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OLD NGC 1333 SFR

Could omit some stages e.g. 7 depending on time/availability of data,

1. Start with 2MASS K image (better still make JHK image)
2. 2MASS catalogue gives JHK mags. Use VOPlot to exclude sources with large flux measurment errors, form and plot J-H and H-K colours.
   • J/ApJS/101/117 UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995) actually gives ready-made colours but that takes the fun away...
3. Export subset catalogue of sources with JHK colours indicative of YSO and plot in Aladin (could use filters to select colours typical of each class, or use 'blink' capability to refer to VOPlot).
   • H-K < 0.4 mostly Class III
   • H-K > 0.4, J-H < 1.6 mostly class II
   • J-H > 1.6 class I or II
   • If L available, better separation but still some ambiguity/contaimination.
4. Load XMM image (and Preibisch 2003 catalogue if available)
5. Load radio (Rodriguez 1999) catalogue if available. NB Rodriguez classifies all sources with a<0 in S(freq)=freq^a as extra-galactic but Smith et al. 1999 A&A 349 475 finds a probable proto-AeBe or dwarf star with a negative radio spectral index.
6. Load optical image and Halpha if available
7. Make RGB, remove contaminants
   • Radio/X-ray sources with no IR counterpart are probably extra-galactic but radio-only could be v. young (Class 0) - might show up in ISO or in radio spec. line catalogues e.g. masers, CS, thermal CH3OH, check a few.
   • Optical-only are probably MS stars, but check for faint x-ray/slight far-IR-submm(how?) redenning indicating PMS low/high mass stars.
   • Background stars reddened by nebula, Brown Dwarfs, don't have radio or x-ray but need optical/NIR spectroscopy to be sure?
   • Herbig-Haro objects - ends of jets - so associated with young YSO, but can be spatially separate - don't have x-ray
8. Load ISO image(s) if available, compare with other images using contours if catalogues not available (as noted or via ACE)
9. Load ISO catalogue and use filter to select LWS obs. only
10. Use SpecView to examine spectra for H2O line (Nisini ea 2002, Ceccarelli ea 1999), CO (Caux ea 1999) and to derive colours (Pezzuto ea 2002) using VOPlot

Score objects:

• Class implied by JHK colours
• Nature/class implied by presence/absence in radio, optical, x-ray
• Class implied by ISO spectra and colours
• Age/mass implied by presence of Halpha, mol. lines
• Age/mass implied by presence/absence of x-ray
• x-ray spectra - if only harder x-rays seen (>~3 keV) implies more obscured so younger. However low-mass stars in accretion stage have x-ray suppressed (Briggs et al. 2004 IAUS219). So weak but hard x-ray implies v. young massive YSO or ~class 1 low-mass c.f. proplyds? Soft x-ray implies T Tauri i.e. low-mass PMS?

Issues

Classification issues

Binaries

Can we put probabilities or reliability flags on

• accuracy of each diagnostic
• accuracy of matching objects

Already being solved

1. ISO LWS spectra access
2. ISO image access
3. Specview integration

Probably easy to solve but may not be time

• Getting data from Specview into VOPlot to make colour-colour plot
• Tables not yet in Vizier
  1. XMM Preibisch 2003 A&A 401 543 table only available electronically from ADS 2003A&A...401..543P
  2. VLA Rodriguez et al. 1999 ApJS 125 427 tables 1 & 2 1999ApJS..125..427R
  3. Getting VOPlot to plot RA from R to L
  4. High-resolution radio data (MERLIN) - being processed

Don't know

1. XMM spectra (as in Preibisch 2003 A&A 401 543) - may not be suitable, XMM expert consulted
2. Halpha spectra - probably not available in suitable form for this region.

Flow Diagram

-- AnitaRichards - 16 Nov 2003