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2019A&A...626A..60Angelakis+
J/A+A/626/A60 F-GAMMA 2.64-43GHz radio data over 2007-2015 (Angelakis+, 2019)
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F-GAMMA: Multi-frequency radio monitoring of Fermi blazars.
The 2.64 to 43 GHz Effelsberg light curves from 2007-2015.
Angelakis E., Fuhrmann L., Myserlis I., Zensus J.A., Nestoras I.,
Karamanavis V., Marchili N., Krichbaum T.P., Kraus A., Rachen J.P.
=2019A&A...626A..60A (SIMBAD/NED BibCode)
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ADC_Keywords: Active gal. nuclei ; BL Lac objects ; QSOs ; Galaxies, radio ;
Galaxies, Markarian ; Radio sources ; Radio continuum ;
Energy distributions ; Surveys
Keywords: astronomical databases: miscellaneous - galaxies: active -
galaxies: jets - radio continuum: galaxies - quasars: general -
BL Lacertae objects: general
Abstract:
The advent of the Fermi gamma-ray space telescope with its superb
sensitivity, energy range, and unprecedented capability to monitor the
entire 4{pi} sky within less than 2-3 h, introduced a new standard in time
domain gamma-ray astronomy. Among several breakthroughs, Fermi has -
for the first time - made it possible to investigate, with high cadence,
the variability of the broadband spectral energy distribution (SED),
especially for active galactic nuclei (AGN). This is necessary for
understanding the emission and variability mechanisms in such systems.
To explore this new avenue of extragalactic physics the Fermi-GST AGN
Multi-frequency Monitoring Alliance (F-GAMMA) programme undertook the
task of conducting nearly monthly, broadband radio monitoring of selected
blazars, which is the dominant population of the extragalactic gamma-ray
sky, from January 2007 to January 2015. In this work we release all
the multi-frequency light curves from 2.64 to 43 GHz and first order
derivative data products after all necessary post-measurement
corrections and quality checks.
Along with the demanding task to provide the radio part of the broadband
SED in monthly intervals, the F-GAMMA programme was also driven by a
series of well-defined fundamental questions immediately relevant to
blazar physics. On the basis of the monthly sampled radio SEDs, the
F-GAMMA aimed at quantifying and understanding the possible multiband
correlation and multi-frequency radio variability, spectral evolution
and the associated emission, absorption and variability mechanisms.
The location of the gamma-ray production site and the correspondence
of structural evolution to radio variability have been among the
fundamental aims of the programme. Finally, the programme sought to
explore the characteristics and dynamics of the multi-frequency radio
linear and circular polarisation.
The F-GAMMA ran two main and tightly coordinated observing programmes.
The Effelsberg 100 m telescope programme monitoring 2.64, 4.85, 8.35,
10.45, 14.6, 23.05, 32, and 43 GHz, and the IRAM 30 m telescope programme
observing at 86.2, 142.3, and 228.9 GHz. The nominal cadence was one month
for a total of roughly 60 blazars and targets of opportunity. In a less
regular manner the F-GAMMA programme also ran an occasional monitoring
with the APEX 12 m telescope at 345 GHz. We only present the Effelsberg
dataset in this paper. The higher frequencies data are released elsewhere.
The current release includes 155 sources that have been observed at least
once by the F-GAMMA programme. That is, the initial sample, the revised
sample after the first Fermi release, targets of opportunity, and sources
observed in collaboration with a monitoring programme following up on
Planck satellite observations. For all these sources we release all
the quality-checked Effelsberg multi-frequency light curves. The suite
of post-measurement corrections and flagging and a thorough system
diagnostic study and error analysis is discussed as an assessment of
the data reliability. We also release data products such as flux density
moments and spectral indices. The effective cadence after the quality
flagging is around one radio SED every 1.3 months. The coherence of each
radio SED is around 40 min.
The released dataset includes more than 3x104 measurements for some
155 sources over a broad range of frequencies from 2.64 GHz to 43 GHz
obtained between 2007 and 2015. The median fractional error at the lowest
frequencies (2.64-10.45 GHz) is below 2%. At the highest frequencies
(14.6-43 GHz) with limiting factor of the atmospheric conditions, the
errors range from 3% to 9%, respectively.
Description:
The Fermi-GST AGN Multi-frequency Monitoring Alliance (F-GAMMA)
programme conducted nearly monthly, broadband radio monitoring of
selected blazars -- the dominant population of the extragalactic
gamma-ray sky -- from January 2007 to January 2015. The F-GAMMA ran
two main and tightly coordinated observing programmes. The Effelsberg
100 m telescope programme monitoring 2.64, 4.85, 8.35, 10.45, 14.6,
23.05, 32, and 43GHz, and the IRAM 30m telescope programme observing
at 86.2, 142.3, and 228.9GHz. The nominal cadence was one month for a
total of roughly 60 blazars and targets of opportunity. In a less
regular manner the F-GAMMA programme also ran an occasional monitoring
with the APEX 12m telescope at 345GHz. Here we only present the
Effelsberg dataset. The higher frequencies data are released
elsewhere.
In this work we release all the multi-frequency light curves from 2.64
to 43GHz and first order derivative data products after all necessary
post-measurement corrections and quality checks. The current data
release includes 155 sources that have been observed at least once by
the F-GAMMA programme. That is, the initial sample, the revised sample
after the first Fermi release, targets of opportunity, and sources
observed in collaboration with a monitoring programme following up on
Planck satellite observations. For all these sources we release all
the quality-checked Effelsberg multi-frequency light curves. The suite
of post-measurement corrections and flagging and a thorough system
diagnostic study and error analysis is discussed in detail in the
paper, as an assessment of the data reliability. We also release data
products such as flux density moments and spectral indices. The
effective cadence after the quality flagging is around one radio SED
every 1.3 months. The coherence of each radio SED is around 40
minutes.
The released dataset includes more than 30000 measurements for some
155 target sources and 10 reference sources over a broad range of
frequencies from 2.64GHz to 43GHz obtained between 2007 and 2015.
The median fractional error at the lowest frequencies (2.64-10.45GHz)
is below 2%. At the highest frequencies (14.6-43GHz) with limiting
factor of the atmospheric conditions, the errors range from 3% to 9%,
respectively. Here we provide the data presented in Tables 7, 9 and 10
of the manuscript, which contain the multi-frequency light curves,
flux density moments and spectral indices of the observed sources,
respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sources.dat 50 165 List of studied sources
table9.dat 69 1080 Flux density moments and light curve parameters
table10.dat 109 157 Spectral indices in three sub-bands
table7.dat 42 32411 Multi-frequency light curves
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Byte-by-byte Description of file: sources.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- ID Source identifier
12- 27 A16 --- SurveyID Survey identifier
29- 30 I2 h RAh ? Right ascension (J2000)
32- 33 I2 min RAm ? Right ascension (J2000)
35- 38 F4.1 s RAs ? Right ascension (J2000)
40 A1 --- DE- Declination sign (J2000)
41- 42 I2 deg DEd ? Declination (J2000)
44- 45 I2 arcmin DEm ? Declination (J2000)
47- 50 F4.1 arcsec DEs ? Declination (J2000)
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- ID Source identifier
12- 16 F5.2 GHz Freq Observed frequency
18- 20 I3 --- o_S Number of available flux density measurements
22- 27 F6.3 Jy Smean Mean flux density
29- 34 F6.3 Jy Smedian Median flux density
36- 40 F5.3 Jy s_S ?=- Flux density standard deviation
42- 47 F6.3 Jy b_S Minimum flux density
49- 55 F7.3 Jy B_S Maximum flux density
57- 59 F3.1 yr Dt ?=- Light curve span
61- 64 I4 d Rate ?=- Mean span between consecutive measurements
66- 69 F4.1 yr-1 M ?=- Mean number of measurements in a year
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- ID Source identifier
12- 16 F5.2 --- b_alow ?=- Minimum (softest) spectral index
in the low sub-band (1)
18- 22 F5.2 --- B_alow ?=- Maximum (hardest) spectral index
in the low sub-band (1)
24- 28 F5.2 --- alowmed ?=- Median spectra index
in the low sub-band (1)
30- 34 F5.2 --- ?=- Mean spectral index
in the low sub-band (1)
36- 39 F4.2 --- e_alow ?=- Median spectral uncertainty
in the low sub-band (1)
41- 43 I3 --- o_salow ?=- Number of measured SEDs
in the low sub-band (1)
45- 49 F5.2 --- b_amid ?=- Minimum (softest) spectral index
in the middle sub-band (1)
51- 55 F5.2 --- B_amid ?=- Maximum (hardest) spectral index
in the middle sub-band (1)
57- 61 F5.2 --- amidmed ?=- Median spectra index
in the middle sub-band (1)
63- 67 F5.2 --- ?=- Mean spectral index
in the middle sub-band (1)
69- 72 F4.2 --- e_amid ?=- Median spectral uncertainty
in the middle sub-band (1)
74- 76 I3 --- o_samid ?=- Number of measured SEDs
in the middle sub-band (1)
78- 82 F5.2 --- b_ahig ?=- Minimum (softest) spectral index
in the high sub-band (1)
84- 88 F5.2 --- B_ahig ?=- Maximum (hardest) spectral index
in the high sub-band (1)
90- 94 F5.2 --- ahigmed ?=- Median spectra index
in the high sub-band (1)
96-100 F5.2 --- ?=- Mean spectral index
in the high sub-band (1)
102-105 F4.2 --- e_ahig ?=- Median spectral uncertainty
in the high sub-band (1)
107-109 I3 --- o_sahig ?=- Number of measured SEDs
in the high sub-band (1)
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Note (1): Frequency groups for the low, middle and high sub-bands:
low = 2.64GHz, 4.85GHz and 8.35GHz
middle = 8.35GHz, 10.45GHz and 14.6GHz
high = 14.6GHz, 23.05GHz, 32GHz and 43GHz
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- ID Source identifier
12- 16 F5.2 GHz Freq Observed frequency
18- 28 F11.3 d JD Julian date
30- 36 F7.3 Jy S Flux density
38- 42 F5.3 Jy e_S 1-sigma uncertainty on S
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Acknowledgements:
Emmanouil Angelakis, angelaki(at)mpifr-bonn.mpg.de, agele(at)physics.auth.gr
Ioannis Myserlis, imyserlis(at)mpifr-bonn.mpg.de
This research is based on observations with the 100-m telescope of the
MPIfR (Max-Planck-Institut fuer Radioastronomie) at Effelsberg. I.M.,
I.N. and V.K. were funded by the International Max Planck Research
School (IMPRS) for Astronomy and Astrophysics at the Universities of
Bonn and Cologne.
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(End) Ioannis Myserlis [MPIfR, Germany], Patricia Vannier [CDS] 24-Apr-2019