1. Name: Deep integration on the massive jet source HH80-81: the disk-outflow connection. Authors: D. Shepherd et al. 2. Science Goals: HH 80-81 is a well-collimated jet powered by an intermediate-mass young stellar object with a spectral type later than B1. It is the most massive star known which powers a well-collimated, parsec-scale jet similar to those produced by low-mass young stellar objects. The dynamics of the jet suggest that it is a scaled-up version of a T Tauri star, thus, it should have an accretion disk with a *VERY* powerful wind. Assuming the outflow and central source has been mapped with ALMA and the source powering the outflow jet has been identified, this proposal seeks to map several outflow/disk tracers to get a handle on the disk properties and the outflowing wind as close to the surface of the disk as possible. Obtaining clear evidence for ionized or molecular gas outflow from the disk and providing constraints on where the outflow gas originates will help to determine whether a disk wind or X-wind powers this massive flow. This proposal requires very sensitive observations (to detect faint emission originating from the disk surface) at high resolution to resolve out confusing, extended emission. The disk radius that is relevant should be about 1-100 AU (= 0.5-50 mas at distance of 1.7 kpc). At 450-700 GHz (bands 8 & 9), the array will have a resolution of roughly 8-13 mas - this seems like a reasonable compromise between getting adequate resolution to see the fine-scale structure and not resolving out too much of the disk material. Lines of interest include hydrogen recombination lines (H25a, H21a) to trace ionized outflow, molecular disk tracers (e.g. CH3CN), and molecular outflow tracers (e.g. 12CO, C34S, 13CO, SiO, H13CO+) and even a H2O maser transition. 3. Number of Sources: 1 4. Coordinates: 4.1 Central coordinates: 18 19 12.11 -20 47 30.4 (J2000), (Galactic coordinates: LII= 10.8415 BII= -2.5916) 4.2 Moving target: No 4.3 Time Critical: No 5. Spatial Scales: 5.1 Angular Resolution: 8-13 mas (depending on line) 5.2 Range of spatial scales required: 10-1000 AU = 5-500 mas 5.3 Single dish: No 5.4 ACA: No 5.5 Subarrays: No 6. Frequencies: 6.1 Receiver Bands: 8 & 9 6.2 Band 8 Lines & Frequencies: H25a 396.900857 GHz CO(4-3) 461.040768 GHz CH3CN 25(1)-25(1) 459.698169 GHz SO2 12(2,10)-11(1,11) 463.011403 GHz C34S(10-9) 481.915883 GHz CS(10-9) 489.750952 GHz Band 9 Lines & Frequencies: SO2 8(5,3)-7(4,4) 613.076211 GHz CH3CN 34(4)-33(4) 624.736106 GHz SO2 9(5,5)-8(4,4) 632.193333 GHz CS(13-12) 636.532519 GHz SO 16(15)-15(14) 645.875924 GHz H2O 1(1,0)-1(0,1) v2=1 658.00655 GHz (masing strong in VY CMa) C18O(6-5) 658.553275 GHz 13CO(6-5) 661.067267 GHz H21a 662.404202 GHz CO(6-5) 691.473076 GHz H13CO+(8-7) 693.8766 GHz SiO(16-15 v=0) 694.29416 GHz (representative lines listed here, actual choice may differ). 6.3 Spectral Resolution (km/s): 0.1 to 0.3 km/s (differs with line depending on whether it is an outflow or disk/dense gas tracer). 6.4 Spectral Coverage (km/s or GHz): 20-200 km/s per line 7. Continuum flux density: 7.1 Typical Value: 0.5-10 mJy 7.2 Continuum Peak Value: Unknown. 7.3 Required Continuum RMS: 0.03 mJy (to detect primary driving source of the flow as well as any lower-mass YSOs in the cluster) 7.4 Dynamic Range in Image: > 20 8. Line Intensity: 8.1 Typical value: Unknown at this resolution, this will be a deep survey to see if any are detected. At lower resolution, all lines are strong in star forming regions. We want microJy RMS levels. 8.2 Required RMS per channel: It would be good to get 1 microJy/beam but this is unreasonable. Choose 1 mJy/beam with 0.3 km/s resolution 8.3 Spectral Dynamic Range: > 100 9. Polarization: No 10. Time requested: 10.1 Integration time: For a line with 0.3 km/s resolution: 1 mJy/beam RMS => 37 hrs integration (band 8, 385-500 GHz) 145 hrs integration (band 9, 602-720 GHz) ********************************************************************** Review Munetake Momose: I agree that the deep integration with very high-angular resolution observations toward this source is scientifically interesting, but the present plan is "very" challenging. As stated in this plan, 150- hour integration per line in Band 9 is required to achieve ~1mJy/beam when the beam size is 0.1" and dV=0.3km/s (according to the ALMA sensitivity calculator). This might be too ambitious when one takes into account the difficulties in calibration in this band. It's not clear for me why the velocity resolution of < 1km/s is required in this plan: in the very central regions both the rotation velocity in the disk and the outflow velocity are expected to be large, hence moderate velocity resolution, say 3km/s, seems to be more suitable, which leads us to reduce the required integration time by a factor of 10. Another possibility is to select a more nearby object that has more or less similar nature to HH 80-81. In this plan the author also mentions the observations in band 8, but I believe it is not appropriate at the moment to include this band in which the required integration time cannot be estimated with the ALMA sensitivity calculator. Comment Ewine: Assume that similar science can be done in Band 7. Integration time dominated by Band 9 anyhow.