From erik Mon Jul 10 11:32:59 2000
Subject: PWG-VIL-001.txt meeting
To: gaia-sag@astro.estec.esa.nl (GAIA SAG), straizys@itpa.lt (Vytas Straizys),
	wladas@itpa.lt (Vladas Vansevicius),
	Frederic.Arenou@obspm.fr (F. Arenou),
	Carine.Babusiaux@obspm.fr (Carine Babusiaux),
	catherine.turon@obspm.fr (C. Turon),
	brown@bufadora.astrosen.unam.mx (A. Brown), indus (Jens Knude),
	ntk (Nadia Kaltcheva), helge (Helge J. Sorensen),
	makarov@astro.ku.dk (V.V. Makarov), cf (Claus Fabricius),
	BERNACCA@ASTRAS.pd.astro.it (P.L. Bernacca),
	cflynn@astro.utu.fi (C. Flynn), calj@mpia-hd.mpg.de (Coryn Bailer-Jones),
	csterken@vub.ac.be (Chris Sterken),
	weiss@galileo.astro.univie.ac.at (Werner W. Weiss),
	kerschbaum@astro.univie.ac.at (Franz Kerschbaum)
Date: Mon, 10 Jul 2000 11:32:59 +0200 (MET DST)
X-Mailer: ELM [version 2.5 PL2]
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Status: OR


Photometry workshop in Vilnius, May 22/23, 2000
===============================================

PWG-VIL-001     E. Hoeg, V. Straizys, V. Vansevicius    10 July 2000


ABSTRACT:
Overviews of GAIA mission aspects were given. A software for
simulation of photometric observations based on realistic assumptions
was presented. It includes, e.g., 3-dim automatic classification
(Teff, log g, [Fe/H]). Preliminary results from comparison of MBP
photometry with the 1F and 2G systems by means of the software 
were shown. Comparison with the Q-Q method is planned.


PARTICIPANTS:
Viktoras Deveikis, Saulius Raudeliunas, Julius Sperauskas, 
Jokubas Sudzius from Vilnius University (VU); 
Audrius Bridzius, Dmitrjus Semionovas, Vladas Vansevicius (VV) 
from Institute of Physics (IP);
Antanas Bartkevicius, Kazimieras Cernis, Algis Kazlauskas, 
Arunas Kucinskas, Rimas Liubertas, Vytautas Straizys (VS), 
from Institute of Theoretical Physics and Astronomy (ITPA);
Roma Lazauskaite from Pedagogical University and ITPA;
Erik Hoeg (EH) from Copenhagen University Observatory (CUO).


Agenda with notes
=================

** GAIA Mission Overview (EH)

** GAIA photometry (EH)
especially sampling, simulations, accuracy. 

** GAIA photometric systems (EH+VS)
Overview of all systems relevant for GAIA studies : CUO_71, 
and a report on the 2G system : CUO_72.

** Photometry at the Paschen jump (VS)
VS presented the study from Baltic Astronomy, 1999, vol. 8. 491.
An improved system (3G) will soon be presented.
Actions 1, 5, 14.

** Kinematic tracers (EH)
An update to the CUO_70 report has been provided : CUO_74.
Two tables of the same tracers are presented side by side. The
first table assumes, as in CUO_70, one absolute magnitude for each
tracer, the second table assumes a realistic spread and will 
therefore be more directly understood.

** High-resolution spectrophotometry (EH)
The HRS data obtained for radial velocities at a resolution of 0.75
A/pixel could be used for the measurement of line intensities. This has
often been claimed, but no standard errors have ever been shown, so we
do not know anything quantitative. A report on this task : CUO_73.

J. Sudzius has noted that some DIBs in Munari's library of spectra do
not seem to follow the linear relation with colour excess. 
Actions 9, 10.

** Evaluation of photometric systems (VV)
(There is no progress on Favata/Munari initiative of Dec.1999.)
  V. Deveikis presented the simulation software mentioned in the
abstract. VV presented the results of automatic classification
based on the classification software by A. Bridzius.
Actions 3, 4, 6, 8, 11, 12, 13.

** Automated classification (VV)
Based on recent paper by Bailer-Jones in A&A:
http://www.mpia-hd.mpg.de/homes/calj/gaia.html
  The method is interesting for GAIA, but the data are too unrealistic 
to allow conclusions about systems.
How can the method be used in the comparison of photometric systems ?
  VV had doubts that neural networks could perform well based on input
from filter photometry. But a 4-dim (lg Teff, lg g, [M/H], Av) 
classification would be quite imprecise when only as few as about 
10 bands are provided as input.

** Tycho-2 Catalogue  (EH)
Brief introduction.
http://www.astro.ku.dk/~erik/Tycho-2


Actions
=======

1.  VS, 1 Aug: consider positions of the BBP bands, as input to Action 14.
2.  VS, 1 Sep.: write overview of observational testing of the
Stroemvil system.
3.  VV, 1 Sep.: filter transmissions in files for 1F and 3G; 
CCDs; always in step of 2 nm (0, 2, 4...); spectral types are TBD.
4.  VV+V. Deveikis, 1 Aug.: spectra of some spectral types from 
Kurucz models (lg Teff, log g, [M/H]) [photons/m^2] for V=15.
5.  VS, 1 Sep. : discussion of metal-deficient and peculiar stars.
6.  EH+VV, 1. Aug.: instrument: entrance pupil etc.
7.  ---
8.  VV, 1 Dec.: GAIA Photometric Systems Evaluation.
9.  J. Sudzius, 1 Sep.: DIB versus interstellar extinction.
10. VV+A.Kucinskas 1 Sep.: sigma_DIB versus V, cf CUO_73.
11. VV+A. Bridzius, 1 Sep. : Implement 4-dim classification
                     (lg Teff, log g, [M/H], A_V).
12. VV+A. Bridzius, 1 Nov. : Introduce Galactic model for
                 evaluation of the photometric systems. 
13. J. Sudzius, 1 Oct.: investigate bandwidth effects due to
      strong reddening, especially in Ug, Bg and Vg of the 3G system.
14. EH+VS+VV, 1 Aug.: Describe the 3G system.
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