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Call for Observing Proposals for the Plateau de Bure Interferometer

Conditions for the next winter session

Despite the fact that we still rely on ground transport and transport by helicopter, we are confident that we can support at least three configuration changes this winter. We therefore ask investigators to submit proposals for all four of the primary configurations of the six antenna array. The D, C and B configurations have already been scheduled last winter. With the A configuration, the Plateau de Bure Interferometer will offer anew the possibility to carry out high resolution observations. The A configuration provides an angular resolution of 0.6'' at 230 GHz for targets at $\ge 30^\circ$declination.

A preliminary configuration schedule for the winter period is outlined below. Please note that the more compact configurations (C and D) will be available only at the end of January at the earliest. The scheduling priority will later be adapted according to pressure in right ascension ranges and may further be changed during the winter period depending on weather conditions. The configuration schedule should be taken as a guideline, in particular when astronomical targets are requested that cannot be observed during the entire winter period (45$^\circ $ sun avoidance circle).

Conf Scheduling Priority Winter 2002/2003
B November - December
A December - January
C February - March
D March - April

When the atmospheric conditions are not good enough at 1.3mm, 3mm projects will be observed: last winter, 20-30% of the time was found to be poor at 1.3mm, but was excellent at 3mm. We therefore invite proposers to submit a significant number of proposals also for observations at 3mm.

Finally, we would like to draw attention to the fact that we have started discussions with the CDS about the publication of summary tables with detailed information on PdB proposals. As a further step to making the interferometer results available as widely as possible, we are discussing the introduction of proprietory periods for which the data will be protected before becoming available in an archive.

Call for Proposals

Under normal operating conditions, IRAM schedules and completes between 40 to 60 projects during the winter period, with an elapsed time of at least two months between start and end of any given project. Selection is based on scientific merit, technical feasibility, and adequacy to the instrument.

Details of the PdBI and the observing procedures are given in the document ``An Introduction to the IRAM Plateau de Bure Interferometer''. A copy can be obtained from the address below or from the World-Wide-Web at Proposers should read this document carefully before submitting any proposal.

Proposal templates "proposal.tex" as well as the Latex style file "proposal.sty" are available by anonymous ftp from (in the directory dist/proposal), or from the Internet via the Web at In case of problems, contact the scientific secretary, Mrs Cathy Berjaud (

Do not use characters smaller than 11pt, which could make your proposal illegible when duplicated or faxed. For the same reasons, also avoid sending figures with grey scale maps by fax. In case your proposal reaches us in time, but is incomplete or unreadable when copied, we will try our best to contact you. The Principal Investigator will receive by return mail an acknowledgement of receipt and the proposal number.

The scientific aims of the proposed programme should be explained in 2 pages of text maximum, plus up to two pages of figures, tables, and references. Proposals should be self-explanatory, clearly state their aims, and explain the need of the Plateau de Bure interferometer.

In all cases, indicate on the first page whether your proposal is (or is not) the resubmission of a previously rejected proposal or the continuation of either a 30m telescope or PdBI proposal. In case of a resubmission, state very briefly in the introduction why the proposal is being resubmitted (e.g. improved scientific justification, observational restrictions).

For this call for proposals, please note the following details.

Proposal category

Proposals should be submitted for one of the five categories:
dual freq.:
Proposals that ask simultaneously for observations at 3mm and 1.3mm.
Proposals that ask for 1.3mm data only. 3mm receivers will be used for pointing and calibration purposes, but the scientific goals of the proposal rely on the 1.3mm receivers.
Proposals that ask for 3mm data only. 1.3 mm receivers can still be used to provide either phase stability information or purely qualitative information such as the mere existence of fringes.
time filler:
Proposals that have to be considered as background projects to fill in periods where the atmospheric conditions do not allow mapping, or eventually, to fill in gaps in the scheduling, or periods when only a subset of the standard configurations will be available. These proposals will be carried out on a ``best effort'' basis only.
Exploratory proposals: proposals whose scientific interest justifies the attempt to use the PdB array beyond its guaranteed capabilities. This category includes for example non-standard frequencies for which the tuning cannot be guaranteed, and more generally all non-standard observations. These proposals will be carried out on a ``best effort'' basis only.
The proposal category will have to be specified on the proposal cover sheet and should be carefully considered by proposers.

New configurations for six antennas

New configurations are now available that take full advantage of the sixth antenna.

The six antennas can now be arranged in four primary configurations, instead of the six for the 5-antenna array (the 5-antenna array configurations will still be used during the summer antenna maintenance). The configurations for the winter period will be:

Conf Stations
D W05 W00 E03 N05 N09 N13
C W12 E10 E16 N02 N09 N20
B W12 E04 E23 N07 N17 N29
A W27 W23 E16 E23 N13 N29

The four array configurations can be used in different combinations to improve on angular resolution and sensitivity. Mosaicing is usually done with D or CD, but the combination BCD can also be requested for high resolution mosaics. Enter ANY in the proposal form if the scientific goals can be reached with any of the four configurations or their subsets.

Please consult the documentation on the Plateau de Bure configurations for further details.


All antennas are equipped with fully operational dual frequency receivers. The available frequency range will be 82 to 116 GHz for the 3mm band, and 205 to 245 GHz for the 1.3 mm band. The 3mm and 1.3mm receivers are aligned to within about 2''.

Below 105 GHz, receivers offer best performances in LSB tuning with high rejection (20 dB): expected system temperatures are 100 to 150 K for the winter time. Above 110 GHz, best performances are obtained with USB tuning, low rejection (4 to 6 dB): expected system temperatures are 250 K at 115 GHz.

The 1.3 mm receivers have DSB tuning with typical T $_{\rm REC}$ below 50 K. Expected SSB system temperature are 250 to 350 K. The guaranteed tuning range is 205-245 GHz, but it may be possible to reach some lower frequencies. Higher frequencies are not feasible on all antennas because of limitations in the triplers.

Signal to Noise

The rms noise can be computed from

\begin{displaymath}\sigma = \frac{\mbox{$J_{\rm pK}$ }\mbox{$T_{\rm SYS}$ }}
...{$N_{\rm a}$ }(\mbox{$N_{\rm a}$ }-1) \mbox{$N_{\rm c}$ }T B}}
\end{displaymath} (1)