star formation: the good, the bad, and the ugly
DESCRIPTION
A talk on star formation and stellar clustering. Here we review some of the topics that are well-known (the general picture) to the poorly understood (young massive cluster formation).TRANSCRIPT
Star Formation
GOODBAD
UGLY
TH
E
TH
E
AN
D T
HE
Eli Bressert@astrobiased
GOODTH
E
Molecular clouds
Cores
Young stellar objects
Disks & planets
Molecular cloud
cores
Stars
Gas
1
2 3
123
age < ? million years
10 pc < scale < 500 pc
age < 0.5 million years
scale < 10000 AU
age < 10 million years
scale < 500 AU
PLANET!!!
[Not to scale]
BAD TH
E
Different modes of star formation?
Massive stars only form in massive clusters?
Different modes of star formation?
Distributed
Clustered
[Simulated]
�⇤ = j�1(�r2j )
Casertano & Hut 1985
5th closest
HistogramClusteredDistributed
Clustered
Distributed
Cumulative
Cumulative
Bressert et al. (2010)
Carpenter (2000)Gutermuth et al. (2009)Lada & Lada (2003)Jørgensen et al. (2008)Megeath et al. (in prep.)
Different modes of star formation?
Unlikely
Can massive stars form in isolation?
Why is it important?
12
initial mass function
star formation models
10 x
P( ) P( )=
50 M☉ 50 M☉
P( ) P( )=Stochastic
SortedP( ) P( )=
How can we test it ... and where?
Weidner et al. 2010
log(Mcluster / Msun)
log
(Mst
ar /
Msu
n)
Weidner et al. (2010)
Isolate
d!!!
100 pc
Credit: ESO/VISTA Magellanic Cloud survey
Tarantula Nebula
Line
of sig
ht Plane of sky
NewMolecular filaments (MF)
Bressert et al. (2012)
ESO/M.-R. Cioni/VISTA Magellanic Cloud survey
PI: Chris Evanshttp://arxiv.org/abs/1103.5386
800 OB Stars
300 O-stars
180 Single O-stars
VFTS
Likely
Can massive stars form in isolation?
UGLYAN
D T
HE
How do young massive clusters form?
What do the progenitors look like?
How do we find
them?
Credit: ESO/VISTA Magellanic Cloud survey
100 pc
R1361-2 Myr
>104 M⊙
SFE > 30 %
15 pc
Credit: ESO/S. Guisard
Ophiuchus~2 Myr
~102 M⊙
SFE < 10 %
Meanwhile, back in the Galactic Centre ...
The BrickLongmore et al. (2012)
Credit: NASA/JPL-Caltech/GLIMPSE Team
PI: Jill Rathborne
ALMACycle 0
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
Longmore et al. (2013)
Credit: NASA/JPL-Caltech/GLIMPSE Team
The Brick
bricklets
Not much
How much do we know about YMC formation?
?