A5000637556- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- High-pressure geophysics and materials
- Particle physics theoretical and experimental studies
- Planetary Science and Exploration
- Astro and Planetary Science
- Neutrino Physics Research
- Particle Detector Development and Performance
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Particle Accelerators and Free-Electron Lasers
- Mechanics and Biomechanics Studies
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- GNSS positioning and interference
- Iron-based superconductors research
- Lightning and Electromagnetic Phenomena
- Stellar, planetary, and galactic studies
- Geophysics and Sensor Technology
University of Science and Technology of China
2003-2025
Chinese Academy of Sciences
2011-2024
Chongqing University
2024
National Center of Ocean Standards and Metrology
2024
University of Maryland, College Park
2008-2024
Xinjiang Astronomical Observatory
2024
University of Chinese Academy of Sciences
2024
Purple Mountain Observatory
2023-2024
Guangxi University of Science and Technology
2024
Beijing Aerospace Flight Control Center
2020-2024
We present the third Fermi Large Area Telescope (LAT) source catalog (3FGL) of sources in 100 MeV–300 GeV range. Based on first 4 yr science data from Gamma-ray Space mission, it is deepest yet this energy Relative to Second LAT catalog, 3FGL incorporates twice as much data, well a number analysis improvements, including improved calibrations at event reconstruction level, an updated model for Galactic diffuse γ-ray emission, refined procedure detection, and methods associating with...
We present the fourth Fermi Large Area Telescope catalog (4FGL) of gamma-ray sources. Based on first eight years science data from Gamma-ray Space mission in energy range 50 MeV to 1 TeV, it is deepest yet this range. Relative 3FGL catalog, 4FGL has twice as much exposure well a number analysis improvements, including an updated model for Galactic diffuse emission, and two sets light curves (1-year 2-month intervals). The includes 5064 sources above 4 sigma significance, which we provide...
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...
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...
The fourth catalog of active galactic nuclei (AGNs) detected by the Fermi Gamma-ray Space Telescope Large Area (4LAC) between 2008 August 4 and 2016 2 contains 2863 objects located at high Galactic latitudes (|b|>10{\deg}). It includes 85% more sources than previous 3LAC based on years data. AGNs represent least 79% high-latitude in Fermi-Large Source Catalog (4FGL), which covers energy range from 50 MeV to 1 TeV. In addition, 344 gamma-ray are found low latitudes. Most 4LAC blazars (98%),...
We present a catalog of sources detected above 50 GeV by the {\it Fermi}-Large Area Telescope (LAT) in 80 months data. The newly delivered Pass 8 event-level analysis allows detection and characterization GeV--2 TeV energy range. In this band, Fermi}-LAT has 360 sources, which constitute second hard (2FHL). improved angular resolution enables precise localization point ($\sim$1.7$'$ radius at 68 % C.~L.) spatially extended sources. find that 86 can be associated with counterparts other...
On 2015 June 16, Fermi-LAT observed a giant outburst from the flat spectrum radio quasar 3C 279 with peak $>100$ MeV flux of $\sim3.6\times10^{-5}\;{\rm photons}\;{\rm cm}^{-2}\;{\rm s}^{-1}$ averaged over orbital period intervals. It is historically highest $\gamma$-ray source including past EGRET observations, isotropic luminosity reaching $\sim10^{49}\;{\rm erg}\;{\rm s}^{-1}$. During outburst, Fermi spacecraft, which has an 95.4 min, was operated in special pointing mode to optimize...
Abstract We present 294 pulsars found in GeV data from the Large Area Telescope (LAT) on Fermi Gamma-ray Space Telescope. Another 33 millisecond (MSPs) discovered deep radio searches of LAT sources will likely reveal pulsations once phase-connected rotation ephemerides are achieved. A further dozen optical and/or X-ray binary systems colocated with also harbor gamma-ray MSPs. This catalog thus reports roughly 340 and candidates, 10% all known pulsars, compared to ≤11 before Fermi. Half...
The Fermi Large Area Telescope (LAT) light curve repository (LCR) is a publicly available, continually updated library of gamma-ray curves variable Fermi-LAT sources generated over multiple timescales. LCR aims to provide publication-quality binned on timescales 3 days, 7 and 30 days for 1525 deemed in the source catalog first 10 years observations. consists through full likelihood analyses that model surrounding region, providing fluxes photon indices each time bin. intended as resource...
Abstract Swift J1727.8–1613 is a black hole X-ray binary newly discovered in 2023. We perform spectral analysis with simultaneous Insight-HXMT, NICER, and NuSTAR observations when the source was approaching hard intermediate state. Such joint view reveals an additional component apart from normally observed reflection spectrum, to be distinguished usual systems. By including this extra we have measured high spin of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">...
ABSTRACT To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed first systematic survey energies from 1 to 100 GeV using data Fermi Large Area Telescope (LAT). Based on spatial overlap sources detected with SNRs known radio surveys, classify 30 as likely SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which positions are scrambled Galactic longitude allows us an limit 22% number candidates falsely...
The transition temperature ${T}_{C}\ensuremath{\approx}26\text{ }\text{ }\mathrm{K}$ of the recently discovered superconductor ${\mathrm{LaFeAsO}}_{1\ensuremath{-}x}{\mathrm{F}}_{x}$ is extremely sensitive to lanthanide ion, reaching 55 K for Sm containing oxypnictides. Therefore, it important determine how moment on affects overall magnetism in these systems. Here we report a neutron diffraction study Nd Long-ranged antiferromagnetic order apparent NdFeAsO below 1.96 K. Rietveld refinement...
We present the fourth Fermi Large Area Telescope catalog (4FGL) of gamma-ray sources. Based on first eight years science data from Gamma-ray Space mission in energy range 50 MeV to 1 TeV, it is deepest yet this range. Relative 3FGL catalog, 4FGL has twice as much exposure well a number analysis improvements, including an updated model for Galactic diffuse emission, and two sets light curves (1-year 2-month intervals). The includes 5064 sources above 4 sigma significance, which we provide...
An incremental version of the fourth catalog active galactic nuclei (AGNs) detected by Fermi-Large Area Telescope is presented. This (4LAC-DR3) derives from third data release 4FGL based on 12 years E>50 MeV gamma-ray data, where spectral parameters, energy distributions (SEDs), yearly light curves, and associations have been updated for all sources. The new reported AGNs include 587 blazar candidates four radio galaxies. We describe properties sample outline changes affecting previously...
Polarized and unpolarized neutron-diffraction measurements have been carried out to investigate the iron magnetic order in undoped NdFeAsO. Antiferromagnetic is observed below 141(6) K, which close proximity structural distortion this material. The structure consists of chains parallel spins that are arranged antiparallel between chains, same in-plane spin arrangement as all other oxypnictide materials. Nearest-neighbor along $c$ axis like LaFeAsO. ordered moment...
Abstract The Fermi Large Area Telescope (LAT) has opened the way for comparative studies of cosmic rays (CRs) and high-energy objects in Milky Way (MW) other, external, star-forming galaxies. Using 2 yr observations with LAT, Local Group galaxy M31 was detected as a marginally extended gamma-ray source, while only an upper limit been derived other nearby M33. We revisited emission direction M33 using more than 7 LAT Pass 8 data energy range <?CDATA $0.1\mbox{--}100\,\mathrm{GeV}$?> <mml:math...
ABSTRACT The Fermi Large Area Telescope (LAT) has an instantaneous field of view (FoV) covering <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>∼</mml:mo> <mml:mn>1</mml:mn> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:mn>5</mml:mn> </mml:math> the sky and it completes a survey entire in high-energy gamma-rays every 3 hr. It enables searches for transient phenomena over timescales from milliseconds to years. Among these could be...
The detection of high-redshift ($z>$3) blazars enables the study evolution most luminous relativistic jets over cosmic time. More importantly, tend to host massive black holes and can be used constrain space density heavy in early Universe. Here, we report first with \fermi-Large Area Telescope five \gm-ray emitting beyond $z=3.1$, more distant than any previously detected $\gamma$-rays. Among these objects, NVSS J151002+570243 is now known blazar at $z=4.31$. These objects have steeply...
Galaxy clusters are one of the prime sites to search for dark matter (DM) annihilation signals. Depending on substructure DM halo a galaxy cluster and cross sections channels, these signals might be detectable by latest generation $\gamma$-ray telescopes. Here we use three years Fermi Large Area Telescope (LAT) data, which most suitable searching very extended emission in vicinity nearby Virgo cluster. Our analysis reveals statistically significant can well characterized uniformly emitting...
Abstract We report on the Fermi -LAT detection of high-energy emission from behind-the-limb (BTL) solar flares that occurred 2013 October 11, and 2014 January 6 September 1. The observations are associated with active regions originating behind both eastern western limbs, as determined by STEREO . All three very fast coronal mass ejections (CMEs) strong energetic particle events. present updated localizations >100 MeV photon emission, hard X-ray (HXR) EUV images, broadband spectra 10 keV...
High mass X-ray binaries are among the brightest sources in Milky Way, as well nearby Galaxies. Thanks to their highly variable emissions and complex phenomenology, they have attracted interest of high energy astrophysical community since dawn Astronomy. In more recent years, challenged our comprehension physical processes many bands, ranging from infrared very energies. this review, we provide a broad but concise summary dominating emission across virtually whole electromagnetic spectrum....
The Large Area Telescope (LAT), the primary instrument for Fermi Gamma-ray Space (Fermi) mission, is an imaging, wide field-of-view, high-energy gamma-ray telescope, covering energy range from 30 MeV to more than 300 GeV. We describe performance of at 10-year milestone. LAT remains well within specifications defined during planning phase, validating design choices and supporting compelling case extend duration mission. details provided here will be useful when designing next generation observatories.
Abstract We propose a method based on the Hilbert–Huang transform (HHT) to recover high-energy waveform of low-frequency quasiperiodic oscillations (QPOs). Based method, we successfully obtain modulation phase-folded light curve above 170 keV using QPO phase reconstructed at lower energies in MAXI J1535–571 with Insight-HXMT observations. A comprehensive simulation study is conducted demonstrate that such indeed originates from QPO. Thus, highest turn out significantly exceed upper limit...