A5042586259- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Neutrino Physics Research
- Nuclear Physics and Applications
- Literature: history, themes, analysis
- Medical Imaging Techniques and Applications
- Particle physics theoretical and experimental studies
- Radiation Therapy and Dosimetry
- Particle Accelerators and Free-Electron Lasers
- Photocathodes and Microchannel Plates
- Genomics and Phylogenetic Studies
- Cosmology and Gravitation Theories
- Radioactivity and Radon Measurements
- Geophysics and Gravity Measurements
- American Constitutional Law and Politics
- Solar and Space Plasma Dynamics
- Caribbean history, culture, and politics
- Postcolonial and Cultural Literary Studies
- Historical Economic and Social Studies
Natural Resources Canada
2016-2025
University College Cork
2013-2020
APC Microbiome Institute
2017-2020
McGill University
2008-2019
University of Chicago
2012-2016
Geological Survey of Canada
2016
Fermi National Accelerator Laboratory
2016
Princess Alexandra Hospital
2014
Kavli Institute for Particle Astrophysics and Cosmology
2013
Universidad Veritas
2011-2013
Abstract Lactobacilli are a diverse group of species that occupy nutrient-rich niches associated with humans, animals, plants and food. They used widely in biotechnology food preservation, being explored as therapeutics. Exploiting lactobacilli has been complicated by metabolic diversity, unclear identity uncertain relationships between them other commercially important lactic acid bacteria. The capacity for biotransformations catalysed is an untapped resource. Here we report the genome...
The widespread use of antibiotics in association with high-density clinical care has driven the emergence drug-resistant bacteria that are adapted to thrive hospitalized patients. Of particular concern globally disseminated methicillin-resistant Staphylococcus aureus (MRSA) clones cause outbreaks and epidemics associated health care. most rapidly spreading tenacious health-care-associated clone Europe currently is EMRSA-15, which was first detected UK early 1990s subsequently spread...
The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles energies exceeding 10^12 electron Volts (eV) and are bright sources very-high-energy (VHE) gamma-ray emission, it not yet known where VHE emission originates. Here we report on radio observations galaxy M87, revealing period extremely strong flares accompanied by increase flux from its nucleus. These results...
This detection constrains the mechanism and emission region of gamma-ray radiation in pulsar’s magnetosphere.
We report the discovery of TeV gamma-ray emission from Type Ia supernova remnant (SNR) G120.1+1.4, known as Tycho's remnant. Observations performed in period 2008-2010 with VERITAS ground-based observatory reveal weak coming direction remnant, compatible a point source located at $00^{\rm h} \ 25^{\rm m} 27.0^{\rm s},\ +64^{\circ} 10^{\prime} 50^{\prime\prime}$ (J2000). The photon spectrum measured by can be described power-law $dN/dE = C(E/3.42\;\textrm{TeV})^{-\Gamma}$ $\Gamma 1.95 \pm...
LS I +61 303 is one of only a few high-mass X-ray binaries currently detected at high significance in very energy gamma-rays. The system was observed over several orbital cycles (between September 2006 and February 2007) with the VERITAS array imaging air-Cherenkov telescopes. A signal gamma-rays energies above 300 GeV found statistical 8.4 standard deviations. flux measured to be strongly variable; maximum during most apastron. spectrum for period emission can characterized by power law...
We present evidence that the very high energy (VHE, E > 100 GeV) gamma-ray emission coincident with supernova remnant IC 443 is extended. contains one of best studied sites remnant/molecular cloud interaction and pulsar wind nebula CXOU J061705.3+222127, both which are important targets for VHE observations. VERITAS observed 37.9 hr during 2007 detected above 300 GeV an excess 247 events, resulting in a significance 8.3 standard deviations (σ) before trials 7.5σ after point-source search....
Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated and, on account weak energy losses, can accumulate, suggesting that may also sources very high (VHE; E > 100 GeV) gamma-ray emission. We report here VHE observations the Coma cluster with VERITAS array imaging Cerenkov telescopes, complementing Fermi Large Area Telescope at GeV energies. No significant emission from Cluster was detected. Integral flux...
The VERITAS array of Cherenkov telescopes has carried out a deep observational program on the nearby dwarf spheroidal galaxy Segue 1. We report results nearly 48 hours good quality selected data, taken between January 2010 and May 2011. No significant $\ensuremath{\gamma}$-ray emission is detected at nominal position 1, upper limits integrated flux are derived. According to recent studies, 1 most dark matter-dominated currently known. derive stringent bounds various annihilating decaying...
Salmonella enterica serovar Agona has caused multiple food-borne outbreaks of gastroenteritis since it was first isolated in 1952. We analyzed the genomes 73 isolates from global sources, comparing five distinct with sporadic infections as well food contamination and environment. consists three lineages minimal mutational diversity: only 846 single nucleotide polymorphisms (SNPs) have accumulated non-repetitive, core genome evolved 1932 subsequently underwent a major population expansion...
The very high energy (VHE; E > 100 GeV) blazar Markarian 501 has a well-studied history of extreme spectral variability and is an excellent laboratory for studying the physical processes within jets active galactic nuclei. However, there are few detailed multiwavelength studies during its quiescent state, due to low luminosity. A short-term study was coordinated in March 2009, focusing around multi-day observation with Suzaku X-ray satellite including {\gamma}-ray data from VERITAS, MAGIC,...
Outbursts from gamma-ray quasars provide insights on the relativistic jets of active galactic nuclei and constraints diffuse radiation fields that fill universe. The detection significant emission above 100 GeV a distant quasar would show some radiated gamma-rays escape pair-production interactions with low-energy photons, be it extragalactic background light (EBL), or near supermassive black hole lying at jet's base. VERITAS detected up to ∼200 PKS 1441+25 (z = 0.939) during 2015 April,...
The high-frequency-peaked BL Lacertae object 1ES 0229+200 is a relatively distant (z = 0.1396), hard-spectrum (Gamma ~ 2.5), very-high-energy-emitting (E > 100 GeV) gamma-ray blazar. Very-high-energy measurements of this active galactic nucleus have been used to place constraints on the intensity extragalactic background light and intergalactic magnetic field. A multi-wavelength study centered around very-high-energy observations by VERITAS presented. This obtained, over period three years,...
The observations of gamma-ray emission from pulsars with the Fermi-LAT detector and detection Crab pulsar VERITAS array Cherenkov telescopes at energies above 100 GeV make it unlikely that curvature radiation is main source photons in many other pulsars. We outline a model which broad UV-X-ray component very high energy \gamma-ray are explained within Synchrotron-Self-Compton (SSC) framework. argue bulk observed generated by secondary plasma, produced cascades outer gaps magnetosphere. find...
High-energy gamma-ray emission from supernova remnants (SNRs) has provided a unique perspective for studies of Galactic cosmic-ray acceleration. Tycho's SNR is particularly good target because it young, type Ia that well-studied over wide range energies and located in relatively clean environment. Since the detection by VERITAS Fermi-LAT, there have been several theoretical models proposed to explain its broadband high-energy morphology. We report on an update measurements with 147 hours 84...
It has become increasingly accepted that establishing and maintaining a complex diverse gut microbiota is fundamental to human health. There are growing efforts identify means of modulating influencing the microbiota, especially in individuals who have experienced disruption their native microbiota. Faecal transplantation (FMT) one method restores diversity an individual by introducing microbes from healthy donor. FMT introduces total microbial load into recipient, including bacteria,...
The multiwavelength observation of the nearby radio galaxy M87 provides a unique opportunity to study in detail processes occurring active galactic nuclei from waves TeV γ-rays. Here we report detection γ-ray emission above 250 GeV spring 2007 with VERITAS atmospheric Cerenkov telescope array and discuss its correlation X-ray emission. is measured be pointlike an intrinsic source radius less than 4.5'. differential energy spectrum fitted well by power-law function: dΦ/dE = (7.4 ± 1.3stat...
We report results from an intensive multiwavelength campaign on the intermediate-frequency-peaked BL Lacertae object W Com (z=0.102) during a strong outburst of very high energy gamma-ray emission in June 2008. The signal was detected by VERITAS 2008 7-8 with flux F(>200 GeV) = (5.7+-0.6)x10^-11 cm-2s-1, about three times brighter than discovery March. initial detection this flare at energies above 200 GeV followed observations gamma-rays (AGILE, E>100 MeV), and X-rays (Swift XMM-Newton),...
The intermediate-frequency peaked BL Lacertae (IBL) object 3C 66A is detected during 2007 - 2008 in VHE (very high energy: E > 100 GeV) gamma-rays with the VERITAS stereoscopic array of imaging atmospheric Cherenkov telescopes. An excess 1791 events detected, corresponding to a significance 21.2 standard deviations (sigma), these observations (32.8 hours live time). observed integral flux above 200 GeV 6% Crab Nebula's and shows evidence for variability on time-scale days. measured energy...
We report on observations of very high energy γ rays from the shell-type supernova remnant (SNR) Cassiopeia A with Very Energetic Radiation Imaging Telescope Array System stereoscopic array four imaging atmospheric Cherenkov telescopes in Arizona. The total exposure time for these is 22 hr, accumulated between September and November 2007. γ-ray source associated SNR was detected above 200 GeV a statistical significance 8.3σ. estimated integral flux this about 3% Crab-Nebula flux. photon...
VERITAS, an Imaging Atmospheric Cherenkov Telescope (IACT) system for gammma‐ray astronomy in the GeV‐TeV range, has recently completed its first season of observations with a full array four telescopes. A number astrophysical gamma‐ray sources have been detected, both galactic and extragalactic, including previously unknown at TeV energies. We describe status some highlight results, assess technical performance, sensitivity shower reconstruction capabilities.
The high-frequency-peaked BL Lacertae object RGB J0710+591 was observed in the very high-energy (VHE; E > 100 GeV) wave band by VERITAS array of atmospheric Cherenkov telescopes. observations, taken between 2008 December and 2009 March totaling 22.1 hr, yield discovery VHE gamma rays from source. is detected at a statistical significance 5.5 standard deviations (5.5σ) above background, corresponding to an integral flux (3.9 +/- 0.8) x 10-12 cm-2 s-1 (3% Crab Nebula's flux) 300 GeV....