1. Massive
Cluster Formation
Eli Bressert
Bolton Fellow
@astrobiased

2. 1 How do YMCs form?
2 Where are the
progenitors?

3. What is a young
massive cluster?

4. > 10 M
4
M ~ ☉
r ~ 5 pc
t ~ 2 Myr
Portegies-Zwart et al. 2010

5. 100 pc
R136
1-2 Myr
>104 M⊙
SFE > 30 %
Credit: ESO/VISTA Magellanic Cloud survey

6. 15 pc
Ophiuchus
~2 Myr
~102 M⊙
SFE < 10 %
Credit: ESO/S. Guisard

7. 15 pc
Ophiuchus
~2 Myr
~102 M⊙
SFE < 10 %
Credit: ESO/S. Guisard

8. Theory

9. Clump
Cluster

10. Kinetic
Potential

12. vesc > CII
Bressert et al. (2012)

13. vesc > CII
10 km/s
Bressert et al. (2012)

14. vesc
⌦= CII
Bressert et al. (2012)

15. Ω<1
Ω >1

16. Are these precursors
important?

17. We clusters

18. Meanwhile,
back in the
Galactic
Centre ...

19. Longmore et al. (2012)
The Brick
Credit: NASA/JPL-Caltech/GLIMPSE Team

20. Bressert et al. (2012)
Ginsburg et al. (2012)

21. d < 40 Mpc
F = 78 mJy
500
F = 8 mJy
850
F = 2 mJy
1200
d < 20 kpc
F = 31 Jy
500
F = 4 Jy
850
F = 2 Jy
1100

22. We are able to
detect all YMC
progenitors in
the observed
Milky Way

23. ?

24. h i 2
10 2 Df
Pw ⇠ 10 dynes cm ... 2 pc
h i 2
10 2 Df
Prad ⇠ 10 dynes cm ... 2 pc
h i 3/2
9 2 Df
PH ii ⇠ 10 dynes cm ... 2 pc
Bressert et al. (2012)