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Full-Text Articles in Physical Sciences and Mathematics
Discovery Of Very High Energy Gamma Rays From Pks 1424+240 And Multiwavelength Constraints On Its Redshift, P. T. Reynolds, Et Al
Discovery Of Very High Energy Gamma Rays From Pks 1424+240 And Multiwavelength Constraints On Its Redshift, P. T. Reynolds, Et Al
Physical Sciences Publications
We report the first detection of very high energy83Gamma-ray emission above 100 GeV. (VHE) gamma-ray emission above 140 GeV from PKS 1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140 GeV measured by VERITAS is well described by a power law with a photon index of 3.8 ± 0.5stat ± 0.3syst and a flux normalization at 200 GeV of (5.1 ± 0.9stat ± 0.5syst) × 10–11 TeV–1 cm–2 s–1, where stat and syst denote the statistical and systematical uncertainties, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (from …
Detection Of Extended Vhe Gamma Ray Emission From G106.3+2.7 With Veritas, P. T. Reynolds, Et Al
Detection Of Extended Vhe Gamma Ray Emission From G106.3+2.7 With Veritas, P. T. Reynolds, Et Al
Physical Sciences Publications
We report the detection of very-high-energy (VHE) gamma-ray emission from supernova remnant (SNR) G106.3+2.7. Observations performed in 2008 with the VERITAS atmospheric Cherenkov gamma-ray telescope resolve extended emission overlapping the elongated radio SNR. The 7.3σ (pre-trials) detection has a full angular extent of roughly 06 by 04. Most notably, the centroid of the VHE emission is centered near the peak of the coincident 12CO (J = 1-0) emission, 04 away from the pulsar PSR J2229+6114, situated at the northern end of the SNR. Evidently the current-epoch particles from the pulsar wind nebula are not participating in the gamma-ray production. …
Observation Of Extended Very High Energy Emission From The Supernova Remnant Ic 443 With Veritas, P. T. Reynolds, Et Al
Observation Of Extended Very High Energy Emission From The Supernova Remnant Ic 443 With Veritas, P. T. Reynolds, Et Al
Physical Sciences Publications
We present evidence that the very high energy (VHE, E > 100 GeV) gamma-ray emission coincident with the supernova remnant IC 443 is extended. IC 443 contains one of the best studied sites of supernova remnant/molecular cloud interaction and the pulsar wind nebula CXOU J061705.3+222127, both of which are important targets for VHE observations. VERITAS observed IC 443 for 37.9 hr during 2007 and detected emission above 300 GeV with an excess of 247 events, resulting in a significance of 8.3 standard deviations (σ) before trials and 7.5σ after trials in a point-source search. The emission is centered at 6h16m51s + …
Veritas Observations Of A Very High Energy Gamma-Ray Flare From The Blazar 3c 66a, P. T. Reynolds, Et Al
Veritas Observations Of A Very High Energy Gamma-Ray Flare From The Blazar 3c 66a, P. T. Reynolds, Et Al
Physical Sciences Publications
The intermediate-frequency peaked BL Lacertae (IBL) object 3C 66A is detected during 2007-2008 in VHE (very high energy; E > 100 GeV) γ rays with the VERITAS stereoscopic array of imaging atmospheric Cherenkov telescopes. An excess of 1791 events is detected, corresponding to a significance of 21.2 standard deviations (σ), in these observations (32.8 hr live time). The observed integral flux above 200 GeV is 6% of the Crab Nebula's flux and shows evidence for variability on the timescale of days. The measured energy spectrum is characterized by a soft power law with photon index Γ = 4.1 ± 0.4stat ± …