VLA Science Opportunities

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VLA capabilities September 2013 - January 2014

1. General

The 2013B call for proposals (http://science.nrao.edu/enews/6.1) details the general capabilities being offered for the Karl G. Jansky Very Large Array (VLA) in the 2013B semester (August 23, 2013 to January 6, 2014) with flexible tuning of sub-band spectral line windows using the 8-bit samplers (enabling up to 2 GHz total bandwidth), use of the 3-bit samplers at higher frequencies in a mode that is suitable for wide-band continuum and extragalactic lines and line searches, use of up to 3 independent sub-arrays and a phased array capability for VLBI.

In addition to the general capabilities, NRAO continues to offer shared risk observing options for those who would like to push the capabilities of the VLA beyond those offered for general use.   These are the "Shared Risk Observing" and "Resident Shared Risk Observing" (RSRO) programs.     Details of what is being offered for the shared risk programs and what is required to write a proposal for them are available on the web at: https://science.nrao.edu/facilities/vla/proposing/sro2013b.

2. P-band

P-band (230-470 MHz) is available for shared-risk proposals in 2013b.

The new EVLA Lowband receiver system consists of two bands, P: (230-470 MHz) and 4: (54-86 MHz).  Lowband is in the final stages of construction and commissioning has begun. The 4-band part of the system is not ready for open observing yet but P-band is ready for simple, shared-risk continuum projects.  We expect at least 20 antennas to be working at P-band during 2013b. The Lowband system is mounted near the prime focus and, unlike the rest of the VLA bands, uses linear polarization. The wide-band system is significantly more sensitive than the old VLA P-band, due to a lower system temperature and the use of the WIDAR correlator.  We are not yet ready to provide polarization calibration but the system works adequately for simple continuum observations of unpolarized sources. For now the default path for calibration uses AIPS; however, for most projects, the imaging is best done in CASA using its wideband clean algorithm with nterms=2. Calibrated uv data can be ported from AIPS to CASA.