VLBA Calibrator Survey for observing remaining flat-spectrum sources (VCS11)
Goals
We propose here VLBA observations to complete two large VLBA surveys
to search for gravitational lens candidates based on multiple compact
components that we can then follow up with VLBA observations to verify
or disprove any candidate lenses, which we will use to test cold dark
matter (CDM) versus alternative dark matter models.
The observations we propose are:
- CLASS VLBA observations of 1,215 AGN brighter than 50 mJy at
8.4 GHz, which will augment existing archival VLBA observations
of 5,122 CLASS objects brighter than 50 mJy at 8.4 GHz and hence
make up a complete flux density limited sample of 6,337 CLASS AGN
brighter than 50 mJy at 8.4 GHz. This sample, being
statistically complete, will provide a firm statistical foundation
for cosmological studies that aim to determine or limit
the cosmological density of compact objects in the
106 M⊙ – 3 × 109 M⊙
range. The proposed program to look for gravitational lensing
signatures in 6,337 AGN will provide a factor of 20 improvement
over previous studies.
- CRATES VLBA observations of 1,047 AGN above declination -40°,
will augment the existing archival VLBA observations of 6504
CRATES objects to complete the VLBA observations of all CRATES
objects north of declination -40°. This will provide a second
large sample of compact flat spectrum objects suitable for
gravitational lensing searches for compact objects in the above
mass range.
The target source list consists of 1929 objects.
These two samples complement one another since the CLASS sample is statistically
complete down to 50 mJy at 8.4 GHz, while the CRATES sample selects for compact
flat spectrum objects.
The main goal of the problem is to find gravitational lenses at scales less than
200~mas what will impose important upper limits on the numbers of
mass condensations with high enough central densities to produce strong lensing,
which would place interesting limits on various dark matter candidates, such
as black holes and some important exotic particle models.
Results
The list of observed sources.
Status on 2021.02.12
| The total number of sources observed: | 3313 | |
| The number calibrator sources processed: | 305 | |
| The number target sources processed: | 3008 | |
| The number of segments observed: | 18 | |
| The number of segments correlated: | 18 | |
| The number of segments with preliminary solution: | 18 | |
| The number of segments imaged: | 1 | |
| The number images | 483 | |
| The number of target sources detected at C band: | 2298 | |
| The number of target sources detected at X band: | 2080 | |
| The number of target sources detected at both bands: | 2298 | |
| Detection rate: | 76% | |
| Nominal campaign duration: | 112.25 hours | |
| On source time: | 64.3 hours | |
<--
The catalogue of positions of 2280 target sources from C-band observations:
vcs11_c.sou
The catalogue of positions of 2080 target sources from X-band observations:
vcs11_x.sou
The catalogue of positions of 2074 target sources from dual-band C/X observations:
vcs11_xc.sou
The list of 710 sources were observed, but not detected at C-band
The list of 510 sources were observed, but not detected at X-band
The list of 578 sources were observed, but not detected at both bands
simultaneosly
483 images of observed sources are available.
-->
Change Log
- 2021.03.16 Preliminary analysis of BR235R. The last segment.
- 2021.03.15 Preliminary analysis of BR235Q.
- 2021.03.09 Preliminary analysis of BR235M, BR235N, BR235O, BR235P.
- 2021.02.16 The last segment was observed
- 2021.01.11 Processed segement BG235J, BR235K, BR235L
- 2020.12.19 Processed segement BG235G, BR235H, BR235I
- 2020.12.02 Processed segement BG235F
- 2020.11.22 BR235A was imaged.
- 2020.11.21 Processed all segments BR235A through BR235E
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This web page was prepared by Leonid Petrov
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Last update: 2021.03.17_10:11:13