Science in the Spanish Virtual Observatory

Enrique Solano

LAEFF-CAB / INTA-CSIC

SVO Principal Investigator

EuroVO-AIDA workshop. ESAC Dec 08

Outline

How can VO help astronomical research?

What kind of research is easier/more efficient in the VO

framework?

Science and the VO projects

(Spanish)-VO papers

EuroVO-AIDA workshop. ESAC Dec 08

VO and astronomical research

What can VO do for science?

Foster new and/or more efficient science.

How?

Facilitating the work of astronomers in fields like:

Data discovery, access, retrieval and analysis

– VO standards and toolsStds

Tools

Science

EuroVO-AIDA workshop. ESAC Dec 08

Science that benefits from VO

Multiwavelength astronomy

Identification of “exotic” objects

EuroVO-AIDA workshop. ESAC Dec 08

Science that benefits from VO

Multiwavelength astronomy

Searching the pieces.

Retrieving the pieces.

EuroVO-AIDA workshop. ESAC Dec 08

Science that benefits from VO

Multiwavelength astronomy

Putting the pieces together.

EuroVO-AIDA workshop. ESAC Dec 08

Science that benefits from VO

EuroVO-AIDA workshop. ESAC Dec 08

Science that benefits from VO

“Exotic” objects and the VO

EuroVO-AIDA workshop. ESAC Dec 08

Science and the VO projects

A concern for VO projects

EuroVO-AIDA workshop. ESAC Dec 08

SVO: Support to VO Science

VO is something new.

If the services developed by the VO are not scientifically

oriented, they will not be used by the scientific community.

Goal: Liaison between SVO and research groups who have

identified scientific drivers to motivate the adoption of a Virtual

Observatory methodology in their science cases

SVO role:

Evaluation of the science case from the VO point of view.

Provision of information about the existing VO tools.

If needed, develop new tools.

EuroVO-AIDA workshop. ESAC Dec 08

SVO: On-going projects

Identification and characterization of ultracool objects.

Characterization of stellar & substellar population in clusters.

Identification of hot subdwarfs.

EuroVO-AIDA workshop. ESAC Dec 08

Brown dwarfs: link between low-mass stars and planets.

The formation process is still a matter of debate:

Scenarios:

Photo-erosion of massive prestellar cores by nearby ionising stars

(Whitworth & Zinnecker 2004)

– Only operate in the vicinity of a massive star. Cannot be a major source of BDs.

Ejection theory (Reipurth & Clarke AJ, 2001): BDs are leftovers of a prematurely interrupted accretion process. BUT

– High velocity dispersions No disks

EuroVO-AIDA workshop. ESAC Dec 08

Star-like (fragmentation and collapse of a molecular cloud.)

– Supersonic turbulence in molecular clouds may generate a complex density field with large contrast BD mass cores gravitationally unstable (Padoan & Nordlun, ApJ 2004).

Fragmentation of massive extended discs around Sun-like stars of the outer parts of the stellar disks (Stamatellos et al., MNRAS’07,’08)

– Released into the field by interactions among themselves.

» Low velocity dispersion (< 2 km/s) ability of retaining the disk IR excess and accretion.

» Can explain the brown dwarf desert, i.e. the lack of close BD companions to Sun-like stars.

EuroVO-AIDA workshop. ESAC Dec 08

Search young BD by cross-correlating IPHAS and 2MASS

Outside SFRs (for the first time)

1600 square degrees

Filtering using appropriate color criteria.

Methodology: Aladin in script mode

Handling large area regions leads to memory problems.

Mosaic of 30’ radius regions.

EuroVO-AIDA workshop. ESAC Dec 08

Follow-up of 113 candidates. 33 spectroscopically confirmed.

EuroVO-AIDA workshop. ESAC Dec 08

New cross-match using the IPHAS Initial Data Release (González-Solares et al. 2008).

PhotoObjBest: observations in good photometric conditions and with good photometric calibration.

Follow-up spectroscopic observations have been requested in two telescopes.

Spatial distribution: association with molecular clouds

EuroVO-AIDA workshop. ESAC Dec 08

λOri SFR: 400 pc, low extinction (Av~0.36 mag) in the inner area.

EuroVO-AIDA workshop. ESAC Dec 08

Goal: Physical parameters (Teff, bolom. luminosity, mass

and age) of candidate members using SED fitting.

Compilation of the available multi-λ information.

Comparison with different collection of models.

– Tedious and time consuming Tedious and time consuming

EuroVO-AIDA workshop. ESAC Dec 08

EuroVO-AIDA workshop. ESAC Dec 08

Upper-limit of 12.3-16 Myr

(consistent with the

estimated ages for the

cluster by other authors).

Other physical parameters

also in good agreement

with prev. determinations.

20 minutes for the whole 20 minutes for the whole

workflow.workflow.

EuroVO-AIDA workshop. ESAC Dec 08

Similar study in Taurus using UKIDSS, Spitzer and optical data.

EuroVO-AIDA workshop. ESAC Dec 08

Identification and characterization of new regions to search substellar objects.

BDs are much brighter when younger… BUT

Young clusters have variable extinction

σ Ori: young (3 Myr), close (390 pc) and free of extinction (Av < 0.3 mag)

EuroVO-AIDA workshop. ESAC Dec 08

Tycho-2 / 2MASS correlationMembers: Signsposts of youth

O,B, LiI in absorption, strong X-ray or Hα emission, IR excess.

Unknown status: Proper motions and small deviations from the young-star seq.

EuroVO-AIDA workshop. ESAC Dec 08

Boundary determination

Candidate characterization. Removal of:

Foreground and reddened background sources

Extended objects

DENIS / 2MASS correlation

EuroVO-AIDA workshop. ESAC Dec 08

Catalogue of 509 confirmed and candidate young stars and

brown dwarfs.

Characterization of the mass function from 15 to 0.07 solar masses.

Excellent starting-point for further, follow-up dedicated studies.

Spatial distribution, presence of disks,…

Intensive use of VO for data discovery and characterizationIntensive use of VO for data discovery and characterization

EuroVO-AIDA workshop. ESAC Dec 08

And as a bonus…

CPD-20 1123 (1896) TYC 5940 962 1 (2000) 2MASS J06061339-2021072 (2003).

EuroVO-AIDA workshop. ESAC Dec 08

Hot subdwarfs

• Originally classified as the brightest white dwarf in the last 40 years, it turned out to be a very rare object: a bright He-B subdwarf.

EuroVO-AIDA workshop. ESAC Dec 08

Hot subdwarfs

“(He-sdB) stars are extremely rare hot subluminous stars whose existence cannot be explained by canonical stellar evolution theories nor by normal sdB evolution.” (Ahmad, 2004)

SEA Scientific Meeting, July’08

Identification of new hot subdwarfs.

Data Mining tools to distinguish them from WDs and CVs

Characterisation using asteroseismological information from COROT and Kepler.

EuroVO-AIDA workshop. ESAC Dec 08

Conclusions

The Virtual Observatory

Discovery tool

Capable of analyzing large, worldwide-distributed data sets

Now it’s time to demonstrate that it works!!

Strength the links between the VO community and the astronomical community is compulsory.

SVO: 4 / 12 (2007-08)SVO: 4 / 12 (2007-08)

EuroVO-AIDA workshop. ESAC Dec 08

The Spanish VOhttp://svo.laeff.inta.es

10 FTEs + Network of almost 100 researches from 17 centres.

Lines of work:

Management of VO-compliant archives

Development of VO-tools (including Data Mining tools).

Support to VO-Science Key aspect in the project.