J/A+A/410/813 2001 Flare of Mkn 421 in gamma-ray (Aharonian+ 2003)
TeV gamma-ray light curve and energy spectrum of Mkn 421 during its 2001 flare
as measured with HEGRA CT1.
Aharonian F.A., Akhperjanian A.G., Beilicke M., Bernloehr K., Boerst H.-G.,
Bojahr H., Bolz O., Coarasa J.A., Contreras J.L., Cortina J.,
Denninghoff S., Fonseca M.V., Girma M., Goebel F., Goetting N.,
Heinzelmann G., Hermann G., Heusler A., Hofmann W., Horns D., Jung I.,
Kankanyan R., Kestel M., Kettler J., Kohnle A., Konopelko A., Kranich D.,
Krawczynski H., Lampeitl H., Lopez M., Lorenz E., Lucarelli F., Mang O.,
Meyer H., Mirzoyan R., Moralejo A., Ona-Wilhelmi E., Paneque D.,
Panter M., Plyasheshnikov A., Puehlhofer G., de los Reyes R., Rhode W.,
Ripken J., Rowell G.P., Sahakian V., Samorski M., Schilling M.,
Schweizer T., Sevilla I., Siems M., Sobczynska D., Stamm W., Tluczykont M.,
Tonello N., Vitale V., Voelk H.J., Wagner R.M., Wiedner C.A.,W.Wittek.
<Astron. Astrophys. 410, 813 (2003)>
=2003A&A...410..813A 2003A&A...410..813A
ADC_Keywords: Active gal. nuclei ; BL Lac objects ; Gamma rays
Keywords: gamma rays: observations -
BL Lacertae objects: individual: Mkn 421
Abstract:
In the first months of 2001 the AGN Mkn 421 showed highly variable,
strong TeV activity at flux levels frequently exceeding 1 Crab. Here
we present the light curve and energy spectrum of Mkn 421 as measured
with the HEGRA stand alone telescope CT1. Around 30% of the data were
taken under moonlight conditions. The spectrum shows a significant
exponential energy cutoff at around 3.4 TeV. The results from the dark
night- and the moon data are in excellent agreement with each other. A
significant spectral shape variation depending on the flux level has
been found. The TeV light curve is also found to be highly correlated
with the X-ray light curve of the RXTE/ASM satellite, showing no
significant time lag larger than 0.2d. The derived correlation
coefficient of 0.83 corresponds to a 5.2σ significance.
Description:
The integral Flux above 1TeV for the BL Lac object Mkn 421 as measured
by the HEGRA Cherenkov telescope CT1. The data was taken during the
2001 high state of the object.
Objects:
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RA (2000) DE Designation(s)
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11 04 27 +38 12.5 Mkn 421 = QSO B1101+384
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 33 336 Integral flux values of Mkn 421
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 --- MJD Modified Julian Date (MJD=JD-2400000.5)
12- 16 F5.2 10-11/cm2/s Flux Integral Flux above 1 TeV (1)
19- 22 F4.2 10-11/cm2/s e_Flux error on the Integral Flux (1)
25- 27 F3.1 h ExpTime observation time
30- 33 A4 --- HV HV setting of the PMTs (2)
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Note (1): Integral flux above 1 TeV in units of 10-11cm-2s-1
Note (2):
The photo multipliers of the telescope are operated under nominal high
voltage (HV) during dark nights (Nominal setting: NOM) and for low
moon illumination (denoted by HV00) and with a number of reduced HV
settings depending on the moon illumination and the angular distance
between the moon and the observed object (HV04, HV08 and HV12
settings, respectively standing for 4%, 8% and 12% reduction of the
nominal HV).
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Acknowledgements: Daniel Kranich
(End) Daniel Kranich 19-Aug-2003