arXiv subjects

S. Fegan

Publications and source records attributed to S. Fegan.

311 records · Page 18Linked to original sources

arXiv2008

Section on Prospects for Dark Matter Detection of the White Paper on the Status and Future of Ground-Based TeV Gamma-Ray Astronomy

This is a report on the findings of the dark matter science working group for the white paper on the status and future of TeV gamma-ray astronomy. The white paper was commissioned by the American Physical Society, and the full white paper can be found on astro-ph (arXiv:0810.0444). This detailed section discusses the prospects for dark matter detection with future gamma-ray experiments, and the complementarity of gamma-ray measurements with other indirect, direct or accelerator-based searches. We conclude that any comprehensive search for dark matter should include gamma-ray observations, both to identify the dark matter particle (through the charac- teristics of the gamma-ray spectrum) and to measure the distribution of dark matter in galactic halos.

astro-ph↗

arXiv2008

Technology Section of the White Paper on the Status and Future of Ground-based TeV Gamma-ray Astronomy

This is a report on the findings of the technology working group for the white paper on the status and future of TeV gamma-ray astronomy. The white paper is an APS commissioned document, and the overall version has also been released and can be found on astro-ph. This detailed section of the white paper discusses different technology opportunities and the technical feasibility for substantially improving IACTS and ground based particle detectors to achieve an order of magnitude better sensitivity than the instruments employed today as well as their planned upgrades. A technology roadmap for improving IACTS and ground based particle detectors is presented.

astro-ph↗

arXiv2005

High Energy All Sky Transient Radiation Observatory

The scientific discoveries made by H.E.S.S. during its first year of operation encourage a reexamination of the open problems in high energy astrophysics and of the capabilities of the atmospheric Cherenkov technique, which could be employed to address them. We report on an initial Monte Carlo exploration of a ground-based instrument for observing cosmologically distant high energy transient phenomena. Such observations would require combining an order of magnitude increase in collecting area over existing instruments, with a similarly large increase in field of view for routine sky monitoring, and a factor of five decrease in energy threshold to extend the visibility range to redshifts exceeding one. A large array of moderately sized Imaging Atmospheric Cherenkov Telescopes (IACTs) through which the total array collecting area, array field of view and array data rates can be distributed, appears to be able to meet these requirements. To be practically feasible for construction, however, a cost effective imaging solution, with resolution of ~1 minute of arc within ~15 degrees field of view needs to be found. If image intensifier based technology provides such a solution in future, then, combined with super-fast parallel data processing, it may become a technological foundation for the next breakthrough in ground-based gamma-ray astronomy.

astro-ph↗

arXiv2001

VHE observations of unidentified EGRET sources

Observations of unidentified EGRET sources were made with the Whipple 10m imaging atmospheric Cherenkov telescope between Fall 1999 and Spring 2001. During this period, a high resolution 490 pixel camera with 4 degree field of view was present on the telescope. Characterization of the off-axis response of this instrument was done using observations of the Crab Nebula. No significant emission was detected from the eight unidentified EGRET sources observed and upper limits are presented as a function of position.

astro-ph↗

arXiv1999

Correlated variability of Mkn 421 at X-ray and TeV wavelengths on timescales of hours

Mkn 421 was observed for about two days with BeppoSAX, prior to and partly overlapping the start of a 1 week continuous exposure with ASCA in April 1998, as part of a world-wide multiwavelength campaign. A pronounced, well defined, flare observed in X-rays was also observed simultaneously at TeV energies by the Whipple Observatory's 10 m gamma-ray telescope. These data provide the first evidence that the X-ray and TeV intensities are well correlated on time-scales of hours.

astro-ph↗