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Full-Text Articles in Physical Sciences and Mathematics
First Nustar Observations Of Mrk 501 Within A Radio To Tev Multi-Instrument Campaign, P. T. Reynolds, Nustar, Magic, Veritas, F-Gamma
First Nustar Observations Of Mrk 501 Within A Radio To Tev Multi-Instrument Campaign, P. T. Reynolds, Nustar, Magic, Veritas, F-Gamma
Physical Sciences Publications
We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 2013 April 1 and August 10, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL Lac object was observed in both a quiescent and an elevated state. The broadband campaign includes observations with NuSTAR, MAGIC, VERITAS, the Fermi Large Area Telescope, Swift X-ray Telescope and UV Optical Telescope, various ground-based optical instruments, including the GASP-WEBT program, as well as radio observations by OVRO, Metsähovi, and the F-Gamma consortium. Some of the MAGIC observations were affected …
Veritas Observations Of The Bl Lac Object Pg 1553+113, P. T. Reynolds, Et. Al.
Veritas Observations Of The Bl Lac Object Pg 1553+113, P. T. Reynolds, Et. Al.
Physical Sciences Publications
We present results from VERITAS observations of the BL Lac object PG 1553+113 spanning the years 2010, 2011, and 2012. The time-averaged spectrum, measured between 160 and 560 GeV, is well described by a power law with a spectral index of 4.33 ± 0.09. The time-averaged integral flux above 200 GeV measured for this period was (1.69 ± 0.06) × 10–11 photons cm–2 s–1, corresponding to 6.9% of the Crab Nebula flux. We also present the combined γ-ray spectrum from the Fermi Large Area Telescope and VERITAS covering an energy range from 100 MeV to 560 …
Investigating Broadband Variability Of The Tev Blazar 1es 1959+650, P. T. Reynolds, Veritas
Investigating Broadband Variability Of The Tev Blazar 1es 1959+650, P. T. Reynolds, Veritas
Physical Sciences Publications
We summarize broadband observations of the TeV-emitting blazar 1ES 1959+650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift Ultraviolet and Optical Telescope, X-ray observations by the Swift X-ray Telescope, high-energy gamma-ray observations with the Fermi Large Area Telescope, and very-high-energy (VHE) gamma-ray observations by VERITAS above 315 GeV, all taken between 2012 April 17 and 2012 June 1 (MJD 56034 and 56079). The contemporaneous variability of the broadband spectral energy distribution is explored in the context of a simple synchrotron self Compton (SSC) model. In the SSC emission scenario, we find that the …
Constraints On Very High Energy Emission From Grb 130427a, P. T. Reynolds, Et Al
Constraints On Very High Energy Emission From Grb 130427a, P. T. Reynolds, Et Al
Physical Sciences Publications
Prompt emission from the very fluent and nearby (z = 0.34) gamma-ray burst GRB 130427A was detected by several orbiting telescopes and by ground-based, wide-field-of-view optical transient monitors. Apart from the intensity and proximity of this GRB, it is exceptional due to the extremely long-lived high-energy (100 MeV to 100 GeV) gamma-ray emission, which was detected by the Large Area Telescope on the Fermi Gamma-Ray Space Telescope for ~70 ks after the initial burst. The persistent, hard-spectrum, high-energy emission suggests that the highest-energy gamma rays may have been produced via synchrotron self-Compton processes though there is also evidence that …
Very-High Energy Observations Of The Galactic Center Region By Veritas In 2010-2012, P. T. Reynolds, Et. Al.
Very-High Energy Observations Of The Galactic Center Region By Veritas In 2010-2012, P. T. Reynolds, Et. Al.
Physical Sciences Publications
The Galactic center is an interesting region for high-energy (0.1-100 GeV) and very-high-energy (E > 100 GeV) γ-ray observations. Potential sources of GeV/TeV γ-ray emission have been suggested, e.g., the accretion of matter onto the supermassive black hole, cosmic rays from a nearby supernova remnant (e.g., Sgr A East), particle acceleration in a plerion, or the annihilation of dark matter particles. The Galactic center has been detected by EGRET and by Fermi/LAT in the MeV/GeV energy band. At TeV energies, the Galactic center was detected with moderate significance by the CANGAROO and Whipple 10 m telescopes and with high significance by …
Spatially Resolving The Very High Energy Emission From Mgro J2019+37 With Veritas, P. T. Reynolds, Et. Al.
Spatially Resolving The Very High Energy Emission From Mgro J2019+37 With Veritas, P. T. Reynolds, Et. Al.
Physical Sciences Publications
We present very high energy (VHE) imaging of MGRO J2019+37 obtained with the VERITAS observatory. The bright extended (~2°) unidentified Milagro source is located toward the rich star formation region Cygnus-X. MGRO J2019+37 is resolved into two VERITAS sources. The faint, point-like source VER J2016+371 overlaps CTB 87, a filled-center remnant (SNR) with no evidence of a supernova remnant shell at the present time. Its spectrum is well fit in the 0.65-10 TeV energy range by a power-law model with photon index 2.3 ± 0.4. VER J2019+378 is a bright extended (~1°) source that likely accounts for the bulk of …
Test Of Models Of The Cosmic Infrared Background With Multiwavelength Observations Of The Blazar 1es 1218+30.4 In 2009, P. T. Reynolds
Test Of Models Of The Cosmic Infrared Background With Multiwavelength Observations Of The Blazar 1es 1218+30.4 In 2009, P. T. Reynolds
Physical Sciences Publications
We present the results of a multi-wavelength campaign targeting the blazar 1ES 1218+30.4 with observations with the 1.3 m McGraw-Hill optical telescope, the Rossi X-ray Timing Explorer (RXTE), the Fermi Gamma-Ray Space Telescope, and the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The RXTE and VERITAS observations were spread over a 13 day period and revealed clear evidence for flux variability, and a strong X-ray and γ-ray flare on 2009 February 26 (MJD 54888). The campaign delivered a well-sampled broadband energy spectrum with simultaneous RXTE and VERITAS very high energy (VHE, >100 GeV) observations, as well as …
Deep Broadband Observations Of The Distant Gamma-Ray Blazar Pks 1424+240, P. T. Reynolds, Et Al
Deep Broadband Observations Of The Distant Gamma-Ray Blazar Pks 1424+240, P. T. Reynolds, Et Al
Physical Sciences Publications
We present deep VERITAS observations of the blazar PKS 1424+240, along with contemporaneous Fermi Large Area Telescope, Swift X-ray Telescope, and Swift UV Optical Telescope data between 2009 February 19 and 2013 June 8. This blazar resides at a redshift of z ≥ 0.6035, displaying a significantly attenuated gamma-ray flux above 100 GeV due to photon absorption via pair-production with the extragalactic background light. We present more than 100 hr of VERITAS observations over three years, a multiwavelength light curve, and the contemporaneous spectral energy distributions. The source shows a higher flux of (2.1 ± 0.3) × 10–7 photons m–2 …
Observations Of The Unidentified Gamma-Ray Source Tev J2032+4130 By Veritas, P. T. Reynolds, Et. Al.
Observations Of The Unidentified Gamma-Ray Source Tev J2032+4130 By Veritas, P. T. Reynolds, Et. Al.
Physical Sciences Publications
TeV J2032+4130 was the first unidentified source discovered at very high energies (VHEs; E > 100 GeV), with no obvious counterpart in any other wavelength. It is also the first extended source to be observed in VHE gamma rays. Following its discovery, intensive observational campaigns have been carried out in all wavelengths in order to understand the nature of the object, which have met with limited success. We report here on a deep observation of TeV J2032+4130 based on 48.2 hr of data taken from 2009 to 2012 by the Very Energetic Radiation Imaging Telescope Array System experiment. The source is …
A Three-Year Multi-Wavelength Study Of The Very-High-Energy Gamma-Ray Blazar 1es 0229+200, P. T. Reynolds, Et. Al.
A Three-Year Multi-Wavelength Study Of The Very-High-Energy Gamma-Ray Blazar 1es 0229+200, P. T. Reynolds, Et. Al.
Physical Sciences Publications
The high-frequency-peaked BL Lacertae object 1ES 0229+200 is a relatively distant (z = 0.1396), hard-spectrum (Γ ~ 2.5), very-high-energy (VHE; E > 100 GeV) emitting γ-ray blazar. VHE measurements of this active galactic nucleus have been used to place constraints on the intensity of the extragalactic background light and the intergalactic magnetic field (IGMF). A multi-wavelength study of this object centered around VHE observations by Very Energetic Radiation Imaging Telescope Array System (VERITAS) is presented. This study obtained, over a period of three years, an 11.7 standard deviation detection and an average integral flux F(E > 300 GeV) = (23.3 ± 2.8stat …
Long-Term Tev And X-Ray Observations Of The Gamma- Ray Binary Hess J0632+057, P. T. Reynolds, Veritas, Hess
Long-Term Tev And X-Ray Observations Of The Gamma- Ray Binary Hess J0632+057, P. T. Reynolds, Veritas, Hess
Physical Sciences Publications
HESS J0632+057 is the only gamma-ray binary known so far whose position in the sky allows observations with ground-based observatories in both the northern and southern hemispheres. Here we report on long-term observations of HESS J0632+057 conducted with the Very Energetic Radiation Imaging Telescope Array System and High Energy Stereoscopic System Cherenkov telescopes and the X-ray satellite Swift, spanning a time range from 2004 to 2012 and covering most of the system's orbit. The very-high-energy (VHE) emission is found to be variable and is correlated with that at X-ray energies. An orbital period of days is derived from the …
A Search For Enhanced Very High Energy Gamma-Ray Emission From The 2013 March Crab Nebula Flare, P. T. Reynolds, Et Al
A Search For Enhanced Very High Energy Gamma-Ray Emission From The 2013 March Crab Nebula Flare, P. T. Reynolds, Et Al
Physical Sciences Publications
In 2013 March, a flaring episode from the Crab Nebula lasting ~2 weeks was detected by Fermi-LAT (Large Area Telescope on board the Fermi Gamma-ray Space Telescope). The Very Energetic Radiation Imaging Telescope Array System (VERITAS) provides simultaneous observations throughout this period. During the flare, Fermi-LAT detected a 20 fold increase in flux above the average synchrotron flux >100 MeV seen from the Crab Nebula. Simultaneous measurements with VERITAS are consistent with the non-variable long-term average Crab Nebula flux at TeV energies. Assuming a linear correlation between the very high energy flux change >1 TeV and the flux …
Veritas Observations Of The Microquasar Cygnus X-3, P. T. Reynolds, Et Al
Veritas Observations Of The Microquasar Cygnus X-3, P. T. Reynolds, Et Al
Physical Sciences Publications
We report results from TeV gamma-ray observations of the microquasar Cygnus X-3. The observations were made with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) over a time period from 2007 June 11 to 2011 November 28. VERITAS is most sensitive to gamma rays at energies between 85 GeV and 30 TeV. The effective exposure time amounts to a total of about 44 hr, with the observations covering six distinct radio/X-ray states of the object. No significant TeV gamma-ray emission was detected in any of the states, nor with all observations combined. The lack of a positive signal, especially …
Multiwavelength Observations And Modeling Of 1es 1959+650 In A Low Flux State, P. T. Reynolds, Et. Al.
Multiwavelength Observations And Modeling Of 1es 1959+650 In A Low Flux State, P. T. Reynolds, Et. Al.
Physical Sciences Publications
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 (σ) significance in 7.6 hr of observation in a low flux state. A multiwavelength spectral energy distribution (SED) is constructed from contemporaneous data from VERITAS, Fermi-LAT, RXTE PCA, and Swift UVOT. Swift XRT data is not included in the SED due to a lack of simultaneous observations with VERITAS. In contrast to the orphan γ-ray flare exhibited by this source in 2002, the X-ray flux of the source …
Discovery Of Tev Gamma-Ray Emission From Cta 1 By Veritas, P. T. Reynolds, Et. Al.
Discovery Of Tev Gamma-Ray Emission From Cta 1 By Veritas, P. T. Reynolds, Et. Al.
Physical Sciences Publications
We report the discovery of TeV gamma-ray emission coincident with the shell-type radio supernova remnant (SNR) CTA 1 using the VERITAS gamma-ray observatory. The source, VER J0006+729, was detected as a 6.5 standard deviation excess over background and shows an extended morphology, approximated by a two-dimensional Gaussian of semimajor (semiminor) axis 0fdg30 (0fdg24) and a centroid 5' from the Fermi gamma-ray pulsar PSR J0007+7303 and its X-ray pulsar wind nebula (PWN). The photon spectrum is well described by a power-law dN/dE = N 0(E/3 TeV)–Γ, with a differential spectral index of Γ = 2.2 ± 0.2stat ± 0.3sys, and normalization …
Rapid Tev Gamma-Ray Flaring Of Bl Lacertae, P. T. Reynolds, Veritas
Rapid Tev Gamma-Ray Flaring Of Bl Lacertae, P. T. Reynolds, Veritas
Physical Sciences Publications
We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The flaring activity was observed during a 34.6 minute exposure, when the integral flux above 200 GeV reached (3.4 ± 0.6) × 10–6 photons m–2 s–1, roughly 125% of the Crab Nebula flux measured by VERITAS. The light curve indicates that the observations missed the rising phase of the flare but covered a significant portion of the decaying phase. The exponential decay time was determined to be 13 ± 4 minutes, …
Veritas Observations Of Six Bright, Hard-Spectrum Fermi-Lat Blazars, P. T. Reynolds, Et Al
Veritas Observations Of Six Bright, Hard-Spectrum Fermi-Lat Blazars, P. T. Reynolds, Et Al
Physical Sciences Publications
We report on VERITAS very high energy (VHE; E ≥ 100 GeV) observations of six blazars selected from the Fermi Large Area Telescope First Source Catalog (1FGL). The gamma-ray emission from 1FGL sources was extrapolated up to the VHE band, taking gamma-ray absorption by the extragalactic background light into account. This allowed the selection of six bright, hard-spectrum blazars that were good candidate TeV emitters. Spectroscopic redshift measurements were attempted with the Keck Telescope for the targets without Sloan Digital Sky Survey spectroscopic data. No VHE emission is detected during the observations of the six sources described here. Corresponding TeV …
Constraints On Cosmic Rays, Magnetic Fields, And Dark Matter From Gamma-Ray Observations Of The Coma Cluster Of Galaxies With Veritas And Fermi, P. T. Reynolds, Et. Al.
Constraints On Cosmic Rays, Magnetic Fields, And Dark Matter From Gamma-Ray Observations Of The Coma Cluster Of Galaxies With Veritas And Fermi, P. T. Reynolds, Et. Al.
Physical Sciences Publications
Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated and, on account of weak energy losses, can accumulate, suggesting that clusters may also be sources of very high energy (VHE; E > 100 GeV) gamma-ray emission. We report here on VHE gamma-ray observations of the Coma galaxy cluster with the VERITAS array of imaging Cerenkov telescopes, with complementing Fermi Large Area Telescope observations at GeV energies. No significant gamma-ray emission from the Coma Cluster was detected. Integral flux upper limits at the 99% confidence level were measured to be on the order …
Multiwavelength Observations Of The Agn 1es 0414+009 With Veritas, Fermi-Lat, Swift-Xrt, And Mdm, P. T. Reynolds, Et. Al.
Multiwavelength Observations Of The Agn 1es 0414+009 With Veritas, Fermi-Lat, Swift-Xrt, And Mdm, P. T. Reynolds, Et. Al.
Physical Sciences Publications
We present observations of the BL Lac object 1ES 0414+009 in the >200 GeV gamma-ray band by the VERITAS array of Cherenkov telescopes. 1ES 0414+009 was observed by VERITAS between 2008 January and 2011 February, resulting in 56.2 hr of good quality pointed observations. These observations resulted in a detection of 822 events from the source corresponding to a statistical significance of 6.4 standard deviations (6.4σ) above the background. The source flux, showing no evidence for variability, is measured as (5.2 ± 1.1stat ± 2.6sys) × 10–12 photons cm–2 s–1 above 200 GeV, equivalent to approximately 2% of the Crab …
Veritas Observations Of The Nova In V407 Cygni, P. T. Reynolds, Et. Al.
Veritas Observations Of The Nova In V407 Cygni, P. T. Reynolds, Et. Al.
Physical Sciences Publications
We report on very high energy (E > 100 GeV) gamma-ray observations of V407 Cygni, a symbiotic binary that underwent a nova outburst producing 0.1-10 GeV gamma rays during 2010 March 10-26. Observations were made with the Very Energetic Radiation Imaging Telescope Array System during 2010 March 19-26 at relatively large zenith angles due to the position of V407 Cyg. An improved reconstruction technique for large zenith angle observations is presented and used to analyze the data. We do not detect V407 Cygni and place a differential upper limit on the flux at 1.6 TeV of 2.3 × 10–12 erg cm–2 …
Discovery Of Tev Gamma-Ray Emission Toward Supernova Remnant Snr G78.2+2.1, P. T. Reynolds, Et. Al.
Discovery Of Tev Gamma-Ray Emission Toward Supernova Remnant Snr G78.2+2.1, P. T. Reynolds, Et. Al.
Physical Sciences Publications
We report the discovery of an unidentified, extended source of very-high-energy gamma-ray emission, VER J2019+407, within the radio shell of the supernova remnant SNR G78.2+2.1, using 21.4 hr of data taken by the VERITAS gamma-ray observatory in 2009. These data confirm the preliminary indications of gamma-ray emission previously seen in a two-year (2007-2009) blind survey of the Cygnus region by VERITAS. VER J2019+407, which is detected at a post-trials significance of 7.5 standard deviations in the 2009 data, is localized to the northwestern rim of the remnant in a region of enhanced radio and X-ray emission. It has an intrinsic …
Discovery Of High-Energy And Very High Energy Gamma-Ray Emission From The Blazar Rbs 0413, P. T. Reynolds, Et. Al.
Discovery Of High-Energy And Very High Energy Gamma-Ray Emission From The Blazar Rbs 0413, P. T. Reynolds, Et. Al.
Physical Sciences Publications
We report on the discovery of high-energy (HE; E > 0.1 GeV) and very high energy (VHE; E > 100 GeV) γ-ray emission from the high-frequency-peaked BL Lac object RBS 0413. VERITAS, a ground-based γ-ray observatory, detected VHE γ rays from RBS 0413 with a statistical significance of 5.5 standard deviations (σ) and a γ-ray flux of (1.5 ± 0.6stat ± 0.7syst) × 10–8 photons m–2 s–1 (~1% of the Crab Nebula flux) above 250 GeV. The observed spectrum can be described by a power law with a photon index of 3.18 ± 0.68stat ± 0.30syst. Contemporaneous observations with the Large Area …
Veritas Observations Of Day-Scale Flaring Of M 87 In 2010 April, P. T. Reynolds, Et. Al.
Veritas Observations Of Day-Scale Flaring Of M 87 In 2010 April, P. T. Reynolds, Et. Al.
Physical Sciences Publications
VERITAS has been monitoring the very-high-energy (VHE; > 100 GeV) gamma-ray activity of the radio galaxy M 87 since 2007. During 2008, flaring activity on a timescale of a few days was observed with a peak flux of (0.70 ± 0.16) × 10–11 cm–2 s–1 at energies above 350 GeV. In 2010 April, VERITAS detected a flare from M 87 with peak flux of (2.71 ± 0.68) × 10–11 cm–2 s–1 for E > 350 GeV. The source was observed for six consecutive nights during the flare, resulting in a total of 21 hr of good-quality data. The most rapid flux variation …
The 2010 Very High Energy Gamma-Ray Flare And 10 Years Of Multi-Wavelength Observations Of M 87, P. T. Reynolds, Hess, Magic, Veritas, Et. Al.
The 2010 Very High Energy Gamma-Ray Flare And 10 Years Of Multi-Wavelength Observations Of M 87, P. T. Reynolds, Hess, Magic, Veritas, Et. Al.
Physical Sciences Publications
The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3 – 6) × 109 M ☉) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) γ-ray emission generated in relativistic outflows and the surroundings of supermassive black holes. M 87 has been established as a VHE γ-ray emitter since 2006. The VHE γ-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in …
Veritas Observations Of Gamma-Ray Bursts Detected By Swift, P. T. Reynolds, Et. Al.
Veritas Observations Of Gamma-Ray Bursts Detected By Swift, P. T. Reynolds, Et. Al.
Physical Sciences Publications
We present the results of 16 Swift-triggered Gamma-ray burst (GRB) follow-up observations taken with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) telescope array from 2007 January to 2009 June. The median energy threshold and response time of these observations were 260 GeV and 320 s, respectively. Observations had an average duration of 90 minutes. Each burst is analyzed independently in two modes: over the whole duration of the observations and again over a shorter timescale determined by the maximum VERITAS sensitivity to a burst with a t –1.5 time profile. This temporal model is characteristic of GRB afterglows …
Veritas Observations Of The Tev Binary Ls I+61 Degrees 303 During 2008-2010, P. T. Reynolds, Et. Al.
Veritas Observations Of The Tev Binary Ls I+61 Degrees 303 During 2008-2010, P. T. Reynolds, Et. Al.
Physical Sciences Publications
We present the results of observations of the TeV binary LS I +61° 303 with the VERITAS telescope array between 2008 and 2010, at energies above 300 GeV. In the past, both ground-based gamma-ray telescopes VERITAS and MAGIC have reported detections of TeV emission near the apastron phases of the binary orbit. The observations presented here show no strong evidence for TeV emission during these orbital phases; however, during observations taken in late 2010, significant emission was detected from the source close to the phase of superior conjunction (much closer to periastron passage) at a 5.6 standard deviation (5.6σ) post-trials …
Veritas Observations Of The Unusual Extragalactic Transient Swift J164449.3+573451, P. T. Reynolds, Et Al
Veritas Observations Of The Unusual Extragalactic Transient Swift J164449.3+573451, P. T. Reynolds, Et Al
Physical Sciences Publications
We report on very high energy (>100 GeV) gamma-ray observations of Swift J164449.3+573451, an unusual transient object first detected by the Swift Observatory and later detected by multiple radio, optical, and X-ray observatories. A total exposure of 28 hr was obtained on Swift J164449.3+573451 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) during 2011 March 28-April 15. We do not detect the source and place a differential upper limit on the emission at 500 GeV during these observations of 1.4 × 10–12 erg cm–2 s–1 (99% confidence level). We also present time-resolved upper limits and use a …
Discovery Of Tev Gamma Ray Emission From Tycho's Supernova Remnant, P. T. Reynolds, Et Al
Discovery Of Tev Gamma Ray Emission From Tycho's Supernova Remnant, P. T. Reynolds, Et Al
Physical Sciences Publications
We report the discovery of TeV gamma-ray emission from the Type Ia supernova remnant (SNR) G120.1+1.4, known as Tycho's SNR. Observations performed in the period 2008-2010 with the VERITAS ground-based gamma-ray observatory reveal weak emission coming from the direction of the remnant, compatible with a point source located at 00h25m270, + 64°10'50'' (J2000). The TeV photon spectrum measured by VERITAS can be described with a power law dN/dE = C(E/3.42 TeV)–Γ with Γ = 1.95 ± 0.51stat ± 0.30sys and C = (1.55 ± 0.43stat ± 0.47sys) × 10–14 cm–2 s–1 TeV–1. The integral …
Spectral Energy Distribution Of Markarian 501: Quiescent State Versus Extreme Outburst, P. T. Reynolds, Veritas, Magic
Spectral Energy Distribution Of Markarian 501: Quiescent State Versus Extreme Outburst, P. T. Reynolds, Veritas, Magic
Physical Sciences Publications
The very high energy (VHE; E > 100 GeV) blazar Markarian 501 (Mrk 501) has a well-studied history of extreme spectral variability and is an excellent laboratory for studying the physical processes within the jets of active galactic nuclei. However, there are few detailed multiwavelength studies of Mrk 501 during its quiescent state, due to its low luminosity. A short-term multiwavelength study of Mrk 501 was coordinated in 2009 March, focusing around a multi-day observation with the Suzaku X-ray satellite and including γ-ray data from VERITAS, MAGIC, and the Fermi Gamma-ray Space Telescope with the goal of providing a well-sampled multiwavelength …
Multi-Wavelength Observations Of The Flaring Gamma-Ray Blazar 3c 66a In 2008 October, P. T. Reynolds, Fermi-Lat, Veritas, Gasp-Webt
Multi-Wavelength Observations Of The Flaring Gamma-Ray Blazar 3c 66a In 2008 October, P. T. Reynolds, Fermi-Lat, Veritas, Gasp-Webt
Physical Sciences Publications
The BL Lacertae object 3C 66A was detected in a flaring state by the Fermi Large Area Telescope (LAT) and VERITAS in 2008 October. In addition to these gamma-ray observations, F-GAMMA, GASP-WEBT, PAIRITEL, MDM, ATOM, Swift, and Chandra provided radio to X-ray coverage. The available light curves show variability and, in particular, correlated flares are observed in the optical and Fermi-LAT gamma-ray band. The resulting spectral energy distribution can be well fitted using standard leptonic models with and without an external radiation field for inverse Compton scattering. It is found, however, that only the model with an external …