MIGALE: the Databases
Chilingarian, I. V.1,2,*; Prugniel, P.2
1 - Sternberg
Astronomical Institute of the Moscow State University, Russia
de Recherche Astronomique de Lyon - Observatoire de Lyon, France
- Visiting investigator
2 - Centre
*
Introduction.
PLEINPOT
MIGALE (The Multiparametric Virtual Instrument to Study Galaxy Evolution) is a collaboration between
French (GEPI Observatoire de Paris, CRAL Observatoire de Lyon), Russian (Sternberg Astronomical
Institute) and Bulgarian (Sofia Observatory) laboratories. The scientific goal of the project is to study the
evolution of galaxies during the last 9 Gigayears.
PLEINPOT is an open source software package, developed and
maintained by MIGALE. After being installed, PLEINPOT provides a
ready-to-use DBMS system based on PostgreSQL with the
HyperLEDA data and name resolving mechanism fed by it.
Missions of MIGALE are:
PLEINPOT has a modular structure containing the following major
parts:
•To develop and maintain astronomical databases related to studying the evolution of galaxies
•To support international collaborations on the indicated scientific topic
•To maintain the Pleinpot open-source software package that integrates different tools constituting the
backbone of the project. These tools will construct a Virtual Instrumentation
Presently, MIGALE is in charge of the following database
projects:
1) astronomical and statistical functions and procedures
2) database access layer
3) data processing pipeline
4) output formatting routines
Data processing pipeline provides a set of tools
for online processing of images and spectra. It
is easily extensible with user-written dynamically loadable procedures.
•HyperLEDA (http://leda.univ-lyon1.fr): the database,
containing homogenized data for 3 million galaxies
•GIRAFFE archive (http://dbgiraf.obspm.fr/ArchiveGiraffe/)
distributing reduced data obtained with Giraffe integral field
spectrograph on VLT
Output formatting routines provide a data output
in different formats, including VO-table format.
•HiGi (http://klun.obs-nancay.fr/) the database distributing
radio spectral data for spiral galaxies obtained with Nancay
radiotelescope
C and Fortran APIs are provided within the
standard installation. APIs for Java, PHP, Perl,
Python are optional features.
•ASPID (http://alcor.sao.ru/db/aspid/) distributing the raw
data obtained using selected instruments on the Russian 6m telescope since 1992 (including all the 3D spectroscopic
data)
PLEINPOT is a platform to build astronomyrelated database projects. All the databases
listed above are based on it.
Beside them, a very nice example of a standalone project not connected directly to MIGALE
is an ELODIE archive in the Observatoire de
Haute Provence (http://atlas.obs-hp.fr/elodie/). It
is a telescope archive containing homogeneous
data: more than 4000 reduced flux-calibrated
spectra obtained with the ELODIE spectrograph
at the 1.93m telescope at OHP. On-the-fly data
processing can be done using a PLEINPOT
pipeline.
Figure 1 (left). The reconstruction of the velocity field of distant galaxy observed with FLAMES using the
HST imagery as a reference. Credits of the figure: H. Flores
Figure 2 (bottom). The simulation of the reconstruction process using Fabry-Perot data for a nearby galaxy
(NGC2403). The images on the figure are (from left to right): image of the galaxy, velocity field derived from
Fabry-Perot data, smoothed field, reconstruction of the field. Credits of the figure: H. Flores
We are going to provide access to the ELODIE
archive using new VO standard SSAP (Simple
Spectral Access Protocol) [1].
Virtual Instrumentation
MIGALE built the prototypes of the tools that would constitute the proposed virtual instrumentation:
• DisGal3D - the tool to make deconvolution of 3D spectral data using high-resolution direct images (for instance HST) as references [3]. The technique allows to determine the
velocity profiles of distant galaxies using very small velocity fields obtained by the means of integral field spectroscopy. The examples in Fig.1 and Fig.2 show the simulation and
reconstruction of the velocity field of a distant galaxy obtained with the FLAMES-Giraffe spectrograph at VLT.
• PEGASE.HR - a new generation facility to build high-resolution (R=10000) synthetic spectra of galaxies using the ELODIE.3 library [4].
• SPIKeR (Stellar Population and Internal Kinematics Reconstruction tool). Using PEGASE.HR models with the penalized pixel fitting algorithm [2] it is possible to extract internal
kinematics and put the constrains on the properties of stellar populations. The example of the fit is shown in Fig.3
The online versions of the tools will have significant advantages compared to the standalone versions.
1. Though the software is available, it is quite complex and its installation takes time. Online version allows to avoid this procedure.
2. The data may be either taken from the archive or provided by user. In the first case the data reduction will be done on the fly (if necessary) and this will save time for downloading
and processing raw data.
3. The proposed techniques require rather complex computation, so the big amount of computer time is necessary. Online versions will propose the power of PC cluster.
Figure 3. Example of the fitting procedure. Upper plot is a spectrum of the dwarf elliptical galaxy IC3653 obtained with
MPFS integral field spectrograph at the Russian 6-m telescope. Middle plot is the best fit composed of several
PEGASE.HR SSPs (single-age single-metallicity model). The bottom line shows the residuals.
Acknowledgements
Authors appreciate the organizing committee for the financial support provided for attending the
conference, CNRS for financial support of visits between France and Russia (bilateral collaboration),
Francois Simien (CRAL Observatoire de Lyon) for useful tips concerning this presentation
References
1. J. McDowell, D. Tody on befalf of the DAL group. IVOA working draft.
2. Cappellari, M. & Emsellem, E., PASP, 2004, v.116, p.138
3. Flores, H.; Puech, M.; Hammer, F.; Garrido, O.; Hernandez, O. A&A,
2004, v.420, p.31
4. Le Borgne, D.; Rocca-Volmerange, B.; Prugniel, P.; Lancon, A.; Fioc, M.;
Soubiran, C. A&A, 2004 in press, astro-ph/040819