
%\input{call_s09_declarations.tex}

\section{News from the Plateau de Bure Interferometer}

\subsection{Aluminum panels for antenna 4}

By the end of last summers' antenna maintenance period the reflector
of  antenna 4 was equipped with new aluminum panels, 
replacing the previous carbon fiber panels. The
antenna was moved out of the maintenance hall on October 17 and the
surface was subsequently adjusted to an accuracy of better 
than 50 $\mu m$ rms in a series of
holographic measurements and panel adjustments. 

\subsection{Weather conditions and observing}

The current winter semester was affected by quite variable  weather
conditions so far with periods of excellent atmospheric stability and
transparency in particular at the end of November and the beginning of
January but with very poor weather during most of December and the
second half of January. Bure entered into the winter observing period
with the array in its C-configuration and we switched to the B
configuration already on December 28. The most extended  A
configuration was available from January 30 and it is now planned  to
move back  to the C configuration by beginning of March. Compared with
the original planning, scheduling of the B and A configuration has
been interchanged due to the already acceptable though not exceptional
atmospheric conditions in late December. The switch back to the
compact D configuration is foreseen before the end of April.  Global
VLBI observations, which include the array in the 3\,mm phased-array
mode, are planned from May 7 to 12, 2009.  According to these plans,
it will not be possible to complete projects requesting deep
integrations using the compact configurations before the end of the
current observing period.

As far as A-rated projects are concerned, we expect to bring most 
of these to completion before the end of the current winter
semester. B-rated projects are likely to be observed only if they fall
in a favorable LST range. We remind users of the Plateau de Bure
interferometer that B-rated proposals which are not started before the
end of the winter period have to be resubmitted.

Investigators, who wish to check the status of their project may
consult the interferometer schedule on the Web at
../PDBI/ongoing.html. This page is updated daily.

\signed {Jan Martin WINTERS}

\section{Call for Observing Proposals on the Plateau de Bure Interferometer}

%\subsection{Important information}
%
%{\bf Please note that the proposal.sty file and the proposal.tex
%template have been changed considerably. We urge proposers to download
%the most recent version from our web page\\
%../GENERAL/proposal/. Proposals using older versions of the
%style/template files will not be accepted.}

\subsection{Conditions for the next summer period} 

As every year, we plan to carry out extensive technical work during
the summer semester, including the regular maintenance of the
antennas. In particular, yet another antenna will be fully equipped
with new aluminum panels replacing its current carbon fiber
panels. During this period, regular scientific observations will
therefore mostly be carried out with the five element array. We plan
to start the maintenance at the latest by the end of May and to
schedule the D configuration between June and October.

We strongly encourage observers to submit proposals that can be
executed during summer operating conditions. To keep the procedure as
simple as possible, we ask to focus on:

\begin{itemize}
\item[$\circ$] observations requesting the use of the 2\,mm and 3\,mm receivers
\item[$\circ$] circumpolar sources or sources transiting at night between 
June and September,
\item[$\circ$] observations that qualify for the 5D, 6D, and 6C configurations
\end{itemize}

\subsection{Proposal category}
Proposals should be submitted for one of the five  categories:
\begin{description}
\item[{\sc 1.3mm:}\/] Proposals that ask for 1.3\,mm data.
2\,mm or 3\,mm receivers can be used for pointing and calibration purposes, 
but cannot
provide any imaging. 
During the summer semester, proposals requesting the extended tuning range 
(256-267\,GHz) will be carried out on a 
``best effort'' basis only.
\item[{\sc 2mm:}\/] Proposals that ask for 2\,mm data. 3\,mm receivers can be 
used for pointing and calibration purposes, but cannot
provide any imaging. 
\item[{\sc 3mm:}\/] Proposals that ask for 3\,mm data.
\item[{\sc time filler:}\/] Proposals that have to be considered as
background projects to fill in periods where the atmospheric
conditions do not allow mapping, to fill in gaps in the
scheduling, or even to fill in periods when only a subset of the standard
5-antenna configurations will be available. These proposals will be
carried out on a ``best effort'' basis only.
\item[{\sc special:}\/] 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,
non-standard configurations and more generally all non-standard
observations. These proposals will be carried out on a ``best effort''
basis only.
\item[{\sc Large Program:}\/] This category is offered on 
both IRAM instruments since the winter 2008/2009 observing period. 
See Section {\it Large Observing Programs} 
for a detailed explanation.  
\end{description}
The proposal category will have to be specified on the proposal cover
sheet and should be carefully considered by proposers.

\subsection{Configurations}
Configurations planned for the summer period are:
\vskip 4mm 
\begin{center}
\begin{tabular}{|l|c|}
\hline
Name & Stations  \\
\hline
5Dq & W08 E03 N07 N11 W05  \\
6Dq & W08 E03 N07 N11 N02 W05  \\
6Cq & W12 E10 N17 N11 E04 W09  \\
\hline
\end{tabular}
\end{center}
\vskip 4mm 
Part of the projects will be scheduled at the end of the summer period
when the six-element array (likely in C-configuration) is expected to
be  back to operation. Projects that should be observed with a subset
of the five-element array will be adjusted in uv-coverage and
observing time.\\

The following configuration sets are available:

\begin{itemize}

\item[$\circ$] {\tt D\/} is best suited for deep integration and
coarse mapping experiments (resolution $\sim 5''$ at 100\,GHz). 
This configuration provides both the
highest sensitivity and the lowest atmospheric phase noise.
\item[$\circ$] {\tt CD\/} is well adapted for low angular resolution studies
($\sim$3.5$''$ at 100\,GHz, $\sim$1.5$''$ at 230\,GHz.
\item[$\circ$] {\tt C\/} is appropriate for mapping, snapshot, and size 
measurements and for detection experiments at low declination. 
It provides a spatial resolution of $\sim 2.8''$ at 100\,GHz.

\end{itemize}

Finally, enter {\sc any}\/ in the proposal form if your project
doesn't need any particular configuration. 

Please consult the documentation {\it An} {\it Introduction} {\it to} 
{\it the} {\it IRAM} {\it inter\-fero\-meter} 
(../IRAMFR/PDB/docu.html) for further details.

\subsection{Receivers}

All antennas are equipped with dual polarization
receivers for the 3\,mm, 2\,mm, and 1.3\,mm atmospheric windows.  The
frequency range is 80\,GHz to 116\,GHz for the 3\,mm band, 129\,GHz to
174\,GHz for the 2\,mm band, and 201 to 267\,GHz for the 1.3\,mm band.

\vskip 4mm 
\begin{center}
\begin{tabular}{lccc}
\hline
                       & Band 1   & Band 2   & Band 3   \\
\hline
 RF range$^*$/[GHz]    & 80--116  & 129--174 & 201--267 \\
 $\rm T_{rec}$/[K] LSB &  40--55  & 30--50   & 40--60   \\
 $\rm T_{rec}$/[K] USB &  40--55  & 40--80   & 50--70   \\
 $\rm G_{im}$/[dB]     &  -10     & -12 ... -10 &-12 ... -8 \\
 RF LSB/[GHz]          &  80--104 & 129--168 & 201--267 \\
 RF USB/[GHz]          & 104--116 & 147--174 &          \\
\hline
\end{tabular}
\end{center}
\mbox {} \hskip 2mm $^*$ center of the 4-8\,GHz IF band
\vskip 4mm 

Each band of the receivers is dual-polarization  with the two RF
channels of one band observing at the same frequency.  The three different
bands are not co-aligned in the focal plane (and therefore on the
sky).  Due to the pointing offsets between the different frequency
bands, only one band can be observed at any time. One of the two other
bands is in stand-by mode (power on and local oscillator phase-locked)
and is available, e.g., for pointing. Time-shared observations between
different RF bands are presently being tested. Please contact the
Interferometer Science Operations Group (sog@iram.fr) to discuss the
feasibility in case you are interested to use this mode.

The mixers are single-sideband, backshort-tuned; they will usually be
tuned LSB,  except for the upper part of the frequency range in all 
three bands where the mixers will be tuned USB.

The typical image rejection is 10\,dB. Each IF channel is 4~GHz wide
(4-8~GHz).  The two 4~GHz wide IF-channels (one per polarization)  can
be processed only partially by the existing correlator.  A dedicated
IF processor converts selected 1~GHz wide slices of the 4-8~GHz first
IFs down to 0.1-1.1~GHz, the input range of the existing correlator.
Further details are given in the section describing the correlator
setup and the IF processor.

\subsection{Signal to Noise}

The rms noise can be computed from
\begin{equation}
 \sigma = \frac{J_{\rm pK} T_{\rm sys}} {\eta \sqrt{N_{\rm a} (N_{\rm a}-1) 
N_{\rm c} T_{\rm ON} B}} \frac{1}{\sqrt{N_{\rm pol}}}
\end{equation}
where
\begin{itemize}
\item $J_{\rm pK}$\ is the conversion factor from Kelvin to Jansky (22
Jy/K at 3\,mm, 29 Jy/K at 2\,mm, and 35 Jy/K at 1.3\,mm)
\item $T_{\rm sys}$ is the system temperature ($T_{\rm sys}$ = 100\,K
below 110\,GHz,  180\,K at 115\,GHz, 180\,K at 150\,GHz, and 250\,K at 
230\,GHz for sources at
$\delta \ge 20^\circ$ and for typical summer conditions).
\item $\eta$ is an efficiency factor due to atmospheric phase noise   
and instrumental phase jitter
(0.9 at 3\,mm, 0.8 at 2\,mm, and 0.6 at 1.3\,mm) in typical summer conditions.
\item $N_{\rm a}$ is the number of antennas (5), and $N_{\rm c}$ 
is the number of
configurations: 1 for D, 2 for CD, 1 for C.
\item $T_{\rm ON}$ is the on-source integration time per configuration
in seconds (2 to 8 hours, depending on source declination). Because of
various calibration observations the total observing time is typically
1.6 $T_{\rm ON}$.
\item $B$ is the spectral bandwidth in Hz (up to 2\,GHz for continuum, 
40\,kHz to 2.5\,MHz for spectral line, according to the spectral correlator
setup)
\item $N_{\rm pol}$ is the number of polarizations: 1 for single polarization 
and 2 for dual polarization (see section {\it Correlator} for details).
\end{itemize}

Investigators have to specify in the ``technical justification'' 
{\bf and on the Technical Sheet}  the one sigma noise level which is
necessary to achieve each individual goal of a proposal, and
particularly for projects aiming at deep integrations.

\subsection{Coordinates and Velocities}

For best position accuracy, source coordinates must be in the J2000.0
system.

Please do not forget to specify LSR velocities for the sources. For
pure continuum projects, the ``special'' velocity {\tt NULL} (no
Doppler tracking) can be used.

\subsection{Correlator}

\subsubsection{IF processor} 

At any given time, only one frequency band can be observed, but with the two
polarizations available. Each polarization delivers a 4 GHz bandwidth 
(from IF=4 to 8~GHz). The two 4-GHz bandwidths coincide in the sky
frequency scale. The current correlator accepts
as input two signals of 1~GHz bandwidth, that must be selected within
the 4~GHz delivered by the receiver. In practice, the IF
processor splits the two input 4--8~GHz bands in four 1~GHz
``quarters'', labeled {\em Q1...Q4}. Two of these quarters must be
selected as correlator inputs. The system allows the following
choices:
\begin{itemize}
\item first  correlator entry can only be Q1 HOR, or Q2 HOR, 
or Q3 VER, or Q4 VER
\item second correlator entry can only be Q1 VER, or Q2 VER, 
or Q3 HOR, or Q4 HOR
\end{itemize}
where HOR and VER refer to the two polarizations:
\begin{flushleft}
\begin{center}
\begin{tabular}{l|cccc}
\hline\noalign{\smallskip}
Quarter  & Q1 & Q2 & Q3 & Q4 \\
IF1 [GHz]& 4.2-5.2 & 5-6 & 6-7 & 6.8-7.8\\
\noalign{\smallskip}\hline\noalign{\smallskip}
input 1 & HOR  & HOR  & VER  & VER  \\
input 2 & VER  & VER  & HOR  & HOR  \\
\noalign{\smallskip}\hline
\end{tabular}
\end{center}
\end{flushleft}
\bigskip

{\em How to observe two polarizations?} To observe simultaneously two
polarizations at the same sky frequency, one must select the same quarter 
(Q1 or Q2 or Q3 or Q4)
for the two correlator entries. This will necessarily result in each
entry seeing a different polarization. The system thus give access
to 1~GHz $\times$ 2 polarizations. \\

{\em How to use the full 2~GHz bandwidth?} If two different quarters
are selected (any combination is possible), a bandwidth of 2~GHz can
be analyzed by the correlator. But only one polarization per quarter
is available in that case; this may or may not be the same
polarization for the two chunks of 1~GHz. \\

{\em Is there any overlap between the four quarters?} In fact, the
four available quarters are 1~GHz wide each, but with a small overlap
between some of them: Q1 is 4.2 to 5.2~GHz, Q2 is 5 to 6~GHz, Q3 is
6 to 7~GHz, and Q4 is 6.8 to 7.8~GHz. This results from the combination
of filters and LOs used in the IF processor. \\

{\em Is the 2~GHz bandwidth necessarily continuous?} No: any combination
of two quarters can be selected. Adjacent quarters will result in a
continuous 2~GHz band. Non-adjacent quarters will result in two
independent 1~GHz bands. \\

{\em Where is the selected sky frequency in the IF band?} It would be
natural to tune the receivers such that the selected sky frequency
corresponds to the middle of the IF bandwidth, i.e.\ 6.0~GHz. However,
this corresponds to the limit between Q2 and Q3. It is therefore
highly recommended to center a line at the center of a quarter (see
Section ``ASTRO'' below). In all three bands, 3\,mm, 2\,mm, and
1.3\,mm  the receivers offer best performance in terms of receiver
noise and sideband rejection in Q3 (i.e. the line should be centered
at an IF1 frequency of 6500 MHz).

\subsubsection{Spectral units of the correlator} 

The correlator has 8 independent units, which can be placed anywhere
in the 100--1100~MHz band (1~GHz bandwidth). 7 different modes of
configuration are available, characterized in the following by couples
of total bandwidth/number of channels. In the 3 DSB modes (320MHz/128,
160MHz/256, 80MHz/512 -- see Table) the two central channels may be
perturbed by the Gibbs phenomenon if the observed source has a strong
continuum. When using these modes, it is recommended to avoid
centering the most important part of the lines in the middle of the
band of the correlator unit. In the remaining SSB modes (160MHz/128,
80MHz/256, 40MHz/512, 20MHz/512) the two central channels are not
affected by the Gibbs phenomenon and, therefore, these modes may be
preferable for some spectroscopic studies.

\vskip 4mm \begin{center}
\begin{tabular}{crrc}
\hline
\hline
 Spacing & Channels & Bandwidth  & Mode \\
 \multicolumn{1}{c}{(MHz)} & & \multicolumn{1}{c}{(MHz)} & \\
\hline
 0.039 &$ 1 \times 512$ &  20 & SSB \\
 0.078 &$ 1 \times 512$ &  40 & SSB \\
 0.156 &$ 2 \times 256$ &  80 & DSB \\
 0.312 &$ 1 \times 256$ &  80 & SSB \\
 0.625 &$ 2 \times 128$ & 160 & DSB \\
 1.250 &$ 1 \times 128$ & 160 & SSB \\
 2.500 &$ 2 \times  64$ & 320 & DSB \\
\hline
\end{tabular}
\end{center}
\vskip 3mm
\noindent Note that 5\% of the passband is lost at the end of each
subband.  The 8 units can be independently connected to the first or
the second correlator entry, as selected by the IF processor (see
above). Please note that the center frequency is expressed in the 
frequency range seen by the correlator, i.e.\ 100
to 1100~MHz. The correspondence to the sky frequency depends on
the parts of the 4~GHz bandwidth which have been selected as correlator 
inputs and on the selected side band (LSB or USB).

\subsubsection{ASTRO}

The software ASTRO can be used to simulate the 
receiver/correlator configuration. Astronomers are urged to
download the most recent version of GILDAS  at {\tt ../IRAMFR/GILDAS/} 
to prepare their proposals.\\

The previous {\tt LINE} command has been replaced by several new commands
(see internal help; the following description applies to the current
receiver system). The behavior of the {\tt LINE} command can be
changed by the {\tt SET PDBI 1995|2000|2006} command, that selects the
PdBI frontend/backend status corresponding to years 1995 (old
receivers, 500 MHz bandwidth), 2000 (580 MHz bandwidth), 2006 (new
receivers and new IF processor, 1\,GHz bandwidth). Default is 2006:
\begin{itemize}
\item {\tt LINE}: receiver tuning
\item {\tt NARROW}: selection of the narrow-band correlator inputs
\item {\tt SPECTRAL}: spectral correlator unit tuning
\item {\tt PLOT}: control of the plot parameters. 
\end{itemize}
A typical session would be:

\begin{verbatim}
   ! choice of receiver tuning
   line xyz 93.2 lsb low 6500

   ! choice of the correlator windows
   narrow Q3 Q3             

   ! correlator unit #1, on entry 1
   spectral 1  20 600 /narrow 1   

   ! correlator unit #2, on entry 1
   spectral 2  20 735 /narrow 1   

   ! correlator unit #3, on entry 1
   spectral 4 320 300 /narrow 1   

   ! correlator unit #4, on entry 2
   spectral 4 320 666 /narrow 2   
   ...
\end{verbatim}

\vskip 4mm
\subsection{Sun Avoidance}

For safety reasons, a sun avoidance limit is enforced 
at 45 degrees from the sun. We are presently testing a
reduced sun avoidance circle at 35 degrees and expect that projects
observed in the summer semester may already profit from this
reduction. This can however not be guaranteed yet and we therefore
ask proposers to still take into account the 45 degrees
limit for the target sources.

\subsection{Mosaics}
The PdBI has mosaicing capabilities, but the pointing accuracy may be
a limiting factor at the highest frequencies. Please contact the
Science Operations Group (sog@iram.fr) in case of doubts.

\subsection{Local Contact}
A local contact will be assigned to every A or B rated proposal which
does not involve an in-house collaborator. He/she will assist you in
the preparation of the observing procedures and provide help to reduce
the data. Assistance is also provided before a deadline to help
newcomers in the preparation of a proposal. Depending upon the
program complexity, IRAM may require an in-house collaborator
instead of the normal local contact.

\subsection{Data reduction}
Proposers should be aware of constraints for data reduction:
\begin{itemize}
\item[$\circ$] We recommend that proposers 
reduce their data in Grenoble. For the time
being, remote data reduction will only be offered in exceptional cases. 
Please contact your local
contact if you're interested in this possibility.
\item[$\circ$] We keep the data reduction schedule very flexible, but wish to
avoid the presence of more than 2 groups at the same time in
Grenoble. Data reduction will be carried out on dedicated computers at
IRAM. Please contact us in advance.
\item[$\circ$] In certain cases, proposers may have a look at the
uv-tables as the observations progress. If necessary, and upon
request, more information can be provided. Please contact your local contact 
or PdBI's Science
Operations Group (sog@iram.fr) if you are interested in this.
\item[$\circ$] Observers who wish to finish data reduction at their
home institute should obtain the most recent version of CLIC. Because
differences between CLIC versions may potentially result in imaging
errors if new data are reduced with an old package, we advise
observers having a copy of CLIC to take special care in maintaining it
up-to-date. The newer versions are in general downward compatible with 
the previous releases. The recent upgrades of CLIC implied however many
modifications for which backward compatibility with old PdBI receiver data 
has not yet been fully checked. To calibrate data obtained with the ``old''
receiver system (up to September 2006), we urge you to use the January 2007 
version of CLIC.
\end{itemize}

\vspace{-0.4cm}
\subsection{Technical pre-screening}
All proposals will be reviewed for technical feasibility in parallel
to being sent to the members of the program committee. Please help
in this task by submitting technically precise proposals. Note that
your proposal must be complete and exact: the source position and velocity,
as well as the requested frequency setup must be correctly given.

\vspace{-0.3cm}
\subsection{Non-standard observations}
If you plan to execute a non-standard program, please contact the
Interferometer Science Operations Group (sog@iram.fr) to discuss the
feasibility.

\vspace{-0.3cm}
\subsection{Documentation}
The documentation for the IRAM Plateau de Bure Interferometer includes
documents of general interest to potential users, and more specialized
documents intended for observers on the site (IRAM on-duty
astronomers, operators, or observers with non-standard programs). All
documents can be retrieved on the Internet at {\tt
../IRAMFR/PDB/docu.html}.
Note however, that not all the
documentation on  the web has already been updated with respect to the
current receivers. All information presently available on the
current receiver system is given in the {\it Introduction to
the IRAM Plateau de Bure Interferometer} at {\tt
../IRAMFR/GILDAS/doc/html/pdbi-intro-html} and in this call for
proposals.
\smallskip
\renewcommand{\finally}{Finally, we would like to stress again the
importance of the quality of the observing proposal.  The IRAM
interferometer is a powerful, but complex instrument, and proposal
preparation requires special care. Information is available in this 
call and at {\tt ../IRAMFR/PDB/docu.html}. The IRAM staff can help
in case of doubts if contacted well before the deadline. Note that the
proposal should not only justify the scientific interest, but also the
need for the Plateau de Bure Interferometer.}

\begin{latexonly}
\fullbox{3mm}{\finally}
\end{latexonly}
\begin{htmlonly}
{\bf \finally}
\end{htmlonly}
\vspace{-0.3cm}
\signed {Jan Martin WINTERS}


%\end{document}
