************************************************************************* Outline ALMA Design Reference Science Plan =========================================== EvD, SG, AW, update July 5, 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 ======================= DEADLINE FOR FIRST DRAFTS AUGUST 15, 2003 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. Each sub-theme has a leader who can enlist the help of other scientists in the community (preferably ESAC/ANASAG) for help. Several names have been listed; the sub-theme leader should contact them. Those with * have not yet been confirmed or been contacted. Keep the number of people involved relatively small to speed up the process and convergence. The sub-theme leaders provide input to the overall theme leader, who makes an initial coordination and balance of the programs in his/her theme, especially in cases of large "oversubscriptions". (Sub-)leaders should not feel obliged to follow precisely the science described in the ESO document; it is just a starting point. ============================================================================== Topic Leader Others ------------------------------------------------------------------------------ Theme 1: Galaxies and Cosmology [Leader: Guilloteau] ------------------------------- 1.1 The high-redshift universe Guilloteau Cox, Carilli,Shaver, Isaak, Blain 1.2 Gravitational lenses Shaver Wiklind 1.3 Quasar absorption lines Wiklind Combes,Lucas 1.4 SZ with ALMA Hasegawa 1.5 Gas in galactic nuclei Carilli Hasegawa, Schinnerer 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. 1.9 Gamma ray bursts Hasegawa Frail? 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 Tafalla,Mart-Pint.*,Gueth, Wright, di Francesco 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 [Leader: Cox] ------------------------------------ 3.1 The Sun Benz 3.2 Mm continuum from stars Menten Guedel,Olsten 3.3 Circumstellar envelopes Cernicharo Lucas 3.4 Post-AGB sources Cernicharo Cox 3.5 Supernovae Tatematsu Rupen Theme 4: Solar system [Leader: Butler] ----------------------- (to be re-organzed by Bryan) 4.1 Planetary atmospheres Gurwell* Lellouch* 4.2 Asteroids and comets Butler Bockelee-Morvan* 4.3 Extrasolar planets Menten -------------------------------------------------------------------------- * To be contacted/confirmed Wilson / Crutcher* to contribute to description polarization observations, which are part of the various sub-themes. 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 is most appropriate for the ASAC together with the project scientists. 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 will likely be scaled down afterwards for typical "weather/downtime" of 20%): 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 sub-themes 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 by the ASAC/PS. 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 which are based on ALMA memo 393. 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; for multi-line observations in a single band requiring different frequency settings, indicate e.g. "3 frequency settings in Band 7" without specifying each frequency (or give dummies: 340., 350., 360. GHz). For projects of high-z sources with a range of redshifts, specify e.g. "6 frequency settings in Band 3". 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) (optional: provide range of fluxes for 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) (optional: provide range of values for 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 for each observing mode/receiver setting (hr): 11. Total integration time for program (hr): 12. Comments on observing strategy (e.g. line surveys, Target of Opportunity, 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 30 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 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. Integration time per setting: 30 x 10 hrs 11. Total integration time for program: 300 hr Note 1: since this is a substantial amount of time, may want to reconsider fluxes of typical sources, number of sources, choice of line, linewidth, etc. Note 2: for projects having more than one frequency setting, items 6-10 need to be repeated for each setting. For multi-line/chemistry surveys, these can be grouped per band, by simply stating "5 frequency settings in Band 6" etc. ***************************************************************************** Copy of some Science IPT e-mail exchange; for your information ------------------------------------------------------------- June 29, 2003 Dear Science IPT members, Thanks to many of you for your detailed comments on the DRSP. Below are responses to the points raised in the e-mail discussions. Please remember that it is essential to keep this exercise as SIMPLE as possible initially; we can always add further complications and options after we have established the basic structure. We are excited to get this DSRP "on the road" as soon as possible, and urge the leaders of the various (sub)sections to get to work. The time schedule is: ~Aug 10: Deadline to be set by theme leaders to receive input from subthemes for initial coordination Aug 15: Deadline for proposals from (sub)themes Sep 1: First analysis by Project Scientists complete Sep 5-6: Presentation to ASAC Sep 22: Semi-final document sent to all contributors for review Oct. 1: Comments due Oct 15: Delivery of document to project Note that we have to strictly adhere to this time schedule because of the timing of the ASAC meeting and because several other IPTs need the DRSP input urgently. Be prepared to give progress reports at the next Science IPT telecons.... Looking forward to your input by August 15 (or preferably earlier!), Ewine, Al and Stephane ************************************************************************** Comments and recommendations on issues raised in e-mails: ======================================================== 1. Form/Lay-out: an offical cover sheet/proposal form is premature at this stage and not needed for our current purposes. A simple Latex template will be circulated in July for everyone's use. For the moment, please proceed in simple ascii following the outline given below. 2. Parameters: several people have suggested to have primary parameters (to be provided by the proposers) and secondary or tertiary parameters (which can be derived afterwards). This is a O.K. in principle, but in practice it turns out that some secondary parameters (in particular integration time, see below) are best provided by the proposer. Some secondary parameters have been included as "optional" in the template. The DSRP experience will help to provide input to the SSR/computing IPT which parameters are best taken as primary in the ObservingTool. 3. Time estimates: please use the ESO time calculator for all time estimates, which is based on ALMA memo 393. Since the actual receiver and antenna performance will not be known until the first antenna's are installed on the Chajnantor site, this "simple-minded" estimate is more than adequate at this stage. It is more relevant for this exercise that we all use the SAME time estimator. The times should be calculated by the "proposers" themselves, NOT afterwards from the rms. As noted by Stephane and Jerome, only those people intimately involved in the science can make the necessary trade-off between sensitivity, number of targets and time. Experience with previous "DRM" or "guaranteed time" programs on space missions has shown the same: use integration time rather than rms or S/N to define the scope of your program; otherwise, it would require too much "back and forth" interaction between the project and the proposers. The project can always re-check or re-calculate integration times afterwards if there are major changes in receiver specifications etc. 4. Stringency: this parameter does not need to be provided by the proposer but can be evaluated afterwards. It is therefore left out for now. It would be great if Mark can make a tool by September. 5. Coordinates: precise RA and DEC of individual targets are NOT needed at this stage. Rough indications are sufficient. For example: program wants to observe 50 YSO's: 10 in Taurus (+04, +25), 10 in Perseus (+03, +30), 10 in Oph (+16:30, -24), etc. 6. Polarization: most people seem to favor polarization integrated with the different science topics rather than as a separate topic. Accordingly, no separate subtopic on polarization has been added, but Christine Wilson and Dick Crutcher will be asked to provide input and/or review polarization projects. 7. People involved: leaders are free to invite people from the community to participate in the DSRP. Several volunteers have been suggested and listed. This would be a great way to get some people from the community involved in ALMA. On the other hand, in the interest of making rapid progress and converging on a coherent DSRP, it may be best to keep the "teams" relatively small, at most 4-5 people per subtopic. Leaders should take a broad view and make sure that their team focusses on the main science drivers for ALMA, not on `pet-projects' of individuals. 8. Science case: keep as short as possible. One paragraph should be enough! 9. Disclaimer: a note has been added that this DSRP does in NO WAY form the basis for any `claims' on targets or programs for early science observing or for any `key'/`legacy-type' programs (if ALMA would decide to have such programs). 10. Time "allocation": a rough starting division of time over the different subjects is proposed, based on the ALMA Level 1 science drivers and proposal pressure at other telescopes in this wavelength range.