Star Formation in Orion-Monoceros Complex VO Tool Application - online catalog & Aladin

章展誥 (Chang, Chan-Kao)，高仲明 (Ko, Chung-Ming)Institute of Astronomy, National Central University, Taiwan

This report is base on the dissertation of 李昫岱

Outline

Motivation Method Orion-Monocerus Complex Conclusion Using VO tools

Motivation

Destructive or Promotive Do massive stars play a decisively destru

ctive or promotive role in sustaining in the molecular cloud?

Method 2MASS color-color criteria

CTTSs & HAeBe (Not WTTSs) IR excesses Empirical, but confirmed by spectra Effective, select a plenty of candidates Upto ~1pc

CO map Molecular clouds

Hα map Ionization fronts (Orion-Eridanus Superbubble)

Orion-Monoceros ComplexN

E450 pc20-30 deg

12CO, Dame et al. 2001

Orion-Eridanus Superbubble

H alpha, Finkbeiner 2003

Orion-Monoceros Complex

2MASS Color-Color Criteria

CTTSs - diamond HAeBe – triangle B[e] – crosses Classical Be – plus Main Seq. – Solid line CTTS locus – dash lin

e

2MASS Color-Color Criteria

Orion A

Orion B

Mon R2

NGC 2194, vdB64 & Crossbones

The Whole Picture of Star Formationin Orion-Monoceros Complex

Conclusion

The SF in Orion-Monoceros complex appears to be dominated by Orion-Eridanus superbubble.

SF start from 1a, 1b, 1c then 1dSpatial distribution (this study)Age distribution (Brown et. al., 1994)

Benefits & Challenges Benefits

Online Catalog & images + Integrated tool Efficient and easy to retrieve data Data visualization is much easier

Challenges Query limitations – not fully meet

requirements Records limitation Query constrain limitation (sky region, condition…

etc) Large memory resource needs Spectra data is unavailable so far Survey image is not complete

Back Up

CTTSs & HAeBe CTTSs

Low-Mass PMS Class II H alpha emission, CaII (H, K line emission) IR excess

HAeBe Intermediate-Mass PMS H alpha emission IR excess Balmer lines absorption

Other Methods Object-prism (Hα emission)

Sensitive to CTTSs, HAeBe, not WTTSc Contaminated by late-type dwarf

X-ray survey (ROAST All Sky Survey) within hundred pcs Contaminated by chromospherically active K & M dwarfs

Proper motion Magnitude limitation (accuracy)

Variability survey Multi-epoch variability survey is time-consuming

Spectra of CTTSs & HAeBe

CTTSs HAeBe