[News] OAC activity for the 2d half of 2004

[Roberto Silvotti]

Dear  astro-wisers,

In the  coming  two quarters  of 2004,  the main  3 items of OAC
activity  will be:

I)  Variability tool.
After  a few internal discussions at the beginning of this year,
it was clear that the local community was much more interested to
have  a  tool for image subtraction,  which could be used for different
projects  in different time-scale domains.
Hence we started a phase of tests on two independent existing
packages, both  based on the  Alard (1999,  A&A 343, 10)  method.
The two packages are:  ISIS  (Alard) and ISS (Wozniak), both are free.
After some tests on WFI images, we decided  for the second one, which
is  better written and has more documentation.
Therefeore,  we defined  to  modify the software  of  Wozniak, in order
to  improve  a few items that were not satisfactory for our purposes,
and in order to render it compatible with the AW  platform.
1)  Implement masks on each single image.
2)  Define  different classes of variables.
3)  WCS:  move from x,y  to  AR,DEC
4)  Improve selection of objects  for PSF  construction.
5)  Absolute photometry  and relative amplitudes  (??).
6)  Times from headers.
7)  Stamps  of variable candidates.
8)  Parallelization.
9)  Python interface and AW compatibility.
Currently  items 1), 4) and 7)  were done and Alfredo is working
on  item  3).

Schedule:  we plan to have a preliminary version of the modified
software
by the end of 3d quarter

II)  QC.
OAC  is participating in the second phase of QC  of calibration frames
(BIAS, FF and fringing).
Concerning BIAS and FF,  the goal is to define  how to apply the tools
written last year, which are  already in the pipeline  but not used yet.

Concerning fringing QC,  we are currently making tests  and we  just
made a very preliminary proposal  on  how to  vertify  the quality of
the fringing correction.  The next step,  after  some discussions with
the partners, will be  to write the code for fringing QC.

Moreover  OAC  participates also on the other three groups  on QC:
- Astrometry;
- Photometric calibration;
- Overall  pipeline.

III)  Pipeline validation.
The report  written  by us  recently  on the  first  validation  of the
AW pipeline
has revealed a few problems  and  produced some discussions on how
to solve these problems and how to improve the  output products.
After this phase will be concluded and these problems solved,  we plan
to continue with a second series of tests, applying the AW  pipeline in
the case of
 more critical situations  (e.g. very poor  vs  very crowded fields,
variable background fields, etc. ...)   in order to  check  how the
pipeline
behaves  in critical conditions.


Kind regards,
                                 Roberto

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         Dr. Roberto Silvotti
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INAF (Istituto Nazionale di AstroFisica)
Osservatorio Astronomico di Capodimonte
via Moiariello 16, I-80131 Napoli, Italy
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tel/fax:  +39-081-5575583/456710
e-mail:   silvotti at na.astro.it
web:    http://www.na.astro.it/~silvotti
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