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Record 13 of 21
Four Years of EUVE Observations of the Bursting Gamma-Ray Emitting Blazar Markarian 421
Author and Affiliation:
Cagnoni, Ilaria(Smithsonian Astrophysical Observatory, Center for Astrophysics, Cambridge, MA United States)
Fruscione, Antonella(Smithsonian Astrophysical Observatory, Center for Astrophysics, Cambridge, MA United States)
Papadakis, Iossif(Southampton Univ., United Kingdom)
Abstract: We present spectral and timing analysis of all the data collected by the Extreme Ultraviolet Explorer Satellite (EUVE) for the bright, nearby BL Lacertae object, Markarian 421, during the four-year period 1994-1997. During these years Mrk 421 has been observed by EUVE 4 times with the Deep-Survey/Spectrograph and 2 times with the imaging telescopes for a total of approximately 1.4 7nillions seconds. From 1993 to 1996 three very bright gamma ray flares were also detected by the Whipple observatory. In 1994 Mrk 421 was observed simultaneously by EUVE (Apr 2-12) and IUE one month before the TeV flare; of the 2 EUVF, observations (Feb 4-7 and Apr 25-May 13) of 1995, the second was part of a multiwavelength campaign that mapped the evolution of the TeV flare. In 1996 we observed Mrk 421 twice simultaneously with XTE: one immediately before (Apr 17-30) and another one (May 10-11) right after the May 7 1996 TeV flare. And finally in 1997 from Feb. 7 to Feb. ll. The total light curve seems to be smoothly varying on the long time-scale while on a shorter time-scale there is evidence of an EUVE flare well correlated to the TeV energy 1995 flare. We have analysed the three spectral data set in an homogenous way using the appropriate calibration data for the off-axis observations and our analysis confirms the presence of the absorption features around approximately 70A, in the entire 1995 dataset and possibly in the 1996 data set. We also show the first power spectrum analysis of the Mrk 421 EUVE lightcurves and a comparison with the power spectra predicted by current theoretical models.
Publication Date: Jan 01, 1998
Document ID:
19990111695
(Acquired Nov 26, 1999)
Subject Category: SPACE RADIATION
Document Type: Reprint
Meeting Information: 5-17 Mar. 1998; Milan; Italy
Contract/Grant/Task Num: NAS8-39073
Financial Sponsor: NASA Marshall Space Flight Center; Huntsville, AL United States
Organization Source: Smithsonian Astrophysical Observatory; Center for Astrophysics; Cambridge, MA United States
Description: In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: EXTREME ULTRAVIOLET EXPLORER SATELLITE; EMISSION SPECTRA; BLAZARS; MARKARIAN GALAXIES; GAMMA RAY BURSTS; GAMMA RAY ASTRONOMY; SPECTRUM ANALYSIS; LIGHT CURVE; SPECTROGRAPHS; TELESCOPES; IMAGING TECHNIQUES; POWER SPECTRA; STELLAR FLARES; TIME MEASUREMENT; DATA PROCESSING; SATELLITE OBSERVATION
Availability Source: Other Sources
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