J/A+A/630/A108 MG B2016+112 radio images (Spingola+, 2019)
Proper motion in lensed radio jets at redshift 3:
A possible dual super-massive black hole system in the early Universe.
Spingola C., McKean J.P., Massari D., Koopmans L.V.E.
<Astron. Astrophys. 630, A108 (2019)>
=2019A&A...630A.108S 2019A&A...630A.108S (SIMBAD/NED BibCode)
ADC_Keywords: Gravitational lensing ; Radio sources
Keywords: galaxies: active - galaxies: jets - gravitational lensing: strong -
instrumentation: high angular resolution -
instrumentation: interferometers - radio continuum: galaxies
Abstract:
In this paper, we exploit the gravitational lensing effect to detect
proper motion in the highly magnified gravitationally lensed source MG
B2016+112. We find positional shifts up to 6mas in the lensed images
by comparing two very long baseline interferometric (VLBI) radio
observations at 1.7GHz that are separated by 14.359 years, and provide
an astrometric accuracy of the order of tens of as. From lens
modelling, we exclude a shift in the lensing galaxy as the cause of
the positional change of the lensed images, and we assign it to the
background source. The source consists of four sub-components,
separated by 175 pc, with proper motion of the order of tens µas/yr
for the two components at highest magnification (µ∼350) and of the
order of a few mas/yr for the two components at lower magnification
(µ∼2). We propose single Active Galactic Nuclei (AGN) and dual AGN
scenarios to explain the source plane. Although, the latter
interpretation is supported by the archival multi-wavelength
properties of the object. In this case, MG B2016+112 would represent
the highest redshift dual radio-loud AGN system discovered thus far,
and would support the merger interpretation for such systems. Also,
given the low probability (∼10-5) of detecting a dual AGN system
that is also gravitationally lensed, if confirmed, this would suggest
that such dual AGN systems must be more abundant in the early Universe
than currently thought.
Description:
Self-calibrated image of VLBA only visibilities of the global VLBI
experiment GP030 at 1.7GHz (epoch1mJycds.fits) and self-calibrated
image of VLBA experiment BS251E at 1.7GHz (epoch2mJycds.fits)
Objects:
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RA (2000) DE Designation(s)
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20 19 18.1 +11 27 11 MG B2016+112 = NAME MG 2016+112 System
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 155 2 List of fits files
fits/* . 2 Individual fits files
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Byte-by-byte Description of file: list.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- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 39 A10 "date" Obs.date Observation date
41- 45 I5 Kibyte size Size of FITS file
47- 61 A15 --- FileName Name of FITS file, in subdirectory fits
63-155 A93 --- Title Title of the FITS file
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Acknowledgements:
Cristiana Spingola, spingola(at)astro.rug.nl
(End) Patricia Vannier [CDS] 23-Sep-2019