J/A+A/627/A140 FSRQ PKS 0346-27 light curves (Angioni+, 2019)
The large gamma-ray flare of the flat-spectrum radio quasar PKS 0346-27.
Angioni R., Nesci R., Finke J.D., Buson S., Ciprini S
<Astron. Astrophys. 627, A140 (2019)>
=2019A&A...627A.140A 2019A&A...627A.140A (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Gamma rays ; Photometry
Keywords: galaxies: active - galaxies: jets - quasars: individual: PKS 0346-27 -
gamma rays: galaxies
Abstract:
In this paper, we characterize the first-ray flaring episode of the
flat-spectrum radio quasar PKS 034-27 (z=0.991), as revealed by
Fermi-LAT monitoring data, and the concurrent multi-wavelength
variability observed from radio through X-rays.
We studied the long- and short-term flux and spectral variability from
PKS 0346-27 by producing-ray light curves with different time binning.
We complement theFermi-LAT data with multi-wavelength observations
from the Atacama Large MillimeterArray (radio mm-band), the Rapid Eye
Mount telescope (near-infrared) and Swift (optical-UV and X-rays).
This quasi-simultaneous multi-wavelength coverage allowed us to
construct time-resolved spectral energy distributions (SEDs) of PKS
0346-27 and compare the broadband spectral properties of the source
between different activity states using a one-zone leptonic emission
model. PKS 0346-27 entered an elevated-ray activity state starting
from the beginning of 2018. The high-state continued through-out the
year, displaying the highest fluxes in May 2018. We find evidence of
short-time scale variability down to approximately 1.5 hours, which
constrains the-ray emission region to be compact. The extended flaring
period was characterized by a persistently harder spectrum with
respect to the quiescent state, indicating changes in the broadband
spectral properties of the source. This was confirmed by the
multi-wavelength observations, which show a shift in the position of
the two SED peaks by approximately two orders of magnitude in energy
and peak flux value. As a result, the non-thermal jet emission
completely outshines the thermal contribution from the dust torus and
accretion disk during the high state. The broadband SED of PKS 0346-27
transitions from a typical low-Synchrotron-Peaked (LSP) to the
Intermediate-Synchrotron-Peaked (ISP) class, a behavior previously
observed in other flaring-ray sources. Our one-zone leptonic emission
model of the high-state SEDs constrains the gamma-ray emission region
to have a lower magnetic field, larger radius, and higher maximum
electron Lorentz factors with respect to the quiescent SED. Finally,
we note that the bright and hard-ray spectrum observed during the peak
of flaring activity in May 2018 implies that PKS 0346-27 could be a
promising target for future ground-based Cherenkov observatories such
as the Cherenkov Telescope Array (CTA). The CTA could detect such a
flare in the low-energy tail of its energy range during a high state
such as the one observed in May 2018.
Description:
Gamma-ray light curves of PKS 0346-27 from Fermi-LAT data with binning
of seven days (2008-2018, Fig.1), six, three, 1.5 hours (May 2018,
Fig.2). Multi-wavelength light curves (Fig.4) in X-rays (Swift-XRT),
optical-UV (Swift-UVOT), near-infrared (REM), radio-mm (ALMA).
Objects:
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RA (2000) DE Designation(s)
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03 48 38.14 -27 49 13.6 PKS0346-27 = QSO B0346-279
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1.dat 148 530 Weekly binned gamma-ray light curve
fig2a.dat 103 45 Six-hours binned gamma-ray light curve
fig2b.dat 103 90 Three-hours binned gamma-ray light curve
fig2c.dat 103 168 Orbit-binned gamma-ray light curve
fig4c.dat 32 56 E>10GeV photons
fig4d.dat 31 11 Swift-XRT light curve
fig4e.dat 55 38 Swift-UVOT light curve
fig4f.dat 85 47 REM light curve
fig4g.dat 61 33 ALMA light curve
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Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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3- 15 F13.8 yr Time Time
19- 33 F15.13 yr e_Time Time error
37- 55 E19.14 --- TS Test Statistic
57- 73 E17.11 1/cm2/s PhotonFlux 0.1-300 GeV photon flux
77- 93 E17.11 1/cm2/s e_PhotonFlux 0.1-300 GeV photon flux error
97-109 F13.11 --- PhotonIndex PowerLaw photon index
112-126 E15.10 --- e_PhotonIndex ?=- PowerLaw photon index error
133-148 E16.11 1/cm2/s PhotonFluxUL 95% confidence upper limit
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Byte-by-byte Description of file: fig2a.dat fig2b.dat fig2c.dat
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Bytes Format Units Label Explanations
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3- 15 F13.8 yr Time Time
17- 32 E16.11 yr e_Time Time error
34- 50 E17.11 --- TS Test Statistic
52- 68 E17.11 1/cm2/s PhotonFlux 0.1-300 GeV photon flux
70- 86 E17.11 1/cm2/s e_PhotonFlux 0.1-300 GeV photon flux error
88-103 E16.11 1/cm2/s PhotonFluxUL 95% confidence upper limit
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Byte-by-byte Description of file: fig4c.dat
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Bytes Format Units Label Explanations
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3- 20 F18.13 yr Time Time
22- 32 F11.7 GeV Energy Energy
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Byte-by-byte Description of file: fig4d.dat
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Bytes Format Units Label Explanations
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3- 20 F18.13 --- Time Time
22- 31 E10.4 mW/m2 Flux 0.2-10 keV flux (in erg/cm2/s)
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Byte-by-byte Description of file: fig4e.dat
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Bytes Format Units Label Explanations
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3- 20 F18.13 --- Time Time
22- 26 F5.3 mJy S Flux density
35- 42 E8.5 mJy e_S Flux density error
54- 55 A2 --- Filter [UBV W1 W2 M1] UVOT filter
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Byte-by-byte Description of file: fig4f.dat
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Bytes Format Units Label Explanations
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3- 20 F18.13 yr Time Time
22- 26 F5.2 mag Jmag ?=- J magnitude
28- 31 F4.2 mag e_Jmag ?=- J magnitude error
40- 44 F5.2 mag Hmag ?=- H magnitude
46- 49 F4.2 mag e_Hmag ?=- H magnitude error
58- 62 F5.2 mag rmag ?=- r magnitude
64- 67 F4.2 mag e_rmag ?=- r magnitude error
76- 80 F5.2 mag imag ?=- i magnitude
82- 85 F4.2 mag e_imag ?=- i magnitude error
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Byte-by-byte Description of file: fig4g.dat
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Bytes Format Units Label Explanations
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3- 15 F13.8 --- Time Time
17- 21 F5.3 Jy S Flux density
30- 34 F5.3 Jy e_S Flux density error
49- 61 E13.8 Hz Freq Frequency
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Acknowledgements:
Roberto Angioni, angioni(at)mpifr-bonn.mpg.de
(End) Patricia Vannier [CDS] 01-Jul-2019