An Exceptional Radio Flare in Markarian 421
نویسندگان
چکیده
منابع مشابه
THE TeV GAMMA-RAY SPECTRUM OF MARKARIAN 421 DURING AN INTENSE FLARE
We present the gamma-ray spectrum of the BL Lacertae object, Markarian 421, above 500 GeV during its most intense recorded TeV flare, on 1996 May 7. The spectrum is well fitted by a power law with an exponent of (statistical and systematic errors). The spectrum extends above 5 TeV with no evidence 22.56 5 0.07 5 0.1 for a cutoff, favoring determinations of the extragalactic infrared energy dens...
متن کاملSimultaneous X-Ray and TeV Observations of a Rapid Flare from Markarian 421.
Mrk 421 was observed for about 2 days with BeppoSAX in 1998 April as part of a worldwide multiwavelength campaign. A large, well-defined flare was observed in X-rays. The same flare was observed simultaneously at TeV energies by the Whipple Observatory gamma-ray telescope. These data provide (1) the first evidence that the X-ray and TeV intensities are well correlated on timescales of hours and...
متن کاملThe June 2008 Flare of Markarian 421 from Optical to Tev Energies
We present optical, X-ray, high energy (/ 30 GeV) and very high energy (' 100 GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between 2008 May 24 and June 23. A high energy γ-ray signal was detected by AGILE with √ TS = 4.5 on June 9–15, with F (E > 100 MeV) = 42 −12 × 10 photons cm s. This flaring state is brighter than the average flux observed by EGRET by a factor of...
متن کاملMarkarian 421’s Unusual Satellite Galaxy
We present Hubble Space Telescope (HST) imagery and photometry of the active galaxy Markarian 421 and its companion galaxy 14 arcsec to the ENE. The HST images indicate that the companion is a morphological spiral rather than elliptical as previous ground–based imaging has concluded. The companion has a bright, compact nucleus, appearing unresolved in the HST images. This is suggestive of Seyfe...
متن کاملXMM − Newton observations of Markarian 421 ?
The BL Lac object Mrk 421 was observed on May 25, 2000 during the XMM−Newton Cal/PV phase. The high throughput of the X-ray telescopes and the spectral capabilities of the instruments allow an uninterrupted temporal and spectral study of the source with unprecedented time resolution. Mrk 421 was found at a relatively high state with a 2−6 keV flux of (1.3−1.9)×10−10 erg cm−2 s−1. The observed i...
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ژورنال
عنوان ژورنال: EPJ Web of Conferences
سال: 2013
ISSN: 2100-014X
DOI: 10.1051/epjconf/20136104010