Searching for disks around high-mass (proto)stars with ALMA R. Cesaroni, H. Zinnecker, M.T. Beltrán, S. Etoka, D. Galli, C. Hummel, N. Kumar, L. Moscadelli, T. Preibisch, T. Ratzka, Á. Sánchez-Monge, T. Stanke, F. Van der Tak, S. Vig, C.M. Walmsley, K.-S. Wang Cycle 0 proposal after meeting at ESO in 2011

Immediate Goal (Cycle 0) Increase the number of bona-fide circumstellar (Keplerian?) disks around B-type (proto)stars Demonstrate that B-type stars form through disk accretion Assess disk structure and rotation curve  M star Long-term Goal (Cycle 2…) Search for circumstellar rotating disks around O-type (proto)stars

Targets G N and G : Closeby: 2.2 kpc and 3.4 kpc Luminosities (~10 4 L O )  B-type Free-free emission (VLA)  thermal jets/H II regions Bipolar nebulosities, green “fuzzies”, broad SiO wings  bipolar outflows/jets  disks??? Prominent CH 3 CN emission (single dish)  hot molecular cores

Observations Band 7: 350 GHz Most extended Cycle 0 array configuration Resolutions: 0.4 arcsec and 0.4 km/s Primary beam: 18 arcsec Maximum structure: 2 arcsec Correlator setup: CH 3 CN(19-18), CH 3 OH(7-6), SiO(8-7), C 34 S(7-6), C 17 O(3-2), H 13 CO + (3-2), and many others

Results Rich spectra with many hot-core tracers (CH 3 CN) “Filaments” across hour-glass nebulosities Molecular cores with velocity gradients roughly perpendicular to bipolar nebulosities PV patterns typical of (sub)Keplerian rotation Problems: –“extended” tracers (C 34 S, C 17 O, H 13 CO + ) resolved out by ALMA –SiO line partly blended and difficult to interpret

CH 3 CN CH 3 OH v t =1 CH 3 OH

CH 3 CN CH 3 OH CH 3 OH v t =1

Results Rich spectra with many hot-core tracers (CH 3 CN) “Filaments” across hour-glass nebulosities Molecular cores with velocity gradients roughly perpendicular to bipolar nebulosities PV patterns typical of (sub)Keplerian rotation Problems: –“extended” tracers (C 34 S, C 17 O, H 13 CO + ) resolved out by ALMA –SiO line partly blended and difficult to interpret

IRAC 4.5 µm Hi-RES image Filament or edge-on sheet? Mass of “filament” ~80 M O ≥ 5 cores along “filament” 0.05 pc

IRAC 4.5 µm Hi-RES image ≥ 4 cores along filament Prominent core (~4 M O ) at center of bipolar nebula 0.05 pc

Results Rich spectra with many hot-core tracers (CH 3 CN) “Filaments” across hour-glass nebulosities Molecular cores with velocity gradients roughly perpendicular to bipolar nebulosities PV patterns typical of (sub)Keplerian rotation Problems: –“extended” tracers (C 34 S, C 17 O, H 13 CO + ) resolved out by ALMA –SiO line partly blended and difficult to interpret

CH 3 CN line and 3.6 cm continuum (Gibb et al. 2003) overlayed on CH 3 CN velocity map Velocity gradients roughly perpendicular to bipolar nebula 1000 au

Intensity and velocity maps in different molecules Velocity gradient roughly perpendicular to bipolar nebula

Results Rich spectra with many hot-core tracers (CH 3 CN) “Filaments” across hour-glass nebulosities Molecular cores with velocity gradients roughly perpendicular to bipolar nebulosities PV patterns typical of (sub)Keplerian rotation Problems: –“extended” tracers (C 34 S, C 17 O, H 13 CO + ) resolved out by ALMA –SiO line partly blended and difficult to interpret

G N core B Position-velocity plots along velocity gradient White pattern: Keplerian rotation about 18 M O

G main core Position-velocity plots along velocity gradient White pattern: Keplerian rotation about about 6 M O

Results Rich spectra with many hot-core tracers (CH 3 CN) “Filaments” across hour-glass nebulosities Molecular cores with velocity gradients roughly perpendicular to bipolar nebulosities PV patterns typical of (sub)Keplerian rotation Problems: –“extended” tracers (C 34 S, C 17 O, H 13 CO + ) resolved out by ALMA –SiO line partly blended and difficult to interpret

G N: Core B Sánchez-Monge et al. (subm. to A&A)

Core A compact Core B resolved M gas (A) = 4.4 M O M gas (B) = 2.8 M O T gas ~ 100 K A B 1000 au Image: CH 3 CN K=2 Contours.: continuum

CH 3 CNCH 3 CN, CH 3 OH, HC 3 N Keplerian disk 500 au Dots: peaks from 2D Gaussian fit to CH 3 CN K=2 line emission in each channel (i.e. velocity) Curves: 50% contour levels of CH 3 CN K=2 emission in each channel

Best fit to velocity pattern with Keplerian disk:  M star = 18 M O  angle disk-l.o.s. = 19°  disk P.A. = 157°  star position very close to continuum peak  systemic velocity: V LSR (star) = 30.0 km/s Peaks distribution  R disk = 2500 au 350 GHz continuum  M disk = 3 M O < M star  consistent with Keplerian rotation

Line emission skewed to NE  flared disk? M star = 18 M O  L star ≥ L bol = L O  binary system needed  precessing outflow? SW NE

Luminosity of binary system with M p +M s =18 M O L bol (G35.20)

Conclusions Hot, dense cores detected at geometrical center of bipolar nebulae Velocity gradients in cores, roughly perpendicular to axes of bipolar nebulae PV plots suggestive of (sub)Keplerian rotation Possible circumbinary Keplerian disk detected in G N

Future ALMA projects? G35.20 & G35.03: Unresolved cores with <0.4” resol. SiO jets at 3mm (less blending) 1”-2” resol.  direction of jets close to cores “filaments” in C 17 O, CS, etc. with >2” beam  velocity field of gas  filaments or rotating edge-on sheets? Disks around O-type stars: E.g. 13 CH 3 CN in HMCs with <0.1” resolution

Core B lies at center of bipolar structure A B

CH 3 CN line and 3.6 cm continuum (free-free) emission maps over IRAC 4.5 micron image Both A and B contain free- free sources B lies at center of possible N- S thermal jet A B

CH 3 CN line map over IRAC 4.5 µm image enhanced with HIRES Stars are free-free continuum sources Core at center of bipolar structure is prominent in CH 3 CN and associated with free-free source

50% level contours of CH 3 CN emission in different velocity channels. The solid circles are the peaks of the emission in different channels, obtained with 2-D Gaussian fits. Colours correspond to velocities. Extreme red- and blue- shifted peaks converge towards same position, as expected for (sub)Keplerian rotation