star formation & alma · leonardo testi: star formation & alma, 3 sep 2012 young bds can have...

Leonardo Testi: Star Formation & ALMA, 3 Sep 2012

Star Formation & ALMA

Leonardo Testi (ESO/Arcetri)

Thanks: J. Ascenso (ESO), E. Bressert (Exeter/ESO), G. Costigan (ESO/DIAS), G. Fuller (UManchester), C. Goddi (ESO), S. Longmore (ESO), C. Manara (ESO/LMU), N. Peretto (Saclay), L. Ricci (Caltech), J. Tan (UFlorida), ...

è Star Formation as a “local” processè The extremes of SF as a testbedè (Setting the stage for Planet Formation)


From Cores to Planetary Systems

LCore

Disk

Debris Disk


è FilamentsØTurbulence (?)

è CoresØGravity

è Core formation threshold related to filament instability

(Her

sche

l Gou

ld B

elt

Proj

et: A

ndre

’ Ph.

et

al.)

From Clouds to Cores


(Her

sche

l Gou

ld B

elt

Proj

et: A

ndre

’ Ph.

et

al.)

From Cores to Stars IMF CO

Salpeter’s

× εN

umbe

r pe

r m

ass b

in:

Mass

CMF

0.6

è Core Mass FunctionØMatches IMF, with ~30% efficiency

è Spatial distribution of YSOs matches cores distributionè Output of SF determined by cloud fragmentation

Leonardo Testi: Star Formation & ALMA, 3 Sep 2012(L

ada

et a

l. 20

12)

Is Star Formation a Local Process?

è Star Formation is consistent with high efficiency conversion of dense gas into stars

è Clouds -> Filaments -> Cores -> Stars


Check the Extremes

è Formation of Brown Dwarfs and Planetary mass objectsØCan BDs for as stars from isolated cores?

è Formation of massive stars and groups/clustersØAre clusters “needed” to form massive stars?ØAre filaments and dense cores the right basic recipe?

è Formation of Young Massive ClustersØDo the simple laws break down?ØDo YMCs require “different” conditions to form?

http://www.eso.org/ sci/meetings/ 2011/vlms2011.html

11–14 October 2011

Garching, Germany

SOC

Leonardo Testi (ESO, co-chair)Monika Petr-Gotzens (ESO, co-chair)

Isabelle Baraffe (Uni. of Exeter)Matthew Bate (Uni. of Exeter)

Andreas Burkert (LMU)Fernando Comerón (ESO)

Ewine van Dishoeck (Leiden Obs.)Gregory Herczeg (MPE)

Kevin Luhman (Penn State)Thomas Preibisch (LMU)

Thomas Stanke (ESO)Paula Teixeira (ESO)

LOC

Christina Stoffer Joana AscensoGiacomo BeccariEli BressertSebastian Daemgen Monika Petr-Gotzens Leonardo Testi

11–14 October 2011

Garching, Germany

http://www.eso.org/ sci/meetings/ 2011/vlms2011.html

SOC

Leonardo Testi (ESO, co-chair)Monika Petr-Gotzens (ESO, co-chair)

Isabelle Baraffe (Uni. of Exeter)Matthew Bate (Uni. of Exeter)

Andreas Burkert (LMU)Fernando Comerón (ESO)

Ewine van Dishoeck (Leiden Obs.)Gregory Herczeg (MPE)

Kevin Luhman (Penn State)Thomas Preibisch (LMU)

Thomas Stanke (ESO)Paula Teixeira (ESO)

LOC

Christina Stoffer Joana AscensoGiacomo BeccariEli BressertSebastian Daemgen Monika Petr-Gotzens Leonardo Testi


Formation of Brown Dwarfs

è Can Brown Dwarfs fit in the paradigm?è Formation and Early Evolution of VLMS and BDs

(http://www.eso.org/sci/meetings/2011/vlms2011.html)

(Bate 2002; 2012)

(Dul

lem

ond,

Nat

ta &

Tes

ti 20

06)

http://www.eso.org/sci/meetings/2011/vlms2011.htmlhttp://www.eso.org/sci/meetings/2011/vlms2011.html


Accretion vs mass/ageè NIR hydrogen

recombination lines NTT/VLT survey

è -Oph vs -Oriè ~0.5-1Myr vs

~3-5Myr

(Nat

ta e

t al

. 06;

Gat

ti e

t al

. 08)


Accretion vs mass/age

(Rig

liac

o e

t al

. 11

)

VLT U-Band survey(N

atta

et

al. 0

6;

Gat

ti e

t al

. 08)


Accuracy matters in the BDs domain...

(Man

ara

et

al. 1

2)

(Nat

ta e

t al

. 20

04

; R

igli

aco

et

al. 2

01

2)



(Rig

liac

o e

t al

. 11

)


~3-5Myr

-Ori



(Rig

liac

o e

t al

. 11

)


~3-5Myr

-Ori

-Oph (Natta et al. 06)Tr 37 (Sicilia-Aguilar et al. 10)-Ori

è Possible evidence for a change of slope with stellar mass

è possible evidence for a faster evolution at the low mass end



(Rig

liac

o e

t al

. 11

)


~3-5Myr

-Ori

-Oph (Natta et al. 06)Tr 37 (Sicilia-Aguilar et al. 10)-Ori

è Possible evidence for a change of slope with stellar mass

è possible evidence for a faster evolution at the low mass end ONC

Manara et al. 2012

0.1-0.2 Msun

0.6-1.0 Msun


XShooter surveysè Simultaneous observation of photosphere, accretion

and wind indicators across a broad wavelength rangeè Surveys:

ØAlcalaʼ et al. GTO program: TW Hya, Lupus, -Ori, +• Alcalaʼ et al. 2011, Rigliaco et al. 2012, Manara et al. 2012b

ØTesti et al.: -OphØHerczeg et al.: Chamaeleon + ØSeveral smaller programs

!"#$%#&'()*+,,"-.'/01'2.,3.#45''' ' ' '' '6'&%3+"7'%&'8'9.7'

:%47'%7'",'7";.,4']#^#'-"'#$S'_ZZQE'3%C-7'797"-4#A=#$$9'$,H-.'C#$;-7'"+#&'$%&-'$;4%&,7%"9`'2,77%G$9'',&$9'Q'@&,H&'H%'"+-'*VeD'-4%77%,&'$%&-7'#&


Disk properties

è Disk properties in the substellar domain: a major topic for ALMA (sensitivity and angular resolution)

(Ph

an

-Bao

et

al. 0

8)

(Ric

ci e

t al.

2012

)


è Young BDs can have similar characteristics as low mass starsØConsistent with same formation and evolution

mechanisms

è Ejection/interaction pathways have to become important for the lowest mass objects

è Open questions for ALMAØ Identification of pre-BDs cores?ØDisk properties around young BDs?ØPlanet formation in the BDs regime?

Lessons and questions from BDs


Intermediate-mass stars

Memories from a few yrs ago(The clustered vs dispersed population debate)

• Low-mass stars in nearby associations are found in isolation or loose groups (ρ*~ few */pc3)

• High-mass stars are found in dense and well populated stellar clusters (ρ*~ 104 */pc3)


(Tes

ti et

al.

1997

, 199

8, 1

999

de W

itt e

t al.

2004

, 200

5)Clustering properties of HAeBe and O stars

è Possible correlation between clusters and massive stars

è Random sampling not excluded


“Isolated” O-stars in 30Dor field

è Candidate “isolated” O-stars from the VLT Tarantual Survey

(Bre

sser

t et a

l. 20

12)


The birthplaces of O-stars

è ALMA Cycle 0 observations of deuterated species in IRDCsè Dense massive cores in virial equilibrium

(Tan

et a

l. 20

12; K

ong

et a

l. 20

12)

ALMA N2H+(1-‐0) los velocity (4”)


The filamentary structure of IRDCs

è ALMA Cycle 0 observations of N2H+(1-0)è Coherent kinematic structure of filaments

(Peretto et al. 2012)

ALMA (res: 4’’)


Disk-outflow systems in high-mass YSO

è Orion: the nearest high-mass YSOsè Reflected IR VLT spectroscopy and mm/cm

data consistent with disk-outflow systemè Scaled-up version of TTauri stars

100 AUSiO v=0 J=1-0 (VLA)

SiO v=0 J=2-1 (CARMA)

motions over 9 yrs

1700 AU

SiO v=1,2 (VLBA) Radio Cont

(Mat

thew

s et

al.

2010

; God

di e

t al.

2011

)

(Tes

ti et

al.

2010

)


...not so simple!(N

iede

rhof

er e

t al.

2012

)

28SiO 5-4 ALMA (image)28SiO 2-1 CARMA (cntrs)

Velocity-Integrated


Velocity-Integrated

Red

Blue


è Evidence for interaction with other massive YSOsè Evidence for interaction with surrounding cloud coresè Are environment and interactions more important than

initial conditions?è High resolution of ALMA essential to expand sample

ALMA Science Verification Data


Young Massive Clusters precursors

Sgr B2 Sgr CSgr A*

Quintuplet

Arches

(Molinari et al. 2011)

Ncol

Td

VLT/

NAC

OH

ersc

hel 7

0um(Lo

ngm

ore

et a

l. 20

12)


Young Massive Clusters precursors(L

ongm

ore

et a

l. 20

12; R

athb

orne

et a

l 201

2)

MO

PRA

HCO+ HNCO SiO

SiO

HNCOè Very dense and compact molecular clump

è Widespread SiO, little evidence for ongoing star formation

è Internal structure/filaments?è Rosetta Stone for origin of

Young Massive Clusters


è Continuum distribution of stellar densitiesØNo strong evidence (so far) of causal relationship

between clusters and high-mass stars (!highly debated!)

ØHM-stars may form as low mass stars

è Formation of cores from filaments is observed

è Open questions for ALMAØStructure of HM cores and relation with filaments?ØDisk/outflow properties around young HMYSOs?ØFormation of YMCs and Super Star Clusters?

Lessons and questions from HM-YSOs


è We think we have a “simple” framework for understanding star formation

è The complexity of star formation seems to be captured in the process of converting gas into dense cores

è Most of the “extremes” seem to fit in this overall frameworkØThe path of more exotic formation mechanisms is open

for a small minority of systemsØThese “minority systems” may be dominant SF modes in

some peculiar environments

Summary


è The complex physics of the formation and evolution of a single object and multiple systems (and what this imply for the fate of disks and planetary systems)

è The effects that an object or a population has on other forming stars (and the fate of their disks)

è The processes within disks and of the disk-star interactions that set the stage for the formation of planetary systems

è How the formation of our own Solar System may fit into the overall picture

I have consciously avoided:

ALMA Science Results, June 2012

ALMA SV Science Results The multiple protostar IRAS16293

Ø Jorgensen et al. 2012; Pineda et al. 2012; Dumas et al. 2012

(Mau

ry e

t al./

Hen

nebe

lle e

t al.)


Gas 50 cm

• Disk structures, grain trapping, planet formation

(Cos

sins

, Lod

ato,

Tes

ti 20

10)Slowing down radial drift: grain trapping

ALMA 850 GHz (Wol

f & DʼA

ngel

o)


A problem of timescales

Inner disk clearing:e-folding time t~2-3 Myr(

Her

nand

ez e

t al.

2007

)

è Evolution too fast to reconcile with SS meteoritic evidence

è Need to study the (small) population of long-lived disks

(Man

ara

et a

l. 20

12)

star formation & alma · leonardo testi: star formation & alma, 3 sep 2012 young bds can have...

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