hawaii), and Arcetri Astrophysical Observatory (Italy). The design of the ATST multiple etalon system will reply on the existing experience from these observatories.

Multiple-etalon systems for the Advanced Technology Solar Telescope

Science.gov (United States)

Gary, G. Allen; Balasubramaniam, K. S.; Sigwarth, Michael

2003-01-01

Multiple etalon systems are discussed that meet the science requirements for a narrow-passband imaging system for the 4-meter National Solar Observatory (NSO)/Advance Technology Solar Telescope (ATST). A multiple etalon system can provide an imaging interferometer that works in four distinct modes: as a spectro-polarimeter, a filter-vector magnetograph, an intermediate-band imager, and broadband high-resolution imager. Specific dual and triple etalon configurations are described that provide a spectrographic passband of 2.0-3.5 micron and reduce parasitic light levels to 10(exp -4) as required for precise polarization measurement, e.g., Zeeman measurements of magnetic sensitive lines. A TESOS-like (Telecentric Etalon SOlar Spectrometer) triple etalon system provides a spectral purity of 10(exp -5). The triple designs have the advantage of reducing the finesse requirement on each etalon; allow the use of more stable blocking filters, and have very high spectral purity. A dual-etalon double-pass (Cavallini-like) system can provide a competing configuration. Such a dual-etalon design can provide high contrast. The selection of the final focal plane instrument will depend on a trade-off between an ideal instrument and practical reality. The trade study will include the number of etalons, their aperture sizes, complexities of the optical train, number of blocking filters, configuration of the electronic control system, computer interfaces, temperature controllers, etalon controllers, and their associated feedback electronics. The heritage of single and multiple etalon systems comes from their use in several observatories, including the Marshall Space Flight Center (MSFC) Solar Observatory, Sacramento Peak Observatory (NSO), and Kiepenheuer-Institut fur Sonnenphysik (KIS, Germany), Mees Solar Observatory (University of Hawaii), and Arcetri Astrophysical Observatory (Italy). The design of the ATST multiple etalon system will benefit from the experience gained at these

Gamma ray astronomy

International Nuclear Information System (INIS)

Fichtel, C.E.

1975-01-01

The first certain detection of celestial high energy gamma rays came from a satellite experiment flown on the third Orbiting Solar Observatory (OSO-111). A Gamma ray spark chamber telescope with substantively greater sensitivity and angular resolution (a few degrees) flown on the second Small Astronomy Satellite (SAS-II) has now provided a better picture of the gamma ray sky, and particularly the galactic plane and pulsars. This paper will summarize the present picture of gamma ray astronomy as it has developed at this conference from measurements made with experiments carried out on balloons, those remaining on the ground, and ones flown on satellites. (orig.) [de

The Advanced Gamma-ray Imaging System (AGIS) Telescope Optical System Designs

Science.gov (United States)

Bugaev, V.; Buckley, J.; Diegel, S.; Falcone, A.; Fegan, S.; Finley, J.; Guarino, V.; Hanna, D.; Kaaret, P.; Konopelko, A.; Krawczynski, H.; Ramsey, B.; Romani, R.; Vassiliev, V.; Weekes, T.

2008-12-01

AGIS is a conceptual design for a future ground-based gamma-ray observatory operating in the energy range 25 GeV-100 TeV, which is based on an array of ~20-100 imaging atmospheric Cherenkov telescopes (IACTs). The desired improvement in sensitivity, angular resolution, and reliability of operation of AGIS imposes demanding technological and cost requirements on the design of the IACTs. We are considering several options for the optical system (OS) of the AGIS telescopes, which include the traditional Davies-Cotton design as well as novel two-mirror design. Emerging mirror production technologies based on replication processes such as cold and hot glass slumping, cured carbon fiber reinforced plastic (CFRP), and electroforming provide new opportunities for cost-effective solutions for the design of the OS.

Method of composing two-dimensional scanned spectra observed by the New Vacuum Solar Telescope

Science.gov (United States)

Cai, Yun-Fang; Xu, Zhi; Chen, Yu-Chao; Xu, Jun; Li, Zheng-Gang; Fu, Yu; Ji, Kai-Fan

2018-04-01

In this paper we illustrate the technique used by the New Vacuum Solar Telescope (NVST) to increase the spatial resolution of two-dimensional (2D) solar spectroscopy observations involving two dimensions of space and one of wavelength. Without an image stabilizer at the NVST, large scale wobble motion is present during the spatial scanning, whose instantaneous amplitude can reach 1.3″ due to the Earth’s atmosphere and the precision of the telescope guiding system, and seriously decreases the spatial resolution of 2D spatial maps composed with scanned spectra. We make the following effort to resolve this problem: the imaging system (e.g., the TiO-band) is used to record and detect the displacement vectors of solar image motion during the raster scan, in both the slit and scanning directions. The spectral data (e.g., the Hα line) which are originally obtained in time sequence are corrected and re-arranged in space according to those displacement vectors. Raster scans are carried out in several active regions with different seeing conditions (two rasters are illustrated in this paper). Given a certain spatial sampling and temporal resolution, the spatial resolution of the composed 2D map could be close to that of the slit-jaw image. The resulting quality after correction is quantitatively evaluated with two methods. A physical quantity, such as the line-of-sight velocities in multiple layers of the solar atmosphere, is also inferred from the re-arranged spectrum, demonstrating the advantage of this technique.

A new perspective on solar active regions

Science.gov (United States)

Strong, K. T.; Bruner, M. E.

1996-01-01

A flood of new observations of the solar corona have been made with high spatial resolution, good temporal coverage and resolution, and large linear dynamic range by the Soft X-ray Telescope (SXT) on Yohkoh. These data are changing our fundamental understanding of how solar magnetic fields emerge, interact, and dissipate. This paper reviews some of the results from Yohkoh in the context of earlier results from the Solar Maximum Mission (SMM) and in comjunction with ground-based optical and radio observations.

Solar Adaptive Optics.

Science.gov (United States)

Rimmele, Thomas R; Marino, Jose

Adaptive optics (AO) has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO) and Ground-Layer AO (GLAO) will be given. Supplementary material is available for this article at 10.12942/lrsp-2011-2.

YOHKOH Observations at the Y2K Solar Maximum

Science.gov (United States)

Aschwanden, M. J.

1999-05-01

Yohkoh will provide simultaneous co-aligned soft X-ray and hard X-ray observations of solar flares at the coming solar maximum. The Yohkoh Soft X-ray Telescope (SXT) covers the approximate temperature range of 2-20 MK with a pixel size of 2.46\\arcsec, and thus complements ideally the EUV imagers sensitive in the 1-2 MK plasma, such as SoHO/EIT and TRACE. The Yohkoh Hard X-ray Telescope (HXT) offers hard X-ray imaging at 20-100 keV at a time resolution of down to 0.5 sec for major events. In this paper we review the major SXT and HXT results from Yohkoh solar flare observations, and anticipate some of the key questions that can be addressed through joint observations with other ground and space-based observatories. This encompasses the dynamics of flare triggers (e.g. emerging flux, photospheric shear, interaction of flare loops in quadrupolar geometries, large-scale magnetic reconfigurations, eruption of twisted sigmoid structures, coronal mass ejections), the physics of particle dynamics during flares (acceleration processes, particle propagation, trapping, and precipitation), and flare plasma heating processes (chromospheric evaporation, coronal energy loss by nonthermal particles). In particular we will emphasize on how Yohkoh data analysis is progressing from a qualitative to a more quantitative science, employing 3-dimensional modeling and numerical simulations.

Observation of solar gamma-ray by Hinotori

International Nuclear Information System (INIS)

Yoshimori, Masato; Okudaira, Kiyoaki; Hirashima, Yo; Kondo, Ichiro.

1982-01-01

The solar gamma-ray emitted by solar flare was observed. The gamma-ray is the electromagnetic radiation with the energy more than 300 keV. The line gamma-ray intensity and the time profile were observed. The gamma-ray detector CsI (Tl) was loaded on Hinotori, and the observed gamma-ray was analyzed by a multi-channel analyzer. The observed line gamma-ray was the radiation from Fe-56 and Ne-20. The line gamma-ray from C-12 and O-16 was also seen. These gamma-ray is the direct evidence of the nuclear reaction on the sun. The observed spectrum suggested the existence of the lines from Mg-24 and Si-28. The intensity of the 2.22 MeV gamma-line was small. This fact showed that the origin of this line was different from other nuclear gamma-ray. Two kinds of hard X-ray bursts were detected. The one was impulsive burst, and the other was gradual burst. There was no time difference between the hard X-ray and the gamma-ray of the impulsive burst. The impulsive burst may be explained by the beam model. The delay of time profile in the high energy gamma-ray of the gradual burst was observed. This means that the time when accelerated electrons cause bremsstrahlung depends on the electron energy. The long trapping of electrons at the top of magnetic loop is suggested. (Kato, T.)

Deduction of solar neutron fluences from large gamma-ray flares

International Nuclear Information System (INIS)

Yoshimori, Masato; Watanabe, Hiroyuki; Takahashi, Kazuyoshi.

1986-01-01

Solar neutron fluences from large gamma-ray flares are deduced from accelerated proton spectra and numbers derived from the gamma-ray observations. The deduced solar neutron fluences range from 1 to 200 neutrons cm -2 . The present result indicates a possibility that high sensitivity ground-based neutron monitors can detect solar neutron events, just as detected by the Jungfraujoch and Rome neutron monitors. (author)

THE SECOND FERMI LARGE AREA TELESCOPE CATALOG OF GAMMA-RAY PULSARS

Energy Technology Data Exchange (ETDEWEB)

Abdo, A. A. [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030 (United States); Ajello, M. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Allafort, A.; Bloom, E. D.; Bottacini, E. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L. [Università di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d' Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Baring, M. G. [Rice University, Department of Physics and Astronomy, MS-108, P.O. Box 1892, Houston, TX 77251 (United States); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Belfiore, A. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bhattacharyya, B. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune 411 007 (India); Bissaldi, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, and Università di Trieste, I-34127 Trieste (Italy); Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Brigida, M., E-mail: hartog@stanford.edu [Dipartimento di Fisica ' ' M. Merlin' ' dell' Università e del Politecnico di Bari, I-70126 Bari (Italy); and others

2013-10-01

This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.

The second FERMI large area telescope catalog of gamma-ray pulsars

Energy Technology Data Exchange (ETDEWEB)

Abdo, A. A.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bhattacharyya, B.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burgay, M.; Burnett, T. H.; Busetto, G.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Camilo, F.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chaty, S.; Chaves, R. C. G.; Chekhtman, A.; Chen, A. W.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cognard, I.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D' Ammando, F.; de Angelis, A.; DeCesar, M. E.; De Luca, A.; den Hartog, P. R.; de Palma, F.; Dermer, C. D.; Desvignes, G.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Espinoza, C. M.; Falletti, L.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Freire, P. C. C.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gotthelf, E. V.; Grenier, I. A.; Grondin, M. -H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hessels, J.; Hewitt, J.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Jackson, M. S.; Janssen, G. H.; Jogler, T.; Jóhannesson, G.; Johnson, R. P.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Johnston, S.; Kamae, T.; Kataoka, J.; Keith, M.; Kerr, M.; Knödlseder, J.; Kramer, M.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Lyne, A. G.; Manchester, R. N.; Marelli, M.; Massaro, F.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; McLaughlin, M. A.; Mehault, J.; Michelson, P. F.; Mignani, R. P.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nemmen, R.; Nuss, E.; Ohno, M.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Perkins, J. S.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Pletsch, H. J.; Porter, T. A.; Possenti, A.; Rainò, S.; Rando, R.; Ransom, S. M.; Ray, P. S.; Razzano, M.; Rea, N.; Reimer, A.; Reimer, O.; Renault, N.; Reposeur, T.; Ritz, S.; Romani, R. W.; Roth, M.; Rousseau, R.; Roy, J.; Ruan, J.; Sartori, A.; Saz Parkinson, P. M.; Scargle, J. D.; Schulz, A.; Sgrò, C.; Shannon, R.; Siskind, E. J.; Smith, D. A.; Spandre, G.; Spinelli, P.; Stappers, B. W.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Theureau, G.; Thompson, D. J.; Thorsett, S. E.; Tibaldo, L.; Tibolla, O.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Venter, C.; Vianello, G.; Vitale, V.; Wang, N.; Weltevrede, P.; Winer, B. L.; Wolff, M. T.; Wood, D. L.; Wood, K. S.; Wood, M.; Yang, Z.

2013-09-19

This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.

The second fermi large area telescope catalog of gamma-ray pulsars

Energy Technology Data Exchange (ETDEWEB)

Abdo, A. A.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bhattacharyya, B.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burgay, M.; Burnett, T. H.; Busetto, G.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Camilo, F.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chaty, S.; Chaves, R. C. G.; Chekhtman, A.; Chen, A. W.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cognard, I.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D' Ammando, F.; de Angelis, A.; DeCesar, M. E.; De Luca, A.; den Hartog, P. R.; de Palma, F.; Dermer, C. D.; Desvignes, G.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Espinoza, C. M.; Falletti, L.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Freire, P. C. C.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gotthelf, E. V.; Grenier, I. A.; Grondin, M. -H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hessels, J.; Hewitt, J.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Jackson, M. S.; Janssen, G. H.; Jogler, T.; Jóhannesson, G.; Johnson, R. P.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Johnston, S.; Kamae, T.; Kataoka, J.; Keith, M.; Kerr, M.; Knödlseder, J.; Kramer, M.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Lyne, A. G.; Manchester, R. N.; Marelli, M.; Massaro, F.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; McLaughlin, M. A.; Mehault, J.; Michelson, P. F.; Mignani, R. P.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nemmen, R.; Nuss, E.; Ohno, M.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Perkins, J. S.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Pletsch, H. J.; Porter, T. A.; Possenti, A.; Rainò, S.; Rando, R.; Ransom, S. M.; Ray, P. S.; Razzano, M.; Rea, N.; Reimer, A.; Reimer, O.; Renault, N.; Reposeur, T.; Ritz, S.; Romani, R. W.; Roth, M.; Rousseau, R.; Roy, J.; Ruan, J.; Sartori, A.; Saz Parkinson, P. M.; Scargle, J. D.; Schulz, A.; Sgrò, C.; Shannon, R.; Siskind, E. J.; Smith, D. A.; Spandre, G.; Spinelli, P.; Stappers, B. W.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Theureau, G.; Thompson, D. J.; Thorsett, S. E.; Tibaldo, L.; Tibolla, O.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Venter, C.; Vianello, G.; Vitale, V.; Wang, N.; Weltevrede, P.; Winer, B. L.; Wolff, M. T.; Wood, D. L.; Wood, K. S.; Wood, M.; Yang, Z.

2013-09-19

This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.

GREEN BANK TELESCOPE AND SWIFT X-RAY TELESCOPE OBSERVATIONS OF THE GALACTIC CENTER RADIO MAGNETAR SGR J1745–2900

Energy Technology Data Exchange (ETDEWEB)

Lynch, Ryan S.; Archibald, Robert F.; Kaspi, Victoria M.; Scholz, Paul, E-mail: rlynch@physics.mcgill.ca [Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, H3A 2T8 (Canada)

2015-06-20

We present results from eight months of Green Bank Telescope 8.7 GHz observations and nearly 18 months of Swift X-ray telescope observations of the radio magnetar SGR J1745–2900. We tracked the radio and X-ray flux density, polarization properties, profile evolution, rotation, and single-pulse behavior. We identified two main periods of activity. The first is characterized by approximately 5.5 months of relatively stable evolution in radio flux density, rotation, and profile shape, while in the second these properties varied substantially. Specifically, a third profile component emerged and the radio flux also became more variable. The single pulse properties also changed, most notably with a larger fraction of pulses with pulse widths ∼5–20 ms in the erratic state. Bright single pulses are well described by a log-normal energy distribution at low energies, but with an excess at high energies. The 2–10 keV flux decayed steadily since the initial X-ray outburst, while the radio flux remained stable to within ∼20% during the stable state. A joint pulsar timing analysis of the radio and X-ray data shows a level of timing noise unprecedented in a radio magnetar, though during the time covered by the radio data alone the timing noise was at a level similar to that observed in other radio magnetars. While SGR J1745–2900 is similar to other radio magnetars in many regards, it differs by having experienced a period of relative stability in the radio that now appears to have ended, while the X-ray properties evolved independently.

Thermal forming of glass microsheets for x-ray telescope mirror segments

DEFF Research Database (Denmark)

Jimenez-Garate, M.A.; Hailey, C.J.; Craig, W.W.

2003-01-01

envisioned for future x-ray observatories. The glass microsheets are shaped into mirror segments at high temperature by use of a guiding mandrel, without polishing. We determine the physical properties and mechanisms that elucidate the formation process and that are crucial to improve surface quality. We......We describe a technology to mass-produce ultrathin mirror substrates for x-ray telescopes of near Wolter-I geometry. Thermal glass forming is a low-cost method to produce high-throughput, spaceborne x-ray mirrors for the 0.1-200-keV energy band. These substrates can provide the collecting area...... develop a viscodynamic model for the glass strain as the forming proceeds to find the conditions for repeatability. Thermal forming preserves the x-ray reflectance and scattering properties of the raw glass. The imaging resolution is driven by a large wavelength figure. We discuss the sources of figure...

Chandra's X-ray Vision

Indian Academy of Sciences (India)

1999-07-23

Jul 23, 1999 ... CXO is 13.8 metres long and its solar arrays have a wingspan of. 19.5 metres as shown in ... the Universe (for example, coronae of stars, matter ejected from .... The telescope system and the scientific instruments were put through ..... solve the puzzle about the origin of cosmic X-ray background- one of the ...

SphinX: The Solar Photometer in X-Rays

Czech Academy of Sciences Publication Activity Database

Gburek, S.; Sylwester, J.; Kowalinski, M.; Bakala, J.; Kordylewski, Z.; Podgorski, P.; Plocieniak, S.; Siarkowski, M.; Sylwester, B.; Trzebinski, W.; Kuzin, S.; Pertsov, A.A.; Kotov, Yu. D.; Fárník, František; Reale, F.; Phillips, K. J. H.

2013-01-01

Roč. 283, č. 2 (2013), s. 631-649 ISSN 0038-0938 Institutional support: RVO:67985815 Keywords : solar corona * solar instrumentation * X-rays Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.805, year: 2013

Stellar and solar X-ray polarimetry

Energy Technology Data Exchange (ETDEWEB)

Novick, R [Columbia Univ., New York (USA)

1975-12-01

The scientific motivation for X-ray polarimetry is discussed with particular emphasis on the information that might be obtained on the binary X-ray pulsars in addition to a number of other classes of objects including solar flares. Detailed discussions are given for Thomson-scattering and Bragg-crystal polarimeters with numerical estimates for the sensitivity of various existing and proposed instruments.

The First Wide-field X-ray Imaging Telescope for Observations of Charge Exchange

Data.gov (United States)

National Aeronautics and Space Administration — Soft x-ray emission from the interaction of solar wind with the earth's exosphere provides a very significant foreground to all soft x-ray observations. It is...

The first telescope of the HEGRA air Cherenkov imaging telescope array

International Nuclear Information System (INIS)

Mirzoyan, R.; Kankanian, R.; Krennrich, F.; Mueller, N.; Sander, H.; Sawallisch, P.; Aharonian, F.; Akhperjanian, A.; Beglarian, A.; Fernandez, J.; Fonseca, V.; Grewe, W.; Heusler, A.; Konopelko, A.K.; Lorenz, E.; Merck, M.; Plyasheshnikov, A.V.; Renker, D.; Samorski, M.; Sauerland, K.; Smarsch, E.; Stamm, W.; Ulrich, M.; Wiedner, C.A.; Wirth, H.

1994-01-01

In search of VHE γ ray emission from cosmic point sources a system of imaging Cherenkov telescopes is constructed at present on the Canarian island of La Palma; the first telescope has been operational since 1992. The Cherenkov light from air shower particles is collected by a 5 m 2 reflector. The camera at the focus contains 37 photomultipliers which sample the images of the Cherenkov flashes. The subsequent image analysis allows the discrimination of γ ray induced events from the much more abundant charged cosmic ray induced showers. The telescope has an effective energy threshold for γ showers of about 1.5 TeV. During the first year of operation a signal from the Crab nebula was detected. ((orig.))

Perspectives of the lobster-eye telescope: The promising types of cosmic X-ray sources

Science.gov (United States)

Šimon, V.

2017-07-01

We show the astrophysical aspects of observing the X-ray sky with the planned lobster-eye telescope. This instrument is important because it is able to provide wide-field X-ray imaging. For the testing observations, we propose to include also X-ray binaries in which matter transfers onto the compact object (mostly the neutron star). We show the typical features of the long-term X-ray activity of such objects. Observing in the soft X-ray band is the most promising because their X-ray intensity is the highest in this band. Since these X-ray sources tend to concentrate toward the center of our Galaxy, several of them can be present in the field of view of the tested instrument.

Time stamp technique using a nuclear emulsion multi-stage shifter for gamma-ray telescope

International Nuclear Information System (INIS)

Takahashi, Satoru; Aoki, Shigeki; Rokujo, Hiroki; Hamada, Kaname; Komatsu, Masahiro; Morishima, Kunihiro; Nakamura, Mitsuhiro; Nakano, Toshiyuki; Niwa, Kimio; Sato, Osamu; Yoshioka, Teppei; Kodama, Koichi

2010-01-01

Nuclear emulsion has a potential use as a gamma-ray telescope with high angular resolution. For this application it is necessary to know the time when each track was recorded in the emulsion. In previous experiments using nuclear emulsion, various efforts were used to associate time to nuclear emulsion tracks and to improve the time resolution. Using a high speed readout system for nuclear emulsion together with a clock-based multi-stage emulsion shifter, we invented a technique to give a time-stamp to emulsion tracks and greatly improve the time resolution. A test experiment with a 2-stage shifter was used to demonstrate the principle of multi-stage shifting, and we achieved a time resolution 1.5 s for 12.1 h (about 1 part in 29 000) with the time stamp reliability 97% and the time stamp efficiency 98%. This multi-stage shifter can achieve the time resolution required for a gamma-ray telescope and can also be applied to another cosmic ray observations and accelerator experiments using nuclear emulsion.

Simulated gamma-ray pulse profile of the Crab pulsar with the Cherenkov Telescope Array

Science.gov (United States)

Burtovoi, A.; Zampieri, L.

2016-07-01

We present simulations of the very high energy (VHE) gamma-ray light curve of the Crab pulsar as observed by the Cherenkov Telescope Array (CTA). The CTA pulse profile of the Crab pulsar is simulated with the specific goal of determining the accuracy of the position of the interpulse. We fit the pulse shape obtained by the Major Atmospheric Gamma-Ray Imaging Cherenkov (MAGIC) telescope with a three-Gaussian template and rescale it to account for the different CTA instrumental and observational configurations. Simulations are performed for different configurations of CTA and for the ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) mini-array. The northern CTA configuration will provide an improvement of a factor of ˜3 in accuracy with an observing time comparable to that of MAGIC (73 h). Unless the VHE spectrum above 1 TeV behaves differently from what we presently know, unreasonably long observing times are required for a significant detection of the pulsations of the Crab pulsar with the high-energy-range sub-arrays. We also found that an independent VHE timing analysis is feasible with Large Size Telescopes. CTA will provide a significant improvement in determining the VHE pulse shape parameters necessary to constrain theoretical models of the gamma-ray emission of the Crab pulsar. One of such parameters is the shift in phase between peaks in the pulse profile at VHE and in other energy bands that, if detected, may point to different locations of the emission regions.

THE FIRST FOCUSED HARD X-RAY IMAGES OF THE SUN WITH NuSTAR

Energy Technology Data Exchange (ETDEWEB)

Grefenstette, Brian W.; Madsen, Kristin K.; Forster, Karl; Harrison, Fiona A. [Cahill Center for Astrophysics, 1216 E. California Blvd, California Institute of Technology, Pasadena, CA 91125 (United States); Glesener, Lindsay [School of Physics and Astronomy, University of Minnesota—Twin Cities, Minneapolis, MN 55455 (United States); Krucker, Säm; Hudson, Hugh; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Hannah, Iain G. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Smith, David M.; Marsh, Andrew J. [Physics Department and Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Vogel, Julia K. [Physics Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); White, Stephen M. [Air Force Research Laboratory, Albuquerque, NM (United States); Caspi, Amir [Southwest Research Institute, Boulder, CO 80302 (United States); Chen, Bin [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Shih, Albert [Solar Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kuhar, Matej [University of Applied Sciences and Arts Northwestern Switzerland, CH-5210 Windisch (Switzerland); Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Hailey, Charles J., E-mail: bwgref@srl.caltech.edu [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); and others

2016-07-20

We present results from the the first campaign of dedicated solar observations undertaken by the Nuclear Spectroscopic Telescope ARray ( NuSTAR ) hard X-ray (HXR) telescope. Designed as an astrophysics mission, NuSTAR nonetheless has the capability of directly imaging the Sun at HXR energies (>3 keV) with an increase in sensitivity of at least two magnitude compared to current non-focusing telescopes. In this paper we describe the scientific areas where NuSTAR will make major improvements on existing solar measurements. We report on the techniques used to observe the Sun with NuSTAR , their limitations and complications, and the procedures developed to optimize solar data quality derived from our experience with the initial solar observations. These first observations are briefly described, including the measurement of the Fe K-shell lines in a decaying X-class flare, HXR emission from high in the solar corona, and full-disk HXR images of the Sun.

The First Focused Hard X-Ray Images of the Sun with NuSTAR

Science.gov (United States)

Grefenstette, Brian W.; Glesener, Lindsay; Kruckner, Sam; Hudson, Hugh; Hannah, Iain G.; Smith, David M.; Vogel, Julia K.; White, Stephen M.; Madsen, Kristin K.; Marsh, Andrew J.;

On the expected γ-ray emission from nearby flaring stars

Science.gov (United States)

Ohm, S.; Hoischen, C.

2018-02-01

Stellar flares have been extensively studied in soft X-rays (SXRs) by basically every X-ray mission. Hard X-ray (HXR) emission from stellar superflares, however, have only been detected from a handful of objects over the past years. One very extreme event was the superflare from the young M-dwarf DG CVn binary star system, which triggered Swift/BAT as if it was a γ-ray burst. In this work, we estimate the expected γ-ray emission from DG CVn and the most extreme stellar flares by extrapolating from solar flares based on measured solar energetic particles (SEPs), as well as thermal and non-thermal emission properties. We find that ions are plausibly accelerated in stellar superflares to 100 GeV energies, and possibly up to TeV energies in the associated coronal mass ejections. The corresponding π0-decay γ-ray emission could be detectable from stellar superflares with ground-based γ-ray telescopes. On the other hand, the detection of γ-ray emission implies particle densities high enough that ions suffer significant losses due to inelastic proton-proton scattering. The next-generation Cherenkov Telescope Array (CTA) should be able to probe superflares from M dwarfs in the solar neighbourhood and constrain the energy in interacting cosmic rays and/or their maximum energy. The detection of γ-ray emission from stellar flares would open a new window for the study of stellar physics, the underlying physical processes in flares and their impact on habitability of planetary systems.

Nuclear collisions in measurements of the cosmic ray charge spectrum with a counter telescope

International Nuclear Information System (INIS)

Lindstam, S.

1975-06-01

The importance of nuclear collisions of cosmic ray particles in a counter detector telescope is studied by simple Monte Carlo techniques. The interest concentrates on the charge region just below iron and the calculations are restricted to fully relativistic cosmic rays. It is found that it is difficult to avoid a blurring in the charge spectrum from nuclear collisions leading to considerable systematic errors in some abundance ratios. (Auth.)

The First Focused Hard X-Ray Images of the Sun With NuSTAR

DEFF Research Database (Denmark)

Grefenstette, Brian W.; Glesener, Lindsay; Krucker, Sam

2016-01-01

We present results from the the first campaign of dedicated solar observations undertaken by the Nuclear Spectroscopic Telescope ARray (NuSTAR) hard X-ray (HXR) telescope. Designed as an astrophysics mission, NuSTAR nonetheless has the capability of directly imaging the Sun at HXR energies (>3 ke......V) with an increase in sensitivity of at least two magnitude compared to current non-focusing telescopes. In this paper we describe the scientific areas where NuSTAR will make major improvements on existing solar measurements. We report on the techniques used to observe the Sun with NuSTAR, their limitations......, and full-disk HXR images of the Sun....

The Phobos low energy telescope charged particle experiment

Energy Technology Data Exchange (ETDEWEB)

Marsden, R.G.; Henrion, J.P.G.; Wenzel, K.P. (European Space Agency, Noordwijk (Netherlands). Space Science Dept.); Afonin, V.V. (AN SSSR, Moscow (USSR). Inst. Kosmicheskikh Issledovanij); Balazs, A.; Erdoes, G.; Rusznyak, P.; Somogyi, A.; Szalai, S.; Varga, A.; Varhalmi, L. (Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics); Richter, A.K.; Witte, M. (Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany, F.R.))

1990-05-01

The Low Energy Telescope (LET) experiment on board the Phobos 1 and 2 spacecraft measures the flux, energy spectra and elemental composition of solar energetic particles and cosmic ray nuclei from hydrogen up to iron in the energy range {proportional to}1 to {proportional to}75 MeV/n. The LET sensor system comprises a double dE/dX vs E solid-state detector telescope surrounded by a cylindrical plastic scintillator anticoincidence shield, and the instrument is equipped with a comprehensive particle identifier and event priority system that enables rare nuclei to be analysed in preference to the more common species. Isotope separation for light nuclei such as He is also achieved. The sensor is mounted on a rotating platform to enable coarse anisotropy measurements of low energy protons to be made. (orig.).

Solar wind velocity and daily variation of cosmic rays

International Nuclear Information System (INIS)

Ahluwalia, H.S.; Riker, J.F.

1985-01-01

Recently parameters applicable to the solar wind and the interplanetary magnetic field (IMF) have become much better defined. Superior quality of data bases that are now available, particularly for the post-1971 period, make it possible to believe the long-term trends in the data. These data are correlated with the secular changes observed in the diurnal variation parameters obtained from neutron monitor data at Deep River and underground muon telescope data at Embudo (30 MEW) and Socorro (82 MWE). The annual mean amplitudes appear to have large values during the epochs of high speed solar wind streams. Results are discussed

Experiment and application of soft x-ray grazing incidence optical scattering phenomena

Science.gov (United States)

Chen, Shuyan; Li, Cheng; Zhang, Yang; Su, Liping; Geng, Tao; Li, Kun

2017-08-01

For short wavelength imaging systems，surface scattering effects is one of important factors degrading imaging performance. Study of non-intuitive surface scatter effects resulting from practical optical fabrication tolerances is a necessary work for optical performance evaluation of high resolution short wavelength imaging systems. In this paper, Soft X-ray optical scattering distribution is measured by a soft X-ray reflectometer installed by my lab, for different sample mirrors、wavelength and grazing angle. Then aim at space solar telescope, combining these scattered light distributions, and surface scattering numerical model of grazing incidence imaging system, PSF and encircled energy of optical system of space solar telescope are computed. We can conclude that surface scattering severely degrade imaging performance of grazing incidence systems through analysis and computation.

ISS-Lobster: A Proposed Wide-Field X-Ray Telescope on the International Space Station

Science.gov (United States)

Camp, Jordan

2012-01-01

The Lobster wide-field imaging telescope combines simultaneous high FOV, high sensitivity and good position resolution. These characteristics can open the field of X-Ray time domain astronomy, which will study many interesting transient sources, including tidal disruptions of stars, supernova shock breakouts, and high redshift gamma-ray bursts. Also important will be its use for the X-ray follow-up of gravitational wave detections. I will describe our present effort to propose the Lobster concept for deployment on the International Space Station through a NASA Mission of Opportunity this fall.

Discovery of Pulsations from the Pulsar J0205 6449 in SNR 3C 58 with the Fermi Gamma-Ray Space Telescope

Energy Technology Data Exchange (ETDEWEB)

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, Marco; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, William B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, Ronaldo; /INFN, Pisa; Berenji, Bijan; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Blandford, Roger D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, Anders W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bouvier, A.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Columbia U. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /NASA, Goddard /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /LPCE, Orleans /Montpellier U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Manchester U. /Montpellier U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

2011-12-01

We report the discovery of {gamma}-ray pulsations ({ge}0.1 GeV) from the young radio and X-ray pulsar PSR J0205 + 6449 located in the Galactic supernova remnant 3C 58. Data in the {gamma}-ray band were acquired by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope (formerly GLAST), while the radio rotational ephemeris used to fold {gamma}-rays was obtained using both the Green Bank Telescope and the Lovell telescope at Jodrell Bank. The light curve consists of two peaks separated by 0.49 {+-} 0.01 {+-} 0.01 cycles which are aligned with the X-ray peaks. The first {gamma}-ray peak trails the radio pulse by 0.08 {+-} 0.01 {+-} 0.01, while its amplitude decreases with increasing energy as for the other {gamma}-ray pulsars. Spectral analysis of the pulsed {gamma}-ray emission suggests a simple power law of index -2.1 {+-} 0.1 {+-} 0.2 with an exponential cutoff at 3.0{sub -0.7}{sup +1.1} {+-} 0.4 GeV. The first uncertainty is statistical and the second is systematic. The integral {gamma}-ray photon flux above 0.1 GeV is (13.7 {+-} 1.4 {+-} 3.0) x 10{sup -8} cm{sup -2} s{sup -1}, which implies for a distance of 3.2 kpc and assuming a broad fan-like beam a luminosity of 8.3 x 10{sup 34} erg s{sup -1} and an efficiency {eta} of 0.3%. Finally, we report a 95% upper limit on the flux of 1.7 x 10{sup -8} cm{sup -2} s{sup -1} for off-pulse emission from the object.

Discovery of Pulsations from the Pulsar J0205 6449 in SNR 3C 58 with the Fermi Gamma-Ray Space Telescope

International Nuclear Information System (INIS)

Abdo, Aous A.; Ackermann, M.; Ajello, Marco; Atwood, William B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, Guido; Bastieri, Denis; Baughman, B.M.; Bechtol, K.; Bellazzini, Ronaldo; Berenji, Bijan; Blandford, Roger D.; Bloom, Elliott D.; Bonamente, E.; Borgland, Anders W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.

2009-01-01

We report the discovery of γ-ray pulsations ((ge)0.1 GeV) from the young radio and X-ray pulsar PSR J0205 + 6449 located in the Galactic supernova remnant 3C 58. Data in the γ-ray band were acquired by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope (formerly GLAST), while the radio rotational ephemeris used to fold γ-rays was obtained using both the Green Bank Telescope and the Lovell telescope at Jodrell Bank. The light curve consists of two peaks separated by 0.49 ± 0.01 ± 0.01 cycles which are aligned with the X-ray peaks. The first γ-ray peak trails the radio pulse by 0.08 ± 0.01 ± 0.01, while its amplitude decreases with increasing energy as for the other γ-ray pulsars. Spectral analysis of the pulsed γ-ray emission suggests a simple power law of index -2.1 ± 0.1 ± 0.2 with an exponential cutoff at 3.0 -0.7 +1.1 ± 0.4 GeV. The first uncertainty is statistical and the second is systematic. The integral γ-ray photon flux above 0.1 GeV is (13.7 ± 1.4 ± 3.0) x 10 -8 cm -2 s -1 , which implies for a distance of 3.2 kpc and assuming a broad fan-like beam a luminosity of 8.3 x 10 34 erg s -1 and an efficiency η of 0.3%. Finally, we report a 95% upper limit on the flux of 1.7 x 10 -8 cm -2 s -1 for off-pulse emission from the object.

DISCOVERY OF PULSATIONS FROM THE PULSAR J0205+6449 IN SNR 3C 58 WITH THE FERMI GAMMA-RAY SPACE TELESCOPE

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bouvier, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bonamente, E.

2009-01-01

We report the discovery of γ-ray pulsations (≥0.1 GeV) from the young radio and X-ray pulsar PSR J0205 + 6449 located in the Galactic supernova remnant 3C 58. Data in the γ-ray band were acquired by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope (formerly GLAST), while the radio rotational ephemeris used to fold γ-rays was obtained using both the Green Bank Telescope and the Lovell telescope at Jodrell Bank. The light curve consists of two peaks separated by 0.49 ± 0.01 ± 0.01 cycles which are aligned with the X-ray peaks. The first γ-ray peak trails the radio pulse by 0.08 ± 0.01 ± 0.01, while its amplitude decreases with increasing energy as for the other γ-ray pulsars. Spectral analysis of the pulsed γ-ray emission suggests a simple power law of index -2.1 ± 0.1 ± 0.2 with an exponential cutoff at 3.0 +1.1 -0.7 ± 0.4 GeV. The first uncertainty is statistical and the second is systematic. The integral γ-ray photon flux above 0.1 GeV is (13.7 ± 1.4 ± 3.0) x 10 -8 cm -2 s -1 , which implies for a distance of 3.2 kpc and assuming a broad fan-like beam a luminosity of 8.3 x 10 34 erg s -1 and an efficiency η of 0.3%. Finally, we report a 95% upper limit on the flux of 1.7 x 10 -8 cm -2 s -1 for off-pulse emission from the object.

Solar System science with the Large Synoptic Survey Telescope

Science.gov (United States)

Jones, Lynne; Brown, Mike; Ivezić, Zeljko; Jurić, Mario; Malhotra, Renu; Trilling, David

2015-11-01

The Large Synoptic Survey Telescope (LSST; http://lsst.org) will be a large-aperture, wide-field, ground-based telescope that will survey half the sky every few nights in six optical bands from 320 to 1050 nm. It will explore a wide range of astrophysical questions, ranging from performing a census of the Solar System, to examining the nature of dark energy. It is currently in construction, slated for first light in 2019 and full operations by 2022.The LSST will survey over 20,000 square degrees with a rapid observational cadence, to typical limiting magnitudes of r~24.5 in each visit (9.6 square degree field of view). Automated software will link the individual detections into orbits; these orbits, as well as precisely calibrated astrometry (~50mas) and photometry (~0.01-0.02 mag) in multiple bandpasses will be available as LSST data products. The resulting data set will have tremendous potential for planetary astronomy; multi-color catalogs of hundreds of thousands of NEOs and Jupiter Trojans, millions of asteroids, tens of thousands of TNOs, as well as thousands of other objects such as comets and irregular satellites of the major planets.LSST catalogs will increase the sample size of objects with well-known orbits 10-100 times for small body populations throughout the Solar System, enabling a major increase in the completeness level of the inventory of most dynamical classes of small bodies and generating new insights into planetary formation and evolution. Precision multi-color photometry will allow determination of lightcurves and colors, as well as spin state and shape modeling through sparse lightcurve inversion. LSST is currently investigating survey strategies to optimize science return across a broad range of goals. To aid in this investigation, we are making a series of realistic simulated survey pointing histories available together with a Python software package to model and evaluate survey detections for a user-defined input population. Preliminary

Pulsed Gamma-Rays From PSR J2021 3651 with the Fermi Large Area Telescope

International Nuclear Information System (INIS)

Abdo, Aous A.; Ackermann, M.; Ajello, Marco; Atwood, William B.; Baldini, L.; Ballet, J.; Barbiellini, Guido; Bastieri, Denis; Battelino, Milan; Baughman, B.M.; Bechtol, K.; Bellazzini, Ronaldo; Berenji, Bijan; Bloom, Elliott D.; Bogaert, G.; Borgland, Anders W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, Thompson H.

2009-01-01

We report the detection of pulsed gamma-rays from the young, spin-powered radio pulsar PSR J2021+3651 using data acquired with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The light curve consists of two narrow peaks of similar amplitude separated by 0.468 ± 0.002 in phase. The first peak lags the maximum of the 2 GHz radio pulse by 0.162 ± 0.004 ± 0.01 in phase. The integral gamma-ray photon flux above 100 MeV is (56 ± 3 ± 11) x 10 -8 cm -2 s -1 . The photon spectrum is well-described by an exponentially cut-off power law of the form dF/dE = kE -# Gamma#e (-E/E c ) where the energy E is expressed in GeV. The photon index is Γ = 1.5 ± 0.1 ± 0.1 and the exponential cut-off is E c = 2.4 ± 0.3 ± 0.5 GeV. The first uncertainty is statistical and the second is systematic. The integral photon flux of the bridge is approximately 10% of the pulsed emission, and the upper limit on off-pulse gamma-ray emission from a putative pulsar wind nebula is -2 but a poorly constrained magnetic geometry. Re-analysis of Chandra data enhanced the significance of the weak X-ray pulsations, and the first peak is roughly phase-aligned with the first gamma-ray peak. We discuss the emission region and beaming geometry based on the shape and spectrum of the gamma-ray light curve combined with radio and X-ray measurements, and the implications for the pulsar distance. Gamma-ray emission from the polar cap region seems unlikely for this pulsar.

Design of the data management system for hard X-ray modulation telescope based on real-time Linux

International Nuclear Information System (INIS)

Jia Tao; Zhang Zhi

2004-01-01

Hard X-ray Modulation Telescope is an electronic subsystem, the data management system for capturing the data of the telescope, then managing and transferring them. The data management system also deals with the communication with the satellite. Because of these functions, it needs highly steady quality and good real-time performance. This paper describes the design of the system. (authors)

Pulsed Gamma-Rays From the Millisecond Pulsar J0030+0451 with the Fermi Large Area Telescope

International Nuclear Information System (INIS)

Abdo, Aous A.; Ackermann, M.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, Guido; Bastieri, Denis; Battelino, M.; Baughman, B.M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, Elliott D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, Thompson H.

2009-01-01

We report the discovery of gamma-ray pulsations from the nearby isolated millisecond pulsar PSR J0030+0451 with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). This discovery makes PSR J0030+0451 the second millisecond pulsar to be detected in gamma-rays after PSR J0218+4232, observed by the EGRET instrument on the Compton Gamma Ray Observatory. The spin-down power (dot E) = 3.5 x 10 33 ergs s -1 is an order of magnitude lower than the empirical lower bound of previously known gamma-ray pulsars. The emission profile is characterized by two narrow peaks, respectively 0.07 ± 0.01 and 0.08 ± 0.02 wide, separated by 0.44 ± 0.02 in phase. The first gamma-ray peak falls 0.15 ± 0.01 after the main radio peak. The pulse shape is similar to that of the 'normal' gamma-ray pulsars. An exponentially cut-off power-law fit of the emission spectrum leads to an integral photon flux above 100 MeV of (6.76 ± 1.05 ± 1.35) x 10 -8 cm -2 s -1 with cut-off energy (1.7 ± 0.4 ± 0.5) GeV. Based on its parallax distance of (300 ± 90) pc, we obtain a gamma-ray efficiency L γ /(dot E) ≅ 15% for the conversion of spin-down energy rate into gamma-ray radiation, assuming isotropic emission.

PULSED GAMMA RAYS FROM THE MILLISECOND PULSAR J0030+0451 WITH THE FERMI LARGE AREA TELESCOPE

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Bechtol, K.; Berenji, B.; Bloom, E. D.; Borgland, A. W.; Atwood, W. B.; Axelsson, M.; Battelino, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bonamente, E.; Brigida, M.; Bruel, P.

2009-01-01

We report the discovery of gamma-ray pulsations from the nearby isolated millisecond pulsar (MSP) PSR J0030+0451 with the Large Area Telescope on the Fermi Gamma-ray Space Telescope (formerly GLAST). This discovery makes PSR J0030+0451 the second MSP to be detected in gamma rays after PSR J0218+4232, observed by the EGRET instrument on the Compton Gamma-Ray Observatory. The spin-down power E-dot=3.5x10 33 erg s -1 is an order of magnitude lower than the empirical lower bound of previously known gamma-ray pulsars. The emission profile is characterized by two narrow peaks, 0.07 ± 0.01 and 0.08 ± 0.02 wide, respectively, separated by 0.44 ± 0.02 in phase. The first gamma-ray peak falls 0.15 ± 0.01 after the main radio peak. The pulse shape is similar to that of the 'normal' gamma-ray pulsars. An exponentially cutoff power-law fit of the emission spectrum leads to an integral photon flux above 100 MeV of (6.76 ± 1.05 ± 1.35) x 10 -8 cm -2 s -1 with cutoff energy (1.7 ± 0.4 ± 0.5) GeV. Based on its parallax distance of (300 ± 90) pc, we obtain a gamma-ray efficiency L γ /E-dot≅15 percent for the conversion of spin-down energy rate into gamma-ray radiation, assuming isotropic emission.

Pulsed Gamma-Rays From the Millisecond Pulsar J0030+0451 with the Fermi Large Area Telescope

Energy Technology Data Exchange (ETDEWEB)

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M. /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Battelino, M.; /Stockholm U., OKC /Royal Inst. Tech., Stockholm; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /LPCE, Orleans /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /ASDC, Frascati /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Trieste /Hiroshima U.; /more authors..

2011-11-17

We report the discovery of gamma-ray pulsations from the nearby isolated millisecond pulsar PSR J0030+0451 with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). This discovery makes PSR J0030+0451 the second millisecond pulsar to be detected in gamma-rays after PSR J0218+4232, observed by the EGRET instrument on the Compton Gamma Ray Observatory. The spin-down power {dot E} = 3.5 x 10{sup 33} ergs s{sup -1} is an order of magnitude lower than the empirical lower bound of previously known gamma-ray pulsars. The emission profile is characterized by two narrow peaks, respectively 0.07 {+-} 0.01 and 0.08 {+-} 0.02 wide, separated by 0.44 {+-} 0.02 in phase. The first gamma-ray peak falls 0.15 {+-} 0.01 after the main radio peak. The pulse shape is similar to that of the 'normal' gamma-ray pulsars. An exponentially cut-off power-law fit of the emission spectrum leads to an integral photon flux above 100 MeV of (6.76 {+-} 1.05 {+-} 1.35) x 10{sup -8} cm{sup -2} s{sup -1} with cut-off energy (1.7 {+-} 0.4 {+-} 0.5) GeV. Based on its parallax distance of (300 {+-} 90) pc, we obtain a gamma-ray efficiency L{sub {gamma}}/{dot E} {approx_equal} 15% for the conversion of spin-down energy rate into gamma-ray radiation, assuming isotropic emission.

A generalized ray-tracing procedure for an atmospheric Cherenkov imaging telescope and optical characteristics of the TACTIC light collector

International Nuclear Information System (INIS)

Tickoo, A.K.; Suthar, R.L.; Koul, R.; Sapru, M.L.; Kumar, N.; Kaul, C.L.; Yadav, K.K.; Thoudam, S.; Kaul, S.K.; Venugopal, K.; Kothari, M.; Goyal, H.C.; Chandra, P.; Dhar, V.K.; Rannot, R.C.; Koul, M.K.; Kaul, S.R.

2005-01-01

A generalized ray-tracing procedure has been developed, which facilitates the design of a multimirror-based light collector used in atmospheric Cherenkov telescopes. This procedure has been employed to study the optical characteristics of the 3.5 m diameter light collector of the TACTIC Imaging telescope. Comparison of the measured point-spread function of the light collector with the simulated performance of ideal Davies-Cotton and paraboloid designs has been made to determine an optimum arrangement of the 34 spherical mirror facets used in the telescope to obtain the best possible point-spread function. A description of the ray-tracing subroutine used for processing CORSIKA-generated Cherenkov data, required for carrying out Monte-Carlo simulation studies, is also discussed in the paper

FERMI-LARGE AREA TELESCOPE OBSERVATIONS OF THE EXCEPTIONAL GAMMA-RAY OUTBURSTS OF 3C 273 IN 2009 SEPTEMBER

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bouvier, A.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bonamente, E.; Brigida, M.; Bruel, P.; Burnett, T. H.

2010-01-01

We present the light curves and spectral data of two exceptionally luminous gamma-ray outbursts observed by the Large Area Telescope experiment on board the Fermi Gamma-ray Space Telescope from 3C 273 in 2009 September. During these flares, having a duration of a few days, the source reached its highest γ-ray flux ever measured. This allowed us to study, in some details, their spectral and temporal structures. The rise and the decay are asymmetric on timescales of 6 hr, and the spectral index was significantly harder during the flares than during the preceding 11 months. We also found that short, very intense flares put out the same time-integrated energy as long, less intense flares like that observed in 2009 August.

DETECTION OF GAMMA-RAY EMISSION FROM THE STARBURST GALAXIES M82 AND NGC 253 WITH THE LARGE AREA TELESCOPE ON FERMI

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Bloom, E. D.; Borgland, A. W.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bonamente, E.; Brigida, M.; Bruel, P.; Burnett, T. H.

2010-01-01

We report the detection of high-energy γ-ray emission from two starburst galaxies using data obtained with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. Steady point-like emission above 200 MeV has been detected at significance levels of 6.8σ and 4.8σ, respectively, from sources positionally coincident with locations of the starburst galaxies M82 and NGC 253. The total fluxes of the sources are consistent with γ-ray emission originating from the interaction of cosmic rays with local interstellar gas and radiation fields and constitute evidence for a link between massive star formation and γ-ray emission in star-forming galaxies.

CO-ANALYSIS OF SOLAR MICROWAVE AND HARD X-RAY SPECTRAL EVOLUTIONS. I. IN TWO FREQUENCY OR ENERGY RANGES

International Nuclear Information System (INIS)

Song Qiwu; Huang Guangli; Nakajima, Hiroshi

2011-01-01

Solar microwave and hard X-ray spectral evolutions are co-analyzed in the 2000 June 10 and 2002 April 10 flares, and are simultaneously observed by the Owens-Valley Solar Array in the microwave band and by Yohkoh/Hard X-ray Telescope or RHESSI in the hard X-ray band, with multiple subpeaks in their light curves. The microwave and hard X-ray spectra are fitted by a power law in two frequency ranges of the optical thin part and two photon energy ranges, respectively. Similar to an earlier event in Shao and Huang, the well-known soft-hard-soft pattern of the lower energy range changed to the hard-soft-hard (HSH) pattern of the higher energy range during the spectral evolution of each subpeak in both hard X-ray flares. This energy dependence is actually supported by a positive correlation between the overall light curves and spectral evolution in the lower energy range, while it becomes an anti-correlation in the higher energy range. Regarding microwave data, the HSH pattern appears in the spectral evolution of each subpeak in the lower frequency range, which is somewhat similar to Huang and Nakajima. However, it returns back to the well-known pattern of soft-hard-harder for the overall spectral evolution in the higher frequency range of both events. This frequency dependence is confirmed by an anti-correlation between the overall light curves and spectral evolution in the lower frequency range, but it becomes a positive correlation in the higher frequency range. The possible mechanisms are discussed, respectively, for reasons why hard X-ray and microwave spectral evolutions have different patterns in different energy and frequency intervals.

GAMMA-RAY OBSERVATIONS OF THE SUPERNOVA REMNANT RX J0852.0-4622 WITH THE FERMI LARGE AREA TELESCOPE

International Nuclear Information System (INIS)

Tanaka, T.; Allafort, A.; Funk, S.; Tajima, H.; Uchiyama, Y.; Ballet, J.; Giordano, F.; Hewitt, J.; Lemoine-Goumard, M.; Tibolla, O.

2011-01-01

We report on gamma-ray observations of the supernova remnant (SNR) RX J0852.0-4622 with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. In the Fermi-LAT data, we find a spatially extended source at the location of the SNR. The extension is consistent with the SNR size seen in other wavelengths such as X-rays and TeV gamma rays, leading to the identification of the gamma-ray source with the SNR. The spectrum is well described as a power law with a photon index of Γ = 1.85 ± 0.06 (stat) +0.18 -0.19 (sys), which smoothly connects to the H.E.S.S. spectrum in the TeV energy band. We discuss the gamma-ray emission mechanism based on multiwavelength data. The broadband data can be fit well by a model in which the gamma rays are of hadronic origin. We also consider a scenario with inverse Compton scattering of electrons as the emission mechanism of the gamma rays. Although the leptonic model predicts a harder spectrum in the Fermi-LAT energy range, the model can fit the data considering the statistical and systematic errors.

Solar Coronal Events with Extended Hard X-ray and Gamma-ray Emission

Science.gov (United States)

Hudson, H. S.

2017-12-01

A characteristic pattern of solar hard X-ray emission, first identified in SOL1969-03-31 by Frost & Dennis (1971) now has been linked to prolonged high-energy gamma-ray emission detected by the Fermi/LAT experiment, for example in SOL2014-09-01. The distinctive features of these events include flat hard X-ray spectra extending well above 100 keV, a characteristic pattern of time development, low-frequency gyrosynchrotron peaks, CME association, and gamma-rays identifiable with pion decay originating in GeV ions. The identification of these events with otherwise known solar structures nevertheless remains elusive, in spite of the wealth of imagery available from AIA. The quandary is that these events have a clear association with CMEs in the high corona, and yet the gamma-ray production implicates the photosphere itself. The vanishingly small loss cone in the nominal acceleration region makes this extremely difficult. I propose direct inward advection of a part of the SEP particle population, as created on closed field structures, as a possible resolution of this puzzle, and note that this requires retracting magnetic structures on long time scales following the flare itself.

Variations in Solar Parameters and Cosmic Rays with Solar Magnetic Polarity

Energy Technology Data Exchange (ETDEWEB)

Oh, S. [Department of Earth Science Education, Chonnam National University, Gwangju, 61186 (Korea, Republic of); Yi, Y., E-mail: suyeonoh@jnu.ac.kr [Department of Astronomy, Space Science and Geology, Chungnam National University, Daejeon, 34134 (Korea, Republic of)

2017-05-01

The sunspot number varies with the 11-year Schwabe cycle, and the solar magnetic polarity reverses every 11 years approximately at the solar maximum. Because of polarity reversal, the difference between odd and even solar cycles is seen in solar activity. In this study, we create the mean solar cycle expressed by phase using the monthly sunspot number for all solar cycles 1–23. We also generate the mean solar cycle for sunspot area, solar radio flux, and cosmic ray flux within the allowance of observational range. The mean solar cycle has one large peak at solar maximum for odd solar cycles and two small peaks for most even solar cycles. The odd and even solar cycles have the statistical difference in value and shape at a confidence level of at least 98%. For solar cycles 19–23, the second peak in the even solar cycle is larger than the first peak. This result is consistent with the frequent solar events during the declining phase after the solar maximum. The difference between odd and even solar cycles can be explained by a combined model of polarity reversal and solar rotation. In the positive/negative polarity, the polar magnetic field introduces angular momentum in the same/opposite direction as/to the solar rotation. Thus the addition/subtraction of angular momentum can increase/decrease the motion of plasma to support the formation of sunspots. Since the polarity reverses at the solar maximum, the opposite phenomenon occurs in the declining phase.

FERMI LARGE AREA TELESCOPE STUDY OF COSMIC RAYS AND THE INTERSTELLAR MEDIUM IN NEARBY MOLECULAR CLOUDS

Energy Technology Data Exchange (ETDEWEB)

Ackermann, M. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bottacini, E.; Buehler, R. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L.; Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brandt, T. J. [CNRS, IRAP, F-31028 Toulouse cedex 4 (France); Brigida, M. [Dipartimento di Fisica ' M. Merlin' dell' Universita e del Politecnico di Bari, I-70126 Bari (Italy); Bruel, P., E-mail: hayashi@hep01.hepl.hiroshima-u.ac.jp, E-mail: mizuno@hep01.hepl.hiroshima-u.ac.jp [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Palaiseau (France); and others

2012-08-10

We report an analysis of the interstellar {gamma}-ray emission from the Chamaeleon, R Coronae Australis (R CrA), and Cepheus and Polaris flare regions with the Fermi Large Area Telescope. They are among the nearest molecular cloud complexes, within {approx}300 pc from the solar system. The {gamma}-ray emission produced by interactions of cosmic rays (CRs) and interstellar gas in those molecular clouds is useful to study the CR densities and distributions of molecular gas close to the solar system. The obtained {gamma}-ray emissivities above 250 MeV are (5.9 {+-} 0.1{sub stat}{sup +0.9}{sub -1.0sys}) Multiplication-Sign 10{sup -27} photons s{sup -1} sr{sup -1} H-atom{sup -1}, (10.2 {+-} 0.4{sub stat}{sup +1.2}{sub -1.7sys}) Multiplication-Sign 10{sup -27} photons s{sup -1} sr{sup -1} H-atom{sup -1}, and (9.1 {+-} 0.3{sub stat}{sup +1.5}{sub -0.6sys}) Multiplication-Sign 10{sup -27} photons s{sup -1} sr{sup -1} H-atom{sup -1} for the Chamaeleon, R CrA, and Cepheus and Polaris flare regions, respectively. Whereas the energy dependences of the emissivities agree well with that predicted from direct CR observations at the Earth, the measured emissivities from 250 MeV to 10 GeV indicate a variation of the CR density by {approx}20% in the neighborhood of the solar system, even if we consider systematic uncertainties. The molecular mass calibrating ratio, X{sub CO} = N(H{sub 2})/W{sub CO}, is found to be (0.96 {+-} 0.06{sub stat}{sup +0.15}{sub -0.12sys}) Multiplication-Sign 10{sup 20} H{sub 2}-molecule cm{sup -2} (K km s{sup -1}){sup -1}, (0.99 {+-} 0.08{sub stat}{sup +0.18}{sub -0.10sys}) Multiplication-Sign 10{sup 20} H{sub 2}-molecule cm{sup -2} (K km s{sup -1}){sup -1}, and (0.63 {+-} 0.02{sub stat}{sup +0.09}{sub -0.07sys}) Multiplication-Sign 10{sup 20} H{sub 2}-molecule cm{sup -2} (K km s{sup -1}){sup -1} for the Chamaeleon, R CrA, and Cepheus and Polaris flare regions, respectively, suggesting a variation of X{sub CO} in the vicinity of the solar system. From the

UPDATED ANALYSIS OF THE UPWIND INTERPLANETARY HYDROGEN VELOCITY AS OBSERVED BY THE HUBBLE SPACE TELESCOPE DURING SOLAR CYCLE 23

International Nuclear Information System (INIS)

Vincent, Frederic E.; Ben-Jaffel, Lotfi; Harris, Walter M.

2011-01-01

The interplanetary hydrogen (IPH), a population of neutrals that fill the space between planets inside the heliosphere, carries the signature of the interstellar medium (ISM) and the heliospheric interface. As the incoming ISM-ionized component deflects at the heliopause, charge exchange reactions decelerate the bulk motion of the neutrals that penetrate the heliosphere. Inside the heliosphere, the IPH bulk velocity is further affected by solar gravity, radiation pressure, and ionization processes, with the latter two processes dependent on solar activity. Solar cycle 23 provided the first partial temporal map of the IPH velocity, including measurements from the Hubble Space Telescope (HST) spectrometers (Goddard High Resolution Spectrograph (GHRS) and Space Telescope Imaging Spectrograph (STIS)) and the Solar and Heliospheric Observatory/Solar Wind ANisotropies (SWAN) instrument. We present an updated analysis of IPH velocity measurements from GHRS and STIS and compare these results with those of SWAN and two different time-dependent models. Our reanalysis of STIS data reveals a significant change in IPH velocity relative to earlier reports, because of the contamination by geocoronal oxygen that was not accounted for. While current models of the heliospheric interface predict the observed IPH velocity for solar maximum, they are not consistent with data covering solar minimum. With updates to the HST data points, we now find that all data can be fit by the existing models to within 1σ, with the exception of SWAN observations taken at solar minimum (1997/1998). We conclude that the current data lack the temporal coverage and/or precision necessary to determine the detailed characteristics of the solar cycle dependence. Hence, new observations are merited.

Observational capabilities of solar satellite "Coronas-Photon"

Science.gov (United States)

Kotov, Yu.

Coronas-Photon mission is the third satellite of the Russian Coronas program on solar activity observation The main goal of the Coronas-Photon is the study of solar hard electromagnetic radiation in the wide energy range from UV up to high energy gamma-radiation sim 2000MeV Scientific payload for solar radiation observation consists of three type of instruments 1 monitors Natalya-2M Konus-RF RT-2 Penguin-M BRM Phoka Sphin-X Sokol for spectral and timing measurements of full solar disk radiation with timing in flare burst mode up to one msec Instruments Natalya-2M Konus-RF RT-2 will cover the wide energy range of hard X-rays and soft Gamma rays 15keV to 2000MeV and will together constitute the largest area detectors ever used for solar observations Detectors of gamma-ray monitors are based on structured inorganic scintillators with energy resolution sim 5 for nuclear gamma-line band to 35 for GeV-band PSD analysis is used for gamma neutron separation for solar neutron registration T 30MeV Penguin-M has capability to measure linear polarization of hard X-rays using azimuth are measured by Compton scattering asymmetry in case of polarization of an incident flux For X-ray and EUV monitors the scintillation phoswich detectors gas proportional counter CZT assembly and Filter-covered Si-diodes are used 2 Telescope-spectrometer TESIS for imaging solar spectroscopy in X-rays with angular resolution up to 1 in three spectral lines and RT-2 CZT assembly of CZT

COMPTEL gamma-ray observations of the C4 solar flare on 20 January 2000

International Nuclear Information System (INIS)

Young, C.A.; Arndt, M.B.; Bennett, K.; Winkler, C.; Connors, A.; Debrunner, H.; Diehl, R.; Rank, G.; Schoenfelder, V.; McConnell, M.; Miller, R.S.; Ryan, J.M.

2001-01-01

The 'Pre-SMM' (Vestrand and Miller 1998) picture of gamma-ray line (GRL) flares was that they are relatively rare events. This picture was quickly put in question with the launch of the Solar Maximum Mission (SMM). Over 100 GRL flares were seen with sizes ranging from very large GOES class events (X12) down to moderately small events (M2). It was argued by some (Bai 1986) that this was still consistent with the idea that GRL events are rare. Others, however, argued the opposite (Vestrand 1988; Cliver, Crosby and Dennis 1994), stating that the lower end of this distribution was just a function of SMM's sensitivity. They stated that the launch of the Compton Gamma-ray Observatory (CGRO) would in fact continue this distribution to show even smaller GRL flares. In response to a BACODINE cosmic gamma-ray burst alert, COMPtonTELescope on the CGRO recorded gamma rays above 1 MeV from the C4 flare at 0221 UT 20 January 2000. This event, though at the limits of COMPTEL's sensitivity, clearly shows a nuclear line excess above the continuum. Using new spectroscopy techniques we were able to resolve individual lines. This has allowed us to make a basic comparison of this event with the GRL flare distribution from SMM and also compare this flare with a well-observed large GRL flare seen by OSSE

Time-dependent search for neutrino emission from X-ray binaries with the ANTARES telescope

Energy Technology Data Exchange (ETDEWEB)

Albert, A. [GRPHE—Université de Haute Alsace—Institut universitaire de technologie de Colmar, 34 rue du Grillenbreit, BP 50568, Colmar, 68008 France (France); André, M. [Technical University of Catalonia, Laboratory of Applied Bioacoustics, Rambla Exposició, Vilanova i la Geltrú, Barcelona, 08800 Spain (Spain); Anton, G. [Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, Erlangen, 91058 Germany (Germany); Ardid, M. [Institut d' Investigació per a la Gestió Integrada de les Zones Costaneres (IGIC), Universitat Politècnica de València, C/ Paranimf 1, Gandia, 46730 Spain (Spain); Aubert, J.-J. [Aix-Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, 13288 France (France); Avgitas, T.; Baret, B. [APC, Université Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cité, Paris, 75205 France (France); Barrios-Martí, J., E-mail: antares.spokesperson@in2p3.fr [IFIC—Instituto de Física Corpuscular (CSIC—Universitat de València), c/ Catedrático José Beltrán, 2, Paterna, Valencia, E-46980 Spain (Spain); and others

2017-04-01

ANTARES is currently the largest neutrino telescope operating in the Northern Hemisphere, aiming at the detection of high-energy neutrinos from astrophysical sources. Neutrino telescopes constantly monitor at least one complete hemisphere of the sky, and are thus well-suited to detect neutrinos produced in transient astrophysical sources. A time-dependent search has been applied to a list of 33 X-ray binaries undergoing high flaring activities in satellite data (RXTE/ASM, MAXI and Swift/BAT) and during hardness transition states in the 2008–2012 period. The background originating from interactions of charged cosmic rays in the Earth's atmosphere is drastically reduced by requiring a directional and temporal coincidence with astrophysical phenomena. The results of this search are presented together with comparisons between the neutrino flux upper limits and the neutrino flux predictions from astrophysical models. The neutrino flux upper limits resulting from this search limit the jet parameter space for some astrophysical models.

Gamma ray observations of the solar system

International Nuclear Information System (INIS)

1981-01-01

Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed

Gamma ray observations of the solar system

Energy Technology Data Exchange (ETDEWEB)

1981-01-01

Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed.

Gamma ray observations of the solar system

Science.gov (United States)

1981-01-01

Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach; and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed.

Quantitative relationship between VLF phase deviations and 1-8 A solar X-ray fluxes during solar flares

Energy Technology Data Exchange (ETDEWEB)

Muraoka, Y; Murata, H; Sato, T [Hyogo Coll. Of Medicine (Japan). Dept. of Physics

1977-07-01

An attempt is made to investigate the quantitative relationship between VLF phase deviations in SPA (sudden phase anomalies) events and associated solar X-ray fluxes in the 1 to 8 A band during solar flares. The phase deviations (..delta..phi) of the 18.6 kHz VLF wave transmitted from NLK, USA are used in this analysis which were recorded at Nishinomiya, Japan during the period June 1974 to May 1975. The solar X-ray fluxes (F/sub 0/) in the 1 to 8 A band are estimated from fsub(min) variations using the empirical expression given by Sato (J.Geomag.Geoelectr.;27: 95(1975)), because no observed data were available on the 1 to 8 a X-ray fluxes during the period of the VLF observation. The result shows that the normalized phase variation, ..delta..phi/coschisub(min), where chisub(min) represents the minimum solar zenith angle on the VLF propagation path, increases with increasing logF/sub 0/. A theoretical explanation for this is presented assuming that enhanced ionizations produced in the lower ionosphere by a monochromatic solar X-ray emission are responsible for the VLF phase deviations. Also it is found that a threshold X-ray flux to produce a detectable SPA effect is approximately 1.5 x 10/sup -3/ cm/sup -2/ sec/sup -1/ in the 1 to 8 a band.

The GILDA mission: a new technique for a gamma-ray telescope in the energy range 20 MeV-100 GeV

International Nuclear Information System (INIS)

Barbiellini, G.; Candusso, M.; Pascale, M.P. de; Morselli, A.; Picozza, P.; Ricci, M.; Sparvoli, R.; Spillantini, P.; Vacchi, A.

1995-01-01

In this article a new technique for the realization of a high energy gamma-ray telescope is presented, based on the adoption of silicon strip detectors and lead scintillating fibers. The simulated performances of such an instrument (GILDA) are significatively better than those of EGRET, the last successful experiment of a high energy gamma-ray telescope, launched on the CGRO satellite, though having less volume and weight. ((orig.))

Comparison cosmic ray irradiation simulation and particle beam test on UFFO Burst Alert & Trigger telescope(UBAT) detectors

DEFF Research Database (Denmark)

Jeong, H. M.; Jeong, S.; Kim, M. B.

2017-01-01

Ultra-Fast Flash Observatory pathfinder(UFFO-p) was launched onboard Lomonosov on 28th of April, 2016, and now is under various types of calibration for detection of Gamma Ray Bursts (GRBs). Since last September UFFO-p has taken X-ray data in space with UFFO Burst Alert &Trigger telescope (UBAT),...

Solar atmospheric neutrinos and the sensitivity floor for solar dark matter annihilation searches

Energy Technology Data Exchange (ETDEWEB)

Argüelles, C.A. [Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA (United States); De Wasseige, G. [Vrije Universiteit Brussel, Pleinlaan 2, 1050 Elsene, Brussels (Belgium); Fedynitch, A. [Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany); Jones, B.J.P., E-mail: caad@mit.edu, E-mail: gdewasse@vub.ac.be, E-mail: anatoli.fedynitch@desy.de, E-mail: ben.jones@uta.edu [University of Texas at Arlington, 108 Science Hall, 502 Yates St, Arlington TX (United States)

2017-07-01

Cosmic rays interacting in the solar atmosphere produce showers that result in a flux of high-energy neutrinos from the Sun. These form an irreducible background to indirect solar WIMP self-annihilation searches, which look for heavy dark matter particles annihilating into final states containing neutrinos in the Solar core. This background will eventually create a sensitivity floor for indirect WIMP self-annihilation searches analogous to that imposed by low-energy solar neutrino interactions for direct dark matter detection experiments. We present a new calculation of the flux of solar atmospheric neutrinos with a detailed treatment of systematic uncertainties inherent in solar atmospheric shower evolution, and we use this to derive the sensitivity floor for indirect solar WIMP annihilation analyses. We find that the floor lies less than one order of magnitude beyond the present experimental limits on spin-dependent WIMP-proton cross sections for some mass points, and that the high-energy solar atmospheric neutrino flux may be observable with running and future neutrino telescopes.

Design and operation of a field telescope for cosmic ray geophysical tomography

Directory of Open Access Journals (Sweden)

N. Lesparre

2012-04-01

Full Text Available The cosmic ray muon tomography gives an access to the density structure of geological targets. In the present article we describe a muon telescope adapted to harsh environmental conditions. In particular the design optimizes the total weight and power consumption to ease the deployment and increase the autonomy of the detector. The muon telescopes consist of at least two scintillator detection matrices readout by photosensors via optical fibres. Two photosensor options have been studied. The baseline option foresees one multianode photomultiplier (MAPM per matrix. A second option using one multipixel photon counter (MPPC per bar is under development. The readout electronics and data acquisition system developed for both options are detailed. We present a first data set acquired in open-sky conditions compared with the muon flux detected across geological objects.

CELESTE an atmospheric Cherenkov telescope for high energy gamma astrophysics

CERN Document Server

Paré, E; Bazer-Bachi, R; Bergeret, H; Berny, F; Briand, N; Bruel, P; Cerutti, M; Collon, J; Cordier, A; Cornebise, P; Debiais, G; Dezalay, J P; Dumora, D; Durand, E; Eschstruth, P T; Espigat, P; Fabre, B; Fleury, P; Gilly, J; Gouillaud, J C; Gregory, C; Herault, N; Holder, J; Hrabovsky, M; Incerti, S; Jouenne, A; Kalt, L; Legallou, R; Lott, B; Lodygensky, O; Manigot, P; Manseri, H; Manitaz, H; Martin, M; Morano, R; Morineaud, G; Muenz, F; Musquere, A; Naurois, M D; Neveu, J; Noppe, J M; Olive, J F; Palatka, M; Pérez, A; Quebert, J; Rebii, A; Reposeur, T; Rob, L; Roy, P; Sans, J L; Sako, T; Schovanek, P; Smith, D A; Snabre, P; Villard, G

2002-01-01

CELESTE is an atmospheric Cherenkov telescope based on the sampling method which makes use of the de-commissioned THEMIS solar electrical plant in the French Pyrenees. A large (2000 m sup 2) mirror surface area from 40 independent heliostats followed by a secondary optic, a trigger system using analog summing techniques and signal digitization with 1 GHz flash ADCs make possible the detection of cosmic gamma-rays down to 30 GeV. This paper provides a detailed technical description of the CELESTE installation.

SOLAR-LIKE OSCILLATIONS IN A METAL-POOR GLOBULAR CLUSTER WITH THE HUBBLE SPACE TELESCOPE

International Nuclear Information System (INIS)

Stello, Dennis; Gilliland, Ronald L.

2009-01-01

We present analyses of variability in the red giant stars in the metal-poor globular cluster NGC 6397, based on data obtained with the Hubble Space Telescope. We use a nonstandard data reduction approach to turn a 23 day observing run originally aimed at imaging the white dwarf population, into time-series photometry of the cluster's highly saturated red giant stars. With this technique we obtain noise levels in the final power spectra down to 50 parts per million, which allows us to search for low-amplitude solar-like oscillations. We compare the observed excess power seen in the power spectra with estimates of the typical frequency range, frequency spacing, and amplitude from scaling the solar oscillations. We see evidence that the detected variability is consistent with solar-like oscillations in at least one and perhaps up to four stars. With metallicities 2 orders of magnitude lower than those of the Sun, these stars present so far the best evidence of solar-like oscillations in such a low-metallicity environment.

Search for interplanetary shock signals using the Tupi telescope at the ascending phase of the solar cycle 24

International Nuclear Information System (INIS)

Augusto, C.R.A.; Kopenkin, V.; Navia, C.E.; Tsui, K.H.; Shigueoka, H.; Fauth, A.C.; Kemp, E.; Manganote, E.J.T.; Oliveira, M.A. Leigui de; Miranda, P.; Ticona, R.; Velarde, A.

2012-01-01

Full text: This paper presents the results of an on-going survey on the association between the muon flux variation at ground level registered by the Tupi telescopes (Niteroi-Brazil, 22.9 deg S; 43.2 deg W, 3 m above sea level) in the South Atlantic Anomaly (SAA) region and interplanetary shocks detected by space-borne detectors (SOHO, ACE, GOES). The SAA provides favorable conditions for observation of shock driven geomagnetic storms, including those of very small scale. Geomagnetic storms are usually originated by the transient events such as solar flares, coronal mass ejections (CMEs) and corotating interaction regions (CIRs). In most cases scientific research showed variation in the cosmic particle flux at ground level in correlation with large scale CMEs solar flares characterized by high absolute values of geomagnetic activity Kp index. In our analysis we found that the muon flux associated with the interplanetary shock signals changes also in response to low solar activity and to fast rise in Kp index. We report experimental data obtained by the Tupi telescopes in the period from June 2010 to December 2011. This time period corresponds to the rising phase of the solar cycle 24. These observations are compared with publicly available observations from the CELIAS/MTOF Proton Monitor on SOHO satellite in order to study the origin of the shocks. Among 28 interplanetary shocks reported in present analysis, there are 12 possibly associated with the CMEs and solar flares, 2 events - with the CIR related shocks (forward or reverse shocks), and the origin of the remaining 13 events has not been determined by the satellite detectors. By comparing the observed time (delayed or anticipated) of the shock related signal on Earth (the Tupi telescopes) with the trigger time of the shock registered by satellites located at the Lagrange point L1 (SOHO, ACE), we find that it is possible to estimate the type of the shock (forward or reverse). This method can be useful in

Search for interplanetary shock signals using the Tupi telescope at the ascending phase of the solar cycle 24

Energy Technology Data Exchange (ETDEWEB)

Augusto, C.R.A.; Kopenkin, V.; Navia, C.E.; Tsui, K.H.; Shigueoka, H. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Fisica; Fauth, A.C.; Kemp, E.; Manganote, E.J.T. [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin; Oliveira, M.A. Leigui de [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas; Miranda, P.; Ticona, R.; Velarde, A. [Universidad Mayor de San Andres (UMSA), La Paz (Bolivia, Plurinational State of). Inst. de Investigaciones Fisicas

2012-07-01

Full text: This paper presents the results of an on-going survey on the association between the muon flux variation at ground level registered by the Tupi telescopes (Niteroi-Brazil, 22.9 deg S; 43.2 deg W, 3 m above sea level) in the South Atlantic Anomaly (SAA) region and interplanetary shocks detected by space-borne detectors (SOHO, ACE, GOES). The SAA provides favorable conditions for observation of shock driven geomagnetic storms, including those of very small scale. Geomagnetic storms are usually originated by the transient events such as solar flares, coronal mass ejections (CMEs) and corotating interaction regions (CIRs). In most cases scientific research showed variation in the cosmic particle flux at ground level in correlation with large scale CMEs solar flares characterized by high absolute values of geomagnetic activity Kp index. In our analysis we found that the muon flux associated with the interplanetary shock signals changes also in response to low solar activity and to fast rise in Kp index. We report experimental data obtained by the Tupi telescopes in the period from June 2010 to December 2011. This time period corresponds to the rising phase of the solar cycle 24. These observations are compared with publicly available observations from the CELIAS/MTOF Proton Monitor on SOHO satellite in order to study the origin of the shocks. Among 28 interplanetary shocks reported in present analysis, there are 12 possibly associated with the CMEs and solar flares, 2 events - with the CIR related shocks (forward or reverse shocks), and the origin of the remaining 13 events has not been determined by the satellite detectors. By comparing the observed time (delayed or anticipated) of the shock related signal on Earth (the Tupi telescopes) with the trigger time of the shock registered by satellites located at the Lagrange point L1 (SOHO, ACE), we find that it is possible to estimate the type of the shock (forward or reverse). This method can be useful in

Solar observations with a low frequency radio telescope

Science.gov (United States)

Myserlis, I.; Seiradakis, J.; Dogramatzidis, M.

2012-01-01

We have set up a low frequency radio monitoring station for solar bursts at the Observatory of the Aristotle University in Thessaloniki. The station consists of a dual dipole phased array, a radio receiver and a dedicated computer with the necessary software installed. The constructed radio receiver is based on NASA's Radio Jove project. It operates continuously, since July 2010, at 20.1 MHz (close to the long-wavelength ionospheric cut-off of the radio window) with a narrow bandwidth (~5 kHz). The system is properly calibrated, so that the recorded data are expressed in antenna temperature. Despite the high interference level of an urban region like Thessaloniki (strong broadcasting shortwave radio stations, periodic experimental signals, CBs, etc), we have detected several low frequency solar radio bursts and correlated them with solar flares, X-ray events and other low frequency solar observations. The received signal is monitored in ordinary ASCII format and as audio signal, in order to investigate and exclude man-made radio interference. In order to exclude narrow band interference and calculate the spectral indices of the observed events, a second monitoring station, working at 36 MHz, is under construction at the village of Nikiforos near the town of Drama, about 130 km away of Thessaloniki. Finally, we plan to construct a third monitoring station at 58 MHz, in Thessaloniki. This frequency was revealed to be relatively free of interference, after a thorough investigation of the region.

High-energy particle production in solar flares (SEP, gamma-ray and neutron emissions). [solar energetic particles

Science.gov (United States)

Chupp, E. L.

1987-01-01

Electrons and ions, over a wide range of energies, are produced in association with solar flares. Solar energetic particles (SEPs), observed in space and near earth, consist of electrons and ions that range in energy from 10 keV to about 100 MeV and from 1 MeV to 20 GeV, respectively. SEPs are directly recorded by charged particle detectors, while X-ray, gamma-ray, and neutron detectors indicate the properties of the accelerated particles (electrons and ions) which have interacted in the solar atmosphere. A major problem of solar physics is to understand the relationship between these two groups of charged particles; in particular whether they are accelerated by the same mechanism. The paper reviews the physics of gamma-rays and neutron production in the solar atmosphere and the method by which properties of the primary charged particles produced in the solar flare can be deduced. Recent observations of energetic photons and neutrons in space and at the earth are used to present a current picture of the properties of impulsively flare accelerated electrons and ions. Some important properties discussed are time scale of production, composition, energy spectra, accelerator geometry. Particular attention is given to energetic particle production in the large flare on June 3, 1982.

Design and Performance of the GAMMA-400 Gamma-Ray Telescope for Dark Matter Searches

Science.gov (United States)

Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu V.;

Using the Chandra Source-Finding Algorithm to Automatically Identify Solar X-ray Bright Points

Science.gov (United States)

Adams, Mitzi L.; Tennant, A.; Cirtain, J. M.

2009-01-01

This poster details a technique of bright point identification that is used to find sources in Chandra X-ray data. The algorithm, part of a program called LEXTRCT, searches for regions of a given size that are above a minimum signal to noise ratio. The algorithm allows selected pixels to be excluded from the source-finding, thus allowing exclusion of saturated pixels (from flares and/or active regions). For Chandra data the noise is determined by photon counting statistics, whereas solar telescopes typically integrate a flux. Thus the calculated signal-to-noise ratio is incorrect, but we find we can scale the number to get reasonable results. For example, Nakakubo and Hara (1998) find 297 bright points in a September 11, 1996 Yohkoh image; with judicious selection of signal-to-noise ratio, our algorithm finds 300 sources. To further assess the efficacy of the algorithm, we analyze a SOHO/EIT image (195 Angstroms) and compare results with those published in the literature (McIntosh and Gurman, 2005). Finally, we analyze three sets of data from Hinode, representing different parts of the decline to minimum of the solar cycle.

Early Fermi Gamma-ray Space Telescope Observations of the Quasar 3C454.3

Energy Technology Data Exchange (ETDEWEB)

Abdo, A

2009-05-07

This is the first report of Fermi Gamma-ray Space Telescope observations of the quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from the Large Area Telescope (LAT), covering 2008 July 7-October 6, indicate strong, highly variable {gamma}-ray emission with an average flux of {approx} 3 x 10{sup -6} photons cm{sup -2} s{sup -1}, for energies > 100 MeV. The {gamma}-ray flux is variable, with strong, distinct, symmetrically-shaped flares for which the flux increases by a factor of several on a time scale of about three days. This variability indicates a compact emission region, and the requirement that the source is optically thin to pair-production implies relativistic beaming with Doppler factor {delta} > 8, consistent with the values inferred from VLBI observations of superluminal expansion ({delta} {approx} 25). The observed {gamma}-ray spectrum is not consistent with a simple power-law, but instead steepens strongly above {approx} 2 GeV, and is well described by a broken power-law with photon indices of {approx} 2.3 and {approx} 3.5 below and above the break, respectively. This is the first direct observation of a break in the spectrum of a high luminosity blazar above 100 MeV, and it is likely direct evidence for an intrinsic break in the energy distribution of the radiating particles. Alternatively, the spectral softening above 2GeV could be due to -ray absorption via photonphoton pair production on the soft X-ray photon field of the host AGN, but such an interpretation would require the dissipation region to be located very close ({approx}< 100 gravitational radii) to the black hole, which would be inconsistent with the X-ray spectrum of the source.

Cosmic rays, solar activity and the climate

International Nuclear Information System (INIS)

Sloan, T; Wolfendale, A W

2013-01-01

Although it is generally believed that the increase in the mean global surface temperature since industrialization is caused by the increase in green house gases in the atmosphere, some people cite solar activity, either directly or through its effect on cosmic rays, as an underestimated contributor to such global warming. In this letter a simplified version of the standard picture of the role of greenhouse gases in causing the global warming since industrialization is described. The conditions necessary for this picture to be wholly or partially wrong are then introduced. Evidence is presented from which the contributions of either cosmic rays or solar activity to this warming is deduced. The contribution is shown to be less than 10% of the warming seen in the twentieth century. (letter)

FERMI LARGE AREA TELESCOPE OBSERVATION OF A GAMMA-RAY SOURCE AT THE POSITION OF ETA CARINAE

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Borgland, A. W.; Bouvier, A.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bonamente, E.; Brandt, T. J.; Brigida, M.; Bruel, P.

2010-01-01

The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope detected a γ-ray source that is spatially consistent with the location of Eta Carinae. This source has been persistently bright since the beginning of the LAT survey observations (from 2008 August to 2009 July, the time interval considered here). The γ-ray signal is detected significantly throughout the LAT energy band (i.e., up to ∼100 GeV). The 0.1-100 GeV energy spectrum is well represented by a combination of a cutoff power-law model ( 10 GeV). The total flux (>100 MeV) is 3.7 +0.3 -0.1 x 10 -7 photons s -1 cm -2 , with additional systematic uncertainties of 10%, and consistent with the average flux measured by AGILE. The light curve obtained by Fermi is consistent with steady emission. Our observations do not confirm the presence of a γ-ray flare in 2008 October, as reported by Tavani et al., although we cannot exclude that a flare lasting only a few hours escaped detection by the Fermi LAT. We also do not find any evidence for γ-ray variability that correlates with the large X-ray variability of Eta Carinae observed during 2008 December and 2009 January. We are thus not able to establish an unambiguous identification of the LAT source with Eta Carinae.

The Gamma-ray Sky with Fermi

Science.gov (United States)

Thompson, David

2012-01-01

Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

Cooling a solar telescope enclosure: plate coil thermal analysis

Science.gov (United States)

Gorman, Michael; Galapon, Chriselle; Montijo, Guillermo; Phelps, LeEllen; Murga, Gaizka

2016-08-01

The climate of Haleakalā requires the observatories to actively adapt to changing conditions in order to produce the best possible images. Observatories need to be maintained at a temperature closely matching ambient or the images become blurred and unusable. The Daniel K. Inouye Solar Telescope is a unique telescope as it will be active during the day as opposed to the other night-time stellar observatories. This means that it will not only need to constantly match the ever-changing temperature during the day, but also during the night so as not to sub-cool and affect the view field of other telescopes while they are in use. To accomplish this task, plate coil heat exchanger panels will be installed on the DKIST enclosure that are designed to keep the temperature at ambient temperature +0°C/-4°C. To verify the feasibility of this and to validate the design models, a test rig has been installed at the summit of Haleakalā. The project's purpose is to confirm that the plate coil panels are capable of maintaining this temperature throughout all seasons and involved collecting data sets of various variables including pressures, temperatures, coolant flows, solar radiations and wind velocities during typical operating hours. Using MATLAB, a script was written to observe the plate coil's thermal performance. The plate coil did not perform as expected, achieving a surface temperature that was generally 2ºC above ambient temperature. This isn't to say that the plate coil does not work, but the small chiller used for the experiment was undersized resulting in coolant pumped through the plate coil that was not supplied at a low enough temperature. Calculated heat depositions were about 23% lower than that used as the basis of the design for the hillers to be used on the full system, a reasonable agreement given the fact that many simplifying assumptions were used in the models. These were not carried over into the testing. The test rig performance showing a 23% margin

Ground-based VHE γ ray astronomy with air Cherenkov imaging telescopes

International Nuclear Information System (INIS)

Mirzoyan, R.

2000-01-01

The history of astronomy has been one of the scientific discovery following immediately the introduction of new technology. In this report, we will review shortly the basic development of the atmospheric air Cherenkov light detection technique, particularly the imaging telescope technique, which in the last years led to the firm establishment of a new branch in experimental astronomy, namely ground-based very high-energy (VHE) γ ray astronomy. Milestones in the technology and in the analysis of imaging technique will be discussed. The design of the 17 m diameter MAGIC Telescope, being currently under construction, is based on the development of new technologies for all its major parts and sets new standards in the performance of the ground-based γ detectors. MAGIC is one of the next major steps in the development of the technique being the first instrument that will allow one to carry out measurements also in the not yet investigated energy gap i.e. between 10 and 300 GeV

Solar cosmic rays in the system of solar terrestrial relations

Science.gov (United States)

Miroshnichenko, Leonty I.

2008-02-01

In this brief review, we discuss a number of geophysical effects of solar energetic particles (SEPs) or solar cosmic rays (SCR). We concentrate mainly on the observational evidence and proposed mechanisms of some expected effects and/or poor-studied phenomena discovered within the last three decades, in particular, depletion of the ozone layer, perturbations in the global electric current, effects on the winter storm vorticity, change of the atmospheric transparency and production of nitrates. Some "archaeological" data on SCR fluxes in the past and upper limit of total energy induced by SEPs are also discussed. Due attention is paid to the periodicities in the solar particle fluxes. Actually, many solar, heliospheric and terrestrial parameters changing generally in phase with the solar activity are subjected to a temporary depression close to the solar maximum ("Gnevyshev Gap"). A similar gap has been found recently in the yearly numbers of the >10 MeV proton events. All the above-mentioned findings are evidently of great importance in the studies of general proton emissivity of the Sun and long-term trends in the behaviour of solar magnetic fields. In addition, these data can be very helpful for elaborating the methods for prediction of the radiation conditions in space and for estimation of the SEPs' contribution to solar effects on the geosphere, their relative role in the formation of terrestrial weather and climate and in the problem of solar-terrestrial relations (STR) on the whole.

Discovery of Pulsed Gamma Rays from the Young Radio Pulsar PSR J1028-5819 with the Fermi Large Area Telescope

Energy Technology Data Exchange (ETDEWEB)

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Baring, Matthew G.; /Rice U.; Bastieri, Denis; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle; Caliandro, G.A.; /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /NASA, Goddard /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Trieste /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

2009-05-15

Radio pulsar PSR J1028-5819 was recently discovered in a high-frequency search (at 3.1 GHz) in the error circle of the Energetic Gamma-Ray Experiment Telescope (EGRET) source 3EG J1027-5817. The spin-down power of this young pulsar is great enough to make it very likely the counterpart for the EGRET source. We report here the discovery of {gamma}-ray pulsations from PSR J1028-5819 in early observations by the Large Area Telescope (LAT) on the Fermi Gamma-Ray Space Telescope. The {gamma}-ray light curve shows two sharp peaks having phase separation of 0.460 {+-} 0.004, trailing the very narrow radio pulse by 0.200 {+-} 0.003 in phase, very similar to that of other known {gamma}-ray pulsars. The measured {gamma}-ray flux gives an efficiency for the pulsar of {approx}10-20% (for outer magnetosphere beam models). No evidence of a surrounding pulsar wind nebula is seen in the current Fermi data but limits on associated emission are weak because the source lies in a crowded region with high background emission. However, the improved angular resolution afforded by the LAT enables the disentanglement of the previous COS-B and EGRET source detections into at least two distinct sources, one of which is now identified as PSR J1028-5819.

Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data

International Nuclear Information System (INIS)

Abdollahi, S.; Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.

2017-01-01

We present the Large Area Telescope on board the Fermi Gamma-ray Space Telescope that has collected the largest ever sample of high-energy cosmic-ray electron and positron events since the beginning of its operation. Potential anisotropies in the arrival directions of cosmic-ray electrons or positrons could be a signature of the presence of nearby sources. We use almost seven years of data with energies above 42 GeV processed with the Pass 8 reconstruction. The present data sample can probe dipole anisotropies down to a level of 10"-"3. We take into account systematic effects that could mimic true anisotropies at this level. We present a detailed study of the event selection optimization of the cosmic-ray electrons and positrons to be used for anisotropy searches. Since no significant anisotropies have been detected on any angular scale, we present upper limits on the dipole anisotropy. Lastly, the present constraints are among the strongest to date probing the presence of nearby young and middle-aged sources.

Pulsed Gamma-Rays From PSR J2021 3651 with the Fermi Large Area Telescope

Energy Technology Data Exchange (ETDEWEB)

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, Marco; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, William B.; /UC, Santa Cruz; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Battelino, Milan; /Royal Inst. Tech., Stockholm; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, Ronaldo; /INFN, Pisa; Berenji, Bijan; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bogaert, G.; /Ecole Polytechnique; Borgland, Anders W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Columbia U. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /IASF, Milan /IASF, Milan /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /LPCE, Orleans /Montpellier U. /Sonoma State U. /Royal Inst. Tech., Stockholm /Stockholm U. /ASI, Rome /NRAO, Charlottesville /Naval Research Lab, Wash., D.C. /INFN, Trieste /Pavia U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Manchester U. /Montpellier U. /Bari U. /INFN, Bari; /more authors..

2011-11-30

We report the detection of pulsed gamma-rays from the young, spin-powered radio pulsar PSR J2021+3651 using data acquired with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The light curve consists of two narrow peaks of similar amplitude separated by 0.468 {+-} 0.002 in phase. The first peak lags the maximum of the 2 GHz radio pulse by 0.162 {+-} 0.004 {+-} 0.01 in phase. The integral gamma-ray photon flux above 100 MeV is (56 {+-} 3 {+-} 11) x 10{sup -8} cm{sup -2} s{sup -1}. The photon spectrum is well-described by an exponentially cut-off power law of the form dF/dE = kE{sup -{Gamma}}e{sup (-E/E{sub c})} where the energy E is expressed in GeV. The photon index is {Gamma} = 1.5 {+-} 0.1 {+-} 0.1 and the exponential cut-off is E{sub c} = 2.4 {+-} 0.3 {+-} 0.5 GeV. The first uncertainty is statistical and the second is systematic. The integral photon flux of the bridge is approximately 10% of the pulsed emission, and the upper limit on off-pulse gamma-ray emission from a putative pulsar wind nebula is < 10% of the pulsed emission at the 95% confidence level. Radio polarization measurements yield a rotation measure of RM = 524 {+-} 4 rad m{sup -2} but a poorly constrained magnetic geometry. Re-analysis of Chandra data enhanced the significance of the weak X-ray pulsations, and the first peak is roughly phase-aligned with the first gamma-ray peak. We discuss the emission region and beaming geometry based on the shape and spectrum of the gamma-ray light curve combined with radio and X-ray measurements, and the implications for the pulsar distance. Gamma-ray emission from the polar cap region seems unlikely for this pulsar.

Calibration of the Nustar High-Energy Focusing X-Ray Telescope

DEFF Research Database (Denmark)

Madsen, Kristin K.; Harrison, Fiona A.; Markwardt, Craig B.

2015-01-01

We present the calibration of the Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray satellite. We used the Crab as the primary effective area calibrator and constructed a piece-wise linear spline function to modify the vignetting response. The achieved residuals for all off-axis angles...... and energies, compared to the assumed spectrum, are typically better than +/- 2% up to 40 keV and 5%-10% above due to limited counting statistics. An empirical adjustment to the theoretical two-dimensional point-spread function (PSF) was found using several strong point sources, and no increase of the PSF half-power...

Cosmic and solar gamma-ray x-ray and particle measurements from high altitude balloons in Antarctica

International Nuclear Information System (INIS)

Lin, R.P.

1990-01-01

For measurements of cosmic and solar gamma-rays, hard X-rays, and particles, Antarctica offers the potential for very long, 10--20 day, continuous, twenty-four-hour-a-day observations, with balloon flights circling the South Pole during austral summer. For X-ray/gamma-ray sources at high south latitude the overlying atmosphere is minimized, and for cosmic ray measurements the low geomagnetic cutoff permits entry of low rigidity particles. The first Antarctic flight of a heavy (∼2400 lb.) payload on a large (11.6x10 6 cu. ft.) balloon took place in January, 1988, to search for the gamma-ray lines of 56 Co produced in the new supernova SN 1987A in the Large Magellanic Cloud. The long duration balloon flights presently planned from Antarctica include those for further gamma-ray/hard X-ray studies of SN 1987A and for the NASA Max '91 program for solar flare studies

Quiet Sun X-rays as Signature for New Particles

CERN Document Server

Zioutas, Konstantin; Di Lella, L; Hoffmann, Dieter H H; Jacoby, J; Papaevangelou, T

2004-01-01

We have studied published data from the Yohkoh solar X-ray mission, with the purpose of searching for signals from radiative decays of new, as yet undiscovered massive neutral particles. This search is based on the prediction that solar axions of the Kaluza-Klein type should result in the emission of X-rays from the Sun direction beyond the limb with a characteristic radial distribution. These X-rays should be observed more easily during periods of quiet Sun. An additional signature is the observed emission of hard X-rays by SMM, NEAR and RHESSI. The recent observation made by RHESSI of a continuous emission from the non-flaring Sun of X-rays in the 3 to ~15 keV range fits the generic axion scenario. This work also suggests new analyses of existing data, in order to exclude instrumental effects; it provides the rationale for targeted observations with present and upcoming (solar) X-ray telescopes, which can provide the final answer on the nature of the signals considered here. Such measurements become more pr...

Multi-parametric Effect of Solar Activity on Cosmic Rays V. K. Mishra ...

Indian Academy of Sciences (India)

Key words. Sun—solar parameters—cosmic ray modulation—running ... Neutron monitors are most sensitive to cosmic rays in the energy range. 0.5–20 GeV ... been considered as a primary indicator to define the level of solar activity, which.

Detection of soft X-rays from α Lyrae and eta Bootis with an imaging X-ray telescope

International Nuclear Information System (INIS)

Topka, K.; Fabricant, D.; Harnden, F.R. Jr.; Gorenstein, P.; Rosner, R.

1979-01-01

Two nearby stars have been detected in the soft X-ray band with an imaging X-ray telescope flown aboard two sounding rockets. The exposure times were 4.8 and 4.5 s for the images of the AO V star α Lyrae (Vega) and the GO IV star eta Bootis, respectively. Laboratory measurements rule out the possibility that the observed signals were due to UV contamination. These X-ray observations imply luminosities of L/sub X/(0.2--0.8 keV) approx. =3 x 10 28 ergs s -1 for Vega and L/sub X/(0.15--1.5 keV) approx. =1 x 10 29 ergs s -1 for eta Boo. A coronal interpretation of the X-rays from Vega is in serious conflict with simple convective models for early-type main-sequence stars. Magnetic field activity may be responsible for heating the corona, as has been suggested for the Sun. In the case of eta Boo, a coronal interpretation is also favored; however, if the unseen companion of eta Boo is degenerate, the X-ray emission may instead originate in a stellar wind accreting upon a white dwarf or neutron star

The Dutch Open Telescope: History, Status, Prospects

NARCIS (Netherlands)

Rutten, R.J.

1999-01-01

After many years of persistent telescope design and telescope construction, R.H. Hammerschlag has installed his Dutch Open Telescope (DOT) on La Palma. I brie y review its history and design. The future of optical solar physics at Utrecht hinges on a recently-funded three- year DOT science

Exospheric Neutral Density at the Earth's subsolar magnetopause deduced from the XMM-Newton X-ray observations

Science.gov (United States)

Connor, H. K.; Carter, J. A.

2017-12-01

Soft X-rays can be emitted when highly charged solar wind ions and exospheric neutrals exchange electrons. Astrophysics missions, such as XMM-Newton and ROSAT X-ray telescopes, have found that such solar wind charge exchange happens at the Earth's exosphere. The Earth's magnetosphere can be imaged via soft X-rays in order to understand its interaction with solar wind. Consequently, two soft X-ray telescope missions (CuPID and SMILE) are scheduled to launch in 2019 and 2021. They will provide wide field-of-view soft X-ray images of the Earth's dayside magnetosphere. The imagers will track the location and movement of the cusps, magnetopause, and bow shock in response to solar wind variations. To support these missions, an understanding of exospheric neutral density profile is needed. The neutral density is one of the controlling factors of soft X-ray signals. Strong neutral density can help to obtain high-resolution and high-cadence of soft X-ray images. In this study, we estimate the exospheric neutral density at 10 RE subsolar point using XMM X-ray observations, Cluster plasma observations, and OpenGGCM global magnetosphere - ionosphere MHD model. XMM-Newton observes line-of-sight, narrow field-of-view, integrated soft X-ray emissions when it looks through the dayside magnetosphere. OpenGGCM reproduces soft X-ray signals seen by the XMM spacecraft, assuming exospheric neutral density as a function of the neutral density at the 10RE subsolar point and the radial distance. Cluster observations are used to confirm OpenGGCM plasma results. Finally, we deduce the neutral density at 10 RE subsolar point by adjusting the model results to the XMM-Newton soft X-ray observations.

Multitaper spectral analysis of cosmic rays Sao Martinho da Serra's muon telescope and Newark's neutron monitor data

Energy Technology Data Exchange (ETDEWEB)

Silva, Marlos Rockenbach da; Alarcon, Walter Demetrio Gonzalez; Echer, Ezequiel; Lago, Alisson dal; Lucas, Aline de [National Institute for Space Research - INPE-MCT, Sao Jose dos Campos, SP (Brazil); Vieira, Luis Eduardo Antunes; Guarnieri, Fernando Luis [Universidade do Vale do Paraiba - UNIVAP, Sao Jose dos Campos, SP (Brazil); Schuch, Nelson Jorge [Southern Regional Space Research Center - CRSPE/INPE-MCT, Santa Maria, RS (Brazil); Munakata, Kazuoki, E-mail: marlos@dge.inpe.br, E-mail: gonzalez@dge.inpe.br, E-mail: eecher@dge.inpe.br, E-mail: dallago@dge.inpe.br, E-mail: delucas@dge.inpe.br, E-mail: levieira@univap.br, E-mail: guarnieri@univap.br, E-mail: njschuch@lacesm.ufsm.br, E-mail: kmuna00@gipac.shinshu-u.ac.jp [Physics Department, Shinshu University, Matsumoto (Japan)

2007-07-01

In this work we present an analysis on the correction efficiency of atmospheric effects on cosmic ray Sao Martinho da Serra's muon telescope and Newark's neutron monitor data. We use a Multitaper spectral analysis of cosmic rays time series to show the main periodicities present in the corrected and uncorrected data for the atmospheric effects. This kind of correction is very important when intends to study cosmic rays variations of extra-terrestrial origin. (author)

Solar flare neon and solar cosmic ray fluxes in the past using gas-rich meteorites

International Nuclear Information System (INIS)

Nautiyal, C.M.; Rao, M.N.

1986-01-01

Methods were developed earlier to deduce the composition of solar flare neon and to determine the solar cosmic ray proton fluxes in the past using etched lunar samples and at present, these techniques are extended to gas rich meteorites. By considering high temperature Ne data points for Pantar, Fayetteville and other gas rich meteorites and by applying the three component Ne-decomposition methods, the solar cosmic ray and galactic cosmic ray produced spallation Ne components from the trapped SF-Ne was resolved. Using appropiate SCR and GCR production rates, in the case of Pantar, for example, a GCR exposure age of 2 m.y. was estimated for Pantar-Dark while Pantar-Light yielded a GCR age of approx. 3 m.y. However the SCR exposure age of Pantar-Dark is two orders of magnitude higher than the average surface exposure ages of lunar soils. The possibility of higher proton fluxes in the past is discussed

Common observations of solar X-rays from SPHINX/CORONAS-PHOTON and XRS/MESSENGER

Science.gov (United States)

Kepa, Anna; Sylwester, Janusz; Sylwester, Barbara; Siarkowski, Marek; Mrozek, Tomasz; Gryciuk, Magdalena; Phillips, Kenneth

SphinX was a soft X-ray spectrophotometer constructed in the Space Research Centre of Polish Academy of Sciences. The instrument was launched on 30 January 2009 aboard CORONAS-PHOTON satellite as a part of TESIS instrument package. SphinX measured total solar X-ray flux in the energy range from 1 to 15 keV during the period of very low solar activity from 20 February to 29 November 2009. For these times the solar detector (X-ray Spectrometer - XRS) onboard MESSENGER also observed the solar X-rays from a different vantage point. XRS measured the radiation in similar energy range. We present results of the comparison of observations from both instruments and show the preliminary results of physical analysis of spectra for selected flares.

Design and Initial Tests of the Tracker-Converter ofthe Gamma-ray Large Area Space Telescope

Energy Technology Data Exchange (ETDEWEB)

Atwood, W.B.; Bagagli, R.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Belli, F.; Borden, T.; Brez, A.; Brigida, M.; Caliandro, G.A.; Cecchi, C.; Cohen-Tanugi, J.; De; Drell, P.; Favuzzi, C.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Germani, S.; Giannitrapani, R.; Giglietto, N.; /UC, Santa Cruz /INFN, Pisa /Pisa U. /INFN, Trieste /INFN,

2007-04-16

The Tracker subsystem of the Large Area Telescope (LAT) science instrument of the Gamma-ray Large Area Space Telescope (GLAST) mission has been completed and tested. It is the central detector subsystem of the LAT and serves both to convert an incident gamma-ray into an electron-positron pair and to track the pair in order to measure the gamma-ray direction. It also provides the principal trigger for the LAT. The Tracker uses silicon strip detectors, read out by custom electronics, to detect charged particles. The detectors and electronics are packaged, along with tungsten converter foils, in 16 modular, high-precision carbon-composite structures. It is the largest silicon-strip detector system ever built for launch into space, and its aggressive design emphasizes very low power consumption, passive cooling, low noise, high efficiency, minimal dead area, and a structure that is highly transparent to charged particles. The test program has demonstrated that the system meets or surpasses all of its performance specifications as well as environmental requirements. It is now installed in the completed LAT, which is being prepared for launch in early 2008.

Cosmic ray modulation and radiation dose of aircrews during the solar cycle 24/25

Science.gov (United States)

Miyake, Shoko; Kataoka, Ryuho; Sato, Tatsuhiko

2017-04-01

Weak solar activity and high cosmic ray flux during the coming solar cycle are qualitatively anticipated by the recent observations that show the decline in the solar activity levels. We predict the cosmic ray modulation and resultant radiation exposure at flight altitude by using the time-dependent and three-dimensional model of the cosmic ray modulation. Our galactic cosmic ray (GCR) model is based on the variations of the solar wind speed, the strength of the heliospheric magnetic field, and the tilt angle of the heliospheric current sheet. We reproduce the 22 year variation of the cosmic ray modulation from 1980 to 2015 taking into account the gradient-curvature drift motion of GCRs. The energy spectra of GCR protons obtained by our model show good agreement with the observations by the Balloon-borne Experiment with a Superconducting magnetic rigidity Spectrometer (BESS) and the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) except for a discrepancy at the solar maximum. Five-year annual radiation dose around the solar minimum at the solar cycle 24/25 will be approximately 19% higher than that in the last cycle. This is caused by the charge sign dependence of the cosmic ray modulation, such as the flattop profiles in a positive polarity.

Radio Follow-up on All Unassociated Gamma-Ray Sources from the Third Fermi Large Area Telescope Source Catalog

Energy Technology Data Exchange (ETDEWEB)

Schinzel, Frank K. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Petrov, Leonid [Astrogeo Center, Falls Church, VA 22043 (United States); Taylor, Gregory B. [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States); Edwards, Philip G., E-mail: fschinze@nrao.edu [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, 1710 NSW (Australia)

2017-04-01

The third Fermi Large Area Telescope γ -ray source catalog (3FGL) contains over 1000 objects for which there is no known counterpart at other wavelengths. The physical origin of the γ -ray emission from those objects is unknown. Such objects are commonly referred to as unassociated and mostly do not exhibit significant γ -ray flux variability. We performed a survey of all unassociated γ -ray sources found in 3FGL using the Australia Telescope Compact Array and Very Large Array in the range 4.0–10.0 GHz. We found 2097 radio candidates for association with γ -ray sources. The follow-up with very long baseline interferometry for a subset of those candidates yielded 142 new associations with active galactic nuclei that are γ -ray sources, provided alternative associations for seven objects, and improved positions for another 144 known associations to the milliarcsecond level of accuracy. In addition, for 245 unassociated γ -ray sources we did not find a single compact radio source above 2 mJy within 3 σ of their γ -ray localization. A significant fraction of these empty fields, 39%, are located away from the Galactic plane. We also found 36 extended radio sources that are candidates for association with a corresponding γ -ray object, 19 of which are most likely supernova remnants or H ii regions, whereas 17 could be radio galaxies.

CrossRef The CERN Axion Solar Telescope

CERN Document Server

Hasinoff, M D; Arik, E; Autiero, D; Avignone, F; Barth, K; Bingol, E; Brauninger, H; Brodzinski, R; Carmona, J; Chesi, E; Cebrian, S; Cetin, S; Collar, J; Creswick, R; Dafni, T; De Oliveira, R; Dedoussis, S; Delbart, A; Di Lella, L; Eleftheriadis, C; Fanourakis, G; Farach, H; Fischer, H; Formenti, F; Geralis, T; Giomataris, I; Gninenko, S; Goloubev, N; Hartmann, R; Hoffmann, D; Irastorza, I G; Jacoby, J; Kang, D; Konigsmann, K; Kotthaus, R; Krcmar, M; Kuster, M; Lakic, B; Liolios, A; LJubicic, A; Lutz, G; Luzon, G; Miley, H; Morales, A; Morales, J; Mutterer, M; Nikolaidis, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Riege, H; Sarsa, M; Savvidis, I; Schopper, R; Semertzidis, I; Spano, C; Villar, J; Vullierme, B; Walckiers, L; Zachariadou, K; Zioutas, K

2003-01-01

The CAST experiment at CERN is using a decommissioned LHC prototype magnet to search for solar axions through their Primakoff conversion into x-ray photons. The magnet (B = 9.0 Tesla, L = 10 m) can track the sun each day for a total exposure time of ~180 minutes (sunrise + sunset). We expect to reach a sensitivity in axion-photon coupling, gaγγ ≲ 5 × 10-11 GeV-1 for ma ≲ 10-2 eV after ˜1 year's running time. By filling the beam tube with 4He or 3He gas we should be able to extend the sensitive axion mass region into the eV mass range.

Lower Ionosphere Sensitivity to Solar X-ray Flares Over a Complete Solar Cycle Evaluated From VLF Signal Measurements

Science.gov (United States)

Macotela, Edith L.; Raulin, Jean-Pierre; Manninen, Jyrki; Correia, Emília; Turunen, Tauno; Magalhães, Antonio

2017-12-01

The daytime lower ionosphere behaves as a solar X-ray flare detector, which can be monitored using very low frequency (VLF) radio waves that propagate inside the Earth-ionosphere waveguide. In this paper, we infer the lower ionosphere sensitivity variation over a complete solar cycle by using the minimum X-ray fluence (FXmin) necessary to produce a disturbance of the quiescent ionospheric conductivity. FXmin is the photon energy flux integrated over the time interval from the start of a solar X-ray flare to the beginning of the ionospheric disturbance recorded as amplitude deviation of the VLF signal. FXmin is computed for ionospheric disturbances that occurred in the time interval of December-January from 2007 to 2016 (solar cycle 24). The computation of FXmin uses the X-ray flux in the wavelength band below 0.2 nm and the amplitude of VLF signals transmitted from France (HWU), Turkey (TBB), and U.S. (NAA), which were recorded in Brazil, Finland, and Peru. The main result of this study is that the long-term variation of FXmin is correlated with the level of solar activity, having FXmin values in the range (1 - 12) × 10-7 J/m2. Our result suggests that FXmin is anticorrelated with the lower ionosphere sensitivity, confirming that the long-term variation of the ionospheric sensitivity is anticorrelated with the level of solar activity. This result is important to identify the minimum X-ray fluence that an external source of ionization must overcome in order to produce a measurable ionospheric disturbance during daytime.

FERMI LARGE AREA TELESCOPE CONSTRAINTS ON THE GAMMA-RAY OPACITY OF THE UNIVERSE

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bouvier, A.; Atwood, W. B.; Baldini, L.; Bellazzini, R.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Baughman, B. M.; Bhat, P. N.; Bonamente, E.

2010-01-01

The extragalactic background light (EBL) includes photons with wavelengths from ultraviolet to infrared, which are effective at attenuating gamma rays with energy above ∼10 GeV during propagation from sources at cosmological distances. This results in a redshift- and energy-dependent attenuation of the γ-ray flux of extragalactic sources such as blazars and gamma-ray bursts (GRBs). The Large Area Telescope on board Fermi detects a sample of γ-ray blazars with redshift up to z ∼ 3, and GRBs with redshift up to z ∼ 4.3. Using photons above 10 GeV collected by Fermi over more than one year of observations for these sources, we investigate the effect of γ-ray flux attenuation by the EBL. We place upper limits on the γ-ray opacity of the universe at various energies and redshifts and compare this with predictions from well-known EBL models. We find that an EBL intensity in the optical-ultraviolet wavelengths as great as predicted by the 'baseline' model of Stecker et al. can be ruled out with high confidence.

SphinX MEASUREMENTS OF THE 2009 SOLAR MINIMUM X-RAY EMISSION

OpenAIRE

Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Kuzin, S.; Farnik, F.; Reale, F.; Phillips, K. J. H.; Bakala, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B.

2012-01-01

The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 x 10^47 cm^-3 and 1.1 x 10^48 cm^-3. Comparing Sph...

Gamma-ray burst observations with new generation imaging atmospheric Cerenkov Telescopes in the FERMI era

International Nuclear Information System (INIS)

Covino, S.; Campana, S.; Garczarczyk, M.; Galante, N.; Gaug, M.; Antonelli, A.; Bastieri, D.; Longo, F.; Scapin, V.

2009-01-01

After the launch and successful beginning of operations of the FERMI satellite, the topics related to high-energy observations of gamma-ray bursts have obtained a considerable attention by the scientific community. Undoubtedly, the diagnostic power of high-energy observations in constraining the emission processes and the physical conditions of gamma-ray burst is relevant. We briefly discuss how gamma-ray burst observations with ground-based imaging array Cerenkov telescopes, in the GeV-TeV range, can compete and cooperate with FERMI observations, in the MeV-GeV range, to allow researchers to obtain a more detailed and complete picture of the prompt and afterglow phases of gamma-ray bursts.

Impulsive behavior in solar soft X-radiation

Science.gov (United States)

Hudson, H. S.; Strong, K. T.; Dennis, B. R.; Zarro, D.; Inda, M.; Kosugi, T.; Sakao, T.

1994-01-01

The Yohkoh soft X-ray telescope has observed impulsive, thermal, soft X-ray emission at the footpoints of magnetic loops during solar flares. The soft X-ray (thermal) time profiles at the footpoints closely match the hard X-ray (nonthermal) time profiles, directly demonstrating the heating of the lower solar atmosphere on short timescales during the interval of nonthermal energy release. This phenomenon is the rule, rather than the exception, occurring in the majority of flares that we have examined with the Yohkoh data. We illustrate the impulsive behavior with data from the major flare of 1992 January 26. For this flare, the soft X-ray peak times matched the hard X-ray peak times within the time resolution of the soft X-ray measurements (about 10 s), and the soft and hard X-ray locations match within the resolution of the hard X-ray imager. The impulsive soft X-ray emission clearly has a thermal spectral signature, but not at the high temperature of a 'superhot' source. We conclude that the impulsive soft X-ray emission comes from material heated by precipitating electrons at loop footpoints and evaporating from the deeper atmosphere into the flaring flux tube.

OPTICAL SPECTROSCOPIC OBSERVATIONS OF GAMMA-RAY BLAZAR CANDIDATES. VI. FURTHER OBSERVATIONS FROM TNG, WHT, OAN, SOAR, AND MAGELLAN TELESCOPES

Energy Technology Data Exchange (ETDEWEB)

Álvarez Crespo, N.; Massaro, F. [Dipartimento di Fisica, Università degli Studi di Torino, via Pietro Giuria 1, I-10125 Torino (Italy); Milisavljevic, D.; Paggi, A.; Smith, Howard A. [Harvard—Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Landoni, M. [INAF-Osservatorio Astronomico di Brera, Via Emilio Bianchi 46, I-23807 Merate (Italy); Chavushyan, V.; Patiño-Álvarez, V. [Instituto Nacional de Astrofísica, Óptica y Electrónica, Apartado Postal 51-216, 72000 Puebla, México (Mexico); Masetti, N. [INAF—Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna, via Gobetti 101, I-40129, Bologna (Italy); Jiménez-Bailón, E. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. Postal 877, Ensenada, 22800 Baja California, México (Mexico); Strader, J.; Chomiuk, L. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Katagiri, H.; Kagaya, M. [College of Science, Ibaraki University, 2-1-1, Bunkyo, Mito 310-8512 (Japan); Cheung, C. C. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); D’Abrusco, R. [Department of Physical Sciences, University of Napoli Federico II, via Cinthia 9, I-80126 Napoli (Italy); Ricci, F.; La Franca, F. [Dipartimento di Matematica e Fisica, Università Roma Tre, via della Vasca Navale 84, I-00146, Roma (Italy); and others

2016-04-15

Blazars, one of the most extreme classes of active galaxies, constitute so far the largest known population of γ-ray sources, and their number is continuously growing in the Fermi catalogs. However, in the latest release of the Fermi catalog there is still a large fraction of sources that are classified as blazar candidates of uncertain type (BCUs) for which optical spectroscopic observations are necessary to confirm their nature and their associations. In addition, about one-third of the γ-ray point sources listed in the Third Fermi-LAT Source Catalog (3FGL) are still unassociated and lacking an assigned lower-energy counterpart. Since 2012 we have been carrying out an optical spectroscopic campaign to observe blazar candidates to confirm their nature. In this paper, the sixth of the series, we present optical spectroscopic observations for 30 γ-ray blazar candidates from different observing programs we carried out with the Telescopio Nazionale Galileo, William Herschel Telescope, Observatorio Astronómico Nacional, Southern Astrophysical Research Telescope, and Magellan Telescopes. We found that 21 out of 30 sources investigated are BL Lac objects, while the remaining targets are classified as flat-spectrum radio quasars showing the typical broad emission lines of normal quasi-stellar objects. We conclude that our selection of γ-ray blazar candidates based on their multifrequency properties continues to be a successful way to discover potential low-energy counterparts of the Fermi unidentified gamma-ray sources and to confirm the nature of BCUs.

The Gamma-ray Universe through Fermi

Science.gov (United States)

Thompson, David J.

2012-01-01

Gamma rays, the most powerful form of light, reveal extreme conditions in the Universe. The Fermi Gamma-ray Space Telescope and its smaller cousin AGILE have been exploring the gamma-ray sky for several years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge ga.nuna-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

GOES-12 Solar X-ray Imager Archive

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The GOES Solar X-ray Imager is integrated into the GOES-12 satellite, whose primary mission is to provide Earth-weather monitoring. The SXI is operated by NOAA's...

Rotation of the Earth, solar activity and cosmic ray intensity

Energy Technology Data Exchange (ETDEWEB)

Barlyaeva, T.; Bard, E. [Aix-Marseille Univ., CNRS, IRD, Aix-en-Provence (France). CEREGE, College de France; Abarca-del-Rio, R. [Universidad de Concepcion (UDEC) (Chile). Dept. de Geofisica (DGEO)

2014-10-01

We analyse phase lags between the 11-year variations of three records: the semi-annual oscillation of the length of day (LOD), the solar activity (SA) and the cosmic ray intensity (CRI). The analysis was done for solar cycles 20-23. Observed relationships between LOD, CRI and SA are discussed separately for even and odd solar cycles. Phase lags were calculated using different methods (comparison of maximal points of cycles, maximal correlation coefficient, line of synchronization of cross-recurrence plots). We have found different phase lags between SA and CRI for even and odd solar cycles, confirming previous studies. The evolution of phase lags between SA and LOD as well as between CRI and LOD shows a positive trend with additional variations of phase lag values. For solar cycle 20, phase lags between SA and CRI, between SA and LOD, and between CRI and LOD were found to be negative. Overall, our study suggests that, if anything, the length of day could be influenced by solar irradiance rather than by cosmic rays.

Rotation of the Earth, solar activity and cosmic ray intensity

International Nuclear Information System (INIS)

Barlyaeva, T.; Bard, E.

2014-01-01

We analyse phase lags between the 11-year variations of three records: the semi-annual oscillation of the length of day (LOD), the solar activity (SA) and the cosmic ray intensity (CRI). The analysis was done for solar cycles 20-23. Observed relationships between LOD, CRI and SA are discussed separately for even and odd solar cycles. Phase lags were calculated using different methods (comparison of maximal points of cycles, maximal correlation coefficient, line of synchronization of cross-recurrence plots). We have found different phase lags between SA and CRI for even and odd solar cycles, confirming previous studies. The evolution of phase lags between SA and LOD as well as between CRI and LOD shows a positive trend with additional variations of phase lag values. For solar cycle 20, phase lags between SA and CRI, between SA and LOD, and between CRI and LOD were found to be negative. Overall, our study suggests that, if anything, the length of day could be influenced by solar irradiance rather than by cosmic rays.

Optical imaging of gamma-ray bursts with the LONEOS telescope

International Nuclear Information System (INIS)

Wagner, R.M.; Bowell, E.; Koehn, B.W.; Cook, K.H.; Howell, S.B.; Shrader, C.R.; Starrfield, S.G.; Stubbs, C.W.

1998-01-01

The optical identification of gamma-ray bursts discovered and localized by BACODINE/LOCBURST using the Lowell Observatory Near-Earth Object Search (LONEOS) 58-cm Schmidt-type telescope and mosaic CCD camera is described. In its final form, LONEOS images 10 square degrees of the sky (3.2 degree x3.2 degree) to ∼22nd mag (2σ) in a 5 minute integration. Identification of optical transients will be based on variability by comparison with subsequent images or previous scans of the region. To date, optical images have been obtained of three BATSE triggers processed by LOCBURST for development and evaluation purposes. copyright 1998 American Institute of Physics

Solar Effects on Tensile and Optical Properties of Hubble Space Telescope Silver-Teflon(Registered Trademark) Insulation

Science.gov (United States)

deGroh, Kim, K.; Dever, Joyce A.; Snyder, Aaron; Kaminski, Sharon; McCarthy, Catherine E.; Rapoport, Alison L.; Rucker, Rochelle N.

2006-01-01

A section of the retrieved Hubble Space Telescope (HST) solar array drive arm (SADA) multilayer insulation (MLI), which experienced 8.25 years of space exposure, was analyzed for environmental durability of the top layer of silver-Teflon (DuPont) fluorinated ethylene propylene (Ag-FEP). Because the SADA MLI had solar and anti-solar facing surfaces and was exposed to the space environment for a long duration, it provided a unique opportunity to study solar effects on the environmental degradation of Ag-FEP, a commonly used spacecraft thermal control material. Data obtained included tensile properties, solar absorptance, surface morphology and chemistry. The solar facing surface was found to be extremely embrittled and contained numerous through-thickness cracks. Tensile testing indicated that the solar facing surface lost 60% of its mechanical strength and 90% of its elasticity while the anti-solar facing surface had ductility similar to pristine FEP. The solar absorptance of both the solar facing surface (0.155 plus or minus 0.032) and the anti-solar facing surface (0.208 plus or minus 0.012) were found to be greater than pristine Ag-FEP (0.074). Solar facing and anti-solar facing surfaces were microscopically textured, and locations of isolated contamination were present on the anti-solar surface resulting in increased localized texturing. Yet, the overall texture was significantly more pronounced on the solar facing surface indicating a synergistic effect of combined solar exposure and increased heating with atomic oxygen erosion. The results indicate a very strong dependence of degradation, particularly embrittlement, upon solar exposure with orbital thermal cycling having a significant effect.

Comparison of nonflare solar soft x ray flux with 10.7-cm radio flux

International Nuclear Information System (INIS)

Donnelly, R.F.

1982-01-01

The similarities and differences of the nonflare solar 1- to 8-A X ray flux and the daily 10.7-cm Ottawa solar radio flux are examined. The radio flux is shown to be much less sensitive than the soft X ray flux on the average to the coronal emission of active regions located near or beyond the solar chromospheric limb relative to regions near the center of the solar disk. This is caused by the solar soft X ray emission's being optically thin while much of the 10.7-cm active region emission is from optical depths of tauapprox.1. The radio flux includes a large quiet sun flux which is emitted mostly from the tenuous chromosphere-corona transition region (Tapprox.10 4 --10 6 0 K) and partly from the cooler portions of the quiet corona Tapprox.1.5 x 10 6 0 K. Conversely, the solar soft X ray flux has a very small quiet sun component

A Design of Solar Proton Telescope for Next Generation Small Satellite

Directory of Open Access Journals (Sweden)

Jongdae Sohn

2012-12-01

Full Text Available The solar proton telescope (SPT is considered as one of the scientific instruments to be installed in instruments for the study of space storm (ISSS which is determined for next generation small satellite-1 (NEXTSat-1. The SPT is the instrument that acquires the information on energetic particles, especially the energy and flux of proton, according to the solar activity in the space radiation environment. We performed the simulation to determine the specification of the SPT using geometry and tracking 4 (GEANT4. The simulation was performed in the range of 0.6-1,000 MeV considering that the proton, which is to be detected, corresponds to the high energy region according to the solar activity in the space radiation environment. By using aluminum as a blocking material and adjusting the energy detection range, we determined total 7 channels (0.6~5, 5~10, 10~20, 20~35, 35~52, 52~72, and >72 MeV for the energy range of SPT. In the SPT, the proton energy was distinguished using linear energy transfer to compare with or discriminate from relativistic electron for the channels P1-P3 which are the range of less than 20 MeV, and above those channels, the energy was determined on the basis of whether silicon semiconductor detector (SSD signal can pass or not. To determine the optimal channel, we performed the conceptual design of payload which uses the SSD. The designed SPT will improve the understanding on the capture and decline of solar energetic particles at the radiation belt by measuring the energetic proton.

Great microwave bursts and hard X-rays from solar flares

International Nuclear Information System (INIS)

Wiehl, H.J.; Batchelor, D.A.; Crannell, C.J.; Dennis, B.R.; Price, P.N.

1983-06-01

The microwave and hard X-ray charateristics of 13 solar flares that produced microwave fluxes greater than 500 Solar Flux Units were analyzed. These Great Microwave Bursts were observed in the frequency range from 3 to 35 GHz at Berne, and simultaneous hard X-ray observations were made in the energy range from 30 to 500 keV with the Hard X-Ray Burst Spectrometer on the Solar Maximum Mission spacecraft. The principal aim of this analysis is to determine whether or not the same distribution of energetic electrons can explain both emissions. Correlations were found between respective temporal characteristics and, for the first time, between microwave and hard X-ray spectral characteristics. A single-temperature and a multi-temperature model from the literature were tested for consistency with the coincident X-ray and microwave spectra at microwave burst maximum. Four events are inconsistent with both of the models tested, and neither of the models attempts to explain the high-frequency part of the microwave spectrum. A model in which the emissions above and below the peak frequency originate in two different parts of a diverging magnetic loop is proposed. With this model the entire microwave spectrum of all but one of the events is explained

The background counting rates in a balloon borne hard X-ray telescope

International Nuclear Information System (INIS)

Dean, A.J.; Dipper, N.A.; Lewis, R.A.

1986-01-01

A detailed Monte Carlo model of a hard (20-300 keV) X-ray astronomical telescope has been developed in order to calculate the energy loss distribution of the unwanted background noise events in the prime detection elements. The spectral distributions of the background rates measured at balloon altitudes over Palestine, Texas are compared to the predictions of the theoretical model. Good agreement has been found in terms of both the overall intensity level as well as the spectral distribution. (orig.)

Infrared spectro-polarimeter on the Solar Flare Telescope at NAOJ/Mitaka

Science.gov (United States)

Sakurai, Takashi; Hanaoka, Yoichiro; Arai, Takehiko; Hagino, Masaoki; Kawate, Tomoko; Kitagawa, Naomasa; Kobiki, Toshihiko; Miyashita, Masakuni; Morita, Satoshi; Otsuji, Ken'ichi; Shinoda, Kazuya; Suzuki, Isao; Yaji, Kentaro; Yamasaki, Takayuki; Fukuda, Takeo; Noguchi, Motokazu; Takeyama, Norihide; Kanai, Yoshikazu; Yamamuro, Tomoyasu

2018-05-01

An infrared spectro-polarimeter installed on the Solar Flare Telescope at the Mitaka headquarters of the National Astronomical Observatory of Japan is described. The new spectro-polarimeter observes the full Sun via slit scans performed at two wavelength bands, one near 1565 nm for a Zeeman-sensitive spectral line of Fe I and the other near 1083 nm for He I and Si I lines. The full Stokes profiles are recorded; the Fe I and Si I lines give information on photospheric vector magnetic fields, and the helium line is suitable for deriving chromospheric magnetic fields. The infrared detector we are using is an InGaAs camera with 640 × 512 pixels and a read-out speed of 90 frames s-1. The solar disk is covered by two swaths (the northern and southern hemispheres) of 640 pixels each. The final magnetic maps are made of 1200 × 1200 pixels with a pixel size of 1{^''.}8. We have been carrying out regular observations since 2010 April, and have provided full-disk, full-Stokes maps, at the rate of a few maps per day, on the internet.

Solar X-ray Spectrometer (SOXS) Mission – Low Energy Payload ...

Indian Academy of Sciences (India)

Solar X-ray Spectrometer (SOXS)' mission, which was launched onboard GSAT-2 Indian spacecraft on 08 May 2003 by GSLV-D2 rocket to study the solar flares. The SOXS Low Energy Detector (SLD) payload was designed, developed and ...

The James Webb Space Telescope's Plan for Operations and Instrument Capabilities for Observations in the Solar System

Science.gov (United States)

Milam, Stefanie N.; Stansberry, John A.; Sonneborn, George; Thomas, Cristina

2016-01-01

The James Webb Space Telescope (JWST) is optimized for observations in the near- and mid-infrared and will provide essential observations for targets that cannot be conducted from the ground or other missions during its lifetime. The state-of-the-art science instruments, along with the telescope's moving target tracking, will enable the infrared study, with unprecedented detail, for nearly every object (Mars and beyond) in the Solar System. The goals of this special issue are to stimulate discussion and encourage participation in JWST planning among members of the planetary science community. Key science goals for various targets, observing capabilities for JWST, and highlights for the complementary nature with other missions/observatories are described in this paper.

Gamma-ray observations of the Orion Molecular Clouds with the Fermi Large Area Telescope

Energy Technology Data Exchange (ETDEWEB)

Ackermann, M.; Ajello, M.; Allafort, A.; Antolini, E.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cecchi, C.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; D' Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C. D.; do Couto e Silva, E.; Drell, P. S.; Drlica-Wagner, A.; Enoto, T.; Falletti, L.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fukazawa, Y.; Fukui, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hayashi, K.; Horan, D.; Hou, X.; Hughes, R. E.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kerr, M.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Lee, S. -H.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Makishima, K.; Mazziotta, M. N.; Mehault, J.; Mitthumsiri, W.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Naumann-Godo, M.; Nishino, S.; Norris, J. P.; Nuss, E.; Ohno, M.; Ohsugi, T.; Okumura, A.; Orienti, M.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Razzano, M.; Reimer, A.; Reimer, O.; Roth, M.; Sadrozinski, H. F. -W.; Sgrò, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Strong, A. W.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Tibolla, O.; Tinivella, M.; Torres, D. F.; Tramacere, A.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Zimmer, S.

2012-08-08

We report on the gamma-ray observations of giant molecular clouds Orion A and B with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. The gamma-ray emission in the energy band between ~100 MeV and ~100 GeV is predicted to trace the gas mass distribution in the clouds through nuclear interactions between the Galactic cosmic rays (CRs) and interstellar gas. The gamma-ray production cross-section for the nuclear interaction is known to ~10% precision which makes the LAT a powerful tool to measure the gas mass column density distribution of molecular clouds for a known CR intensity. We present here such distributions for Orion A and B, and correlate them with those of the velocity-integrated CO intensity (W CO) at a 1° × 1° pixel level. The correlation is found to be linear over a W CO range of ~10-fold when divided in three regions, suggesting penetration of nuclear CRs to most of the cloud volumes. The W CO-to-mass conversion factor, X CO, is found to be ~2.3 × 10²⁰ cm^-2(K km s^–1)^–1 for the high-longitude part of Orion A (l > 212°), ~1.7 times higher than ~1.3 × 10²⁰ found for the rest of Orion A and B. We interpret the apparent high X CO in the high-longitude region of Orion A in the light of recent works proposing a nonlinear relation between H2 and CO densities in the diffuse molecular gas. W _CO decreases faster than the H₂ column density in the region making the gas "darker" to W CO.

UBAT of UFFO/Lomonosov: The X-Ray Space Telescope to Observe Early Photons from Gamma-Ray Bursts

DEFF Research Database (Denmark)

Jeong, S.; Panasyuk, M. I.; Reglero, V.

2018-01-01

. To estimate a direction vector of a GRB source in its field of view, it employs the well-known coded aperture mask technique. All functions are written for implementation on a field programmable gate array to enable fast triggering and to run the device’s imaging algorithms. The UFFO/Lomonosov satellite...... was launched on April 28, 2016, and is now collecting GRB observation data. In this study, we describe the UBAT’s design, fabrication, integration, and performance as a GRB X-ray trigger and localization telescope, both on the ground and in space....

FARIMA MODELING OF SOLAR FLARE ACTIVITY FROM EMPIRICAL TIME SERIES OF SOFT X-RAY SOLAR EMISSION

International Nuclear Information System (INIS)

Stanislavsky, A. A.; Burnecki, K.; Magdziarz, M.; Weron, A.; Weron, K.

2009-01-01

A time series of soft X-ray emission observed by the Geostationary Operational Environment Satellites from 1974 to 2007 is analyzed. We show that in the solar-maximum periods the energy distribution of soft X-ray solar flares for C, M, and X classes is well described by a fractional autoregressive integrated moving average model with Pareto noise. The model incorporates two effects detected in our empirical studies. One effect is a long-term dependence (long-term memory), and another corresponds to heavy-tailed distributions. The parameters of the model: self-similarity exponent H, tail index α, and memory parameter d are statistically stable enough during the periods 1977-1981, 1988-1992, 1999-2003. However, when the solar activity tends to minimum, the parameters vary. We discuss the possible causes of this evolution and suggest a statistically justified model for predicting the solar flare activity.

The radial distribution of cosmic rays in the heliosphere at solar maximum

Science.gov (United States)

McDonald, F. B.; Fujii, Z.; Heikkila, B.; Lal, N.

2003-08-01

To obtain a more detailed profile of the radial distribution of galactic (GCRs) and anomalous (ACRs) cosmic rays, a unique time in the 11-year solar activity cycle has been selected - that of solar maximum. At this time of minimum cosmic ray intensity a simple, straight-forward normalization technique has been found that allows the cosmic ray data from IMP 8, Pioneer 10 (P-10) and Voyagers 1 and 2 (V1, V2) to be combined for the solar maxima of cycles 21, 22 and 23. This combined distribution reveals a functional form of the radial gradient that varies as G 0/r with G 0 being constant and relatively small in the inner heliosphere. After a transition region between ˜10 and 20 AU, G 0 increases to a much larger value that remains constant between ˜25 and 82 AU. This implies that at solar maximum the changes that produce the 11-year modulation cycle are mainly occurring in the outer heliosphere between ˜15 AU and the termination shock. These observations are not inconsistent with the concept that Global Merged Interaction. regions (GMIRs) are the principal agent of modulation between solar minimum and solar maximum. There does not appear to be a significant change in the amount of heliosheath modulation occurring between the 1997 solar minimum and the cycle 23 solar maximum.

Observations of recurrent cosmic ray decreases during solar cycles 22 and 23

International Nuclear Information System (INIS)

Dunzlaff, P.; Heber, B.; Kopp, A.; Rother, O.; Mueller-Mellin, R.; Klassen, A.; Gomez-Herrero, R.; Wimmer-Schweingruber, R.

2008-01-01

During solar cycle 22, the modulation of several hundred MeV galactic cosmic rays (GCRs) by recurrent and transient cosmic ray decreases was observed by the Ulysses spacecraft on its descent towards the solar south pole. In solar cycle 23, Ulysses repeated this trajectory segment during a similar phase of the solar cycle, but with opposite heliospheric magnetic field polarity. Since cosmic ray propagation in the heliosphere should depend on drift effects, we determine in this study the latitudinal distribution of the amplitude of recurrent cosmic ray decreases in solar cycles 22 and 23. As long as we measure the recurrent plasma structures in situ, we find that these decreases behave nearly the same in both cycles. Measurements in the fast solar wind, however, show differences: in cycle 22 (A>0) the recurrent cosmic ray decreases show a clear maximum near 25 and are still present beyond 40 , whereas we see in cycle 23 (A<0) neither such a pronounced maximum nor significant decreases above 40 . In other words: the periodicity in the cosmic ray intensity, which can be clearly seen in the slow solar wind, appears to vanish there. Theoretical models for drift effects, however, predict quite the opposite behaviour for the two solar cycles. To closer investigate this apparent contradiction, we first put the visual inspection of the data onto a more solid basis by performing a detailed Lomb (spectral) analysis. The next step consists of an analysis of the resulting periodicities at 1 AU in order to distinguish between spatial and temporal variations, so that we can obtain statements about the question in how far there is a correlation between the in-situ data at 1 AU and those measured by Ulysses at larger latitudes. We find a good correlation being present during cycle 22, but not for cycle 23. As one potential explanation for this behaviour, we suggest the difference in the coronal hole structures between the cycles 22 and 23 due to a large, stable coronal hole

Method of separation of celestial gamma-ray bursts from solar flares

International Nuclear Information System (INIS)

Chuang, K.W.; White, R.S.; Klebesadel, R.W.; Laros, J.G.

1991-01-01

We recently discovered 217 ''new'' celestial gamma-ray burst candidates from the ''new'' burst search of the PVO real time data base. 1 The burst search covered the time period from September 1978 to July 1988. Sixty were confirmed by at lest on other spacecraft, e.g., ISEE-3, V-11, V-12, etc. None triggered the PVO high time resolution memory. In this paper we describe a new algorithm based ont eh relationship between time width T w and hardness ratio HR, to distinguish cosmic gamma-ray bursts from solar flares without knowing the directions of the events. The criteria for identification as a gamma-ray burst candidate are: If T ww ≤a then HR≥bT w , or T w >a then HR>c. Otherwise, the event is a solar flare candidate. Here, a, b, and c are parameter which differ for different gamma-ray burst detectors. For PVO, a=18.8 s, b=(1.38/18.8) s -1 , and c=1.38. This algorithm was tested with 83 triggered and 60 nontriggered confirmed gamma-ray burst and 30 confirmed solar flares from PVO

Long-lived sources of solar cosmic rays

International Nuclear Information System (INIS)

Mullan, D.J.

1979-01-01

The high correlation between prompt solar cosmic rays and a flare-induced MHD shock is well known. We point out that the propagation properties of such a shock cause shock heating of the solar atmosphere to be confined to a unipolar magnetic region. As a result, if particles can be accelerated within the shock-processed part of the corona, the fluxes of suc particles will exhibit sharp spatial gradients near quiescent filaments. The passage of an MHD shock leads to the rapid collapse of magnetic neutral regions which prior to shock passage were collapsing too slowly to accelerate particles. We suggest that these newly triggered magnetic acceleration regions provide a third phase of solar flare acceleration regions provide a third phase of solar flare acceleration which may persist for many days after a flare. Collapsing magnetic regions with lengths scales of order 100 km can explain a variety of coronal phenomena

A Compressed Sensing-based Image Reconstruction Algorithm for Solar Flare X-Ray Observations

Energy Technology Data Exchange (ETDEWEB)

Felix, Simon; Bolzern, Roman; Battaglia, Marina, E-mail: simon.felix@fhnw.ch, E-mail: roman.bolzern@fhnw.ch, E-mail: marina.battaglia@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland FHNW, 5210 Windisch (Switzerland)

2017-11-01

One way of imaging X-ray emission from solar flares is to measure Fourier components of the spatial X-ray source distribution. We present a new compressed sensing-based algorithm named VIS-CS, which reconstructs the spatial distribution from such Fourier components. We demonstrate the application of the algorithm on synthetic and observed solar flare X-ray data from the Reuven Ramaty High Energy Solar Spectroscopic Imager satellite and compare its performance with existing algorithms. VIS-CS produces competitive results with accurate photometry and morphology, without requiring any algorithm- and X-ray-source-specific parameter tuning. Its robustness and performance make this algorithm ideally suited for the generation of quicklook images or large image cubes without user intervention, such as for imaging spectroscopy analysis.

A Compressed Sensing-based Image Reconstruction Algorithm for Solar Flare X-Ray Observations

Science.gov (United States)

Felix, Simon; Bolzern, Roman; Battaglia, Marina

2017-11-01

One way of imaging X-ray emission from solar flares is to measure Fourier components of the spatial X-ray source distribution. We present a new compressed sensing-based algorithm named VIS_CS, which reconstructs the spatial distribution from such Fourier components. We demonstrate the application of the algorithm on synthetic and observed solar flare X-ray data from the Reuven Ramaty High Energy Solar Spectroscopic Imager satellite and compare its performance with existing algorithms. VIS_CS produces competitive results with accurate photometry and morphology, without requiring any algorithm- and X-ray-source-specific parameter tuning. Its robustness and performance make this algorithm ideally suited for the generation of quicklook images or large image cubes without user intervention, such as for imaging spectroscopy analysis.

Inferred Cosmic-Ray Spectrum from Fermi Large Area Telescope γ-Ray Observations of Earth’s Limb

Energy Technology Data Exchange (ETDEWEB)

Ackermann, M.; et al.

2014-04-17

Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly-discovered features may offer a clue to the origin of high-energy CRs. We use the ${\\it Fermi}$ Large Area Telescope observations of the $\\gamma$-ray emission from the Earth's limb for an indirect measurement of the local spectrum of CR protons in the energy range $\\sim 90~$GeV-$6~$TeV (derived from a photon energy range $15~$GeV-$1~$TeV). Our analysis shows that single power law and broken power law spectra fit the data equally well and yield a proton spectrum with index $2.68 \\pm 0.04$ and $2.61 \\pm 0.08$ above $\\sim 200~$GeV, respectively.

Lunar radionuclide records of average solar-cosmic-ray fluxes over the last ten million years

International Nuclear Information System (INIS)

Reedy, R.C.

1980-01-01

Because changes in solar activity can modify the fluxes of cosmic-ray particles in the solar system, the nature of the galactic and solar cosmic rays and their interactions with matter are described and used to study the ancient sun. The use of cosmogenic nuclides in meteorites and lunar samples as detectors of past cosmic-ray variations are discussed. Meteorite records of the history of the galactic cosmic rays are reviewed. The fluxes of solar protons over various time periods as determined from lunar radionuclide data are presented and examined. The intensities of solar protons emitted during 1954 to 1964 (11-year solar cycle number 19) were much larger than those for 1965 to 1975 (solar cycle 20). Average solar-proton fluxes determined for the last one to ten million years from lunar 26 Al and 53 Mn data show little variation and are similar to the fluxes for recent solar cycles. Lunar activities of 14 C (and preliminary results for 81 Kr) indicate that the average fluxes of solar protons over the last 10 4 (and 10 5 ) years are several times larger than those for the last 10 6 to 10 7 years; however, cross-section measurements and other work are needed to confirm these flux variations

Swift pointing and gravitational-wave bursts from gamma-ray burst events

International Nuclear Information System (INIS)

Sutton, Patrick J; Finn, Lee Samuel; Krishnan, Badri

2003-01-01

The currently accepted model for gamma-ray burst phenomena involves the violent formation of a rapidly rotating solar-mass black hole. Gravitational waves should be associated with the black-hole formation, and their detection would permit this model to be tested. Even upper limits on the gravitational-wave strength associated with gamma-ray bursts could constrain the gamma-ray burst model. This requires joint observations of gamma-ray burst events with gravitational and gamma-ray detectors. Here we examine how the quality of an upper limit on the gravitational-wave strength associated with gamma-ray bursts depends on the relative orientation of the gamma-ray-burst and gravitational-wave detectors, and apply our results to the particular case of the Swift Burst-Alert Telescope (BAT) and the LIGO gravitational-wave detectors. A result of this investigation is a science-based 'figure of merit' that can be used, together with other mission constraints, to optimize the pointing of the Swift telescope for the detection of gravitational waves associated with gamma-ray bursts

Chromospheric telescope of Baikal Astrophysical Observatory. New light

Directory of Open Access Journals (Sweden)

Skomorovsky V.I.

2016-06-01

Full Text Available A chromospheric telescope is an important instrument for synoptic observations and solar research. After several decades of observations with the chromospheric telescope at the Baikal Astrophysical Observatory, a need arose to improve the characteristics of this telescope and filter. A new reimaging lens to produce full-disk solar images 18 mm in diameter at the CCD camera Hamamatsu C-124 with a 36×24 mm detector (4000×2672 pixels was designed and manufactured to replace the out-of-operation 50×50 mm Princeton Instruments camera. A contrast interference blocking filter and new calcite and quartz crystal plates were made and installed instead of damaged ones in the Hα birefringent filter (BF, manufactured by Bernhard Hallе Nachfl. The optical immersion in the filter was changed. All telescope optics was cleaned and adjusted. We describe for the first time the design features and their related BF passband tuning. The wavefront interferograms of optical elements and telescope as a whole show that the wavefront distortion of the optical path is within 0.25 λ. The BF and prefilter spectral parameters provide high-contrast monochromatic images. Besides, we give examples of solar chromospheric images in the Hα line core and wing.

Planetary X-ray studies: past, present and future

Science.gov (United States)

Branduardi-Raymont, Graziella

2016-07-01

relative contributions of different processes. SWCX X-ray emission from the Earth's exosphere is turning from unwanted variable background in astrophysical observations to a novel and global diagnostic tool for investigating solar-terrestrial interactions: this underpins the development of the ESA-CAS joint mission SMILE (Solar Wind Magnetosphere Ionosphere Link Explorer) due for launch in 2021. On the longer term ATHENA (Advanced Telescope for High ENergy Astrophysics, launch 2028) will provide planetary targets with vastly improved X-ray sensitivity on that currently afforded by XMM-Newton.

THE THERMAL PROPERTIES OF SOLAR FLARES OVER THREE SOLAR CYCLES USING GOES X-RAY OBSERVATIONS

International Nuclear Information System (INIS)

Ryan, Daniel F.; Gallagher, Peter T.; Milligan, Ryan O.; Dennis, Brian R.; Kim Tolbert, A.; Schwartz, Richard A.; Alex Young, C.

2012-01-01

Solar flare X-ray emission results from rapidly increasing temperatures and emission measures in flaring active region loops. To date, observations from the X-Ray Sensor (XRS) on board the Geostationary Operational Environmental Satellite (GOES) have been used to derive these properties, but have been limited by a number of factors, including the lack of a consistent background subtraction method capable of being automatically applied to large numbers of flares. In this paper, we describe an automated Temperature and Emission measure-Based Background Subtraction method (TEBBS), that builds on the methods of Bornmann. Our algorithm ensures that the derived temperature is always greater than the instrumental limit and the pre-flare background temperature, and that the temperature and emission measure are increasing during the flare rise phase. Additionally, TEBBS utilizes the improved estimates of GOES temperatures and emission measures from White et al. TEBBS was successfully applied to over 50,000 solar flares occurring over nearly three solar cycles (1980-2007), and used to create an extensive catalog of the solar flare thermal properties. We confirm that the peak emission measure and total radiative losses scale with background subtracted GOES X-ray flux as power laws, while the peak temperature scales logarithmically. As expected, the peak emission measure shows an increasing trend with peak temperature, although the total radiative losses do not. While these results are comparable to previous studies, we find that flares of a given GOES class have lower peak temperatures and higher peak emission measures than previously reported. The TEBBS database of flare thermal plasma properties is publicly available at http://www.SolarMonitor.org/TEBBS/.

RE-EVALUATION OF THE NEUTRON EMISSION FROM THE SOLAR FLARE OF 2005 SEPTEMBER 7, DETECTED BY THE SOLAR NEUTRON TELESCOPE AT SIERRA NEGRA

Energy Technology Data Exchange (ETDEWEB)

González, L. X. [SCiESMEX, Instituto de Geofísica Unidad Michoacán, Universidad Nacional Autónoma de México, 58190, Morelia, Michoacán (Mexico); Valdés-Galicia, J. F.; Musalem, O.; Hurtado, A. [Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, 04510, D. F. Mexico (Mexico); Sánchez, F. [Instituto de Tecnologías en Detección de Astropartículas, Comisión Nacional de Energía Atómica, 1429, Buenos Aires (Argentina); Muraki, Y.; Sako, T.; Matsubara, Y.; Nagai, Y. [Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Watanabe, K. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Yoshinodai, chuo-ku, Sagamihara 252-5210 (Japan); Shibata, S. [College of Engineering, Chubu University, Kasugai, Aichi 487-8501 (Japan); Sakai, T. [College of Industrial Technologies, Nihon University, Narashino 275-0005 (Japan)

2015-12-01

The X17.0 solar flare of 2005 September 7 released high-energy neutrons that were detected by the Solar Neutron Telescope (SNT) at Sierra Negra, Mexico. In three separate and independent studies of this solar neutron event, several of its unique characteristics were studied; in particular, a power-law energy spectra was estimated. In this paper, we present an alternative analysis, based on improved numerical simulations of the detector using GEANT4, and a different technique for processing the SNT data. The results indicate that the spectral index that best fits the neutron flux is around 3, in agreement with previous works. Based on the numerically calculated neutron energy deposition on the SNT, we confirm that the detected neutrons might have reached an energy of 1 GeV, which implies that 10 GeV protons were probably produced; these could not be observed at Earth, as their parent flare was an east limb event.

Solar Environmental Disturbances

Science.gov (United States)

2007-11-02

Astronomische Nachrichten 324, 303-304: Design and Development of the Advanced Technology Solar Telescope Keller, C.U., Rimmele, T.R., Hill, F...Keil, S.L., Oschmann, J.M., and the ATST Team 2002, Astronomische Nachrichten 323, 294-298: The Advanced Technology Solar Telescope Mozer, J.B

Effect of stars in the field of view of the VHE gamma-ray atmospheric Cherenkov telescope

International Nuclear Information System (INIS)

Badran, H.M.

2004-01-01

Very high energy gamma-ray astronomy in the energy range above 100 GeV has made dramatic progress through the development of imaging atmospheric Cherenkov telescopes (lACTs). The technique has been pivotal in the establishing the existence of a number of discrete gamma-ray sources. Normally due to the presence of stars in the field of view (FOV), a number of photomultiplier tubes (pmts) in the camera has to be turned off. This may have the effect of distorting some images that happens to be in that part of the camera. This may in turn affect the gamma-ray sensitivity of the telescope. The present study aims to shade some light on this possible effect. Experimental data on the extragalactic gamma-ray source Mrk 421 measured using the 10-m Whipple IACT were used for this purpose because of its relative dark FOV compared with other sources; e.g. the Crab nebula. To simulate the presence of star(s) in the FOV, the analysis program selects randomly a number of clusters of pmts to be turned off in the software. The pmts in each cluster have to be adjacent to each other (neighbors) and the selected clusters have to be separated from each other. The significance of the detected signal and the gamma-ray rate were then determined and compared with the original results. Clusters of 2, 3 and 4 pmts were used. The number of clusters was increased up to 12 clusters at various distances from the center of the FOV

Calibration of the High Energy Replicated Optics to Explore the Sun (HEROES) Hard X-ray Telescope

Science.gov (United States)

Wilson-Hodge, Colleen A.; Gaskin, Jessica; Christe, Steven; Shih, Albert; Tennant, Allyn; Swartz, Doug; Kilaru, Kiranmayee; Elsner, Ron; Kolodziejczak, Jeff; Ramsey, Brian

2014-01-01

On September 21-22, 2013, the High Energy Replicated Optics to Explore the Sun (HEROES) hard X-ray telescope, flew as a balloon payload from Ft. Sumner, N.M. HEROES observed the Sun, the black hole binary GRS 1915+105, and the Crab Nebula during its 27 hour flight. In this paper we describe laboratory calibration measurements of the HEROES detectors using line and continuum sources, applications of these measurements to define channel to energy (gain) corrections for observed events and to define detector response matrices. We characterize the HEROES X-ray grazing incidence optics using measurements taken in the Stray-Light (SLF) Facility in Huntsville, AL, and using ray traces.

Simultaneous control of multiple instruments at the Advanced Technology Solar Telescope

Science.gov (United States)

Johansson, Erik M.; Goodrich, Bret

2012-09-01

The Advanced Technology Solar Telescope (ATST) is a 4-meter solar observatory under construction at Haleakala, Hawaii. The simultaneous use of multiple instruments is one of the unique capabilities that makes the ATST a premier ground based solar observatory. Control of the instrument suite is accomplished by the Instrument Control System (ICS), a layer of software between the Observatory Control System (OCS) and the instruments. The ICS presents a single narrow interface to the OCS and provides a standard interface for the instruments to be controlled. It is built upon the ATST Common Services Framework (CSF), an infrastructure for the implementation of a distributed control system. The ICS responds to OCS commands and events, coordinating and distributing them to the various instruments while monitoring their progress and reporting the status back to the OCS. The ICS requires no specific knowledge about the instruments. All information about the instruments used in an experiment is passed by the OCS to the ICS, which extracts and forwards the parameters to the appropriate instrument controllers. The instruments participating in an experiment define the active instrument set. A subset of those instruments must complete their observing activities in order for the experiment to be considered complete and are referred to as the must-complete instrument set. In addition, instruments may participate in eavesdrop mode, outside of the control of the ICS. All instrument controllers use the same standard narrow interface, which allows new instruments to be added without having to modify the interface or any existing instrument controllers.

The Advanced Gamma-ray Imaging System (AGIS): Schwarzschild-Couder (SC) Telescope Mechanical and Optical System Design

Science.gov (United States)

Byrum, Karen L.; Vassiliev, V.; AGIS Collaboration

2010-03-01

AGIS is a concept for the next-generation ground-based gamma-ray observatory. It will be an array of 36 imaging atmospheric Cherenkov telescopes (IACTs) sensitive in the energy range from 50 GeV to 200 TeV. The required improvements in sensitivity, angular resolution, and reliability of operation relative to the present generation instruments imposes demanding technological and cost requirements on the design of AGIS telescopes. In this submission, we outline the status of the development of the optical and mechanical systems for a novel Schwarzschild-Couder two-mirror aplanatic telescope. This design can provide a field of view and angular resolution significantly better to those offered by the traditional Davies-Cotton optics utilized in present-day IACTs. Other benefits of the novel design include isochronous focusing and compatibility with cost-effective, high quantum efficiency image sensors such as multi-anode PMTs, silicon PMTs (SiPMs), or image intensifiers.

Cosmic ray intensity distribution in the vertical direction to solar equator plane

International Nuclear Information System (INIS)

Nosaka, Toru; Mori, Satoru; Sagisaka, Shuji.

1983-01-01

The data of the annual variation of cosmic ray intensity measured by neutron detectors were used to study the distribution of cosmic ray intensity vertical to the solar equator plane and its long term variation. The data used were obtained at Deep River, Kiel, Kerguelen Island, McMurdo, Ottawa, and Mt. Washington. All data showed annual variation. The patterns and degree of variation obtained in northern and southern hemisphere were similar. The summation dial representation of the annual variation and semi-annual variation of cosmic ray was obtained. The inversion of annual variation in 1958 - 1959 and 1968 - 1969 corresponded to the inversion of polarity of solar pole magnetic field. The semi-annual variation showed a complex behavior. The helio-latitudial distribution of cosmic ray intensity was obtained. The asymmetric distribution in relation to the solar equator was observed in the annual variation. The northward gradient of density in 1955 - 1958 and southward gradient in 1959 - 1968 were seen. (Kato, T.)

Proxy magnetometry with the Dutch Open Telescope

NARCIS (Netherlands)

Rutten, R.J.; Hammerschlag, R.H.; Sütterlin, P.; Bettonvil, F.C.M.

1999-01-01

Superb movies from the Dutch Open Telescope (DOT) on La Palma have proven the validity of the open concept of this innovative telescope for high-resolution imaging of the solar atmosphere. A five- camera speckle-burst registration system is being installed that should permit consistent and

EUSO-TA prototype telescope

Energy Technology Data Exchange (ETDEWEB)

Bisconti, Francesca, E-mail: francesca.bisconti@kit.edu

2016-07-11

EUSO-TA is one of the prototypes developed for the JEM-EUSO project, a space-based large field-of-view telescope to observe the fluorescence light emitted by cosmic ray air showers in the atmosphere. EUSO-TA is a ground-based prototype located at the Telescope Array (TA) site in Utah, USA, where an Electron Light Source and a Central Laser Facility are installed. The purpose of the EUSO-TA project is to calibrate the prototype with the TA fluorescence detector in presence of well-known light sources and cosmic ray air showers. In 2015, the detector started the first measurements and tests using the mentioned light sources have been performed successfully. A first cosmic ray candidate has been observed, as well as stars of different magnitude and color index. Since Silicon Photo-Multipliers (SiPMs) are very promising for fluorescence telescopes of next generation, they are under consideration for the realization of a new prototype of EUSO Photo Detector Module (PDM). The response of this sensor type is under investigation through simulations and laboratory experimentation.

EUSO-TA prototype telescope

Science.gov (United States)

Bisconti, Francesca; JEM-EUSO Collaboration

2016-07-01

EUSO-TA is one of the prototypes developed for the JEM-EUSO project, a space-based large field-of-view telescope to observe the fluorescence light emitted by cosmic ray air showers in the atmosphere. EUSO-TA is a ground-based prototype located at the Telescope Array (TA) site in Utah, USA, where an Electron Light Source and a Central Laser Facility are installed. The purpose of the EUSO-TA project is to calibrate the prototype with the TA fluorescence detector in presence of well-known light sources and cosmic ray air showers. In 2015, the detector started the first measurements and tests using the mentioned light sources have been performed successfully. A first cosmic ray candidate has been observed, as well as stars of different magnitude and color index. Since Silicon Photo-Multipliers (SiPMs) are very promising for fluorescence telescopes of next generation, they are under consideration for the realization of a new prototype of EUSO Photo Detector Module (PDM). The response of this sensor type is under investigation through simulations and laboratory experimentation.

Handbook of X-Ray Astronomy

Science.gov (United States)

Arnaud, Keith A. (Editor); Smith, Randall K.; Siemiginowska, Aneta

2011-01-01

X-ray astronomy was born in the aftermath of World War II as military rockets were repurposed to lift radiation detectors above the atmosphere for a few minutes at a time. These early flights detected and studied X-ray emission from the Solar corona. The first sources beyond the Solar System were detected during a rocket flight in 1962 by a team headed by Riccardo Giaccom at American Science and Engineering, a company founded by physicists from MIT. The rocket used Geiger counters with a system designed to reduce non-X-ray backgrounds and collimators limiting the region of sky seen by the counters. As the rocket spun, the field of view (FOV) happened to pass over what was later found to be the brightest non-Solar X-ray source; later designated See X-1. It also detected a uniform background glow which could not be resolved into individual sources. A follow-up campaign using X-ray detectors with better spatial resolution and optical telescopes identified See X-1 as an interacting binary with a compact (neutron star) primary. This success led to further suborbital rocket flights by a number of groups. More X-ray binaries were discovered, as well as X-ray emission from supernova remnants, the radio galaxies M87 and Cygnus-A, and the Coma cluster. Detectors were improved and Geiger counters were replaced by proportional counters, which provided information about energy spectra of the sources. A constant challenge was determining precise positions of sources as only collimators were available.

Gamma ray detector for solar maximum mission (SMM) of NASA

International Nuclear Information System (INIS)

Brunner, W.; Brichzin, K.; Sach, E.