Browsing by Subject "bl-lacertae objects"
Now showing items 1-20 of 21
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A multiwavelength view of the tev blazar markarian 421: correlated variability, flaring, and spectral evolution
(IOP Publishing, 2005-09-01)We report results from an intensive multiwavelength monitoring campaign on the TeV blazar Mrk 421 over the period of 2003 - 2004. The source was observed simultaneously at TeV energies with the Whipple 10 m telescope and ... -
A search for spectral hysteresis and energy-dependent time lags from x-ray and tev gamma-ray observations of mrk 421
(American Astronomical Society, 2016-12-22)Blazars are variable emitters across all wavelengths over a wide range of timescales, from months down to minutes. It is therefore essential to observe blazars simultaneously at different wavelengths, especially in the ... -
A search for tev gamma‐ray emission from high‐peaked flat‐spectrum radio quasars using the whipple air cerenkov telescope
(IOP Publishing, 2004-10-01)Blazars have traditionally been separated into two broad categories based on their optical emission characteristics. Blazars with faint or no emission lines are referred to as BL Lacertae objects ( BL Lacs), and blazars ... -
A very high energy gamma‐ray spectrum of 1es 2344+514
(IOP Publishing, 2005-12-01)The BL Lacertae (BL Lac) object 1ES 2344+514 (1ES 2344), at a redshift of 0.044, was discovered as a source of very high energy (VHE) gamma rays by the Whipple collaboration in 1995 (Catanese et al.). This detection was ... -
Discovery of high-energy and very high energy γ-ray emission from the blazar rbs 0413
(IOP Publishing, 2012-04-18)We report on the discovery of high-energy (HE; E > 0.1 GeV) and very high energy (VHE; E > 100 GeV) gamma-ray emission from the high-frequency-peaked BL Lac object RBS 0413. VERITAS, a ground-based gamma-ray ... -
Discovery of very high energy gamma rays from 1es 1440+122
(Oxford University Press (OUP), 2016-06-08)The BL Lacertae object 1ES 1440+ 122 was observed in the energy range from 85 GeV to 30 TeV by the VERITAS array of imaging atmospheric Cherenkov telescopes. The observations, taken between 2008 May and 2010 June and ... -
Discovery of very high energy gamma rays from pks 1424+240 and multiwavelength constraints on its redshift
(IOP Publishing, 2009-12-18)We report the first detection of very high energy(83) (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 ... -
Fermilarge area telescope observations of markarian 421: the missing piece of its spectral energy distribution
(IOP Publishing, 2011-07-15)We report on the gamma-ray activity of the high-synchrotron-peaked BL Lacertae object Markarian 421 (Mrk 421) during the first 1.5 years of Fermi operation, from 2008 August 5 to 2010 March 12. We find that the Large Area ... -
Multiband variability studies and novel broadband sed modeling of mrk 501 in 2009
(EDP Sciences, 2017-07-01)Aims. We present an extensive study of the BL Lac object Mrk 501 based on a data set collected during the multi-instrument campaign spanning from 2009 March 15 to 2009 August 1, which includes, among other instruments, ... -
Multiwavelength observations and modeling of 1es 1959+650 in a low flux state
(IOP Publishing, 2013-08-27)We report on the VERITAS observations of the high-frequency peaked BL Lac object 1ES 1959+650 in the period 2007-2011. This source is detected at TeV energies by VERITAS at 16.4 standard deviation (sigma) significance in ... -
Multiwavelength observations of a tev-flare from w comae
(IOP Publishing, 2009-11-24)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 2008 June. The very ... -
Multiwavelength observations of markarian 421 in 2005-2006
(IOP Publishing, 2009-03-31)Since 2005 September, the Whipple 10 m 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 the blazar markarian 421 in 2002 december and 2003 january
(IOP Publishing, 2006-04-20)We report on a multiwavelength campaign on the TeV gamma-ray blazar Mrk 421 performed during 2002 December and 2003 January. These target of opportunity observations were initiated by the detection of X-ray and TeV gamma-ray ... -
Multiwavelength observations of the previously unidentified blazar rx j0648.7+1516
(IOP Publishing, 2011-11-15)We report on the VERITAS discovery of very high energy (VHE) gamma-ray emission above 200 GeV from the high-frequency-peaked BL Lac (HBL) object RX J0648.7+1516 (GB J0648+1516), associated with 1FGL J0648.8+1516. The photon ... -
Multiwavelength observations of the very high energy blazar 1es 2344+514
(IOP Publishing, 2011-08-23)Multiwavelength observations of the high-frequency-peaked blazar 1ES 2344+514 were performed from 2007 October to 2008 January. The campaign represents the first contemporaneous data on the object at very high energy (VHE, ... -
Tev and multi-wavelength observations of mrk 421 in 2006-2008
(IOP Publishing, 2011-08-10)We report on TeV gamma-ray observations of the blazar Mrk 421 (redshift of 0.031) with the VERITAS observatory and the Whipple 10m Cherenkov telescope. The excellent sensitivity of VERITAS allowed us to sample the TeV ... -
The discovery of γ-ray emission from the blazar rgb j0710+591
(IOP Publishing, 2010-04-30)The high-frequency-peaked BL Lacertae object RGB J0710+591 was observed in the very high-energy (VHE; E > 100 GeV) wave band by the VERITAS array of atmospheric Cherenkov telescopes. The observations, taken between ... -
The june 2008 flare of markarian 421 from optical to tev energies
(IOP Publishing, 2008-12-30)We present optical, X-ray, high-energy ((sic) 30 GeV) and very high energy ((sic) 100 GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between 2008 May 24 and June 23. A high-energy gamma-ray signal ... -
Upper limits from five years of blazar observations with the veritas cherenkov telescopes
(American Astronomical Society, 2016-05-18)Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E > 100 GeV) ... -
Very high energy outburst of markarian 501 in may 2009
(EDP Sciences, 2016-10-01)The very high energy (VHE; E > 100 GeV) blazar Markarian 501 was observed between April 17 and May 5 (MJD 54 938-54 956), 2009, as part of an extensive multiwavelength campaign from radio to VHE. Strong VHE yray ...