M. Galassi
A5062988292- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- SAS software applications and methods
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Astrophysical Phenomena and Observations
- Nuclear Physics and Applications
- Stellar, planetary, and galactic studies
- Solar and Space Plasma Dynamics
- Radiation Detection and Scintillator Technologies
- Pulsars and Gravitational Waves Research
- Medical Imaging Techniques and Applications
- CCD and CMOS Imaging Sensors
- Atmospheric Ozone and Climate
- Advanced Optical Sensing Technologies
- Laser-Plasma Interactions and Diagnostics
- Methane Hydrates and Related Phenomena
- Planetary Science and Exploration
- Scientific Computing and Data Management
- Atomic and Molecular Physics
- Adaptive optics and wavefront sensing
- Neutrino Physics Research
- Infrared Target Detection Methodologies
Los Alamos National Laboratory
2006-2021
University of Alabama in Huntsville
2008
University of California, Berkeley
2008
Paul Scherrer Institute
2008
Institut de Recherche sur les Lois Fondamentales de l'Univers
2008
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2008
University College London
2008
Joint Institute for Laboratory Astrophysics
2008
Centre for Cosmology and Particle Physics Phenomenology
2008
University of Leicester
2008
We describe and discuss the global properties of 45 gamma-ray bursts (GRBs) observed by HETE-2 during first 3 years its mission, focusing on X-ray flashes (XRFs) X-ray-rich GRBs (XRRs). find that numbers XRFs, XRRs, are comparable, durations sky distributions XRFs XRRs similar to those GRBs. also spectral GRBs, except values peak energy E burst spectrum in νFν, flux Fpeak, fluence SE much smaller (and smaller) than Finally, we all three kinds form a continuum [SE(2-30 keV), SE(30-400) keV]...
We describe and discuss the global properties of 45 gamma-ray bursts (GRBs) observed by HETE-2 during first three years its mission, focusing on X-Ray Flashes (XRFs) X-ray-rich GRBs (XRRs). find that numbers XRFs, XRRs, are comparable. durations sky distributions XRFs XRRs similar to those GRBs. also spectral GRBs, except values peak energy $E^{\rm obs}_{\rm peak}$ burst spectrum in $νF_ν$, flux $\Fp$, fluence $S_E$ much smaller -- than Finally, we all kinds form a continuum [$S_E$(2-30...
We present a spectral analysis of 35 GRBs detected with the HETE-2 gamma-ray detectors (the FREGATE instrument) in energy range 7–400 keV. The GRB sample analyzed is made localized Wide Field X-ray Monitor onboard or Interplanetary Network. derive parameters time-integrated spectra, and distribution low-energy photon index, alpha, peak energy, . then discuss existence nature recently discovered X-Ray Flashes their relationship classical GRBs.
We report High Energy Transient Explorer 2 (HETE-2) Wide Field X-Ray Monitor/French Gamma Telescope observations of the X-ray flash XRF 020903. This event was extremely soft: ratio log(SX/Sγ) = 0.7, where SX and Sγ are fluences in 2-30 30-400 keV energy bands, is most extreme value observed so far by HETE-2. In addition, spectrum has an peak E < 5.0 (99.7% probability upper limit), no photons were detected above ~10 keV. The burst shorter at higher energies, which similar to behavior long...
The authors have developed an automated feature detection/classification system, called GENetic Imagery Exploitation (GENIE), which has been designed to generate image processing pipelines for a variety of tasks. GENIE is hybrid evolutionary algorithm that addresses the general problem finding features interest in multispectral remotely-sensed images. describe their system detail together with experiments involving comparisons several conventional supervised classification techniques, number...
Over 120 million vehicles enter the United States each year. Many are capable of transporting hidden nuclear weapons or material. Currently deployed X-ray radiography systems limited because they cannot be used on occupied and energy dose too low to penetrate many cargos. We present a new technique that overcomes these limitations by obtaining tomographic images using multiple scattering cosmic radiation as it transits vehicle. When coupled with passive detection, muon interrogation could...
Free and open source software (FOSS) is any computer program released under a licence that grants users rights to run the for purpose, study it, modify redistribute it in original or modified form. Our aim explore intersection between FOSS computational reproducibility. We begin by situating relation other ‘open’ initiatives, specifically science, research, scholarship. In this context, we argue anyone who actively contributes research process today researcher, they use computers manage...
Context. As a result of the numerous missions dedicated to detection Gamma-ray bursts (GRBs), observed properties these events are now well known. However, studying their parameters in source frame is not simple since it requires having measurements both bursts' and distances.
An exceptionally intense gamma-ray burst, GRB 030329, was detected and localized by the instruments on board High Energy Transient Explorer satellite (HETE) at 11:37:14 UT 2003 March 29. The burst consisted of two ~10 s pulses roughly equal brightness an X-ray tail lasting more than 100 s. energy fluence in 30-400 keV band Sγ = 1.2 × 10-4 ergs cm-2, making 030329 one brightest GRBs ever detected. Communication a 2' error box 73 minutes after allowed rapid detection counterpart optical,...
A bright, X-ray-rich gamma-ray burst (GRB) was detected by the French Gamma Telescope (FREGATE) and localized with Wide-field X-ray Monitor (WXM) Soft Camera (SXC) instruments on High Energy Transient Explorer 2 satellite (HETE-2) at 11:18:34.03UT (40714.03SOD) 11 December 2002.The WXM flight software to a 14 ′ radius; this relayed astronomical community 22 seconds after start of burst.
The Rapid Telescopes for Optical Response (RAPTOR) experiment is a spatially distributed system of autonomous robotic telescopes that designed to monitor the sky optical transients. core composed two telescope arrays, separated by 38 kilometers, stereoscopically view same 1500 square-degree field with wide-field imaging array and central 4 more sensitive narrow-field "fovea" imager. Coupled each real-time data analysis pipeline identify interesting transients on timescales seconds and, when...
Abstract The Wide-field X-ray Monitor (WXM) is one of the scientific instruments carried on High Energy Transient Explorer 2 (HETE-2) satellite launched 2000 October 9. HETE-2 an international mission consisting a small dedicated to provide broad-band observations and accurate localizations gamma-ray bursts (GRBs). A unique feature this its capability determine transmit GRB coordinates in almost real-time through burst alert network. WXM consists three elements: four identical Xe-filled...
Abstract Using a pulse-fit method, we investigated the spectral lags between traditional gamma-ray band (50–400 keV) and X-ray (6–25 for 8 GRBs with known redshifts (GRB 010921, GRB 020124, 020127, 021211, 030528, 040924, 041006, 050408), detected WXM FREGATE instruments aboard HETE-2 satellite. We found several relations individual pulses lag other observables, such as luminosity, pulse duration, peak energy, $E_{\rm peak}$. The obtained results are consistent those BATSE, indicating that...
On 2001 September 21 at 05:15:50.56 UT, the French Gamma Telescope (FREGATE) on High Energy Transient Explorer (HETE) detected a bright gamma-ray burst (GRB). The was also seen by X-detector Wide-field X-ray Monitor (WXM) instrument and therefore well localized in X-direction; however, outside fully coded field of view WXM Y-detector, information Y-direction limited. Cross-correlation HETE Ulysses time histories yielded an Interplanetary Network (IPN) annulus that crosses error strip ~45°...
We report High Energy Transient Explorer 2 (HETE-2) Wide Field X-ray Monitor (WXM) and French Gamma Telescope observations of XRF 030723 along with the afterglow made using 6.5 m Magellan Clay telescope Chandra. The observed peak energy E νFν burst spectrum is found to lie within (or below) WXM 2-25 keV passband at 98.5% confidence, no counts are detected above 30 keV. Our best-fit value = 8.4 ratio γ-ray flux for follows a correlation GRBs HETE-2, duration similar that typical long-duration...
We have built a detector capable of locating high Z objects in the sampling (middle) region detector. As atomic number increases, radiation length rapidly decreases, yielding larger variance scattering angle. Cosmic ray muon tomography works by tracking muons above region, and them below as well. The difference between two trajectories yield information, via variance, materials contained within region[1]. One most important aspects cosmic is minimizing exposure time. flux about 1/cm\^2/min,...
Here we report the localizations and properties of four short-duration GRBs localized by High Energy Transient Explorer 2 satellite (HETE-2): 010326B, 040802, 051211 060121, all which were detected French Gamma Telescope (Fregate) with Wide-field X-ray Monitor (WXM) and/or Soft Camera (SXC) instruments. We discuss eight possible criteria for determining whether these are "short population bursts" (SPBs) or "long (LPBs). These (1) duration, (2) pulse widths, (3) spectral hardness, (4) lag,...
Here we present the first results of GRB afterglow observations with GROND. Gamma‐Ray burst Optical and Near‐infrared Detector (GROND) is an instrument 4 optical CCDs 3 near‐infrared detectors main aim observing afterglows determining their redshift. With its dynamic scheduling on‐the‐fly data analysis system, GROND combines sensitivity 2.2 m telescope a robotic observation scheme. has been mounted on ESO/MPI at La Silla since May 2007. It automatically observed 10 35 GRBs that happened...