A5085355770- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Neutrino Physics Research
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Medical Imaging Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Black Holes and Theoretical Physics
- Radiation Detection and Scintillator Technologies
- Gamma-ray bursts and supernovae
- Distributed and Parallel Computing Systems
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Pulsars and Gravitational Waves Research
- Radio Astronomy Observations and Technology
- Nuclear physics research studies
- advanced mathematical theories
- Advanced Data Storage Technologies
- Astrophysical Phenomena and Observations
- Muon and positron interactions and applications
- Stochastic processes and statistical mechanics
SLAC National Accelerator Laboratory
2016-2025
Northern Illinois University
2023-2024
Institute for High Energy Physics
2023-2024
Institute of Science and Technology
2023-2024
A. Alikhanyan National Laboratory
2024
Atlas Scientific (United States)
2024
The University of Adelaide
2014-2023
University of Oxford
2023
Brandeis University
2023
Ludwig-Maximilians-Universität München
2011-2019
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...
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
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...
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 on gamma-ray observations of the Crab Pulsar and Nebula using 8 months survey data with Fermi Large Area Telescope (LAT). The high quality light curve obtained ephemeris provided by Nancay Jodrell Bank radio telescopes shows two main peaks stable in phase energy. first peak leads pulse (281 \pm 12 21) mus, giving new constraints production site non-thermal emission pulsar magnetospheres. improved sensitivity unprecedented statistics afforded LAT enable precise measurement spectral...
Recent observations of supernova remnants (SNRs) hint that they accelerate cosmic rays to energies close ~10(15) electron volts. However, the nature particles produce emission remains ambiguous. We report SNR W44 with Fermi Large Area Telescope at between 2 x 10(8) volts and 3 x10(11) The detection a source morphology corresponding shell implies is produced by accelerated there. gamma-ray spectrum well modeled from protons nuclei. Its steepening above approximately 10(9) provides probe which...
The discovery of bright gamma-ray emission coincident with supernova remnant (SNR) W51C is reported using the Large Area Telescope (LAT) on board Fermi Gamma-ray Space Telescope. a middle-aged (~10^4 yr) intense radio synchrotron in its shell and known to be interacting molecular cloud. spatially extended, broadly consistent X-ray extent SNR W51C. energy spectrum 0.2-50 GeV band exhibits steepening toward high energies. luminosity greater than 1x10^{36} erg/s given distance constraint D>5.5...
We report observation of the supernova remnant IC443 (G189.1+3.0) with Fermi Gamma-ray Space Telescope Large Area (LAT) in energy band between 200MeV and 50GeV. is a shell-type mixed morphology located off outer Galactic plane where high-energy emission has been detected X-ray, GeV TeV gamma-ray bands. Past observations suggest interacting surrounding interstellar matter. Proximity dense shocked molecular clouds GeV-TeV regions by EGRET, MAGIC VERITAS suggests an interpretation that...
Gamma-Ray Pulsar Bonanza Most of the pulsars we know about were detected through their radio emission; a few are known to pulse gamma rays but first at other wavelengths (see Perspective by Halpern ). Using Fermi Space Telescope, Abdo et al. (p. 840 , published online 2 July; see cover) report detection 16 previously unknown based on gamma-ray emission alone. Thirteen these coincide with unidentified sources, solving 30-year-old mystery identities. Pulsars fast-rotating neutron stars. With...
We report the detection of high-energy gamma-ray emission from two starburst galaxies using data obtained with Large Area Telescope on board Fermi Gamma-ray Space Telescope. Steady point-like above 200 MeV has been detected at significance levels 6.8 sigma and 4.8 respectively, sources positionally coincident locations M82 NGC 253. The total fluxes are consistent originating interaction cosmic rays local interstellar gas radiation fields constitute evidence for a link between massive star...
This is the first report of Fermi Gamma-Ray Space Telescope observations quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from Large Area Telescope, covering 2008 July 7–October 6, indicate strong, highly variable γ-ray emission with an average flux ∼3 × 10−6 photons cm−2 s−1, for energies >100 MeV. variable, distinct, symmetrically shaped flares increases by a factor several on timescale about 3 days. variability indicates compact region, and...
We report the Fermi Large Area Telescope (LAT) discovery of high-energy (MeV/GeV) γ-ray emission positionally consistent with center radio galaxy M87, at a source significance over 10σ in 10 months all-sky survey data. Following detections Cen A and Per A, this makes M87 third seen LAT. The faint point-like has >100 MeV flux 2.45 (±0.63) × 10−8 photons cm−2 s−1 (photon index = 2.26 ± 0.13) no significant variability detected within LAT observation. This is comparable previous EGRET upper...
The diffuse Galactic gamma-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on Compton Observatory indicated excess > 1 GeV relative to models consistent directly measured CR spectra (the so-called ``EGRET excess''). was observed in all directions sky, a variety of explanations have been proposed, including beyond-the-Standard-Model scenarios like annihilating or...
This Letter presents the first results from observations of LSI +61 303 using Large Area Telescope data Fermi Gamma-Ray Space between 2008 August and 2009 March. Our indicate variability that is consistent with binary period, emission being modulated at 26.6 +/- 0.5 days. constitutes detection orbital periodicity in high-energy gamma rays (20 MeV-100 GeV, HE). The light curve characterized by a broad peak after periastron, as well smaller just before apastron. spectrum best represented power...
The first results from observations of the high-mass X-ray binary LS 5039 using Fermi Gamma-ray Space Telescope data between 2008 August and 2009 June are presented. Our indicate variability that is consistent with period, emission being modulated a period 3.903 ± 0.005 days; detection this modulation at GeV energies. light curve characterized by broad peak around superior conjunction in agreement inverse Compton scattering models. spectrum represented power law an exponential cutoff,...
We report on observations of TeV-selected AGN made during the first 5.5 months with Large Area Telescope (LAT) on-board Fermi Gamma-ray Space (Fermi). In total, 96 were selected for study, each being either (i) a source detected at TeV energies (28 sources) or (ii) an object that has been studied instruments and which upper-limit reported (68 objects). The show clear detections 38 these objects, 21 are joint GeV-TeV sources 29 not in third EGRET catalog. For Fermi-detected sources, spectra...
Context: The Large Magellanic Cloud (LMC) is to date the only normal external galaxy that has been detected in high-energy gamma rays. High-energy rays trace particle acceleration processes and gamma-ray observations allow nature sites of be studied. Aims: We characterise distribution sources cosmic LMC from analysis observations. Methods: analyse 11 months continuous sky-survey obtained with Area Telescope aboard Fermi Gamma-Ray Space compare it tracers interstellar medium models LMC....
Observations by the Large Area Telescope (LAT) on Fermi mission of diffuse γ-rays in a mid-latitude region third quadrant (Galactic longitude l from 200° to 260° and latitude |b| 22° 60°) are reported. The contains no known large molecular cloud most atomic hydrogen is within 1 kpc solar system. contributions γ-ray point sources inverse Compton scattering estimated subtracted. residual intensity exhibits linear correlation with gas column density energy 100 MeV 10 GeV. measured integrated...
The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space discovered a rapid (∼5 days duration), high-energy (E > 100 MeV) gamma-ray outburst from source identified with blazar PKS 1502+106 (OR 103, S3 1502+10, z = 1.839) starting 2008 August 5 (∼23 UTC, MJD 54683.95), and followed by bright variable flux over next few months. Results localization identification, as well spectral temporal behavior during first months of all-sky survey, are reported here in conjunction multiwaveband...
Energetic young pulsars and expanding blast waves (supernova remnants, SNRs) are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near center of compact synchrotron nebula inside supernova remnant CTA 1. pulsar, discovered through its gamma-ray pulsations, period 316.86 ms, derivative 3.614 x 10-13 s s-1 . Its characteristic age 104 years is comparable to that...
Following the recent discovery of γ rays from radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign radio to rays, which was carried out between end 2009 March and beginning July. The source displayed activity at all observed wavelengths: general decreasing trend optical γ-ray frequencies followed by an increase emission after less than two months peak emission. largest flux change, about factor 4, occurred in X-ray band. smallest...
We present multiwavelength studies of the 106.6 ms γ-ray pulsar PSR J1907+06 near TeV source MGRO J1908+06. Timing observations with Fermi result in a precise position determination for R.A. = 19h07m547(2), decl. +06°02'16(2)'' placing firmly within extent, suggesting is wind nebula J1907+0602. Pulsed emission clearly visible at energies from 100 MeV to above 10 GeV. The phase-averaged power-law index energy range E > 0.1 GeV Γ 1.76 ± 0.05 an exponential cutoff Ec 3.6 0.5 energy-dependent...
Abstract This contribution introduces a novel test system developed to evaluate the signal transmission quality in high-speed data links for 2026 Inner Tracker (ITk) upgrade of ATLAS experiment. Using an FPGA-based acquisition (DAQ) framework, setup can run simultaneous Bit Error Rate (BER) tests up 64 channels and generate virtual eye diagrams, qualifying ∼26k electrical at ITk rate 1.28 Gb/s. The paper includes results from calibration, yielding its measured losses, preliminary prototype...
We report the detection of pulsed γ-rays for PSRs J0631+1036, J0659+1414, J0742–2822, J1420–6048, J1509–5850, and J1718–3825 using Large Area Telescope on board Fermi Gamma-ray Space (formerly known as GLAST). Although these six pulsars are diverse in terms their spin parameters, they share an important feature: γ-ray light curves (at least given current count statistics) single peaked. For two pulsars, there hints a double-peaked structure curves. The shapes observed this group discussed...