T. H. Burnett
A5072934190- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Particle Detector Development and Performance
- Radio Astronomy Observations and Technology
- Neutrino Physics Research
- Astrophysical Phenomena and Observations
- Particle Accelerators and Free-Electron Lasers
- Nuclear physics research studies
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Astronomical Observations and Instrumentation
- Radiation Therapy and Dosimetry
- Atomic and Subatomic Physics Research
- Computational Physics and Python Applications
- Nuclear Physics and Applications
- Galaxies: Formation, Evolution, Phenomena
- Nuclear reactor physics and engineering
- Black Holes and Theoretical Physics
- Solar and Space Plasma Dynamics
- Medical Imaging Techniques and Applications
University of Washington
2014-2023
European Organization for Nuclear Research
1992-2022
Seattle University
1992-2011
University of Buenos Aires
2010-2011
Institut National de Physique Nucléaire et de Physique des Particules
2010-2011
Centre National de la Recherche Scientifique
2010-2011
Universidade Federal do ABC
2010-2011
Charles University
2010-2011
Universidade Estadual Paulista (Unesp)
2010-2011
University College Dublin
2011
(Abridged) The Large Area Telescope (Fermi/LAT, hereafter LAT), the primary instrument on Fermi Gamma-ray Space (Fermi) mission, is an imaging, wide field-of-view, high-energy gamma-ray telescope, covering energy range from below 20 MeV to more than 300 GeV. This paper describes LAT, its pre-flight expected performance, and summarizes key science objectives that will be addressed. On-orbit performance presented in detail a subsequent paper. LAT pair-conversion telescope with precision...
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...
ABSTRACT We present a catalog of high-energy gamma-ray sources detected by the Large Area Telescope (LAT), primary science instrument on Fermi Gamma-ray Space (Fermi) , during first 11 months phase mission, which began 2008 August 4. The First -LAT (1FGL) contains 1451 and characterized in 100 MeV to GeV range. Source detection was based average flux over month period, threshold likelihood Test Statistic is 25, corresponding significance just 4σ. 1FGL includes source location regions,...
We present the second catalog of high-energy gamma-ray sources detected by Large Area Telescope (LAT), primary science instrument on Fermi Gamma-ray Space (Fermi), derived from data taken during first 24 months phase mission, which began 2008 August 4. Source detection is based average flux over 24-month period. The Second Fermi-LAT (2FGL) includes source location regions, defined in terms elliptical fits to 95% confidence regions and spectral power-law, exponentially cutoff or log-normal...
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...
(Abridged) We have conducted a detailed investigation of the broad-band spectral properties \gamma-ray selected blazars Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated gamma-ray spectra with Swift, radio, infra-red, optical and other hard X-ray/gamma-ray data, collected within three months LBAS data taking period, we were able to assemble high-quality quasi-simultaneous Spectral Energy Distributions (SED) for 48 blazars.The SED these sources is similar that...
Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with large acceptance exceeding 2 m;{2} sr at 300 GeV. Building on analysis, we have developed efficient detection strategy which provides sufficient background rejection for measurement of steeply falling spectrum up to 1 TeV. Our high precision data show that falls energy E-3.0 and does not exhibit prominent spectral features. Interpretations in terms conventional diffusive...
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 Fermi satellite. Half are neutron stars discovered LAT through periodicity searches in and radio around unassociated source positions. The pulsars evenly divided into groups: millisecond pulsars, young radio-loud radio-quiet pulsars. We characterize pulse profiles energy spectra derive luminosities when distance information exists. Spectral...
The second catalog of active galactic nuclei (AGNs) detected by the Fermi Large Area Telescope (LAT) in two years scientific operation is presented. LAT AGN (2LAC) includes 1017 γ-ray sources located at high Galactic latitudes (|b| > 10°) that are with a test statistic (TS) greater than 25 and associated statistically AGNs. However, some these affected analysis issues multiple Consequently, we define Clean Sample which 886 AGNs, comprising 395 BL Lacertae objects (BL Lac objects), 310...
Satellite galaxies of the Milky Way are among most promising targets for dark matter searches in gamma rays. We present a search consisting weakly interacting massive particles, applying joint likelihood analysis to 10 satellite with 24 months data Fermi Large Area Telescope. No signal is detected. Including uncertainty distribution, robust upper limits placed on annihilation cross sections. The 95% confidence level range from about 10(-26) cm3 s(-1) at 5 GeV 5×10(-23) 1 TeV, depending final...
We report on the first Fermi Large Area Telescope (LAT) measurements of so-called "extragalactic" diffuse gamma-ray emission (EGB). This component is generally considered to have an isotropic or nearly distribution sky with diverse contributions discussed in literature. The derivation EGB based detailed modeling bright foreground Galactic emission, detected LAT sources, and solar emission. find spectrum consistent a power law differential spectral index gamma = 2.41 +/- 0.05 intensity I(>100...
The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on Gamma-ray Space (Fermi) mission, is an imaging, wide field-of-view, high-energy γ-ray telescope, covering energy range from 20 MeV to more than 300 GeV. During first years of LAT team has gained considerable insight into in-flight performance instrument. Accordingly, we have updated analysis used reduce data for public release as well response functions (IRFs), description provided analysis. In this paper,...
We present the first catalog of active galactic nuclei (AGNs) detected by Large Area Telescope (LAT), corresponding to 11 months data collected in scientific operation mode. The First LAT AGN Catalog (1LAC) includes 671 γ-ray sources located at high Galactic latitudes (|b|>10°) that are with a test statistic greater than 25 and associated statistically AGNs. Some multiple AGNs, consequently, 709 comprising 300 BL Lacertae objects, 296 flat-spectrum radio quasars, 41 AGNs other types, 72...
The dramatic increase in the number of known gamma-ray pulsars since launch Fermi Gamma-ray Space Telescope (formerly GLAST) offers first opportunity to study a sizable population these high-energy objects. This catalog summarizes 46 high-confidence pulsed detections using six months data taken by Large Area (LAT), Fermi's main instrument. Sixteen previously unknown were discovered searching for signals at positions bright sources seen with LAT, or objects suspected be neutron stars based on...
ABSTRACT Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope ( ) began a sky survey August. The Large Area (LAT) on three months produced deeper and better resolved map of γ-ray than any previous space mission. We present here initial results for energies above 100 MeV 205 most significant (statistical significance greater ∼10σ) sources these data. These are best characterized localized point-like (i.e., spatially unresolved) early mission
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 the results of our analysis cosmic-ray electrons using about $8\ifmmode\times\else\texttimes\fi{}{10}^{6}$ electron candidates detected in first 12 months on-orbit by Fermi Large Area Telescope. This work extends previously published spectrum down to 7 GeV, giving a spectral range approximately 2.5 decades up 1 TeV. describe detail and its validation beam-test data. In addition, we measured via subset events selected for best energy resolution as cross-check on measurement full...
The first three months of sky-survey operation with the Fermi Gamma Ray Space Telescope (Fermi) Large Area (LAT) reveals 132 bright sources at |b|>10 deg test statistic greater than 100 (corresponding to about 10 sigma). Two methods, based on CGRaBS, CRATES and BZCat catalogs, indicate high-confidence associations 106 these known AGNs. This sample is referred as LAT Bright AGN Sample (LBAS). It contains two radio galaxies, namely Centaurus A NGC 1275, 104 blazars consisting 57 flat...
This paper presents light curves as well the first systematic characterization of variability 106 objects in high-confidence Fermi Large Area Telescope Bright AGN Sample (LBAS). Weekly this sample, obtained during 11 months survey (2008 August 4–2009 July 4), are tested for and their properties quantified through autocorrelation function structure analysis. For brightest sources, 3 or 4 day binned extracted order to determine power density spectra (PDSs) fit temporal major flares. More than...
Pulsars are rapidly-rotating, highly-magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there more than 1800 known radio pulsars, until recently, only seven were observed to pulse in gamma rays and these all discovered at other wavelengths. The Fermi Large Area Telescope makes it possible pinpoint through their gamma-ray pulsations. We report detection of 16 pulsars blind frequency searches using LAT. Most coincident with previously unidentified...
We report the discovery with Fermi/LAT of gamma-ray emission from three radio-loud narrow-line Seyfert 1 galaxies: PKS 1502+036 (z=0.409), 1H 0323+342 (z=0.061) and 2004-447 (z=0.24). In addition to PMN J0948+0022 (z=0.585), first source this type be detected in gamma rays, they may form an emerging new class active galactic nuclei (AGN). These findings can have strong implications on our knowledge about relativistic jets unified model AGN.
We present a catalog of gamma-ray sources at energies above 10 GeV based on data from the Large Area Telescope (LAT) accumulated during first three years Fermi Gamma-ray Space mission. The Fermi-LAT >10GeV (1FHL) has 514 sources. For each source we location, spectrum, measure variability, and associations with cataloged other wavelengths. found that 449 (87%) could be associated known sources, which 393 (76% 1FHL sources) are active galactic nuclei. Of 27 pulsars, find 20 (12) to have...