the transition from agb stars to pne: a scientific case for the vo

Pedro GARCIA-LARIOAVO DEMO2005 @ ESAC - 25/01/2005,

The transition from AGB stars to PNe: The transition from AGB stars to PNe: a scientific case for the VOa scientific case for the VO

ISO Data Centre, ESA-ESAC

P. García-Lario, A. Bayo & M. Sierra


The transition from AGB stars to PNe in the H-R diagram

Late evolutionary stages of low- and intermediate mass stars (1 - 8 M)

- Short transition times (~103 - 104 yr) - Recent AGB mass loss (up to 10-4 M/yr)

- Few objects in this phase

- Many are heavily obscured in the optical

- Need of systematic surveys using infrared data


From AGB stars to Planetary Nebulae

O- rich O- richC- rich

See video...

Dramatic changes in:

-pulsation properties

- mass loss

- chemistry

- overall SED

- morphology


Search for new transition sources using IRAS

Pottasch et al. 1988; Preite Martinez 1988;

García-Lario 1992

All-sky survey

250,000 Sources

4 bands

12, 25, 60 and 100 m

PNe show

characteristic

IRAS colours!

… but unidentified sources in the IRAS two-colour diagram

were found to be transition sources rather than typical PNe


Heavily obscured late-AGB stars

OH 26.5+0.6


Optically bright post-AGB stars

IRAS 19114+0002


Extremely young/dusty planetary nebulae

IRAS 17347- 3139

+


Extremely young/dusty planetary nebulae

IRAS 17347- 3139

+

HST-NICMOS


How can we enlarge the sample?

IRAS had limited sensitivity and a poor spatial resolution (15”- 30”)

4 photometric bands centred at 12,25, 60 and 100 m (~250,000 sources)

All-sky survey - but confusion close to the Galactic Centre

Optical/near-infrared counterparts difficult to identify in crowded areas

Use of MSX data can help…

4 bands A,C.D.E centred at 8. 11, 14 and 21 m (~ 500,000 sources)

Limited to |b|< 6 degrees but this is where most AGB to PN sources are located

Much better spatial resolution than IRAS (1.5”-2”)

Optical/near-infrared counterparts can be easily checked using DSS/2MASS data

Not enough to disentangle YSOs and extragalactic sources from evolved stars


Search for new transition sources using MSX

Young PNe and transition

sources are located in a

well defined region of the

diagram…

…but there is a

lot of overlap with YSOs

Can we get rid of the

‘contaminating’ sources?

…data must be complemented with IRAS photometry at 60 m


An ideal case for the AVO

X-match catalogues (MSX and IRAS) containing ~10X-match catalogues (MSX and IRAS) containing ~105 – 5 – 10106 6 sourcessources

Catalogue manipulation: select/filter/add columns (A-C, D-60)Catalogue manipulation: select/filter/add columns (A-C, D-60)

Query SIMBAD or other Vizier catalogues with lists containing ~ 10Query SIMBAD or other Vizier catalogues with lists containing ~ 104 4

sources to search for yet unidentified sources and/or get a classification sources to search for yet unidentified sources and/or get a classification

for the identified onesfor the identified ones

Create color-color diagrams where the position of different classes of Create color-color diagrams where the position of different classes of

sources can be visualizedsources can be visualized

On-the-fly display SEDs of specific sources including ALL available data in On-the-fly display SEDs of specific sources including ALL available data in

catalogues/data archives (spectroscopy+photometry) for automated catalogues/data archives (spectroscopy+photometry) for automated

classification or modellingclassification or modelling

SEE DEMO !!


Gallery of extremely young planetary nebulae

IRAS 22036+5306

Hen 3-401

IRAS 16594-4656

Stingray Nebula IRAS 17395-0841

the transition from agb stars to pne: a scientific case for the vo

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