J/A+A/545/A117 Monitoring of Mrk 421 at 15 and 24 GHz (Lico+, 2012)
VLBA monitoring of Mrk 421 at 15 and 24GHz during 2011.
Lico R., Giroletti M., Orienti M., Giovannini G., Cotton W., Edwards P.G.,
Fuhrmann L., Krichbaum T.P., Sokolovsky K.V., Kovalev Y.Y., Jorstad S.,
Marscher A., Kino M., Paneque D., Perez-Torres M.A., Piner G.
<Astron. Astrophys. 545, A117 (2012)>
=2012A&A...545A.117L 2012A&A...545A.117L
ADC_Keywords: BL Lac objects ; Radio sources
Keywords: galaxies: active - BL Lacertae objects: Mrk 421 - galaxies: jets
Abstract:
High-resolution radio observations are ideal for constraining the
value of physical parameters in the inner regions of
active-galactic-nucleus jets and complement results on multiwavelength
(MWL) observations. This study is part of a wider multifrequency
campaign targeting the nearby TeV blazar Markarian 421 (z=0.031),
with observations in the sub-mm (SMA), optical/IR (GASP), UV/X-ray
(Swift, RXTE, MAXI), and γ rays (Fermi-LAT, MAGIC, VERITAS).
We investigate the jet's morphology and any proper motions, and the
time evolution of physical parameters such as flux densities and
spectral index. The aim of our wider multifrequency campaign is to try
to shed light on questions such as the nature of the radiating
particles, the connection between the radio and γ-ray emission,
the location of the emitting regions and the origin of the flux
variability.
Description:
File table2 contains all the informations about Gaussian components,
resulting from the model-fit analysis. With this study we are looking
for proper motion in the jet and density flux variations.
For each component Flux density (with uncertainties), radius (with
uncertainties) and position angle in polar coordinates of the
component's center with respect to the core, FWHM of the major and
minor axes of the Gaussian component and the position angle of the
major axis measured from North through East are given.
The other four files are FITS file from which we produced images in
Fig.2 (J1104Jan15.FITS and J1104Jan24.FITS), and the two images in
Fig.3 obtained from the stacking of all the images of the twelve
epochs (Stack15.FITS and Stack24.FITS).
Objects:
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RA (2000) DE Designation(s)
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11 04 27.31 +38 12 31.8 Mrk 421 = UGC 6132
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 63 132 Details of model-fit analysis
fits.dat 64 4 List of fits files
fits/* . 4 FITS images
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "DD/MM/YYYY" Obs.date Observation date
12- 13 I2 GHz Freq [15/24] Observation frequency
15- 18 A4 --- Comp Label of each single component
20- 24 F5.1 mJy S Flux density
26- 29 F4.1 mJy e_S Uncertainty on flux density
31- 36 F6.4 mas r ?=- Distance of the component's center with
respect to the core
38- 41 F4.2 mas e_r ?=- Uncertainty on r
43- 47 F5.1 arcsec PA [-90/90]?=- Position angle of the
component's center with respect to the
core (1)
49- 52 F4.2 mas a FWHM of the major axis of the Gaussian
component
54- 57 F4.2 --- b/a Ratio of major axis and minor axis of the
Gaussian component
59- 63 F5.1 deg phi ?=- Position angle of the major axis (1)
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Note (1): The angle is measured from North through East.
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Byte-by-byte Description of file: fits.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 26 F7.5 arcsec/pix Scale Scale of the image
28- 31 I4 pix Nx Number of pixels along X-axis
32 A1 --- --- [x]
33- 36 I4 pix Ny Number of pixels along Y-axis
38- 44 F7.4 GHz Freq Frequency
50- 64 A15 --- FileName Name of FITS file in subdirectory fits
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Acknowledgements:
Rocco Lico, rocco.lico(at)studio.unibo.it
(End) R. Lico [INAF Inst. Radioastronomia, Italy], P. Vannier [CDS] 03-Aug-2012