GHOST, Brussels, Feb.14th 2006
1
The GHOST in CU8
Coralie NeinerParis-Meudon Observatory
GHOST website: http://www.ster.kuleuven.be/~coralie/gaiahot.html
GHOST, Brussels, Feb.14th 2006
2
GAIA lexicon…CU = Coordination Unit For CU8: manager=CBJ, deputy=Frederic Thevenin, scientific coordinator=CBJ, technical coordinator=Michel Nonon
DU = Development Unit = a group of people contributing to a CU or a sub-part of a CU (with a DU coordinator) GHOST = Gaia Hot Stars Team = a DU
(G)WP = (Gaia) Work Package = a group of tasks to be performed in a CU (with a WP manager and sub-WP managers)
SSU = Specific Stars Unit
GHOST, Brussels, Feb.14th 2006
3
The CUs of GAIA CU1: System architecture (O’Mullan)
CU2: Data simulations (Luri)
CU3: Core processing (Bastian)
CU4: Object processing (Pourbaix, Tanga)
CU5: Photometric processing (van Leeuwen)
CU6: Spectroscopic processing (Katz) D. Katz this morning
CU7: Variability processing (Eyer) C. Aerts this morning
CU8: Astrophysical parameters (Bailer-Jones) now!
(CU9: Catalogue access)
GHOST, Brussels, Feb.14th 2006
4
CU8 Astrophysical parametersWork Beakdown Structure
Top level WPs:
Common packages GWP-C-81xx
Support packages GWP-S-82xx
Algorithmic units GWP-S-83xx (all objects)
GWP-S-84xx (SSU)
GHOST, Brussels, Feb.14th 2006
5
Common WPs:
GWP-C-8110 Coordination and management
GWP-C-8120 Definition of system architecture
GWP-C-8130 Simulations
GWP-C-8140 Configuration management
GWP-C-8150 Hardware/System administration
GHOST, Brussels, Feb.14th 2006
6
Support WPs:
GWP-S-8210 Stellar models/spectra (Korn/Thevenin)
Provide synthetic spectra for single stars across the full AP space expected, at sufficient wavelength resolution and coverage to ensure accurate simulation in BBP, MBP and RVS.
GHOST contribution:
models for hot stars and emission line stars (contributors: Y.Frémat, R. Blomme, C. Martayan, J. Zorec, J.-C. Bouret, F. Martins,…) Y. Frémat this afternoon
GHOST, Brussels, Feb.14th 2006
7
GWP-S-8220 Calibrations and auxiliary data (Soubiran)
Provide the real data and parameters required to calibrate the classification and AP estimation methods. Perform new observations if necessary.
GHOST contribution:
- provide a list of object types than need new observations (contributors: the whole GHOST)
- provide a list of typical targets for this object types (contributors: the whole GHOST)
- help with the observations (contributors: I. Kolka with the Tartu Observatory, A.-M. Hubert, M. Floquet, C. Neiner with the Pic du Midi/TBL,…)
GHOST, Brussels, Feb.14th 2006
8
GWP-S-8230 Interstellar extinction (Straizys)
Establish an optimal method for determining the line-of-sight interstellar extinction to individual stars, based on BBP, MBP and RVS.
GHOST contribution:
make sure the interstellar extinction is treated properly in emission line stars…
GHOST, Brussels, Feb.14th 2006
9
Algorithmic units:
GWP-S-8310 Discrete Source Classifier (DSC) (Bailer-Jones)
Use photometry of unresolved ‘slow’ sources to determine the broad class of the object (single star, binary, QSO, …)
GHOST contribution:
provide typical criteria for hot stars and emission line stars?
GHOST, Brussels, Feb.14th 2006
10
GWP-S-8320 Generalized Stellar Parametrizer – Photometry (GSP-phot) (Bailer-
Jones)
Estimate APs for the full range of type of single stars based on photometry (and parallaxes in late-mission)
GHOST contribution:
provide typical photometric criteria for hot stars and emission line stars?
GHOST, Brussels, Feb.14th 2006
11
GWP-S-8330 Initial Spectral Analyser (ISA) (Manteiga)
For single stars, from RVS spectra, find evidence for binarity, search for emission lines, estimate Av from the DIB
GHOST contribution:
provide typical spectral criteria for hot stars and emission line stars?
GHOST, Brussels, Feb.14th 2006
12
GWP-S-8340 Generalized Stellar Parametrizer – Spectroscopy (GSP-spec) (Recio-Blanco)
Estimate APs for the full range of type of single stars based on RVS and GSP-Phot
GHOST contribution:
provide spectral criteria for hot stars and emission line stars?
GHOST, Brussels, Feb.14th 2006
13
GWP-S-8350 Object Clustering Analysis (OCA) (Sarro)
Identify natural or intrinsic classes of objects (unsupervised classification)
GHOST contribution:
provide algorithms for unsupervised classification for hot stars and emission line stars?
Would the algorithm developed in Leuven be useful here?
GHOST, Brussels, Feb.14th 2006
14
GWP-S-8360 Luminosity, Age and Mass Estimator (LAME) (Lebreton)
Estimate the luminosity, age and mass of single stars based on their APs, parallax and apparent G-band magnitude
GHOST contribution:
help to determine the G-band magnitude and luminosity, which are crucial for the age and mass determination, for hot stars and emission line stars
GHOST, Brussels, Feb.14th 2006
15
GWP-S-8410 SSU: QSOs (Claeskens)
GWP-S-8420 SSU: Unresolved galaxies (Kontizas)
GWP-S-8430 SSU: Solar system objects (Lagerkvist)
GWP-S-8440 SSU: Non-single stars (?)
GWP-S-8450 Extended stellar parametrizer (Frémat)
51 SSU: Hot stars (Neiner)
52 SSU: Cool stars (Lanzafame)
53 SSU: Ultra cool dwarfs (Barrado)
54 SSU: Abundance anomalous stars (Straizys)
55 SSU: Emission line stars (Neiner)
GWP-S-8460 Outlier analysis (Manteiga)
Study, develop and test algorithms which provide extended parameter estimates for the considered stars.
GHOST, Brussels, Feb.14th 2006
16
GWP-S-8451 (hot stars) & GWP-S-8455 (emission line stars)
Study, develop and test algorithms which provide extended parameter estimates
GHOST contribution: everything in these 2 WPs!
Tasks:
1. Develop, implement and test classification algorithms
2. Obtain synthetic data to operate and test algorithms
3. Obtain auxiliary data (via GWP-S-8210!)
4. Analyse test data and GAIA data
5. Participate in final catalogue
GHOST, Brussels, Feb.14th 2006
17
Deliverables:
1. Project plan (March 2006)
2. Reports on performance of various algorithms (2006- 2008)
3. Final version of algorithms (2010)
4. Documentation (2010)
5. Improved version from real GAIA data (2012-2016)
6. Progress reports
GHOST, Brussels, Feb.14th 2006
18
Observations:
- To converge on a list of objects types for which we need new observations, via the GHOST mailing list and website in the coming months
- To converge on a list of targets for these object types, via the GHOST mailing list and website in the coming months
- To organize, obtain and reduce observations, in collaboration with GWP-S-8210, in particular in Tartu and in France (and with belgian telecopes?) for the semesters 2007A and 2007B
What needs to be done(before launch in 2011)
GHOST, Brussels, Feb.14th 2006
19
Models:
- Develop RVS synthetic spectra for OB stars (Frémat et al.) 2006-2007
- Develop RVS synthetic spectra with emission (Zorec et al.) 2006-2008
- Develop photometric models for OB stars with and without emission (Frémat et al.) 2006-2008
GHOST, Brussels, Feb.14th 2006
20
Criteria:
- Find suitable criteria to classify hot stars from RVS spectra (Fremat et al.) 2006
- Find suitable criteria to classify emission line stars from RVS spectra (Martayan et al.) 2006
- Find suitable criteria to classify hot stars from GAIA photometry (Fabregat et al.?) 2006-2007
- Find suitable criteria to classify emission line stars from GAIA photometry (Kolka et al.) 2006-2007
GHOST, Brussels, Feb.14th 2006
21
Criteria in practice:
The ‘hot stars’ and ‘emission lines stars’ include:
- O stars - Wolf-Rayet
- B stars - Luminous Blue Variable (LBV)
- Be stars - β Cep stars
- B[e] stars - Slowly Pulsating B (SPB) stars
- shell Be stars - T Tauri
- Herbig Ae/Be stars - …
2 millions hot stars in photometry + 400 000 RVS spectra!
400 000 emission line stars + 80 000 RVS spectra!
GHOST, Brussels, Feb.14th 2006
22
Algorithms:
- Study, develop and test algorithms to classify hot stars and provide stellar parameters (Frémat et al.) 2006-2010
- Study, develop and test algorithms to classify emission line stars and provide stellar parameters (Martayan et al.) 2006-2010
- Help with study, development and test of algorithms to provide luminosity, mass and age estimates (GWP-S-8360) (Frémat et al.?) 2006-2010
- Help with study, development and test of algorithms for interstellar extinction (GWP-S-8230) (Who?) 2006-2010
Final versions in Java, with documentation
GHOST, Brussels, Feb.14th 2006
23
Algorithms in practice:
- We can study and test algorithms in any language
- We then select the best algorithm for a certain task (efficiency is an important issue!)
- We write it in Java, with the help of the data center (CNES) if needed
- We test it thoroughly
- We provide it to the data center at the latest in 2010 for integration in the GAIA algorithm
GHOST, Brussels, Feb.14th 2006
24
Where/How can the belgian members of the GHOST contribute:
- Y. Frémat in Brussels is already involved in many tasks. Needs help!?
- Expertise of members from Liege for WR stars would be welcome (for example)
- Will the members from Leuven concentrate on CU7?
- Contributions to observations?
Discussion open!...