Title Survey of the central fields in massive molecular outflow with the ALMA interferometer. Pi D. Shepherd Time 200 hrs DRSP 2.0, re-submittal of DRSP 1.1 project 2.2.8 1. Name: Survey of the central fields in massive molecular outflows with the ALMA interferometer. Authors: D. Shepherd et al. 2. Science goal(s) Molecular outflows from massive and intermediate-mass young stars are generally complex and are the result of the combined energetics from several OB stars and lower mass YSOs in a relatively dense cluster. The global properties of massive flow complexes is important for understanding the star formation efficiency in massive star forming regions and being able to relate galactic and extra-galactic star formation regions. In a companion proposal, 20 molecular outflow sources are chosen to obtain lower resolution observations of the molecular outflows and dust emission near embedded stars in the central clusters. This proposal seeks to obtain high angular resolution molecular line and continuum observations on the central fields in the survey to map the outflowing gas back to specific sources and obtain a census of the number of sources in the cluster and the mass, distribution, and kinematics of circumstellar material. Source and circumstellar properties will then be compared to outflow properties to examine trends in circumstellar material versus outflow evolution. Thus, a sensitive survey of outflow and dense molecular gas from intermediate to high-mass YSOs in lines such as 12CO(J=2-1), 13CO(J=2-1), C18O(J=2-1), C17O(2-1), and hydrogen recombination lines (H28-30alpha) (along with several other shock and high-density tracers in bands 6 & 7 (mm to submm) using the ALMA and ACA combined arrays would provide a uniform sample with accurate, high resolution estimates of high velocity gas near protostars, dense gas, and cluster properties. Continuum observations with at least 2GHz of bandwidth will also detect embedded high- and intermediate-mass stars in the cluster that may be contributing to the outflow dynamics. If the continuum emission can be distributed between 230 & 219 GHz will be used to estimate the millimeter SED of the driving source(s). 3. Number of sources 20 massive YSOs 4. Coordinates: 4.1. Rough RA and DEC: 20 sources distributed through out the galactic plane. There will likely be some clustering toward the inner quadrant of the galaxy. 4.2. Moving target: No 4.3. Time critical: No 4.4. Scheduling constraints: None 5. Spatial scales: 5.1. Angular resolution (arcsec): 0.01" to 0.1" (depending on source) 5.2. Range of spatial scales/FOV (arcsec): 0.01" to 5" (depending on source), FOV = 30" single field 5.3. Required pointing accuracy: (arcsec) 1-2" 6. Observational setup 6.1. Single dish total power data: no (we want to resolve out some of the confusing outflow emission) 6.2. Stand-alone ACA: no 6.3. Cross-correlation of 7m ACA and 12m baseline-ALMA antennas: no 6.4. Subarrays of 12m baseline-ALMA antennas: no 7. Frequencies: 7.1. Receiver band: Band 6 & 7 7.2. Lines and Frequencies (GHz): 7.2.1 Band 6 lines: 3 CO isotopes at 230, 220 & 219 GHz plus others (as many lines as possible) 7.2.2 Band 7 lines: Multiple lines at e.g. 294 & 303 GHz 7.3. 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). 7.4. Bandwidth or spectral coverage (km/s or GHz): 20-100 km/s per line 8. Continuum flux density: 8.1. Typical value (Jy): 0.5-10 mJy 8.2. Required continuum rms (Jy or K): 0.03 mJy 8.3. Dynamic range within image: > 20 Some lines will be a mix of weak & bright emission, others will just show weak emission, depends on the line. 8.4. Calibration requirements: absolute ( 1-3% / 5% / 10% / n/a ) 5% repeatability ( 1-3% / 5% / 10% / n/a ) 5% relative ( 1-3% / 5% / 10% / n/a ) 1-3% 9. Line intensity: 9.1. Typical value (K or Jy): > 10 Jy at 12CO line peak 10-100 mJy in high velocity wings few mJy to microJy for RRLs. 9.2. Required rms per channel (K or Jy): 3-4 mJy/beam *** NOTE: decreased required RMS from previous DRSP 1.1 proposal because decreased antennas and new sensitivity calculations show that previous proposal would have required way too much time. 9.3. Spectral dynamic range: > 100 9.4. Calibration requirements: absolute ( 1-3% / 5% / 10% / n/a ) 5% repeatability ( 1-3% / 5% / 10% / n/a ) 1-3% relative ( 1-3% / 5% / 10% / n/a ) 1-3% 10. Polarization: No 10.1. Required Stokes parameters: 10.2. Total polarized flux density (Jy): 10.3. Required polarization rms and/or dynamic range: 10.4. Polarization fidelity: 10.5. Required calibration accuracy: 11. Integration time for each observing mode/receiver setting (hr): 11.1 Integration time per source for the ALMA array: 50 antennas, 30" primary beam, single field For a typical source/line with 0.3 km/s resolution Band 6 230 GHz: ~3 mJy/beam RMS in each field => 1 hr integration x 20 sources = 20 hrs Band 7 300 GHz: 1 hrs (4mJy/bm RMS) x 20 sources = 20 hrs 10.2 ACA observations take about 4 times longer to achieve a similar RMS as the ALMA array. Thus, this project requires Band 6: 1x4 hrs integration x 20 sources = 80 hrs. Band 7: 1x4 hrs x 20 sources = 80 hrs 12. Total integration time for program (hr): * ALMA 12m array = 40 hrs (20 each in Bands 6 & 7) * ACA 7m array = 160 hrs * (no total power requested) 13. Comments on observing strategy : (optional) (e.g. line surveys, Target of Opportunity, Sun, ...): -------------------------------------------------- Review v2.0: 2.2.8 Shepherd Survey of the central fields in massive molecular outflows There should not be an ACA component in this proposal in sections 11 and 12 they are a mistake due to cutting and pasting. There may also be a problem with emission outside the primary beam affecting the map fidelity. Given that this project follows 2.2.7 it may be desired to place a constraint on extended structures in choosing which regions to observe.