A5038942624- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Earthquake Detection and Analysis
- Particle Accelerators and Free-Electron Lasers
- Astrophysical Phenomena and Observations
- Lightning and Electromagnetic Phenomena
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Advanced Image Fusion Techniques
- Fire effects on ecosystems
- SAS software applications and methods
- Advanced Optical Sensing Technologies
- Astronomical Observations and Instrumentation
- Radioactivity and Radon Measurements
- Seismic Waves and Analysis
- Ocular and Laser Science Research
- Magnetic confinement fusion research
- Solar Radiation and Photovoltaics
- Stellar, planetary, and galactic studies
- Fire Detection and Safety Systems
- Superconducting Materials and Applications
University of Alabama in Huntsville
2020-2024
Florida Institute of Technology
2023
College of Charleston
2018
Abstract GRB 221009A has been referred to as the brightest of all time (BOAT). We investigate veracity this statement by comparing it with a half century prompt gamma-ray burst observations. This is ever detected measures peak flux and fluence. Unexpectedly, highest isotropic-equivalent total energy identified, while luminosity at ∼99th percentile known distribution. explore how such can be powered discuss potential implications for ultralong high-redshift bursts. By geometric extrapolation...
Abstract We report the discovery of GRB 221009A, highest flux gamma-ray burst (GRB) ever observed by Fermi Gamma-ray Burst Monitor (Fermi-GBM). This has continuous prompt emission lasting more than 600 s, which smoothly transitions to afterglow visible in Fermi-GBM energy range (8 keV–40 MeV), and total energetics higher any other sample. By using a variety new existing analysis techniques we probe spectral temporal evolution 221009A. find no prior trigger time ( t 0 ; 2022 October 9 at...
We report the discovery of unusually bright long-duration gamma-ray burst (GRB), GRB 221009A, as observed by Neil Gehrels Swift Observatory (Swift), Monitor All-sky X-ray Image (MAXI), and Neutron Star Interior Composition Explorer Mission (NICER). This energetic was located relatively nearby (z = 0.151), allowing for sustained observations afterglow. The large luminosity low Galactic latitude (b 4.3 degrees) make 221009A a powerful probe dust in Milky Way. Using echo tomography we map...
Abstract We present the systematic spectral analyses of gamma-ray bursts (GRBs) detected by Fermi Gamma-Ray Burst Monitor during its first ten years operation. This catalog contains two types spectra: time-integrated fits and at brightest time bin, from 2297 GRBs, resulting in a compendium over 18,000 spectra. The four different models used for fitting spectra were selected based on their empirical importance to shape many GRBs. describe detail our procedure criteria analyses, bulk results...
Abstract We report observations of the optical counterpart long gamma-ray burst (GRB) GRB 230812B and its associated supernova (SN) SN 2023pel. The proximity ( z = 0.36) high energy E γ ,iso ∼ 10 53 erg) make it an important event to study as a probe connection between massive star core collapse relativistic jet formation. With phenomenological power-law model for afterglow, we find late-time flattening consistent with presence SN. 2023pel has absolute peak r -band magnitude M −19.46 ± 0.18...
Abstract We present Fermi Gamma-ray Burst Monitor (Fermi-GBM) and Swift Alert Telescope (Swift-BAT) searches for gamma-ray/X-ray counterparts to gravitational-wave (GW) candidate events identified during the third observing run of Advanced LIGO Virgo detectors. Using Fermi-GBM onboard triggers subthreshold gamma-ray burst (GRB) candidates found in ground analyses, Targeted Search Untargeted Search, we investigate whether there are any coincident GRBs associated with GWs. also search...
Abstract The recent discovery of a kilonova from the long-duration gamma-ray burst (GRB) GRB 211211A challenges classification schemes based on temporal information alone. Gamma-ray properties reveal an extreme event, which stands out among both short and long GRBs. We find very variations (few milliseconds) in lightcurve estimate ∼1000 for Lorentz factor outflow. discuss relevance identifying similar GRBs resulting compact mergers. Our findings indicate that future gravitational-wave...
Abstract We present results from offline searches of Fermi Gamma-ray Burst Monitor (GBM) data for gamma-ray transients coincident with the compact binary coalescences observed by gravitational-wave (GW) detectors Advanced LIGO and Virgo during their first second observing runs. In particular, we perform follow-up both confirmed events low significance candidates reported in LIGO/Virgo catalog GWTC-1. search temporal coincidences between these GW signals GBM-triggered bursts (GRBs). also use...
Observing gravitationally lensed objects in the time domain is difficult, and well-observed time-varying sources are rare. Lensed gamma-ray bursts (GRBs) offer improved timing precision to this class of complementing observations quasars supernovae. The rate GRBs highly uncertain, approximately 1 1000. Gamma-ray Burst Monitor (GBM) onboard Fermi Space Telescope has observed more than 3000 making it an ideal instrument uncover bursts. Here we present GRB 210812A showing two emission episodes,...
Abstract The Hunga Tonga–Hunga Ha'apai submarine volcano recently resumed activity. Violent eruptions on 14th and 15th January 2022 launched a tall ash plume that produced extremely high lightning rates. Here we report terrestrial gamma‐ray flash (TGF) was by the volcanic observed from space Fermi Gamma‐ray Burst Monitor (GBM). Observations radio networks especially Geostationary Lightning Mapper show only close enough to produce TGF detectable GBM volcano's plume. With observing duration of...
Abstract We developed a framework merging unsupervised and supervised machine learning to classify lightning radio signals, applied it the possible detection of terrestrial gamma‐ray flashes (TGFs). Recent studies have established tight connection between energetic in‐cloud pulses (EIPs, >150 kA) subset TGFs, enabling continuous large‐scale ground‐based TGF detection. However, even with high peak current threshold, is time‐consuming manually search for EIPs in background many non‐EIP...
We report the discovery of unusually bright long-duration gamma-ray burst (GRB), GRB 221009A, as observed by Neil Gehrels Swift Observatory (Swift), Monitor All-sky X-ray Image (MAXI), and Neutron Star Interior Composition Explorer Mission (NICER). This energetic was located relatively nearby (z = 0.151), allowing for sustained observations afterglow. The large luminosity low Galactic latitude (b 4.3 degrees) make 221009A a powerful probe dust in Milky Way. Using echo tomography we map...
Abstract Many of the details how terrestrial gamma‐ray flashes (TGFs) are produced, including their association with upward‐propagating in‐cloud lightning leader channels, remain poorly understood. Measurements low‐frequency radio emissions associated TGF production continue to provide unique views and key insights into electrodynamics this process. Here we report further on connection between energetic pulses (EIPs) TGFs. With coordinated measurements from both ground‐based sensors...
Abstract We report measurements of a terrestrial gamma ray flash (TGF) detected by the Fermi Gamma‐ray Burst Monitor that was produced during negative cloud‐to‐ground (CG) lightning leader. This is first downward directed TGF occurring CG but space‐based instrument. The photons are 3 ms preceding return stroke ( − 146 kA) and essentially simultaneous with an isolated low frequency radio pulse. Based on timing, pulse estimated to initiate at approximately 6 km altitude, its polarity indicates...
Abstract We analyze pulse properties of short gamma-ray bursts (GRBs) from a new catalog containing 434 pulses 387 BATSE time-tagged event (TTE) GRBs. Short GRB exhibit correlated duration, fluence, hardness, and amplitude, they evolve hard to soft while undergoing similar triple-peaked light curves those found in long/intermediate bursts. classify using their temporal complexities, demonstrating that range complexities smooth highly variable. Most the bright, hard, chaotic emission seen...
At 13:16:59.99 UT on October 9th, 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered gamma-ray burst (GRB) 221009A. This GRB has highest fluence value GBM ever detected. The light curve consists of two distinct emission episodes, a single isolated peak with thermal spectra followed by longer, extremely bright, multi-pulsed event non-thermal spectra. main peaks second event, from $t_{0}$+218 to $t_{0}$+276 seconds and $t_{0}$+508 $t_{0}$+513\,s, had such high photon rates they caused...
Abstract We demonstrate that the “smoke” of limited instrumental sensitivity smears out structure in gamma-ray burst (GRB) pulse light curves, giving each a triple-peaked appearance at moderate signal-to-noise ratio (S/N) and simple monotonic low S/N. minimize this effect by studying six very bright GRB pulses (S/N generally >100), discovering surprisingly exhibits complex time-reversible wavelike residual structures. These “mirrored” structures can have large amplitudes, occur on short...
GRB 221009A has been referred to as the Brightest Of All Time (the BOAT). We investigate veracity of this statement by comparing it with a half century prompt gamma-ray burst observations. This is brightest ever detected measures peak flux and fluence. Unexpectedly, highest isotropic-equivalent total energy identified, while luminosity at $\sim99$th percentile known distribution. explore how such can be powered discuss potential implications for ultra-long high-redshift bursts. By geometric...
Abstract Combining in situ measurements of energetic electrons and remote sensing observations hard X‐rays type III radio bursts, we examine the release times July 23, 2016 event. We find that releases from Sun are delayed those responsible for X‐rays. further time is a function electron energy. Under assumption acceleration mechanism upward propagating Fermi‐type controlled by an energy‐dependent diffusion coefficient, fit these simple functional form, related to turbulence spectral index....
The prompt spectra of gamma-ray bursts are known to follow broadband continuum behavior over decades in energy. GRB 221009A, given the moniker brightest all time (BOAT), is burst identified half a century observations, and was first by Fermi Gamma-ray Burst Monitor (GBM). On behalf Fermi-GBM Team, Lesage et al. (2023) described initial GBM analysis. Ravasio (2024) report identification spectral line part emission this burst, which they describe as evolving 80 s from $\sim$12 MeV 6 MeV. We...
The Time-Domain And MultiMessenger (TDAMM) Communications Science Analysis Group (TDAMMCommSAG) was formulated to describe the unique technical challenges of communicating rapidly and from NASA astrophysics missions studying most variable, transient, extreme objects in Universe. This report describes study if how transition current NASA-operated space ground relays commercial services will adequately serve these missions. Depending on individual mission requirements Concept Operations...
The Interplanetary Network (IPN) is a detection, localization and alert system that utilizes the arrival time of transient signals in gamma-ray detectors on spacecraft separated by planetary baselines to geometrically locate origin these transients. Due changing astrophysical landscape new emphasis domain multi-messenger astrophysics (TDAMM) from Pathways Discovery Astronomy Astrophysics for 2020s, this Gamma-ray Transient Science Analysis Group was tasked understand role IPN high-energy...