The Virtual Observatory and its analysis tools

1
The Virtual Observatory and its analysis tools

• towards virtual telescopes?

Miguel Cerviño (IAA-CSIC/SVO) Elena Terlevich
(INAOE) INAOE VO group SVO
2
What is VO?

• The Virtual Observatory will be a system that
  allows astronomers to interrogate multiple data
  centers in a seamless and transparent way, which
  provides new powerful analysis and visualization
  tools within that system, and which gives data
  centers a standard framework for publishing and
  delivering services using their data. This is
  made possible by standardization of data and
  metadata, by standardization of data exchange
  methods, and by the use of a registry, which
  lists available services and what can be done
  with them.

Where is the system? Does it mean operative
system? NO, it means a working environment, just
like KDE, Gnome or Windows
but it says their data Does it mean using
analysis tools with data from different
machines and formats whatever the operating
system? YES!!
Uhmm, does it mean something like IRAF? But there
is a lot of software already.
Ok, so it is needed a standard more general than
FITS, since it should also include catalogs (but
including FITS that is already common in most
observatories)... and something that describes
the data themselves (metadata) and to
establish the communication between machines
and yellow-pages for search resources
The long term vision is not one of a fixed
specific software package, but rather one of a
framework which enables data centers to provide
competing and co-operating data services, and
which enables software providers to offer a
variety of compatible analysis and visualization
tools and user interfaces. The first priority
for the VO projects worldwide is to develop the
standardized framework, which will allow such
creative diversity.
International Virtual Observatory Alliance
Guidelines for Participation R. J. Hanisch and
P. J. Quinn 2003-07-01 http//www.ivoa.net/pub/in
fo/IVOA-participation-Jul03.pdf
3
Why is VO needed?

• The amount of data is increasing exponentially
  --gt Distributed databases (and interoperability
  between databases)

The International Virtual Observatory R. J.
Hanisch et al. 2003 http//www.ivoa.net/pub/info/
TheIVOA.pdf
4
Why is VO needed (II)?

• Each data-service provides data in their own
  format. As an example there are no universal
  FITS headers.
• Sometimes only the description of the data is
  needed (you do not read a whole book before
  buying it!) --gt A description of what the data
  are becomes mandatory before using them
• Physical inference requires comparing theory with
  observations, but data and models are not in the
  same format

How much time do you spend making drivers to
compare data with theory? How much time do you
spend writing software to do plots?
5
IVOA (http//www.ivoa.net)
6
Roadmap
Applications, Theory
Build Tools to do Science
Create protocols for interoperability Registry,
DAL, VO query, Grid Web services
Take-up Standards Register Resources
Generate Databases in a standard format (images,
spectra, cataloges) VOTable, UCD, Semantics,
Data Model
Agree Build Standards Test Technologies
Euro VO P. Queen Workshop on VO Standards and
Systems for Data Centres and Large Projects 2005
http//www.euro-vo.org/workshop2005/presentation/
EURO-VO-WSintro.pdf
7
Working groups
http//www.ivoa.net ---gt Community
8
1st step Databases
9
2nd Interoperability
What is needed? 1.- To have a yellow pages
registry where data-bases can be found
IVOA task --gt it needs to be in the IVOA
framework --gt one (and
only one) national VO is needed for
each country 2.- To have
applications that uses the registered databases
(Applications only now that they will
retrieve VOTables using a given
protocol, but they do not know the content
a priori ---gt object oriented programs --gt
JAVA tools) 3.- Additional note Java programs
can use methods in other machines ---gt
VO provides large sets of methods --gt It is not
needed to repeat the work!!
10
2nd Interoperability (Applications)
11
Plastic demostracion T. Boch (ADS) IVOA
Interoperability meeting 2006
12
Plastic demostracion T. Boch (ADS) IVOA
Interoperability meeting 2006
13
Plastic demostracion T. Boch (ADS) IVOA
Interoperability meeting 2006
14
Plastic demostracion T. Boch (ADS) IVOA
Interoperability meeting 2006
15
Plastic demostracion T. Boch (ADS) IVOA
Interoperability meeting 2006
16
3rd science

• The last step is the use of the VO by the science
  community
• It implies that the other two steps (Databases
  and Interoperability) are ready.
• It is not completely the case, but they are
  almost ready and feedback from the community is
  needed!
• And some scientific cases can be yet addressed

17
México in the VO

• Observatorio Virtual Solar
• IA-UNAM, DGSCA, UniSon
• http//www.astroscu.unam.mx/ia_cu/proyectos/ovs/in
  dex.htm
• Grupo de ciencia de observatorios virtuales del
  INAOE
• http//ov.inaoep.mx
• PGos3 (http//ov.inaoep.mx/pgos3/)
• INAOE, IA-UNAM, IAA/SVO (Spain)
• Models of irradiated accretion disks around
  pre-main sequence stars by D'Alessio et al.
  (1998,1999,2001).
• SVO (Spain), CRyA
• http//svo.laeff.esa.es/theory/db2vo/html/index.ph
  p?modelDalessio

18
3rd (science) stepsMexican VO - SVO theoretical
efforts PGos3

• ? PGos3 is a very valuable tool in the VO
  context
• 'Star Formation Histories in Galaxies' was the
  extragalactic Science Case chosen for the
  AVO-Demo 2005. This involves retrieving
  multiwavelength datasets that are then compared
  against stellar spectral evolution codes, to
  enable information to be derived on galaxy star
  formation histories.

Synthesis models in the VO E. Solano et al. IVOA
Interoperability meeting 2005
19
An use case

? Comparison between the results given by
different grids of evolutionary synthesis models
(produced by different developers/groups) with
observational data. ? The model that best fit
for any parameter combination does not exist
(sed_at_, Starburst99 are optimized for young
populations Bruzual, Pegase for older
populations). ? Needed to assess the
reliability of the scientific conclusions
obtained from the models.
Synthesis models in the VO E. Solano et al. IVOA
Interoperability meeting 2005
20

21

22

23

Nebular emission not modelized.
24

25
Other use case
? The contribution of Star Forming Regions to the
Soft X-ray emission of Sy 2 galaxies ?
Inclusion of SSP models (including probabilistic
formulation by Cerviño, Luridiana,
Cerviño-Luridiana 2006, AA 451, 475) in the VO
? Inclusion of XXM-Newton data in the VO

M. Guinazzi et al. IAU Praga 2006
26
VO and intrumental projects virtual telescopes?

• There are several projects in the any
  instrumental project that are related with VO
  (besides the Database itself)
• The analysis of the data with VO tools
• The pipe-line process
• The inverse pipe-line (simulators) --gt Virtual
  telescopes
• (a complete calibration of the
  instruments and the telescopes is needed)

27
Virtual Telescopes (Gerad Lemson)
Virtual Telescope and Theory roadmap http//www.iv
oa.net/internal/IVOA/IvoaTheory/lemson_Madrid2005-
theory.pdf
28
Conclusions

• VO is a productivity tool (so that astronomers
  can focus on astronomy instead of computation
  issues).
• It is by its nature a multidisciplinary task
  involving astronomy, computation and technology.
• You are already using the VO, although, maybe,
  you are not aware of it. It is not a new
  strange thing.
• VO will work better, as any tool, if feedback
  from users is provided Your opinion is
  important.
• VO implies a new way to understand astrophysics
  (as any other technological improvement).