Information For:
  Astronomers
  Array Operators
  Data Analysts
  Teachers & Students

Useful Links:
  Very Long Baseline Array (VLBA)
  Press Releases
  Image Gallery
  Frequently Asked Questions
  Tours
  Shopping

VLA Blank Field Proposal Opportunity (June 9, 2005)

During the past two configuration cycles, the VLA has seen an increasing number of proposals requesting time allocations on the order of 100 hours to image areas covered by deep "blank-field" extragalactic surveys conducted both by spacecraft and by ground-based telescopes (e.g., HDF, CDF=South, CGOODS, COSMOS, SWIRE). Our referees have had difficulty distinguishing among the proposals, and the 1000-word limit has made it very difficult for proposers to describe all their ancillary data in a fashion that can be understood by the referees. We have surveyed past and present proposers, referees, and the NRAO Users Committee in order to sample opinions on improving the process for assessment of these proposals.

For the next VLA cycle, extending from January/February 2006 (A configuration) through June 2007 (D configuration), we will change our method of evaluating these blank-field extragalactic survey proposals. In order to provide uniform refereeing and assessment, there will be a single proposal deadline, October 3, 2005, ONLY FOR all proposals requesting a total of 40-199 hours of observing time for blank-field extragalactic surveys. This applies to VLA proposals only, and includes the total amount of observing time summed over all configurations. The "blank-field" category will include both deep integrations at a single pointing and shallower integrations at multiple pointings, in order to cover a wider field of view.

Proposals fitting the above blank-field criteria that are received at the February, June, and October 2006 deadlines will be rejected and will not be refereed. Several proposals asking for A and B configurations have been held over from the previous cycle until the new evaluation method was in place; the PIs of those programs should submit new proposals that include the additional information described in the next paragraph. All proposers should state clearly in the abstract and the body of the proposal that they intend the proposal to be evaluated in the new blank-field category.

In addition to the normal 1000-word proposal limit, these blank-field extragalactic survey proposals will be allocated an additional two pages to describe two items: their ancillary data and the plans for making the VLA and other data available to the community and (if applicable) the National Virtual Observatory. A summary of all other observations of the extragalactic fields that are available to the proposal team will be most helpful to the referees; this summary should include a description of whether the ancillary data are in hand, if telescope time is already guaranteed, or if proposals for such data are submitted or anticipated in the future. Expected dates of availability of the ancillary data also should be provided.

The blank-field survey proposals will be refereed by approximately six to eight "normal" VLA/VLBA referees. Following refereeing, a panel will be convened to evaluate these proposals; the panel may meet in person or by teleconference, depending on the proposal demand. There will be no fixed time allocation for this type of proposal; it is our expectation that we may grant 500-1000 hours to blank-field science during the next VLA configuration cycle, depending on proposal pressure and quality. Allocations made through the separate Large Proposal process may be considered in evaluating the uniqueness of the science of each blank-field proposal. If necessary, we will adjust the time spent in the different VLA configurations in order to respond to proposal pressure.

Potential proposers should be aware that we are in the midst of the EVLA construction project, and they should expect the possibility of having fewer than 27 antennas, as well as non-identical antennas in the array (most antennas will be "old style" VLA antennas, while a few antennas will have been retrofitted with new receivers and feeds). In particular, at 1.4 GHz, we have several antennas with new feeds that give much better performance at low elevations; it also is possible that the differing polarization responses of old and new systems may complicate data reduction at this frequency. In mid-September, we expect to issue an update incorporating our latest predictions for the VLA status in 2006, and we advise prospective proposers to consult this as they complete their proposals. Because of the rapid evolution of the EVLA over the rest of this decade, we will determine at a later date whether to offer this separate blank-field opportunity again at a proposal deadline in 2007.

Jim Ulvestad

Modified on Friday, 26-Sep-2008 12:08:07 MDT by Jim Ulvestad