A. A. Moiseev
A5034178430- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Pulsars and Gravitational Waves Research
- Neutrino Physics Research
- Radio Astronomy Observations and Technology
- Solar and Space Plasma Dynamics
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Radiation Therapy and Dosimetry
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Geophysics and Gravity Measurements
- Atomic and Molecular Physics
- Scientific Research and Discoveries
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Ionosphere and magnetosphere dynamics
- Advanced Semiconductor Detectors and Materials
- Cryospheric studies and observations
University of Maryland, College Park
2015-2024
Goddard Space Flight Center
2012-2023
Deleted Institution
2007-2023
Ritsumeikan University
2018
Waseda University
2018
Heliophysics
2018
Nippon Soken (Japan)
2018
RIKEN
2018
American Society for Radiation Oncology
2018
University of Denver
2007-2017
The γ-ray sky can be decomposed into individually detected sources, diffuse emission attributed to the interactions of Galactic cosmic rays with gas and radiation fields, a residual all-sky component commonly called isotropic background (IGRB). IGRB comprises all extragalactic emissions too faint or resolved in given survey, as well any foregrounds that are approximately isotropic. first measurement Large Area Telescope (LAT) on board Fermi Gamma-ray Space (Fermi) used 10 months sky-survey...
We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because instrument does not have an onboard magnet, we distinguish two species by exploiting Earth's shadow, which is offset in opposite directions for charges due to magnetic field. estimate subtract proton background using different methods that produce consistent results. report electron-only spectrum, positron-only fraction between 20 GeV 200 GeV. confirm rises energy 20-100 range. The...
The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It based on (3FGL) sources between 100 MeV and 300 GeV with a Test Statistic (TS) greater than 25, 2008 August 4 2012 July 31. 3LAC includes 1591 AGNs located at high Galactic latitudes (|b|>10{\deg}), 71% increase over second 2 years data. There are 28 duplicate associations, thus 1563 2192 high-latitude gamma-ray 3FGL AGNs. Most them (98%) blazars. About half newly blazars unknown type, i.e.,...
The dwarf spheroidal satellite galaxies of the Milky Way are some most dark-matter-dominated objects known. Due to their proximity, high dark matter content, and lack astrophysical backgrounds, widely considered be among promising targets for indirect detection via $\ensuremath{\gamma}$ rays. Here we report on $\ensuremath{\gamma}$-ray observations 25 based 4 years Fermi Large Area Telescope (LAT) data. None significantly detected in rays, present flux upper limits between 500 MeV GeV. We...
The Fermi Large Area Telescope (LAT) has provided the most detailed view to date of emission towards Galactic centre (GC) in high-energy gamma-rays. This paper describes analysis data taken during first 62 months mission energy range 1-100 GeV from a $15^\circ \times 15^\circ$ region about direction GC, and implications for interstellar emissions produced by cosmic ray (CR) particles interacting with gas radiation fields inner Galaxy point sources detected. Specialised models (IEMs) are...
Abstract The region around the Galactic Center (GC) is now well established to be brighter at energies of a few GeV than what expected from conventional models diffuse gamma-ray emission and catalogs known sources. We study excess using 6.5 yr data Fermi Large Area Telescope. characterize uncertainty GC spectrum morphology due uncertainties in cosmic-ray source distributions propagation, distribution interstellar gas Milky Way, potential contribution bubbles. also evaluate properties...
We present an incremental version (4FGL-DR3, for Data Release 3) of the fourth Fermi-LAT catalog gamma-ray sources. Based on first twelve years science data in energy range from 50 MeV to 1 TeV, it contains 6658 The analysis improves that used 4FGL over eight data: more sources are fit with curved spectra, we introduce a robust spectral parameterization pulsars, and extend points TeV. parameters, distributions, associations updated all Light curves rebuilt yr intervals (not 2 month...
We present a catalog of sources detected above 10 GeV by the Fermi Large Area Telescope (LAT) in first 7 years data using Pass 8 event-level analysis. This is Third Catalog Hard Fermi-LAT Sources (3FHL), containing 1556 objects characterized - 2 TeV energy range. The sensitivity and angular resolution are improved factors 3 relative to previous LAT at same energies (1FHL). vast majority (79%) associated with extragalactic counterparts other wavelengths, including 16 located very high...
Dark matter particle annihilation or decay can produce monochromatic gamma-ray lines and contribute to the diffuse background. Flux upper limits are presented for spectral from 7 200 GeV background 4.8 264 obtained two years of Fermi Large Area Telescope data integrated over most sky. We give cross-section lifetime lower dark models that spectrum, including proposed as explanations PAMELA cosmic-ray data.
We present observations of the young supernova remnant (SNR) RX J1713.7−3946 with Fermi Large Area Telescope (LAT). clearly detect a source positionally coincident SNR. The is extended best-fit extension 055 ± 004 matching size non-thermal X-ray and TeV gamma-ray emission from remnant. positional coincidence allow us to identify LAT SNR J1713.7−3946. spectrum can be described by very hard power law photon index Γ = 1.5 0.1 that coincides in normalization steeper H.E.S.S.-detected at higher...
Extended results on the cosmic-ray electron $+$ positron spectrum from 11 GeV to 4.8 TeV are presented based observations with Calorimetric Electron Telescope (CALET) International Space Station utilizing data up November 2017. The analysis uses full detector acceptance at high energies, approximately doubling statistics compared previous result. CALET is an all-calorimetric instrument a total thickness of 30 ${X}_{0}$ normal incidence and fine imaging capability, designed achieve large...
In this paper, we present the analysis and results of a direct measurement cosmic-ray proton spectrum with CALET instrument onboard International Space Station, including detailed assessment systematic uncertainties. The observation period used in is from October 13, 2015 to August 31, 2018 (1054 days). We have achieved very wide energy range necessary carry out measurements 50 GeV 10 TeV covering, for first time space, single whole interval previously investigated most cases separate...
We report cosmic-ray proton and helium spectra in energy ranges of 1-120 GeV nucleon-1 1-54 nucleon-1, respectively, measured by a flight the Balloon-borne Experiment with Superconducting Spectrometer (BESS) 1998. The magnetic rigidity cosmic ray was reliably determined highly precise measurement circular track uniform solenoidal field 1 T. Those were within overall uncertainties ±5% for protons ±10% nuclei including statistical systematic errors.
The energy spectrum of cosmic-ray antiprotons ( &pmacr;'s) has been measured in the range 0.18-3.56 GeV, based on 458 &pmacr;'s collected by BESS a recent solar-minimum period. We have detected for first time characteristic peak at 2 GeV originating from interactions with interstellar gas. is reproduced theoretical calculations, implying that propagation models are basically correct and different species undergo universal propagation. Future data still higher statistics will allow us to...
Primary and atmospheric cosmic-ray spectra were precisely measured with the BESS-TeV spectrometer. The spectrometer was upgraded from BESS-98 to achieve seven times higher resolution in momentum measurement. We report absolute fluxes of primary protons helium nuclei energy ranges, 1–540 GeV 1–250 GeV/n, respectively, flux muons range 0.6–400 GeV/c.
We report on the observations of 14 dwarf spheroidal galaxies with Fermi Gamma-Ray Space Telescope taken during first 11 months survey mode operations. The telescope provides a new opportunity to test particle dark matter models through expected gamma-ray emission produced by pair annihilation weakly interacting massive particles (WIMPs). Local Group galaxies, largest galactic substructures predicted cold scenario, are attractive targets for such indirect searches because they nearby and...
The flat-spectrum radio quasar 3C 454.3 underwent an extraordinary 5-day gamma-ray outburst in November 2010 where the daily flux measured with Fermi Large Area Telescope (LAT) at photon energies E>100 MeV reached (66+/-2) x 10^-6 ph cm^-2 s^-1. This is a factor of 3 higher than its previous maximum recorded December 2009 and ~5 times brighter Vela pulsar, which normally brightest source sky. 3-hr peak was (85+/-5) s^-1, corresponding to apparent isotropic luminosity 2.1+/-0.2 10^50 erg...
Dark matter (DM) particle annihilation or decay can produce monochromatic γ rays readily distinguishable from astrophysical sources. γ-ray line limits 30 to 200 GeV obtained 11 months of Fermi Large Area Space Telescope data 20–300 are presented using a selection based on requirements for analysis, and integrated over most the sky. We obtain flux upper in range 0.6–4.5×10−9 cm−2 s−1, give corresponding DM cross-section lifetime limits. Theoretical implications briefly discussed.Received 19...
We present detailed analysis of two gamma-ray sources, 1FGL J1801.3−2322c and J1800.5−2359c, that have been found toward the supernova remnant (SNR) W28 with Large Area Telescope (LAT) on board Fermi Gamma-ray Space Telescope. is to be an extended source within boundary SNR W28, extensively overlap TeV HESS J1801−233, which associated a dense molecular cloud interacting SNR. The spectrum measured LAT from 0.2 100 GeV can described by broken power-law function break at ∼1 photon indices 2.09...
Nearby clusters and groups of galaxies are potentially bright sources high-energy gamma-ray emission resulting from the pair-annihilation dark matter particles. However, no significant has been detected so far in first 11 months observations with Fermi Large Area Telescope. We interpret this non-detection terms constraints on particle properties. In particular for leptonic annihilation final states masses greater than ~200 GeV, inverse Compton scattering CMB photons is expected to dominate...
We have performed an analysis of the diffuse gamma-ray emission with Fermi Large Area Telescope in Milky Way Halo region searching for a signal from dark matter annihilation or decay. In absence robust signal, constraints are presented. consider both gamma rays produced directly annihilation/decay and by inverse Compton scattering e+e- annihilation/decay. Conservative limits derived requiring that does not exceed observed emission. A second set more stringent is based on modeling foreground...
The Fermi Large Area Telescope (LAT) Collaboration has recently released a catalog of 360 sources detected above 50 GeV (2FHL). This was obtained using 80 months data re-processed with Pass 8, the newest event-level analysis, which significantly improves acceptance and angular resolution instrument. Most 2FHL at high Galactic latitude are blazars. Using detailed Monte Carlo simulations, we measure, for first time, source count distribution, dN/dS, extragalactic γ-ray E>50 find that it is...