J/A+A/539/A149 Multiwavelength view of blazar PKS 2155-304 (Abramowski+, 2012)
A multiwavelength view of the flaring state of PKS 2155-304 in 2006.
H.E.S.S. collaboration
<Astron. Astrophys. 539, A149 (2012)>
=2012A&A...539A.149H 2012A&A...539A.149H
ADC_Keywords: BL Lac objects ; X-ray sources ; Gamma rays ; Radio sources ;
Photometry
Keywords: galaxies: active - radiation mechanisms: non-thermal -
gamma rays: galaxies - BL Lacertae objects: individual: PKS 2155-304
Abstract:
Multiwavelength (MWL) observations of the blazar PKS 2155-304 during
two weeks in July and August 2006, the period when two exceptional
flares at very high energies (VHE, E≥100GeV) occurred, provide a
detailed picture of the evolution of its emission. The complete data
set from this campaign is presented, including observations in VHE
gamma-rays (H.E.S.S.), X-rays (RXTE, CHANDRA, SWIFT XRT), optical
(SWIFT UVOT, Bronberg, Watcher, ROTSE), and in the radio band (NRT,
HartRAO, ATCA). Optical and radio light curves from 2004 to 2008 are
compared to the available VHE data from this period, to put the 2006
campaign into the context of the long-term evolution of the source.
The data set offers a close view of the evolution of the source on
different time scales and yields new insights into the properties of
the emission process. The predictions of synchrotron self-Compton
(SSC) scenarios are compared to the MWL data, with the aim of
describing the dominant features in the data down to the hour time
scale.
The spectral variability in the X-ray and VHE bands is explored and
correlations between the integral fluxes at different wavelengths are
evaluated. SSC modelling is used to interpret the general trends of
the varying spectral energy distribution.
Description:
Light curves at different wavelengths detected from the blazar PKS
2155-304 are presented on two different time scales. The first set of
light curves covers the two-week period of the 2006 multiwavelength
campaign on the source. Fluxes were measured in VHE gamma-rays with
H.E.S.S. and CANGAROO, in X-rays with Chandra, RXTE and SWIFT XRT, in
the ultra-violet and optical with SWIFT UVOT and in the optical with
the Bronberg and Watcher telescopes. These light curves correspond to
Figure 1 in the publication. A second set of light curves covers a
period of four years (2004-2008). Fluxes were measured in VHE
gamma-rays with H.E.S.S., in the optical band with the ROTSE-IIIc
telescope and in the radio band with the Nancay Radio Telescope (NRT)
and the HartRAO telescope. This set corresponds to Figure 8 in the
publication. For each light curve, the date of the flux measurement,
the integrated flux and the uncertainty in the integrated flux are
provided.
Objects:
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RA (2000) DE Designation(s)
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21 58 52.1 -30 13 32 PKS 2155-304 = QSO B2155-304
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
hess_av.dat 31 13 H.E.S.S. nightly averaged fluxes
cangaroo.dat 39 5 Cangaroo nightly averaged fluxes
mwl.dat 150 443 Multiwavelength light curves in 10-minute bins
hess.dat 34 214 H.E.S.S. long-term light curve
rotse.dat 33 4194 ROTSE long-term light curve
har_35mm.dat 24 148 HartRAO long-term light curve at 3.5cm
har_60mm.dat 24 161 HartRAO long-term light curve at 6cm
nrt_11cm.dat 27 99 NRT long-term light curve at 11cm
nrt_21cm.dat 27 49 NRT long-term light curve at 21cm
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See also:
J/A+A/469/503 : VRIJHK observations of PKS 2155-304 (Dolcini+, 2007)
Byte-by-byte Description of file: hess_av.dat
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Bytes Format Units Label Explanations
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1- 14 E14.9 d Date Average date of flux measurement (MJD)
16- 23 E8.3 mW/m2 Fint Integrated energy flux above 300GeV
25- 31 E7.2 mW/m2 e_Fint Statistical uncertainty in Fint
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Byte-by-byte Description of file: cangaroo.dat
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Bytes Format Units Label Explanations
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1- 14 E14.9 d Date Average date of flux measurement (MJD)
16- 23 E8.3 d Dur Duration of flux measurement divided by half (MJD)
25- 31 E7.2 mW/m2 Fint Integrated energy flux above 300GeV (1)
33- 39 E7.2 mW/m2 e_Fint Statistical uncertainty in Fint
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Note (1): The fluxes measured with CANGAROO have been extrapolated down to
300GeV. The data were taken with a threshold of 660GeV.
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Byte-by-byte Description of file: mwl.dat
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Bytes Format Units Label Explanations
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1- 14 E14.9 d Date Average date of flux measurement (MJD)
16- 23 E8.3 mW/m2 Fint1 ?=0 Integrated energy flux above 300GeV
measured with H.E.S.S. (1)
25- 31 E7.2 mW/m2 e_Fint1 ?=0 Statistical uncertainty in Fint1
33- 40 E8.3 mW/m2 Fint2 ?=0 Integrated energy flux from 0.5 to 5keV
measured with Chandra (2)
42- 48 E7.2 mW/m2 e_Fint2 ?=0 Statistical uncertainty in Fint2
50- 57 E8.3 mW/m2 Fint3 ?=0 Integrated energy flux from 2 to 10keV
measured with RXTE (2)
59- 65 E7.2 mW/m2 e_Fint3 ?=0 Statistical uncertainty in Fint3
67- 74 E8.3 mW/m2 Fint4 ?=0 Integrated energy flux from 0.3 to 4keV
measured with SWIFT XRT (2)
76- 82 E7.2 mW/m2 e_Fint4 ?=0 Statistical uncertainty in Fint4
84- 91 E8.3 mW/m2 nFn1 ?=0 Flux density measured with SWIFT/UVOT
UVW2 filter (1928Å) (1)
93- 99 E7.2 mW/m2 e_nFn1 ?=0 Statistical and systematic uncertainty
in nFn1
101-108 E8.3 mW/m2 nFn2 ?=0 Flux density measured with SWIFT/UVOT
V filter (5468Å) (1)
110-116 E7.2 mW/m2 e_nFn2 ?=0 Statistical and systematic uncertainty
in nFn2
118-125 E8.3 mW/m2 nFn3 ?=0 Flux density measured with the Bronberg
telescope in the V-band (1)
127-133 E7.2 mW/m2 e_nFn3 ?=0 Statistical uncertainty in nFn3
135-142 E8.3 mW/m2 nFn4 ?=0 Flux density measured with the Watcher
telescope in the V-band (1)
144-150 E7.2 mW/m2 e_nFn4 ?=0 Statistical uncertainty in nFn4
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Note (1): Optical and ultra-violet fluxes have not been corrected for
Galactic absorption
Note (2): X-ray fluxes have been corrected for Galactic absorption assuming
NH=1.7x1020cm-2 (Dickey & Lockman, 1990ARA&A..28..215D 1990ARA&A..28..215D)
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Byte-by-byte Description of file: hess.dat
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Bytes Format Units Label Explanations
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1- 13 E13.8 d Date Average date of flux measurement (MJD)
15- 24 E10.4 ph/cm2/s Phi Integral photon flux above 200GeV (H.E.S.S.)
26- 34 E9.4 ph/cm2/s e_Phi Statistical uncertainty in the photon flux
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Byte-by-byte Description of file: rotse.dat
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Bytes Format Units Label Explanations
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1- 13 E13.8 d Date Average date of flux measurement (MJD)
15- 23 E9.4 Jy F7000A Flux density at 7000 Angstrom (ROTSE) (1)
25- 33 E9.4 Jy e_F7000A Statistical uncertainty in the flux density
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Note (1): Fluxes have not been corrected for Galactic absorption
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Byte-by-byte Description of file: har_35mm.dat
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Bytes Format Units Label Explanations
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1- 10 E10.5 d Date Average date of flux measurement (MJD)
12- 18 E7.2 Jy F3.5cm Flux density at 3.5cm (HartRAO)
20- 24 E5.1 Jy e_F3.5cm Statistical and systematic uncertainty in
the flux density
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Byte-by-byte Description of file: har_60mm.dat
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Bytes Format Units Label Explanations
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1- 10 E10.5 d Date Average date of flux measurement (MJD)
12- 18 E7.2 Jy F6cm Flux density at 6cm (HartRAO)
20- 24 E5.1 Jy e_F6cm Statistical and systematic uncertainty in
the flux density
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Byte-by-byte Description of file: nrt_11cm.dat
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Bytes Format Units Label Explanations
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1- 10 E10.5 d Date Average date of flux measurement (MJD)
12- 19 E8.3 Jy F11cm Flux density at 11cm (NRT)
21- 27 E7.2 Jy e_F11cm Statistical uncertainty in the flux density
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Byte-by-byte Description of file: nrt_21cm.dat
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Bytes Format Units Label Explanations
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1- 10 E10.5 d Date Average date of flux measurement (MJD)
12- 19 E8.3 Jy F21cm Flux density at 21cm (NRT)
21- 27 E7.2 Jy e_F21cm Statistical uncertainty in the flux density
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Acknowledgements:
Andreas Zech, Andreas.Zech(at)obspm.fr,
Catherine Boisson, Catherine.Boisson(at)obspm.fr
(End) Andreas Zech [LUTH, France], Patricia Vannier [CDS] 26-Jan-2012