1. Ji Wang Department of Astronomy University of Florida
Lx-Prot Relationship
Ji Wang
Department of Astronomy
University of Florida

2. X-ray indicators
Lx and Fx are anticorrelated with Prot at slope of -1(99% significance)
Lx/L* has no significant anticorrelation with Prot
Briggs et al 2007

3. Lx-Rrot Relationship
Briggs et al 2007
Preibisch et al 2005

4. Activity-Rossby Number Relation
Briggs et al 2007
Preibisch et al 2005

5. Possible Explaination for Scattering
X-ray variability
Short term variability
Lerm term variability
Unresolved Binaries
Producing scatter of
Stardard deviation 0.7 dex

6. X-ray and circumstellar disks
Ca II Line=Accretion Tracer
Preibisch et al 2005

7. X-ray and Accretion
Briggs et al 2007

8. Possible explaination
Low X-ray luminosity due to higher extinction
Disk-braking mechanism
magnetic reconnection can not heat the dense plasma in mass-loaded accreting field lines to X-ray temperatures.

9. Conclusions
Lx and Fx are anticorrelated with Prot, but Lx/L* is correlated or has no dependence on Prot
The scattering in Lx-Prot relationship for young stars is an combining force of X-ray variability and accreting TTSs.
Relative lower Lx/L* for accreting TTSs is due to the fact that magnetic reconnection cannot heat up dense plasma in mass-loaded accretion region

10. Reference
Preibisch, T., Kim, Y.-C., Favata, F. et al. 2005, ApJS, 160, 401
K. R. Briggs, M. Güdel, A. Telleschi, T. Preibisch, B. Stelzer, J. Bouvier, L. Rebull, M. Audard, L. Scelsi, G. Micela, N. Grosso, and F. Palla A&A 468, 413–424 (2007)