Browsing by Author "Lang, Mark"
Now showing items 21-40 of 64
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Highlight Talk: Recent Results from VERITAS
Lang, Mark; Gillanders, Gary (2009)VERITAS is a state-of-the-art ground-based gamma-ray observatory that operates in the very high-energy (VHE) region of 100 GeV to 50 TeV. The observatory consists of an array of four 12m-diameter imaging atmospheric Cherenkov ... -
The June 2008 flare of Markarian 421 from optical to TeV energies
Lang, Mark (2008)We present optical, X-ray, high energy ($\lessapprox 30$ GeV) and very high energy ($\gtrapprox 100$ GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between 2008 May 24 and June 23. A high energy ... -
The most powerful flaring activity from the NLSyl PMN J0948+0022
Moriarty, P.; Gillanders, Gary; Lang, Mark (Oxford University Press, 2015-01-21)We report on multifrequency observations performed during 2012 December-2013 August of the first narrow-line Seyfert 1 galaxy detected in gamma-rays, PMN J0948+0022 (z = 0.5846). A y -ray flare was observed by the Large ... -
Multiwavelength Observations of 1ES 1959+650, One Year After the Strong Outburst of 2002
Lang, Mark; Gillanders, Gary (2006)In April-May 2003, the blazar 1ES 1959+650 showed an increased level of X-ray activity. This prompted a multiwavelength observation campaign with the Whipple 10 m gamma-ray telescope, the Rossi X-ray Timing Explorer, the ... -
Multiwavelength observations of a TeV-Flare from W Comae
Lang, Mark; Gillanders, Gary (2009)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 very ... -
Multiwavelength Observations of LS I +61 303 with VERITAS, Swift and RXTE
Lang, Mark; Gillanders, Gary (2009)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 ... -
Multiwavelength Observations of Markarian 421 in 2005 - 2006
Lang, Mark; Gillanders, Gary (2009)Since September 2005, the Whipple 10m Gamma-ray Telescope has been operated primarily as a blazar monitor. The five Northern Hemisphere blazars that have already been detected at the Whipple Observatory, Markarian 421, ... -
Multiwavelength Observations of Markarian 421 in March 2001: an Unprecedented View on the X-ray/TeV Correlated Variability
Lang, Mark (2007)(Abridged) We present a detailed analysis of week-long simultaneous observations of the blazar Mrk421 at 2-60 keV X-rays (RXTE) and TeV gamma-rays (Whipple and HEGRA) in 2001. The unprecedented quality of this dataset ... -
Multiwavelength observations of Mrk 501 in 2008
Gillanders, Gary; Lang, Mark (EDP Sciences, 2015-12-17)Context. Blazars are variable sources on various timescales over a broad energy range spanning from radio to very high energy (>100 GeV, hereafter VHE). Mrk 501 is one of the brightest blazars at TeV energies and has been ... -
Multiwavelength Observations of the VHE Blazar 1ES 2344+514
Lang, Mark; Gillanders, Gary (2011)Multiwavelength observations of the high-frequency-peaked blazar 1ES2344+514 were performed from 2007 October to 2008 January. The campaign represents the first contemporaneous data on the object at very high energy (VHE, ... -
Multiwavelength study of quiescent states of MRK 421 with unprecedented hard x-ray coverage provided by NuSTAR in 2013
Connolly, M.P.; Lang, Mark (IOP Publishing, 2016)We present coordinated multiwavelength observations of the bright, nearby BL Lacertae object Mrk 421 taken in 2013 January-March, involving GASP-WEBT, Swift, NuSTAR, Fermi-LAT, MAGIC, VERITAS, and other collaborations and ... -
Observation of Extended VHE Emission from the Supernova Remnant IC 443 with VERITAS
Lang, Mark; Gillanders, Gary (2009)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 ... -
Observation of gamma-ray emission from the galaxy M87 above 250 GeV with VERITAS
Lang, Mark; Gillanders, Gary (2008)The multiwavelength observation of the nearby radio galaxy M87 provides a unique opportunity to study in detail processes occurring in Active Galactic Nuclei from radio waves to TeV gamma-rays. Here we report the detection ... -
Observations of the shell-type SNR Cassiopeia A at TeV energies with VERITAS
Lang, Mark; Gillanders, Gary (2010)We report on observations of very high-energy gamma rays from the shell-type supernova remnant Cassiopeia A with the VERITAS stereoscopic array of four imaging atmospheric Cherenkov telescopes in Arizona. The total exposure ... -
Observations of the Unidentified TeV Gamma-Ray Source TeV J2032+4130 with the Whipple Observatory 10 m Telescope
Lang, Mark; Gillanders, Gary (2006)We report on observations of the sky region around the unidentified TeV gamma-ray source TeV J2032+4130 carried out with the Whipple Observatory 10 m atmospheric Cherenkov telescope for a total of 65.5 hrs between 2003 and ... -
Radio Imaging of the Very-High-Energy Gamma-Ray Emission Region in the Central Engine of a Radio Galaxy
Lang, Mark (2009)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 to energies exceeding 10^12 electron ... -
Recent Results from the VERITAS Collaboration
Lang, Mark; Gillanders, Gary (2002)A decade after the discovery of TeV gamma-rays from the blazar Mrk 421 (Punch et al. 1992), the list of TeV blazars has increased to five BL Lac objects: Mrk 421 (Punch et al. 1992; Petry et al. 1996; Piron et al. 2001), ... -
A search for brief optical flashes associated with the SETI target KIC 8462852
Gillanders, Gary; Lang, Mark (IOP Publishing, 2016-02-18)The F-type star KIC. 8462852 has recently been identified as an exceptional target for search for extraterrestrial intelligence (SETI) observations. We describe an analysis methodology for optical SETI, which we have used ... -
A Search for Dark Matter Annihilation with the Whipple 10m Telescope
Lang, Mark (2008)We present observations of the dwarf galaxies Draco and Ursa Minor, the local group galaxies M32 and M33, and the globular cluster M15 conducted with the Whipple 10m gamma-ray telescope to search for the gamma-ray signature ... -
A search for pulsations from Geminga above 100 GeV with VERITAS
Connolly, M.P.; Gillanders, Gary; Moriarty, P.; Lang, Mark (American Astronomical Society, 2015-02-10)We present the results of 71.6 hr of observations of the Geminga pulsar (PSR J0633+1746) with the VERITAS very-high-energy gamma-ray telescope array. Data taken with VERITAS between 2007 November and 2013 February were ...