The TeV blazar Markarian 421 at the highest spatial resolution
نویسندگان
چکیده
منابع مشابه
TeV OBSERVATIONS OF THE VARIABILITY AND SPECTRUM OF MARKARIAN 421
Markarian 421 was the first extragalactic source to be detected with high statistical certainty at TeV energies. The Whipple Observatory gamma-ray telescope has been used to observe the Active Galactic Nucleus, Markarian 421 in 1996 and 1997. The rapid variability observed in TeV gamma rays in previous years is confirmed. Doubling times as short as 15 minutes are reported with flux levels reach...
متن کاملThe TeV energy spectrum of Markarian 421 measured in a high flaring state
The BL Lac object (blazar) Mrk 421 was observed during its outburst in 2004 April with the Whipple 10 m telescope for a total of about 24.5 hr. The measured g-ray rate varied substantially over the range from 4 to 10 minute 1 and eventually exceeded the steady g-ray rate of the Crab Nebula (standard candle) by a factor of 3. The overall significance of the g-ray signal exceeded 70 j and the tot...
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 کاملTHE 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 radio - interferometric and high - energy TeV observations of the γ - ray blazar Mkn 421
The TeV-emitting BL Lac object Mkn 421 was observed with very long baseline interferometry (VLBI) at three closely-spaced epochs one-month apart in March–April 1998. The source was also monitored at very-high γ-ray energies (TeV measurements) during the same period in an attempt to search for correlations between TeV variability and the evolution of the radio morphology on parsec scales. While ...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2013
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/201321858