1. Debris disks Basic properties Observational methods & constraints
Why “debris”?
Structures
Alexis Brandeker, Lecture 6 in star formation mini-course
Resonance Line Scattering in the beta Pic Disk

2. Discovery of debris disks
From Backman & Parece 1993, PPIII, 1253
Resonance Line Scattering in the beta Pic Disk

3. Discovery of debris disks
From Backman & Parece 1993, PPIII, 1253
Resonance Line Scattering in the beta Pic Disk

4. First disk spatially resolved: b Pictoris
Discovery image by Smith & Terrile 1984 (Sci. 226, 1421)
500 AU
Resonance Line Scattering in the beta Pic Disk

5. Properties
Large (up to 1000 AU) dusty disks found around young main-sequence stars ~ 10 Myr – 1 Gyr
Dust disk mass M ~ 10-3 to a few MEarth.
Essentially free of gas
Cold; typically 30 – 300 K
Dominating dust emission from m to mm sized grains
Resonance Line Scattering in the beta Pic Disk

6. ”The fabulous four” at 850m
3.2 pc
7.7 pc
7.7 pc
20 pc
Resonance Line Scattering in the beta Pic Disk

7. Resonance Line Scattering in the beta Pic Disk

8. b Pictoris in scattered light
Resonance Line Scattering in the beta Pic Disk

9. Resonance Line Scattering in the beta Pic Disk

10. Resonance Line Scattering in the beta Pic Disk

11. Resonance Line Scattering in the beta Pic Disk

12. Resonance Line Scattering in the beta Pic Disk

13. Resonance Line Scattering in the beta Pic Disk

14. Resonance Line Scattering in the beta Pic Disk

15. ZAMS
20 Myr
30 Myr
Barrado y Navascués 1999
50 Myr

16. Resonance Line Scattering in the beta Pic Disk

17. Why “debris”? From Artymowicz 1997, AR 25:175
Resonance Line Scattering in the beta Pic Disk

18.   Frad/Fgrav
2.2
 = 1
0.51
0.1
0.3
0.4
Breakup of Parent Body

19. parent body before breakup
Top view
Orbit of Pluto-mass
parent body before breakup
Side view
 =
Elapsed time: 21 years
Florida Dynamics Group

20. Top view
Side view
 =
Elapsed time: 569 years
Florida Dynamics Group

21. Subaru/COMICS Total (magenta) 0.1mm amorphous olivine (green)
(Y.Okamoto et al. 2004)
Total (magenta)
0.1mm amorphous olivine (green)
2mm amorphous olivine (red)
Crystalline forsterite (blue)
Power-law continuum (cyan)

23. Dust disk lifetimes From Haisch, Lada & Lada 2001, ApJ, 553, 153
Resonance Line Scattering in the beta Pic Disk

24. What about gas? Energy diagram of H 2 30.0 Energy [K] 20.0 10.0
[Pollack et al. 1993]
Total mass
30.0
Energy [K]
20.0
Core mass
10.0
Gas mass

25. mm/submm observations
Liseau & Artymowicz 1998, A&A 335, 935
Resonance Line Scattering in the beta Pic Disk

26. Edge-on  absorption!

27. Gas in emission Sodium D1/2 lines toward b Pictoris
Olofsson, Liseau & Brandeker 2001, ApJL 563
Sodium D1/2 lines toward b Pictoris
Resonance Line Scattering in the beta Pic Disk

28. Dynamical studies... Stellar structure: M*=(1.75±0.1)Mo Gas dynamics:
Mdyn=(1.40±0.05)Mo
Discrepancy probably due to radiation pressure!
Resonance Line Scattering in the beta Pic Disk

29. HR 4796A

32. b Pictoris in scattered lightNE SW
Resonance Line Scattering in the beta Pic Disk

33. NE SW Gemini south / T-ReCS Telesco et al. 2005 24.3 m 18.3 m
FWHM
5 arcsec
18.3 m
100 AU
11.7 m
Gemini south / T-ReCS
Telesco et al. 2005
pixel

34. 1.2 mm (SEST/SIMBA) Liseau et al. 2003
Resonance Line Scattering in the beta Pic Disk

35. Asymmetris in gas disk VLT / UVES (Brandeker et al. 2004)
We found lots of atomic and ionic metallic gas emission in the disk, extending to at least 320 AU radially from the star.
VLT / UVES (Brandeker et al. 2004)
Resonance Line Scattering in the beta Pic Disk

36. Evolution: young vs. old debris
Optical/IR disks
Sub-mm rings/arcs
Credit: M. Liu

37. StarStrider
[AU]
Resonance Line Scattering in the beta Pic Disk