X‐Ray Flaring Activity of Markarian 421
نویسندگان
چکیده
منابع مشابه
X-ray flaring activity of Markarian 421
We report results from a systematic search for X-ray flares from Mrk 421, using archival data from the Rossi X-Ray Timing Explorer (RXTE) satellite. The flares are clearly seen over a wide range of timescales. The quasicontinuous coverage of the source with the All-SkyMonitor (ASM) reveals frequent occurrence of major flares that last for months. On a few occasions, the source was intensively m...
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 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...
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 کاملTeV 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...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2004
ISSN: 0004-637X,1538-4357
DOI: 10.1086/382587