Musings about 30 Dor

Musings about 30 Dor

Hans Zinnecker

DSI @ SOFIA Science Center

NASA-Ames Research Center

Moffett Field, CA

(Univ. Stuttgart, Germany)

Tarantula Nebula ([SII] imageof the 30 Dor giant HII regiontaken by Walborn at CTIO-4m)

LMCGMCs (CO 1-0)

Fukui et al. 2008NANTEN 4m tel.

30 Doradus as seen by HST/WFC3/UVIS (courtesy Erick Young)

F160W (H-band)NICMOS imagecentred on R136(1‘ x 1‘ = 15pc x 15pc)

Andersen/HZ et al. 2009, Ap.J.

30 Dor, NGC 2070, R136

nomenclature (to avoid confusion)

30 Dor = giant HII region (200 pc)

N2070 = starburst cluster (20 pc)

R136 = central cluster (2 pc)

R136 core radius = 0.2 pc

cf. big Galactic cluster NGC 3603

R136NGC 3603Orion Nebula(to scale)

Zinnecker & Yorke(Annual Reviews 45)

1,2) initial conditions, initial location (past)

3,4) cluster IMF, SF history (num. simul.)

5, 6) feedback trigger on adjacent cloud,

two-stage starburst (2nd gen, present)

7, 8) close (“hard”) binaries, runaway stars

9,10) stellar + dynamical evolution (future)

10 question on 30 Dor

Introductory summary (1)

•largest star forming HII region in the Local Group

•closest resolved starburst cluster ("Rosetta Stone“)

•nearby (LMC at 50 kpc) details (e.g. IMF, SFH)

high-masses: ~ 100 O-stars

•stellar population:

low-masses: < 3MO pre-MS

•metallicity and age: Z ~ ZO/2.5 and 3±1.5 Myr

•origin: near LMC stellar bar, gas infall from SMC

•evolution: proto-globular cluster? staying bound?

Introductory summary (2)

stellar cluster ~ 105 MO

•mass total ionised gas 4.105 MO

mol. cloud (CO) ~ 105 MO

•central mass density ~ 105 MO/pc3

•total luminosity ~ 108 LO

•rate of ionising Lyc photons ~ 1052 s-1

•equivalent number O3-stars ~ 100 Ltot

Ekin (HII gas,tot) ~ 1052 ergs

•energetics Ekin (R136 shell) ~ 1051 ergs

Ekin provided by O-star winds, SNRs

kinematic study(slit positions)HII velocity dispersion~ 60km/s over 270pc

Chu & Kennicutt 1994

Violent star formationHII-region (v_rms>c_s)

Terlevich & Melnick 1981

Br (grey)

CO (contours)Poglitsch et al. 1995

NIR images (JHK)

Rubio et al. 1998

NIR images (JHK)red sources:protostars?

Rubio et al. 1998

from Zinnecker & Yorke 2007(Annual Reviews, Vol. 45)

SPH simulation of a turbulent100 pc 106 MO molecular cloud (Bonnell, Clark, & HZ, in prep.)

from Zinnecker & Yorke 2007(Annual Reviews, Vol. 45, 481)

SPH simulation of hierarchicalcluster formation (sub-clustersin the process of „wet“ merging)(Bonnell, Bate, & Vine 2003)

Maybe the N2070/R136 clusterformed by merging of subclusters(cf. WFC3 obs. Sabbi et al. 2012)

Massey & Hunter 1998Weigelt & Baier 1985

Massey & Hunter 1998Pehlemann et al. 1992

R136 – SE quadrant (K-band adaptive optics at ESO/3.6m)

Brandl et al. 1996

Reddening map of 30 Doradus calculated with an adaptive algorithm.The circles are centered in R136 with radii of 5", 15", 25", and 40". The reddening scale goes from AV=0 to AV=3.0, calculated assuming RV=3.05. North is up and east to the left; size is 133" or ~30 pc.

Selman et al. 1999

Selman et al. 1999

SFH of the cluster (3 bursts)

Spatial distribution of stars with M> 20 MO

as a function of age: green for youngest,yellow for middle-aged, and red for oldest

stars (approx. 1.5, 2.5, 5 Myr).WR stars are plotted using an asterisk.

Selman et al. 1999

slope x = 1.37 (obs. fit)

HST/WFPC2 F814Wimage of R136(A, B, C, D IMF)

Sirianni et al. 2000

IMF in 2-3 pc annulus in R136

Sirianni et al. 2000

Andersen et al.2007, Ap.J. subm.

slope x = 1.35 (assumed)

IMF simulationwith variable reddening

ESO 2.2m NIR image(NICMOS finding chart)

Andersen et al. 2007,Ap.J. subm.

F160W (H-band)NICMOS imagecentred on R136(1‘ x 1‘ = 15pc x 15pc)

Andersen/HZ et al. 2009, Ap.J.

Andersen et al.2009, ApJ.

annular IMFs(vertical arrow =completeness limit)

Andersen et al.2009, ApJ.

massive eclipsing binaries in R136 Massey et al. 2002

SB2E: 57 MO + 23 MO SB2E: 40 MO + 32 MO

1) definition "starburst" (SFR density or lum. density)

2) 30 Dor: initial conditions? (irrecognisable after MSF)

3) how to form 100 massive stars in such a small volume?

4) R136: truncated IMF? one-shot or multi-episode burst?

5) R136: initial mass segregation and stellar collisions?(likely conditions for progenitor of GRB or even IMBH?)

6) 30 Dor: a model for the origin of globular clusters?

QUESTIONS for discussion:

24μm green 8μm red2 MASS K-band blue

Brandl, Chu, & Townsley(priv. comm.)

H green8μm redChandra 0.5-2 keV blue

Brandl, Chu, & Townsley(priv. comm.)

Fukui et al. 1999 Kim et al. 2003

Maíz-Apellániz et al. 2004

The structure of NGC 604

IRAC #4 (6.5-9.4m) (Brandl et al. 2004) WFPC2 (Hunter et al. 1996)

Poglitsch et al. 1995 (KAO)

Br (grey)

FIR (contours)

The far-infraredspectral energy distributionof the 30 Dor nebula;the curve is a 75 K blackbody fit.

Werner et al. 1978

( based on KAO observations)

High-flying aircraft --above 40,000 ft -- can observe most of the infrared universe

Airborne infrared telescopes can be more versatile -- and much less expensive -- than space infrared telescopes

NASA’s Kuiper Airborne Observatory (KAO) C-141 with a 36-inch telescope onboard, based at NASA-Ames near San Francisco, flew from 1975 - 1996

,

http://www.sofia.usra.edu

Werner et al. 1978Kennicutt 1984Melnick 1985Weigelt and Baier 1985Walborn and Blades 1987Kennicutt and Chu 1988Hyland et al. 1992Pehlemann et al. 1992de Marchi et al. 1993Parker 1993Parker and Germany 1993Chu and Kennicutt 1994Malumuth and Heap 1994Moffat et al. 1994Hunter et al. 1995Poglitsch et al. 1995Brandl etal. 1996Hunter et al. 1996Massey and Hunter 1998Rubio et al. 1998

References

Bosch et al. 1999Fukui et al. 1999Portegies Zwart et al. 1999Selman et al. 1999Zinnecker et al. 1999Grebel and Chu 2000Sirianni et al. 2000Bosch et al. 2001Massey et al. 2002P. Zwart & McMillan 2002Zinnecker et al. 2002Kim et al. 2003Maíz-Apellániz et al. 2004Maercker and Burton 2005Selman and Melnick 2005Koen 2006Townsley et al. 2006Zinnecker 2006Andersen et al. 2007Zinnecker and Yorke 2007

30 Dor expanding shellsand kinematic features

Chu & Kennicutt 1994

30 Doradus, NGC 2070, and R136:

a brief overview of a resolved starburst

Hans Zinnecker (Astrophysikalisches Institut Potsdam)