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Full-Text Articles in Physical Sciences and Mathematics
Simultaneous Multiwavelength Observations Of Markarian 421 During Outburst, P. T. Reynolds, Veritas, Magic
Simultaneous Multiwavelength Observations Of Markarian 421 During Outburst, P. T. Reynolds, Veritas, Magic
Physical Sciences Publications
We report on the results of two coordinated multiwavelength campaigns that focused on the blazar Markarian 421 during its 2006 and 2008 outbursts. These campaigns obtained UV and X-ray data using the XMM-Newton satellite, while the gamma-ray data were obtained utilizing three imaging atmospheric Cerenkov telescopes, the Whipple 10 m telescope and VERITAS, both based in Arizona, as well as the MAGIC telescope, based on La Palma in the Canary Islands. The coordinated effort between the gamma-ray groups allowed for truly simultaneous data in UV/X-ray/gamma-ray wavelengths during a significant portion of the XMM-Newton observations. This simultaneous coverage allowed for a …
Multiwavelength Observations Of Ls I+61 Degrees 303 With Veritas, Swift, And Rxte, P. T. Reynolds, Et. Al.
Multiwavelength Observations Of Ls I+61 Degrees 303 With Veritas, Swift, And Rxte, P. T. Reynolds, Et. Al.
Physical Sciences Publications
We present results from a long-term monitoring campaign on the TeV binary LSI +61° 303 with VERITAS at energies above 500 GeV, and in the 2-10 keV hard X-ray bands with RXTE and Swift, sampling nine 26.5 day orbital cycles between 2006 September and 2008 February. The binary was observed by VERITAS to be variable, with all integrated observations resulting in a detection at the 8.8σ (2006/2007) and 7.3σ (2007/2008) significance level for emission above 500 GeV. The source was detected during active periods with flux values ranging from 5% to 20% of the Crab Nebula, varying over the course …
Detection Of The Bl Lacertae Object H1426+428 At Tev Gamma-Ray Energies, P. T. Reynolds, Et. Al.
Detection Of The Bl Lacertae Object H1426+428 At Tev Gamma-Ray Energies, P. T. Reynolds, Et. Al.
Physical Sciences Publications
A very high energy γ-ray signal has been detected at the 5.5 σ level from H1426+428, an X-ray-selected BL Lacertae object at a redshift of 0.129. The object was monitored from 1995 to 1998 with the Whipple 10 m imaging atmospheric Cerenkov telescope as part of a general blazar survey; the results of these observations, although not statistically significant, were consistently positive. X-ray observations of H1426+428 during 1999 with the BeppoSAX instrument revealed that the peak of its synchrotron spectrum occurs at greater than 100 keV, leading to the prediction of observable TeV emission from this object. H1426+428 was monitored …
Veritas Observations Of The Bl Lac Object 1es 1218+304, P. T. Reynolds, Et. Al.
Veritas Observations Of The Bl Lac Object 1es 1218+304, P. T. Reynolds, Et. Al.
Physical Sciences Publications
The VERITAS collaboration reports the detection of very-high-energy gamma-ray emission from the high-frequency-peaked BL Lac object 1ES 1218+304 located at a redshift of z = 0.182. A gamma-ray signal was detected with a statistical significance of 10.4 standard deviations (10.4σ) for the observations taken during the first three months of 2007, confirming the discovery of this object made by the MAGIC collaboration. The photon spectrum between ~160 GeV and ~1.8 TeV is well described by a power law with an index of Γ = 3.08 ± 0.34stat ± 0.2sys. The integral flux is Φ(E>200GeV) = (12.2 ± 2.6) × …
Investigating The Tev Morphology Of Mgro J1908+06 With Veritas, P. T. Reynolds, Et. Al.
Investigating The Tev Morphology Of Mgro J1908+06 With Veritas, P. T. Reynolds, Et. Al.
Physical Sciences Publications
We report on deep observations of the extended TeV gamma-ray source MGRO J1908+06 made with the VERITAS very high energy gamma-ray observatory. Previously, the TeV emission has been attributed to the pulsar wind nebula (PWN) of the Fermi-LAT pulsar PSR J1907+0602. We detect MGRO J1908+06 at a significance level of 14 standard deviations (14σ) and measure a photon index of 2.20 ± 0.10stat ± 0.20sys. The TeV emission is extended, covering the region near PSR J1907+0602 and also extending toward SNR G40.5-0.5. When fitted with a two-dimensional Gaussian, the intrinsic extension has a standard deviation of σsrc = 0fdg44 ± …