Slide 1Configuration figures of merit.
The optimization of the configuration minimizing the worst positive side lobe. (Kogan 2000, IEEE Transaction on Antenna and Propagation, 48, 7, 1075. )
Specific features of optimization: VLA transporter, underground environment, “topography” constraints .
Special cost concern.
HI is diffuse & extended, lose flux with interferometer
Galactic HI, HI in bridges, tidal tails, ram pressure stripped gas
Molecular Gas
Cosmic Web
HI column density sensitivity of E-config <1016 cm-2
Connections between galaxies and cosmic web
Recombination lines of ionized material; wide, faint lines
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e.g. radio relics in clusters (ideally w/ LFS),
Polarization in large-scale galactic outflows of nucleated Starbursts
Radio Lobes
Jet-IGM interaction, matter and energy feedback
Radio galaxies with recently shut-off engines
SZ Effect and Cosmology
@30GHz entire cluster in FoV but still resolving structure
Electron density distribution at all z
Pulsar Searches
efficient processing
Compare with D configuration
November 2009, Lunch talk
Configuration figures of merit.
Others
improves the side lobes level implicitly,
but a direct minimal side lobes optimization may produce
better result.
We optimize the configuration minimizing the maximum positive side lobe inside of the primary beam!
November 2009, Lunch talk
November 2009, Lunch talk
November 2009, Lunch talk
November 2009, Lunch talk
November 2009, Lunch talk
November 2009, Lunch talk
November 2009, Lunch talk
November 2009, Lunch talk
Conclusions
The designed E-configuration array has a maximum positive side lobes ~12% for snapshot with natural weighting. VLA-D for comparison has ~60%
The brightness temperature sensitivity is expected ~10 times better than VLA-D
Positions of all antennas satisfy requirements of the loading/reloading by the VLA transporter.
Positions of all antennas satisfy all constrains including underground environment.
The cost of the array is optimized, because
the 11 existed pads are used;
the existing track at the north-east sector is used;
Only one extra track is added….
More job may be needed:
to simplify junctions of the new north-west track with the existed
tracks (north and south-west).
to add the hybrid configuration for the Galactic Center observation.
November 2009, Lunch talk
Ultracompact E-configuration
16 new pads added at the center of the EVLA, +4 for hybrid
Enhanced surface brightness sensitivity for all bands (1h E-conf: 1s of 50-100mK in continuum)
Reduced sidelobe response
Improved mosaicking capabilities
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Zero risk