Call for EVN e-VLBI science proposals - deadline 1st June 2008
Proposals for EVN e-VLBI observations are invited for submission. New features include;
- The Effelsberg 100m telescope has been successfully tested for e-VLBI (see press release) and will participate in future scheduled EVN e-VLBI observations.
- A transmitted data rate of 512Mbit/s is expected for the participating European antennas. Lower bit rates for spectral line observations are also supported.
- Proposals for any science goal, not just rapid response science can be made. In addition a special class of 'triggered' proposal for the pre-set e-VLBI dates is supported. Finally e-VLBI can be combined with EVN session disk observations for denser time monitoring of variable sources.
- e-VLBI can also be used for EVN Target-of-Opportunity (ToO) observations set up at short notice on any date for high priority unanticipated events. For details see the EVN ToO policy.
Upcoming scheduled e-EVN runs are
In the first half of 2009 e-VLBI runs are likely to be scheduled at approximately the same rate between disk sessions. Participating e-EVN antennas are Ef, Wb14 (tied array, except 5cm), Tr, On, Mh, Mc, Jb2, Cm. In addition in some runs other stations (e.g. Ar and Sh) may be added on a best effort basis when technically feasible. Wavelength bands covered are 18/21cm, 6cm, 5cm and 1.3cm. Please see the e-vlbi status table for the availability of different e-VLBI stations per observing band. Note that because of on-going engineering work participation of Jb2 and Cm cannot be guaranteed and/or they may be replaced by other MERLIN telescopes.
TECHNICAL DETAILS
CONTINUUM OBSERVATIONS - will be run at the highest possible reliable bit rate. Based on recent experience it is expected that at least 512 Mbit/s will be achieved (however Cm is presently limited to 128 Mbit/s of useful data by its microwave link). Continuum observations can be proposed for only one of the available bands in any given 24hr session.SPECTRAL LINE OBSERVATIONS - can be carried out at data rates between a minimum of 32 Mbit/s and a maximum of 512Mbit/s. For two-bit, dual-polarisation observations, the lower limit implies at least 4 channels of 4 Msample/sec sampling (Nyquist channel bandwidth = 2MHz; with oversampling possible down to spanned channel bandwidths of 0.5MHz). Observations may be proposed for the 18cm/21cm, 5cm and 1cm bands. Note that only standard and short observation proposal types (see below for definitions) are allowed for spectral line observations. Triggered spectral line proposals will not be accepted.
e-VLBI OBSERVATION CLASSES
Proposals submitted to use of e-VLBI on the fixed dates defined above fall into the three classes defined below. Time within the first two classes will only be allocated in response to proposals submitted for the standard EVN proposal deadlines of 1st Feb, 1st June and 1st Oct. PI's should make clear in the proposal text which class of observation is being requested.1) General e-VLBI proposals
Any proposal requesting e-VLBI observing time during one or several e-VLBI sessions, excluding triggered response science (see below). General e-VLBI proposals can be any scientific purpose and do not need to be justified based on the rapid data delivery of e-VLBI. Proposals for source monitoring may also request complementary observing time during regular EVN sessions using disk recording. Note that the e-VLBI portion of monitoring proposals cannot be guaranteed in every requested run as they may be overridden by higher rated, triggered e-VLBI proposals (see below). General proposals can be either continuum or spectral line. Scheduling will be done by JIVE staff using the technical information included in the proposal; it is therefore vital that all technical aspects are fully specified in the proposal.2) Triggered e-VLBI proposals
A proposal to be scheduled during an e-VLBI run only if a specific triggering criterion is met. Only continuum observations can be proposed for within this class. Triggered proposals must include a precise and justified triggering criterion. They must also give an estimate of likely time intervals between trigger events, and a maximum number of trigger events that will be observed. The maximum period for which a triggered proposal will remain active will be one year. PIs of successful proposals in this class will be informed after proposal review that their trigger requests will be accepted. Such trigger requests should be sent by e-mail to the EVN PC Chair ( Tiziana Venturi) with copies to the EVN Scheduler (Richard Porcas) and JIVE/EXPReS (Bob Campbell, Zsolt Paragi ). These trigger requests must be received no later than 08:00 UT the day before the e-VLBI run. The email should provide evidence that the trigger criterion in the original proposal has been met and give the exact GST range and source position requested. All requested technical parameters must match those in the original proposal. The PC Chairman will evaluate the trigger request (and decide on priorities if more than one conflicting trigger request is received) and will inform the PI by 17:00 UT whether their experiment is to be observed. The experiment will then be scheduled by JIVE staff in accordance with the instructions given in the original proposal.3) Short e-VLBI observations
Short e-VLBI observations may be requested in order to rapidly obtain results in preparation for a later proposal. Examples include checking calibrator or target source compactness. These projects are limited to less than 2 hours in length. Such requests may be submitted up to three weeks prior to the start of any e-VLBI run directly to the EVN PC Chair. There is no need to submit a full proposal via Northstar but the email to the Chair must clearly indicate the purposes and observing details of the proposed observation. A standard VLBI coversheet should also be sent including information on proposed observing modes, station/GST ranges and precise positions for all targets and calibrators. The information sent must be sufficient to allow central scheduling of the observations by JIVE personnel.PROPOSAL DETAILS
Proposals requesting observing time for the above runs should be submitted by the 1 June 2008 deadline. Proposals can be made for any length of time within the above advertised slots up to 24 hours in length. Short time requests (defined above) of up to 2 hours in length can be submitted directly to the PC Chair up to three weeks before each run. Proprietary rights on all e-VLBI data are the standard ones of one year after data distribution (see the archive policy). All standard and triggered proposals must use the Northstar online submission tool (see details below).Because detailed scheduling of e-VLBI runs will be done by JIVE staff all e-VLBI proposals must include the observing frequency, the requested GST range, the minimum bit rate and a minimum number and configuration of telescopes required. It is essential that standard proposals also include accurate target and calibrator positions. For triggered proposals as much information as possible should be given about potential targets and their calibrators, which will ease in evaluating the technical feasibility of the proposed observations. The technical details of all proposals should be discussed with JIVE staff prior to submission to ensure proper and efficient scheduling (contact Bob Campbell).
HOW TO SUBMIT
The on-line proposal submission tool Northstar replaces the old Latex-email way of submission for all proposals which involve the EVN, including proposals for e-VLBI runs (an exception to this is at present are ToO proposals which are submitted by e-mail according to the ToO procedures).To use Northstar proposers should register here (only for the first proposal submission), complete the technical information on-line (equivalent to that previously in the cover-sheet) and upload a scientific justification in pdf or ps format. Standard page limits apply and will be enforced. If there are any problems with running Northstar contact Antonis Polatidis at JIVE. The deadline for submission of standard and triggered proposals is 23:59:59 UTC on 1st June 2008.
ACKNOWLEDGEMENT
The continuing development of e-VLBI within the EVN is made possible via the EXPReS project funded by the EC FP6 IST Integrated infrastructure initiative contract #026642 - with a goal to achieve 1 Gbit/s e-VLBI real time data transfer and correlation. John Conway
Chairman EVN eVSAG (e-VLBI Science Advisory Group)
EVN webmaster (jive{at}jive.nl)