http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Abu-Zayyad, T.,Aida, R.,Allen, M.,Anderson, R.,Azuma, R.,Barcikowski, E.,Belz, J.W.,Bergman, D.R.,Blake, S.A.,Cady, R.,Cheon, B.G.,Chiba, J.,Chikawa, M.,Cho, E.J.,Cho, W.R.,Fujii, H.,Fujii, T.,Fukuda, North-Holland ; Elsevier Science Ltd 2013 Astroparticle physics Vol.48 No.-
We present a measurement of the energy spectrum of ultra-high-energy cosmic rays performed by the Telescope Array experiment using monocular observations from its two new FADC-based fluorescence detectors. After a short description of the experiment, we describe the data analysis and event reconstruction procedures. Since the aperture of the experiment must be calculated by Monte Carlo simulation, we describe this calculation and the comparisons of simulated and real data used to verify the validity of the aperture calculation. Finally, we present the energy spectrum calculated from the merged monocular data sets of the two FADC-based detectors, and also the combination of this merged spectrum with an independent, previously published monocular spectrum measurement performed by Telescope Array's third fluorescence detector [T. Abu-Zayyad et al., The energy spectrum of Telescope Array's middle drum detector and the direct comparison to the high resolution fly's eye experiment, Astroparticle Physics 39 (2012) 109-119, http://dx.doi.org/10.1016/j.astropartphys.2012.05.012, Available from: <arXiv:1202.5141>]. This combined spectrum corroborates the recently published Telescope Array surface detector spectrum [T. Abu-Zayyad, et al., The cosmic-ray energy spectrum observed with the surface detector of the Telescope Array experiment, ApJ 768 (2013) L1, http://dx.doi.org/10.1088/2041-8205/768/1/L1, Available from: <arXiv:1205.5067>] with independent systematic uncertainties.
Abu-Zayyad, T.,Aida, R.,Allen, M.,Anderson, R.,Azuma, R.,Barcikowski, E.,Belz, J.W.,Bergman, D.R.,Blake, S.A.,Cady, R.,Cheon, B.G.,Chiba, J.,Chikawa, M.,Cho, E.J.,Cho, W.R.,Fujii, H.,Fujii, T.,Fukuda, North-Holland ; Elsevier Science Ltd 2012 Astroparticle physics Vol.39 No.-
The Telescope Array's Middle Drum fluorescence detector was instrumented with telescopes refurbished from the High Resolution Fly's Eye's HiRes-1 site. The data observed by Middle Drum in monocular mode was analyzed via the HiRes-1 profile-constrained geometry reconstruction technique and utilized the same calibration techniques enabling a direct comparison of the energy spectra and energy scales between the two experiments. The spectrum measured using the Middle Drum telescopes is based on a three-year exposure collected between December 16, 2007 and December 16, 2010. The calculated difference between the spectrum of the Middle Drum observations and the published spectrum obtained by the data collected by the HiRes-1 site allows the HiRes-1 energy scale to be transferred to Middle Drum. The HiRes energy scale is applied to the entire Telescope Array by making a comparison between Middle Drum monocular events and hybrid events that triggered both Middle Drum and the Telescope Array's scintillator ground array.
Abu-Zayyad, T.,Aida, R.,Allen, M.,Anderson, R.,Azuma, R.,Barcikowski, E.,Belz, J. W.,Bergman, D. R.,Blake, S. A.,Cady, R.,Cheon, B. G.,Chiba, J.,Chikawa, M.,Cho, E. J.,Cho, W. R.,Fujii, H.,Fujii, T.,F IOP Publishing 2013 The Astrophysical journal Vol.777 No.2
<P>We search for correlations between the positions of extragalactic objects and the arrival directions of ultra-high energy cosmic rays (UHECRs) with primary energy E >= 40 EeV as observed by the surface detector array of the Telescope Array (TA) experiment during the first 40 months of operation. We examine several public astronomical object catalogs, including the Veron-Cetty and Veron catalog of active galactic nuclei. We count the number of TA events correlated with objects in each catalog as a function of three parameters: the maximum angular separation between a TA event and an object, the minimum energy of the events, and the maximum redshift of the objects. We determine the combination of these parameters that maximizes the correlations, and we calculate the probability of having the same levels of correlations from an isotropic distribution of UHECR arrival directions. No statistically significant correlations are found when penalties for scanning over the above parameters and for searching in several catalogs are taken into account.</P>
SEARCH FOR ANISOTROPY OF ULTRAHIGH ENERGY COSMIC RAYS WITH THE TELESCOPE ARRAY EXPERIMENT
Abu-Zayyad, T.,Aida, R.,Allen, M.,Anderson, R.,Azuma, R.,Barcikowski, E.,Belz, J. W.,Bergman, D. R.,Blake, S. A.,Cady, R.,Cheon, B. G.,Chiba, J.,Chikawa, M.,Cho, E. J.,Cho, W. R.,Fujii, H.,Fujii, T.,F IOP Publishing 2012 The Astrophysical journal Vol.757 No.1
<P>We study the anisotropy of Ultra-High Energy Cosmic Ray (UHECR) events collected by the Telescope Array (TA) detector in the first 40 months of operation. Following earlier studies, we examine event sets with energy thresholds of 10 EeV, 40 EeV, and 57 EeV. We find that the distributions of the events in right ascension and declination are compatible with an isotropic distribution in all three sets. We then compare with previously reported clustering of the UHECR events at small angular scales. No significant clustering is found in the TA data. We then check the events with E > 57 EeV for correlations with nearby active galactic nuclei. No significant correlation is found. Finally, we examine all three sets for correlations with the large-scale structure (LSS) of the universe. We find that the two higher-energy sets are compatible with both an isotropic distribution and the hypothesis that UHECR sources follow the matter distribution of the universe (the LSS hypothesis), while the event set with E > 10 EeV is compatible with isotropy and is not compatible with the LSS hypothesis at 95% CL unless large deflection angles are also assumed. We show that accounting for UHECR deflections in a realistic model of the Galactic magnetic field can make this set compatible with the LSS hypothesis.</P>
THE COSMIC-RAY ENERGY SPECTRUM OBSERVED WITH THE SURFACE DETECTOR OF THE TELESCOPE ARRAY EXPERIMENT
Abu-Zayyad, T.,Aida, R.,Allen, M.,Anderson, R.,Azuma, R.,Barcikowski, E.,Belz, J. W.,Bergman, D. R.,Blake, S. A.,Cady, R.,Cheon, B. G.,Chiba, J.,Chikawa, M.,Cho, E. J.,Cho, W. R.,Fujii, H.,Fujii, T.,F IOP Publishing 2013 ASTROPHYSICAL JOURNAL LETTERS - Vol.768 No.1
Abu-Zayyad, T.,Aida, R.,Allen, M.,Anderson, R.,Azuma, R.,Barcikowski, E.,Belz, J.W.,Bergman, D.R.,Blake, S.A.,Cady, R.,Cheon, B.G.,Chiba, J.,Chikawa, M.,Cho, E.J.,Cho, W.R.,Fujii, H.,Fujii, T.,Fukuda, Elsevier 2015 Astroparticle physics Vol.61 No.-
<P><B>Abstract</B></P> <P>We measure the spectrum of cosmic rays with energies greater than <SUP> 10 18.2 </SUP> eV with the fluorescence detectors (FDs) and the surface detectors (SDs) of the Telescope Array Experiment using the data taken in our first 2.3-year observation from May 27, 2008 to September 7, 2010. A hybrid air shower reconstruction technique is employed to improve accuracies in determination of arrival directions and primary energies of cosmic rays using both FD and SD data. The energy spectrum presented here is in agreement with our previously published spectra and the HiRes results.</P>
Gamma Ray Showers Observed at Ground Level in Coincidence With Downward Lightning Leaders
Abbasi, R. U.,Abu‐,Zayyad, T.,Allen, M.,Barcikowski, E.,Belz, J. W.,Bergman, D. R.,Blake, S. A.,Byrne, M.,Cady, R.,Cheon, B.G.,Chiba, J.,Chikawa, M.,Fujii, T.,Fukushima, M.,Furlich, G.,Goto, T. American Geophysical Union 2018 Journal of geophysical research. Atmospheres Vol.123 No.13
<P>Bursts of gamma ray showers have been observed in coincidence with downward propagating negative leaders in lightning flashes by the Telescope Array Surface Detector (TASD). The TASD is a 700-km(2) cosmic ray observatory located in southwestern Utah, USA. In data collected between 2014 and 2016, correlated observations showing the structure and temporal development of three shower-producing flashes were obtained with a 3-D lightning mapping array, and electric field change measurements were obtained for an additional seven flashes, in both cases colocated with the TASD. National Lightning Detection Network information was also used throughout. The showers arrived in a sequence of 2-5 short-duration (10s) bursts over time intervals of several hundred microseconds and originated at an altitude of similar or equal to 3-5km above ground level during the first 1-2ms of downward negative leader breakdown at the beginning of cloud-to-ground lightning flashes. The shower footprints, associated waveforms and the effect of atmospheric propagation indicate that the showers consist primarily of downward-beamed gamma radiation. This has been supported by GEANT simulation studies, which indicate primary source fluxes of similar or equal to 10(12)-10(14) photons for 16 degrees half-angle beams. We conclude that the showers are terrestrial gamma ray flashes, similar to those observed by satellites, but that the ground-based observations are more representative of the temporal source activity and are also more sensitive than satellite observations, which detect only the most powerful terrestrial gamma ray flashes.</P>
Abbasi, R. U.,Abe, M.,Zayyad, T. Abu-,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, IOP Publishing 2015 The Astrophysical journal Vol.804 No.2
<P>We report on the search for steady point-like sources of neutral particles around 10(18) eV between 2008 and 2013 May with the scintillator SD of the Telescope Array experiment. We found overall no significant point-like excess above 0.5 EeV in the northern sky. Subsequently, we also searched for coincidence with the Fermi bright Galactic sources. No significant coincidence was found within the statistical uncertainty. Hence, we set an upper limit on the neutron flux that corresponds to an averaged flux of 0.07 km(-2) yr(-1) for E > 1 EeV in the northern sky at the 95% confidence level. This is the most stringent flux upper limit in a northern sky survey assuming point-like sources. The upper limit at the 95% confidence level on the neutron flux from Cygnus X-3 is also set to 0.2 km(-2) yr(-1) for E > 0.5 EeV. This is an order of magnitude lower than previous flux measurements.</P>
Mass composition of ultrahigh-energy cosmic rays with the Telescope Array Surface Detector data
Abbasi, R. U.,Abe, M.,Abu-Zayyad, T.,Allen, M.,Azuma, R.,Barcikowski, E.,Belz, J. W.,Bergman, D. R.,Blake, S. A.,Cady, R.,Cheon, B. G.,Chiba, J.,Chikawa, M.,di Matteo, A.,Fujii, T.,Fujita, K.,Fukushim American Physical Society 2019 Physical review. D Vol.99 No.2