***************************************************************************** Outline ALMA Design Reference Science Plan =========================================== EvD, SG, AW, update June 26, 2003 Goal: to provide a prototype suite of high-priority ALMA projects that could be carried out in 3 years of full ALMA operations. This Design Reference Science Plan (DRSP) serves as a quantitative reference for developing the science operations plan, for performing imaging simulations, for software design, and for other applications within the ALMA project. Specifically, it can be used to: - allow cross-checking of the ALMA specifications against "real" experiments - allow a first look at the time distribution for - configurations - frequencies - experimental difficulty (fraction of projects that are pushing ALMA specs) - start developing observing strategies - derive "use-cases" for the Computing IPT - be ready in case some ALMA rescoping is required, or in case some ALMA specifications cannot be met. Disclaimer: This plan, when written, will contain a representative set of high-priority projects to be carried out by ALMA in a number of different research areas, as envisaged by researchers currently active in (sub)millimeter astronomy. However, since the scientific goals will evolve over time, the actual 3 yr observing plan of ALMA by 2012 may be quite different from this ALMA Design Reference Science Plan. The DRSP is therefore a living document, to be reviewed and updated periodically. Although an effort has been made to cover all subjects and to include some of the most challenging projects, it is unlikely to include all types of science that will be possible with ALMA. This plan does NOT form the basis for any definition of ALMA early science observing programs nor any `key', `large' or `legacy-type' programs. This plan does not not apply to "Early Science Operations" when less than 64 antenna's are available and where a different observing strategy is needed (at least up to 32 antenna's). It considers only the baseline ALMA project with Bands 3, 6, 7 and 9, but includes the option to indicate whether the project would benefit from the ACA. The DSRP should include the types of projects mentioned in the "Science examples for calibration" document by Guilloteau et al. How to develop the DRSP ======================= 1. Science themes: take headings from the European science case submitted to ESO council in late 1999. See: http://www.eso.org/projects/alma/science/alma-science.pdf This gives 4 themes and 21 sub-themes; volunteers are needed to lead each subsection; others may help. Some suggestions are given below: Don't feel obliged to follow precisely the science described in the ESO document; it is just a starting point. ============================================================================== Topic Suggested leader Others ------------------------------------------------------------------------------ Theme 1: Galaxies and Cosmology ------------------------------- 1.1 The high-redshift universe Guilloteau* Cox*, Carilli*,Shaver, Isaak 1.2 Gravitational lenses Shaver 1.3 Quasar absorption lines Lucas* 1.4 SZ with ALMA Hasegawa* 1.5 Gas in galactic nuclei Carilli* Hasegawa 1.6 The AGN engine Carilli* Hasegawa 1.7 Galaxies in the local universe Wilson Turner*, Tatematsu,Isaak 1.8 ALMA and the Magellanic Clouds Aalto* Viallefond*,Rubio*,Tatem. Theme 2: Star and planet formation [Leader: Wootten] ------------------------------------ 2.1 Initial conditions of star formation Wootten Bacmann, Pety, Myers*, Mardones* 2.2 Young stellar objects Richer Bachi*,Mart-Pint.*,Gueth*, Wright, di Frances 2.3 Chemistry of star-forming regions van Dish Wootten,Schilke*,Tatem, Wright 2.4 Protoplanetary disks Dutrey Testi,Guilloteau,Mundy*, Saito Theme 3: Stars and their evolution ------------------------------------ 3.1 The Sun Benz 3.2 Mm continuum from stars ? 3.3 Circumstellar envelopes Cernicharo* Lucas* 3.4 Post-AGB sources Cernicharo* Cox* 3.5 Supernovae Tatematsu 3.6 Gamma ray bursts Hasegawa Theme 4: Solar system [Leader: Butler] ----------------------- 4.1 Planetary atmospheres Gurwell* 4.2 Asteroids and comets Butler Bockelee-Morvan* 4.3 Extrasolar planets ? -------------------------------------------------------------------------- * To be confirmed Wilson / Crutcher to contribute to description polarization observations, which are 2. Priorities and available time: the different science (sub)themes need to be prioritized and assigned certain fractions of the total time (3 yr). This task may be most appropriate for the ASAC, together with the project scientists, but as a starting point the following division over the themes is proposed, based on the ALMA Level 1 science drivers and proposal pressure at other telescopes in this wavelength range. Assuming 100% observing efficiency 24 hr/day for 3 yr leads to (numbers can be scaled afterwards for typical "weather/downtime"): Theme 1: Galaxies and Cosmology: 40% = 14.4 months = 10500 hr Theme 2: Star and Planet Formation: 30% = 10.8 months = 7880 hr Theme 3: Stars and their evolution: 20% = 7.2 months = 5250 hr Theme 4: Solar system: 10% = 3.6 months = 2620 hr This should give the leaders of the various subtopics a rough indication of the scope of the programs they should aim for. Some subtopics, e.g. 1.1 and 2.4, will likely require more than 1/7 respectively 1/4 of the available time in those themes. Based on the first draft of the DSRP and "time pressure" to reach primary science goals, the numbers can be re-adjusted in subsequent iterations. 3. Time estimates: one set of sensitivities needs to be used for integration time calculations. Take those that are now on the ESO ALMA Web at: http://www.eso.org/projects/alma/science/bin/sensitivity.html 4. Write observing proposal: for each subtheme, leaders should provide 1. Name of program and authors 2. One short paragraph with science goal(s) 3. Number of sources (e.g., 1 deep field of 4'x4', 50 YSO's, 300 T Tauri stars with disks, ...; do NOT list individual sources or your "pet object", except in special cases like LMC, Cen A, HDFS) 4. Coordinates: 4.1. Rough RA and DEC (e.g., 30 sources in Taurus, 30 in Oph, 20 in Cha, 30 in Lupus) Indicate if there is significant clustering in a particular RA/DEC range (e.g. if objects in one particular RA range take 90% of the time) 4.2. Moving target: yes/no (e.g. comet, planet, ...) 4.3. Time critical: yes/no (e.g. SN, GRB, ...) 5. Spatial scales: 5.1. Angular resolution (arcsec): 5.2. Range of spatial scales/FOV (arcsec): (optional: indicate whether single-field, small mosaic, wide-field mosaic...) 5.3. Single dish total power data: yes/no 5.4. ACA: yes/no 5.5. Subarrays: yes/no 6. Frequencies: 6.1. Receiver band: Band 3, 6, 7, or 9 6.2. Lines and Frequencies (GHz): (approximate; do NOT go into detail of correlator set-up but indicate whether multi-line or single line; apply redshift correction yourself) 6.3. Spectral resolution (km/s): 6.4. Bandwidth or spectral coverage (km/s or GHz): 7. Continuum flux density: 7.1. Typical value (Jy): (take average value of set of objects) 7.2. Required continuum rms (Jy or K): 7.3. Dynamic range within image: (from 7.1 and 7.2, but also indicate whether e.g. weak objects next to bright objects) 8. Line intensity: 8.1. Typical value (K or Jy): (take average value of set of objects) 8.2. Required rms per channel (K or Jy): 8.3. Spectral dynamic range: 9. Polarization: yes/no (optional) 9.1. Required Stokes 9.2. Total polarized flux density (Jy) 9.3. Required polarization rms and/or dynamic range 9.4. Polarization fidelity 10. Integration time: 10.1. Integration time for each observing mode/receiver setting (hr): 10.2. Total integration time for program (hr): 11. Comments on observing strategy (e.g. line surveys, TOT, Sun, ...): (optional) Example from Al Wootten: ======================== 1. Name: Infall toward protostars Authors: A. Wootten, .... 2. Science goal: Detect molecular line absorption against the continuum of a disk surrounding a protostar. The program is based on the detection of formaldehyde at 1.3 mm in IRAS4A by Di Francesco et al. 2001, ApJ 562, 770. Using IRAM, they detected H$_2$CO absorption at 1.3 mm of $T_b = 10$ K against a continuum of 3000 mJy with a velocity resolution of 0.16 km/s. This provides the best evidence for infall, but it is currently only possible for the few brightest sources. To generalize the result and to study the infall velocity field in detail, we would like to do similar experiments on sources with 10 times weaker disks with a velocity resolution of 0.05 km/s. 3. Number of sources: 30 4. Coordinates: 4.1. 10 sources in Oph (RA=16:30, DEC=-24) 10 sources in Perseus (RA=03, DEC=+30) 10 sources distributed over sky (RA=any, DEC=any visible) 4.2. Moving target: no 4.3. Time critical: no 5. Spatial scales: 5.1. Angular resolution: 0.5" 5.2. Range of spatial scales/FOV: 11"x8" 5.3. Single dish: yes 5.4. ACA: yes 5.5. Subarrays: no 6. Frequencies: 6.1. Receiver band: Band 6 6.2. Line: H2CO 3_12 - 2_11 Frequency: 226 GHz 6.3. Spectral resolution (km/s): 0.05 km/s 6.4. Spectral coverage (km/s or GHz): 20 km/s (optional) 7. Continuum flux density: 7.1. Typical value: O.3 Jy 7.2. Continuum peak value: 0.3 Jy 7.3. Required continuum rms: 0.0002 K 7.4. Dynamic range in image: 8. Line intensity: 8.1. Typical value: 0.03 Jy 8.2. Required rms per channel: 0.1 K 8.3. Spectral dynamic range: 20 9. Polarization: no 10. Time requested: 10.1. Integration time per setting: 30 x 10 hrs 10.2. Total integration time for program: 300 hr [Note: since this is a substantial amount of time, may want to reconsider fluxes of typical sources, number of sources, choice of line, etc.]