1.
Star Formation
GOOD
BAD
UGLY
THE
THE
ANDTHE
Eli Bressert
@astrobiased

2.
GOODTHE
Molecular clouds
Cores
Young stellar objects
Disks & planets

3.
Molecular
cloud
cores
Stars
Gas
1
2 3

4.
1
2
3
age < ? million years
10 pc < scale < 500 pc
age < 0.5 million years
scale < 10000 AU
age < 10 million years
scale < 500 AU

5.
PLANET!!!
[Not to scale]

6.
BAD
THE
Different modes of star formation?
Massive stars only form
in massive clusters?

7.
Different modes
of star formation?

8.
Distributed
Clustered
[Simulated]

9.
⇤ = j 1
( r2
j )
Casertano & Hut 1985
5th closest

10.
Histogram
ClusteredDistributed

11.
Clustered
Distributed
Cumulative

12.
Cumulative
Bressert et al. (2010)
Carpenter (2000)
Gutermuth et al. (2009)
Lada & Lada (2003)
Jørgensen et al. (2008)
Megeath et al. (in prep.)

13.
Different modes
of star formation?
Unlikely

14.
Can massive stars
form in isolation?

15.
Why is it important?
1
2
initial mass function
star formation models

16.
10 x

17.
P( ) P( )=
50 M☉ 50 M☉

18.
P( ) P( )=
Stochastic
Sorted
P( ) P( )=

19.
How can we test it ...
and where?

20.
Weidner et al. 2010
log(Mcluster / Msun)
log(Mstar/Msun)
Weidner et al. (2010)
Isolated!!!

21.
100 pc
Credit: ESO/VISTA Magellanic Cloud survey
Tarantula
Nebula

22.
Line
ofsight
Plane of sky
N
ew
Molecular filaments (MF)
Bressert et al. (2012)

23.
ESO/M.-R. Cioni/VISTA Magellanic Cloud survey
PI: Chris Evans
http://arxiv.org/abs/1103.5386
800 OB Stars
300 O-stars
180 Single O-stars
VFTS

24.
Likely
Can massive stars
form in isolation?

25.
UGLY
ANDTHE
How do young
massive clusters
form?
What do the
progenitors
look like?
How do we find
them
?

26.
Credit: ESO/VISTA Magellanic Cloud survey
100 pc
R136
1-2 Myr
>104 M⊙
SFE > 30 %

27.
15 pc
Credit: ESO/S. Guisard
Ophiuchus
~2 Myr
~102 M⊙
SFE < 10 %

28.
Meanwhile,
back in the
Galactic
Centre ...

29.
The Brick
Longmore et al. (2012)
Credit: NASA/JPL-Caltech/GLIMPSE Team

30.
PI: Jill Rathborne
ALMA
Cycle 0

31.
Prediction
Bressert et al. (2012)
Ginsburg et al. (2012)
All YMC progenitors in MW
are detectable with current
surveys1Like HST on globular clusters,
ALMA will shed light on
extragalactic YMC progenitors2

32.
Longmore et al. (2013)
Credit: NASA/JPL-Caltech/GLIMPSE Team
The Brick
bricklets

33.
Not much
How much do we know
about YMC formation?

34.
?