Memorandum to VLA/VLBA Proposers and Observers

News

News for Proposers

General announcements and news for investigators proposing to use the VLA, VLBA, HSA, and other VLBI facilities for the 2008 June 2 deadline will be available in mid-May.

GLAST Collaborative Observing

Through an agreement with the Gamma-ray Large Area Space Telescope (GLAST) mission, up to 10% of the total observing time on each NRAO telescope was made available for collaborative observing. GLAST Cycle 1 Peer Review was held in 2007 December. GLAST is presently scheduled for launch no earlier than 2008 May 31. Approximately 300 hours of collaborative observing was allocated on the VLBA, with less time allocated on the VLA and the GBT.

Prompt ToO Overrides for VLA Proposal AO229

We will continue a scheme wherein this proposal team is authorized to conduct prompt target-of-opportunity (ToO) overrides in response to stellar superflares. Proposal AO229 expires at the end of trimester 2008-T3. Time taken for such overrides will be rescheduled on a best-effort basis. To minimize the impact of overrides during sessions longer than a few hours, we remind observers that it is always prudent to include more than one observation of a primary flux density calibrator and, if appropriate, a bandpass calibrator.

Current Regular Proposals

General

Information about the status of all current regular proposals on which your name appears has been e-mailed to you, in a format described under Static Information below. That e-mailing (a) includes proposals just considered for trimester 2008-T2 plus those waiting for future trimesters, whatever their date of submission; and (b) does not include proposals submitted earlier that are waiting in the dynamic scheduling queues or multi-configuration VLA proposals for which time in the DnC, D, or subsequent configurations has been previously allocated.

VLA

Scheduling takes two forms, fixed date and dynamic. Some approved proposals will be scheduled on fixed dates; time for them was allocated for the DnC configuration (June 6-23), for the D configuration (June 27 to September 15) or for the associated reconfigurations (May 27 to June 6; June 23-27). Some approved proposals have been accepted for insertion into the VLA dynamic scheduling queue; a Guide to VLA Dynamic Scheduling is available. Proposals requesting future configurations in some cases have been allocated time in those configurations, and in other cases have been retained for future consideration. We rejected proposals which we were unable to schedule or unwilling to queue, and which required only the DnC or D configurations. We also, in most cases, rejected unscheduled proposals which were submitted more than one year ago, or for which it is clear, due to referee ratings or other reasons, that the proposal will not be accepted within one year from its submission date.

VLBA

Scheduling takes two forms, dynamic and fixed date. Most approved proposals have been accepted for insertion into the VLBA dynamic scheduling queue; a Guide to VLBA Dynamic Scheduling is available. Rare proposals, particularly those requiring other resources such as a non-VLBA antenna, will be scheduled on fixed dates with notification to the observers about six weeks in advance.

Statistics

The oversubscription rate for the D configuration was about 2.1, after subtracting time allocated to maintenance and software development, and subtracting time previously allocated either as part of the prior large proposal process or previously allocated as part of a multiconfiguration proposal. There were 27.5 hours requested for the High Sensitivity Array (HSA). There were 1736 hours requested for VLBA observations (540 hours at 128 Mbits/sec (the current sustainable rate), 1078 hours at 256 Mbits/sec, 118 hours at 512 Mbits/sec). For comparison, in a recent trimester the VLBA observed for 1100 hours, of which 207 hours were allocated by the prior large proposal process, not considered here. There were 131 active VLA proposals, 39 active VLBA proposals, and eight new Global Network proposals. We allocated time for 48 VLA proposals, accepted six as target of opportunity proposals waiting for an event of known type, approved 31 for insertion into the VLA dynamic queue, and rejected 44 proposals. We approved four VLBA proposals for fixed date scheduling, one for the HSA. We approved 11 VLBA proposals for the dynamic queue, seven at high priority, four at second priority. We rejected 22 VLBA proposals. The average time per approved proposal was 17 hours for the VLA and 38 hours for the VLBA. Information from the VLA/VLBA Scheduling Officers includes a table of approved VLA/VLBA proposals.

Future Regular Proposals

Trimester 2008-T3 for the VLA and VLBA starts in September and ends in January. The VLA will be in its A configuration. The A configuration daytime will involve RAs between 12h and 20h. Proposals for either the VLA or VLBA for trimester T3 must be received at NRAO by June 2, 2008, 5PM Eastern Time. See the latest NRAO Newsletter for details, including a list of which types of VLA observations are more difficult in daytime than at night. General announcements and news for proposers will be made available in mid-May.

Related Postings

These include the NRAO Proposal Referees' Guide, a complete description of the VLA/VLBA Time Allocation Process, and the proposal process for Rapid Response Science.

Static Information

Proposal Summary

The first line contains the proposal code and title. The second line informs you if we have scheduled time for the proposal, and whether it will be considered for more time in the future. If you expected the proposal to be considered for a future trimester, and this is not indicated in this line, please let us know by the next proposal deadline. This line is followed by comments from the VLA/VLBA Proposal Selection Committee, or from other considerations of the proposal, and then the list of authors of the proposal. For proposals for which we have allocated VLA or VLBA time, a list of the times tentatively allocated, with configuration, and a breakdown in terms of sessions with approximate centering in VLA sidereal time is given. We also list the times requested, with a similar breakdown, and times previously scheduled.

The reports from the referees follow and they contain a numerical rating. The referees use any numerical system with which they are comfortable, subject only to the convention that the smaller the rating, the better the proposal. We include the median of the ratings given us by that particular referee in order to judge the relative rating of your proposal. The referee ratings are strongly advisory to the Committee, which, however, may also apply considerations of similar archival observations, logistics, resources used, etc., to decide which proposals to schedule.

For most proposals that supplied a source list we have searched the VLA or VLBA archive for previous observations of the same sources, except for the Galactic Center and Orion A in which the listings would be too voluminous to be very informative. We include this listing in the e-mailing sent to the lead proposer only. These listings give the name, position, type of observation (blank indicates continuum, codes starting with a number are line modes, VLBA observations show recording mode), frequency of observation, bandwidth, time on source in minutes, number of antennas, proposal code, observer's name, configuration and date. Observations are selected on the basis of positional agreement only. We include this information since it may be of value to the proposer, as it often was to the Committee in evaluating the proposal.

VLBI Global Network Proposals

NRAO evaluates these but the final choice of proposals for scheduling, for either the centimeter or the 3mm sessions, is done by negotiation between the US and European schedulers.

Modifications

Unless stated otherwise, any time allocated is only for the proposal given, and no substantial modification in the program should be made without consulting with schedsoc@nrao.edu (and R. Porcas for VLBI Global Network proposals) before doing so.

Public Outreach

The NRAO can help observers and their home institution prepare joint press releases, and/or help prepare enhanced graphics for publications. The NRAO encourages observers to submit images from their research to its on-line image gallery. Contact: mtadams@nrao.edu.

The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Modified on Monday, 28-Apr-2008 08:29:56 MDT