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European VLBI Network --
Guidelines for proposal submission
Next Deadline 1 October 2012
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The EVN consists of a VLBI network of radio telescopes in Europe and
beyond, operated by an international Consortium of institutes. Real
time observing capabilities are under development in the EVN, and part
of the EVN array is now able to offer real time e-VLBI observations.
The European VLBI Network (EVN)
invites standard (disk recording) and e-VLBI real
time observing
proposals
for the 1 October 2012 deadline
(Call for Proposals here).
See below for general guidelines on the EVN and e-VLBI capabilities,
and details on proposal submission.
Standard
(disk recording) EVN
e-VLBI
Standard EVN
1. Introduction
2. EVN and other available
arrays and special features
3. Submitting EVN proposals
4. Guidelines on proposal
writing
5. Previous EVN observations and
proposals
6. Correlation of EVN
observations
7. Short Observations
8. Targets of Opportunity (ToO)
9. Large Projects
10. Contacts
e-VLBI
1. General information
2. Technical details
3. e-VLBI observation classes
4. Proposal details
5. How to submit
6. Acknowledgement
Standard EVN
1. Introduction
Consult the
EVN User Guide
for the following:
Use of the Network by astronomers not specialised in the VLBI technique
is encouraged. The
Joint Institute for VLBI in Europe (JIVE) can provide support for
schedule making, correlation and data analysis of EVN projects, as well
as advice during proposal preparation. Contact Bob Campbell
(campbell@jive.nl) for information about
EVN User
Support.
The EVN is able to support users via RadioNet, an Integrated
Infrastructure Initiative (I3) that is funded under the EC FP7 (Seventh
Framework Programme), for the period 2009-2011. Eligible
projects are those where both the PI and
at least half of the full list of proposers work at institutes located
in EU Member or Associated States, excluding the Netherlands (host
country of JIVE). As well as providing Transnational Access to the EVN,
the programme provides financial support for visits to the EVN
observatories and JIVE. Contact Bob Campbell (campbell@jive.nl) for
more information or see the "Access to the EVN" menu item of the EVN web page, which in turn links to
the Transnational Access
section of the RadioNet page.
2. Combining EVN
antennas with other arrays
Proposers may request EVN antennas together with other telescopes and
arrays.
EVN + e-MERLIN Observations
e-MERLIN
is an array of 7 radio telescopes connected by a new optical fiber
network. It is located in England, and provides a maximum baseline of 217 km.
Combined EVN+e-MERLIN projects add the short
e-MERLIN baselines (10-217 km), which will help to image more
extended sources, as well as providing VLBI baselines to
the Cambridge antenna. e-MERLIN+EVN time will be allocated by the EVN
Program Committee, but the case for joint observations must be made in
the proposal. Information on e-MERLIN and joint EVN+e-MERLIN observations may
be found here.
Including other antennas
Antennas of the NASA Deep Space Network (DSN), including the 70-m at
Robledo (Spain) may be available
for a small number of projects requiring very high sensitivity.
Global VLBI
GLOBAL projects add the NRAO Very
Long Baseline Array (VLBA) and/or other NRAO antennas (e.g. the VLA
or GBT), creating a larger array suitable for very high dynamic range
imaging and "snap-shot" observations of many sources.
Note that NRAO has moved from a trimester system to a semester
system with proposal deadlines of February 1st and August 1st.
The first semester-based deadline will be 2011 February 1 (see
http://www.nrao.edu/admin/do/vlba-gvlbi.shtml).
PIs wishing to apply for Global VLBI time should continue to submit
their proposals at the EVN deadlines using the Northstar on-line
proposal submission tool (see below).
3. Submitting EVN
Proposals
Deadline
Proposals must be received by 23:59:59 UTC on the appropriate 1st February,
1st June and 1st October.
Contact
Before submission the PI should ensure that all named co-proposers
have given their consent to be included in the list of investigators.
All communication between the Proposer(s), and the EVN Program
Committee
or Scheduler will be via the Contact Author designated in the proposal.
How to submit
- All EVN and GLOBAL proposals (except ToO proposals) must be
submitted with the new ONLINE TOOL
NorthStar.
- EVN proposals can optionally include MERLIN and/or Arecibo
and/or telescopes of the EVN affiliate DSN.
- Global proposals will be copied to both the EVN and to NRAO for
assessment; proposers should not themselves submit to NRAO.
- Proposers WHO DO NOT REQUEST THE EVN, and in particular
proposers who request ONLY NRAO, or the
VLBA+Effelsberg ALONE, or HSA resources, or the Global 3mm VLBI
Array, should NOT use NorthStar, and should continue to follow
instructions in the call for proposals issued by these institutions and
networks separately.
- Requests for inclusion of any other antennas or resources NOT
AFFILIATED with the EVN or NRAO should be indicated in the proposal,
but the PROPOSER MUST SEND A COPY (printable file can be downloaded
from NorthStar) to the Director/Scheduler of the observatory involved,
and will be responsible for arranging all aspects of their
participation, including observing support, disk supply and acquiring
telescope time for the EVN time allocated. See also the Code of
Practice for operational details.
Guidelines on using Northstar
- To use Northstar, people should register (only for the first
proposal submission), enter the information about the investigators and
the technical specifications of the proposed observations (equivalent
to that previously in the coversheet) using the on-line forms, and
upload a scientific justification in pdf or ps format. The preparation
of the scientific justification is a separate activity that can take
place at any time.
- Once people have registered, proposals can be created, edited,
previewed, and, eventually, submitted. Online help is available. An
email notification will be sent by Northstar to all co-proposers when a
proposal is submitted.
- NorthStar supports retraction, further editing, and resubmission
of proposals until the deadline. The final submission remains the
responsibility of the Contact author (others can view or even edit but
not submit or retract a proposal).
- Proposers are STRONGLY ADVISED to prepare and submit proposals A
FEW DAYS BEFORE the deadline; only in this case would you be able to contact JIVE for
assistance, should problems arise (contact Bob Cambpell,
campbell@jive.nl).
Old LaTex/e-mail way
This style of submission has been discontinued for ALL EVN and GLOBALS,
starting with the 1 June 2007 deadline. Its use is continued for
ToO proposals. The template can be downloaded
here.
After submission
A list of all
proposals received will be posted shortly after the deadline.
All communication between the Proposer(s), and the EVN Program
Committee
or Scheduler will be via the Contact Author designated in the proposal.
The
results from proposal review will be communicated after the next
meeting of
the EVN Program Committee, and will be SENT BY EMAIL unless otherwise
requested in the proposal.
4. Guidelines on
proposal writing
All proposals should include a text NOT EXCEEDING 2 SIDES that must be
uploaded to Northstar. This
text should contain both a scientific and a technical justification for
the resources requested. It should include a brief summary of any
related EVN proposals which have already been observed or scheduled.
Proposers should indicate if it is a resubmission of an earlier
proposal. Up to 2 additional sides with diagrams may be included; the
total, including cover sheet, should not exceed 4 sides.
- Proposers should identify any individual antenna(s) whose
inclusion is considered ESSENTIAL for achieving their goals.
- Only a limited amount of time is available at some antennas for
joint observations with the EVN - these include ARECIBO and the DSN. A
SPECIAL JUSTIFICATION is needed for requesting any of these facilities.
- Hartebeesthoek will not normally observe sources north of
declination +30 deg.
Phase-referencing observations
Observers are advised to find phase calibrators as close as possible
to their target source. The
VLBA Calibrator Survey may be useful here. For proposals where
phase-referencing is essential, the calibrator source(s) must be
specified. Note that there cannot be more than 12 source changes per
hour on the Lovell telescope due to slewing limitations.
5. Previous EVN
observations and proposals
A list of previous EVN
observations currently updated at IRA (Pietro Cassaro) can be
used to search
for observations of particular
sources, and provides links to the relevant experiments on the EVN data
archive for experiments correlated at JIVE. In addition, the EVN
archive
itself provides a FITS-finder utility. Searches can key to source names
or coordinates, observing frequency, and/or participating telescopes,
among other characteristics. The EVN archive is accessible as menu
items
in either the main EVN or JIVE web page.
A list of previous EVN proposals is also available:
Most recent EVN proposals
Complete
EVN proposal list
6. Correlation of
EVN observations
Correlation of EVN projects at JIVE
The capacity of the EVN MkIV
Data Processor at JIVE depends on both the physical load (number
of baselines, subbands, polarizations, spectral points) and the output rate
(integration time). In general,
the maximum number of spectral points per baseline/subband/polarization is
2048, but there are modes that cannot attain this in a single correlator pass.
See the
JIVE correlator page for more detailed information about current
spectral and output capabilities, including how the
new recirculation feature can help boost spectral resolution for narrower
subband experiments having more than 8 stations. Multiple correlator
passes can be requested for higher spectral resolution, but would need
to be justified in the proposal.
EVN is now accepting proposals including pulsar gating/binning.
All EVN proposals are subject to a technical assessment by the correlator
staff, and any technical difficulties of correlation are discussed during the
EVN proposal review.
Contact Bob Campbell (campbell@jive.nl) with further questions.
Correlation of EVN projects at Bonn
Limited time may be available for the correlation of EVN experiments
at the
Bonn MK4 VLBI Correlator ,
but only by arrangement with MPIfR correlator staff
PRIOR TO SUBMISSION. The DiFX capabilities are identical to those
offered by NRAO DiFX correlator (see Section 7 of the
VLBA Observational
Status Summary).
Suitable projects will be those for which the scientific advantage of
using
the MPIfR Correlator is given in the proposal, or those which include
an MPIfR collaborator who wishes to have closer "hands-on" approach to
the data flow. For details contact the Correlator Manager, Walter Alef
(walef@mpifr-bonn.mpg.de). The policy can be found at the
Bonn Mk4
Correlator Status Page.
Correlation of Global VLBI Projects
GLOBAL projects must be observed using VLBA/MKIV-compatible recording modes,
and will be processed by either the EVN correlator at JIVE or the VLBA
correlator at NRAO. As of 2010 January 1, the original, hardware-based VLBA
correlator has been replaced by NRAO's implementation of the DiFX software
correlator. Details of the new correlator's capabilities are given in
Section 7 of the
VLBA Observational
Status Summary.
Especially relevant to
global projects is support for Mark 5B recordings. A specific correlator
may be requested for technical reasons, which should be explained in the
proposal. The EVN Program Committee and the NRAO and EVN Schedulers will
consider the correlator requested for each proposal submitted, and assign
one if no preference was given, also taking into account the load on the
correlators, the logistics of disk distribution and the proximity of the PI
to the correlator.
7. Short Observations
"Short" observations (< 4 hours) may be proposed up to 6 weeks
before an observing session begins, by means of a brief justification
to the Chairman of the EVN Program Committee (Tiziana Venturi, INAF,
Istituto di Radioastronomia, tventuri@ira.inaf.it), who will, at her
discretion, authorise scheduling in any gaps in the session plan. They
are intended to facilitate short, pilot observations, if needed in
preparation for a full proposal. They can only be granted limited
resources (number of telescopes, disks, correlator time) and must use
standard recording modes. They should not involve any special observing
set-ups.
8. Targets of Opportunity (ToO)
Targets of opportunity (ToO) are defined to be extremely rare and/or
unpredictable events where there is a limited opportunity to make
scientifically important observations.
This limited opportunity and the potential scientific impact of the
observations together constitute the justification for an exceptional
response to a ToO proposal, by-passing the normal EVN review and scheduling
procedures.
The policy to apply for ToO time can be found
here.
Note that ToOs should not be submitted using NorthStar. Proposers are invited
to use the tex-based
VLBI cover sheet to provide the observational details.
9. Large projects
Most proposals request 12-48hrs observing time. The EVN Program
Committee (PC) also encourages larger projects (>48 hrs); these will
be subject to more detailed scrutiny, and the EVN PC may, in some
cases, attach conditions on the release of the data.
10. Contacts
Informal enquiries about technical feasibility of EVN, EVN+MERLIN, or
global projects may be directed to Bob Campbell (JIVE Science
Operations and Support Group, campbell@jive.nl).
Future EVN Calls for Proposals and other VLBI news can be received
from the
VLBI email exploder. To subscribe, send the message "subscribe vlbi" in
the body (not the subject line) of an email to:
Majordomo@zia.aoc.nrao.edu.
Tiziana Venturi - Chairperson EVN Program Committee
tventuri@ira.inaf.it
e-VLBI
1. General
information and current features
The current antenna capabilities can be found on the e-VLBI status
table. The full array now includes: Ef, Wb (tied array except at 5
cm), Ys,
Tr, On, Mh, Mc, Jb2, Cm, Ar and Sh. The wavebands covered are 18/21 cm,
6 cm, 5 cm and 1.3 cm.
A transmitted data rate of 1024 Mbps 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 eVLBI 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. See the EVN
ToO policy.
Note that because of on-going engineering work in 2010, participation of Jb2
and Cm cannot be guaranteed, and/or they may be replaced by other
MERLIN telescopes.
2. Technical details
Continuum observations
Continuum observations will be run at the highest possible reliable bit
rate. However Cm is presently limited to 128 Mbps of
useful data by its microwave link.
Continuum observations can be proposed for only one of the available
frequency bands in any given 24 hour session.
Spectral line observations
Real-time e-EVN spectral line observations would be similar to those
recorded on disk, but without the possibility of multiple correlation
passes, which may limit the tactics for achieving higher spectral
resolutions. The minimum data rate remains 32 Mbps (e.g. 2 dual-pol 2MHz
subbands). Recirculation can be used during e-VLBI correlation, obviating
the need for oversampling in most cases, see the
correlator-capacity web-page.
Observations may be proposed for the 18/21cm, 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.
3. e-VLBI observation
classes
Proposals submitted to use e-VLBI on the
scheduled runs
fall into the three classes as defined below. Time within the first two
classes will only be
allocated in response to proposals submitted for the standard proposal
deadlines of 1st Feb, 1st June and
1st October. Proposals should make clear in the proposal text which
class of
observations 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 for 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 e-VLBI 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.
Accurate source coordinates need only be included in the trigger
request, not in the original proposal. Only continuum observations can
be proposed for within this
class. Triggered proposals must include a precise and justified
triggering
criterion and a minimum number and configuration of telescopes required.
PIs of successful proposals in this class will be informed after
proposal review that their trigger request has been accepted. Such
trigger request should be sent by
e-mail to the EVN PC Chair (Tiziana Venturi, tventuri@ira.inaf.it) with
copies to the EVN
Scheduler (Richard Porcas, porcas@mpifr-bonn.mpg.de) and
JIVE/EXPReS (Bob Campbell,
campbell@jive.nl and Zsolt paragi, paragi@jive.nl). These trigger
requests must be received
no later than 0800 UT the day before the e-VLBI run. The e-mail
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 Chair will evaluate the trigger request (and decide on
priorities if more than one conflicting trigger requests is received)
and will inform the PI by 1700 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 for checking calibrator or
target source compactness
in preparation for a larger VLBI observation or proposal. 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 PC Chair. There is
no need to submit a full
proposal via Northstar but email to the Chair must clearly indicated
the purposes and observing details of
the proposed observation. A
tex-based VLBI cover
sheet should also be sent including information on
proposed observing modes, stations/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.
4) Generic e-VLBI trigger proposals
Generic trigger e-VLBI proposals are accepted for evaluation, provided
that they present a clear and well argued case as to why the requested
observations cannot be a regular proposal, or a ToO.
Note that both trigger and generic trigger proposals:
- should have very well defined trigger criteria, specified for each
source
separately, if necessary;
- should indicate the desired period for which the proposal should be
active, based on an assessment of the probability of triggering events.
The PC will set a maximum duration of 1 year;
- should indicate the maximum number of trigger events to be observed;
- should demonstrate the capability of the proposers to locate and
respond to triggering events within the period for which the proposal
should be active.
A list of previous e-VLBI proposals is available:
Most recent e-VLBI proposals
Complete e-VLBI proposals list
4. Proposal Details
Proposals requesting observing time for the e-VLBI runs should be
submitted by the normal 1st February, 1st June and 1st October deadline.
Proposals can be made for any length of time within the 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
eVLBI data are the standard ones of one year after data
distribution (see archive
policy). All standard and triggered proposals must use the Northstar online
submission tool (see details below).
Because detailed scheduling of eVLBI runs will be done by JIVE staff
all eVLBI proposals must include
the observing frequency, the requested GST range, the minimum bit rate
and 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
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, campbell@jive.nl).
5. How to submit
The on-line proposal submission tool Northstar replaces the old
Latex-email way of submission for proposals involving EVN, including
proposals for e-VLBI runs (an
exception to this at present are ToO proposals which are submitted by
email according to the procedure
described here).
To use Northstar proposers should register
(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 limitations apply and will be enforced.
The deadline for submission of standard and triggered proposals is
23:59:59 UTC on 1st February, 1st June and 1st October.
6. Acknowledgement
The development of e-VLBI within the EVN has been made possible
via EXPReS project funded by the EC FP6 IST Integrated Infrastructure
Initiative contract #
026642 - with a goal to achieve 1 Gbps e-VLBI real-time data transfer and
correlation.
John Conway - Chairman of EVN eVSAG (E-VLBI Science
Advisory
Group)
john.conway@chalmers.se