Science > Surveys > VLASS

VLA Sky Survey

by Davis Murphy last modified Aug 09, 2016 by Kelly Sharp

VLASS logo (dark)News Update: VLASS status update for July 2016

The VLASS Pilot Survey has been defined by NRAO and the SSG to cover ~2400 square degrees, and 200 hours has been allocated to these observations by the Time Allocation Committee and the NRAO Assistant Director for NM Operations. Further description of the pilot survey can be found in VLASS Memo #2.  Test observations began in June under the TSKY0001 project code.  NRAO staff are currently working on an issue with the pointing metadata, and specialized data reduction scripts are currently required to image these data.  When the pointing problem has been fixed and validated, raw visibility data from the pilot will be immediately available through the NRAO archive under project code TVPILOT. Data products (calibrated visibility data, images) will be made available after undergoing quality assurance.

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A new sky survey for an enhanced VLA

Very Large ArrayIn the 20 years since the initial observations were made for the NRAO VLA Sky Survey (NVSS) and the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST), these pioneering programs have defined the state-of-the-art in centimeter radio sky surveys and produced a steady stream of excellent science. Given the enhanced capabilities of the Jansky Very Large Array (VLA), now is an appropriate time to exploit the scientific potential of new centimeter-wavelength sky surveys.

The astronomy community has already recognized that several of the high priority science goals of the 2010 decadal survey New Worlds, New Horizons in Astronomy and Astrophysics could be addressed by a new VLA sky survey. At the May 2013 Radio Astronomy in the LSST Era held at NRAO-Charlottesville, for example, many scientists expressed keen interest in employing the VLA to conduct new, wide-area centimeter wavelength sky surveys in support of multi-wavelength synoptic surveys using existing and future facilities, such as the Large Synoptic Survey Telescope (LSST).

Thus, we are undertaking a NRAO VLA Sky Survey (VLASS) initiative to design and execute a new centimeter-wavelength survey. A community-led Science Survey Group (SSG) defined the science program and key components of VLASS, and NRAO will support its technical definition and implementation. All VLASS data will be available immediately to the community.

The VLASS will consist of a survey of the entire sky visible to the VLA (34000 square degrees) in three epochs, each epoch reaching a flux density limit of 0.12mJy at 3GHz. The survey will have a resolution of 2.5" and be carried out in the S-band of the VLA in B configuration. The survey will cover the range 2-4GHz (less some excisions due to RFI) and be carried out in full polarization. Observations will be spread out over seven years (six cycles of the B configuration) to both minimize the impact on PI science and to deliver a long time baseline for studies of transients and variability.


VLASS Status Update May 2016

Posted 21 May 2016

We are feverishly preparing for the start of the VLASS Pilot Survey observations, to commence as soon as possible following the readiness assessment to be held on May 25! The Pilot Survey has been defined by NRAO and SSG to cover ~2400 square degrees, and 200 hours has been allocated to these observations by the Time Allocation Committee and the NRAO Socorro Site Director. Further description of the planned pilot survey can be found in VLASS Memo #2.