J/ApJ/906/5 3C 454.3 FeII, MgII & 3000Å measurements (Amaya-Almazan+, 2021)
Multiwavelength Analysis and the Difference in the Behavior of the Spectral
Features during the 2010 and 2014 Flaring Periods of the Blazar 3C 454.3.
Amaya-Almazan R.A., Chavushyan V., Patino-Alvarez V.M.
<Astrophys. J., 906, 5 (2021)>
=2021ApJ...906....5A 2021ApJ...906....5A
ADC_Keywords: Active gal. nuclei; Photometry, ultraviolet
Keywords: Active galaxies ; Galaxy jets ; Gamma-rays ; Emission line
galaxies ; Quasars ; Active galactic nuclei
Abstract:
Over the years, the flat-spectrum radio quasar 3C454.3 has presented
phases of very high activity (flares) in which the different wave
bands increase their flux dramatically. In this work, we perform
multiwavelength analysis from radio to gamma-rays and study the MgII
λ2798 emission line and the UV FeII band from 2008 to 2018. We
found that an increase in the 43GHz flux density of the
quasi-stationary component C coincides with the estimated time at
which a superluminal blob ejected from the radio core (which caused
the brightest flare of 2010) collides with the quasi-stationary
component (at a projected distance of ∼4.6pc from the radio core). The
different behavior of the spectral index in the first
(5000<JD-2,450000<5600) and second (6600<JD-2450000<7900) flaring
periods suggests changes in the physical conditions. The complex
nature of the second period can be a result of a superposition of
multiple events at different locations. The MGII line has an
anticorrelation with the UV continuum while Fe ii correlates
positively, except at the time of the brightest flare of 2010, when
both have a strong response at high continuum luminosities. Our
results suggest that the dominant gamma-ray emission mechanism for the
first flaring period is external Compton. For the second flaring
period the region emitting seed photons is co-spatial with that
emitting gamma-rays. However, a study of the spectral energy
distribution using a multizone jet emission model is required to
confirm the nature of each significant flare during the second period.
Description:
The ground-based observational support of the Fermi Gamma-Ray Space
Telescope at the University of Arizona has been monitoring 3C454.3
over the years as part of its program. Taking advantage of this great
collection of data, in this work we used 529 optical spectra observed
from 2009-2018 calibrated against the V-band magnitude.
The redshift of this source (z=0.859) unlocks the near-UV region of
the spectrum, allowing us to analyze the MgII λ2798 emission
line and the UV FeII band, as well as to obtain the λ3000
continuum.
Objects:
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RA (2000) DE Designation(s)
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22 53 57.75 +16 08 53.6 3C 454.3 = 3C 454.3
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 39 529 Flux measurements for the MgII λ2798Å
emission line, the FeII UV band, and the
λ3000Å continuum
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See also:
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/ApJ/748/49 : Optical spectroscopy of 1LAC broad-line blazars (Shaw+, 2012)
J/ApJ/763/L36 : MgII and FeII flux of the blazar 3C 454.3 (Leon-Tavares+, 2013)
J/ApJ/846/98 : Jet kinematics of blazars at 43GHz with VLBA (Jorstad+, 2017)
J/AJ/155/90 : 1996-2009 optical photometric monitoring for 3C66A (Fan+, 2018)
J/A+A/630/A56 : A gamma-ray emission zone in 3C 279 (Patino-Alvarez+, 2019)
J/ApJ/891/68 : MgII, FeII & 3000Å continuum LCs CTA102 (Chavushyan+, 2020)
J/ApJS/248/8 : 9-yr of Fermi-LAT & Swift obs. of 3C 454.3 flares (Das+, 2020)
J/ApJS/247/33 : The Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 F7.2 d JD [5086/8307] Julian Date of observation,
JD-2450000
9- 13 F5.3 --- Cont [0.04/0.97] Continuum (3000Å) flux,
10-13erg/s/cm2/Å^
15- 19 F5.3 --- e_Cont [0.001/0.03] Uncertainty in Cont
21- 24 F4.2 10-13mW/m2 MgII [0.76/1.8] MgII 2798 flux, 10-13erg/s/cm2
26- 29 F4.2 10-13mW/m2 e_MgII [0.03/0.85] Uncertainty in MgII
31- 34 F4.2 10-13mW/m2 FeII [0.28/1.63] UV FeII flux, 10-13erg/s/cm
36- 39 F4.2 10-13mW/m2 e_FeII [0.04/1.04] Uncertainty in FeII
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 16-May-2022