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Program Selection & Time Allocation on Large Radio Astronomical Telescopes Tim Bastian Observatory Science Operations National Radio Astronomy Observatory
Who we are • Founded in 1956 • Managed by Associated Universities, Inc. • Currently 620 employees • Four locations: • Charlottesville, VA • Green Bank, WV • Socorro, NM • Santiago, CL NSF Large Facilities Workshop
What we do • The National Radio Astronomy Observatory enables forefront research into the Universe at radio wavelengths. • In partnership with the scientific community, we: • provide world leading telescopes, instrumentation and expertise • train the next generation of scientists and engineers • promote astronomy to foster a more scientifically literate society NSF Large Facilities Workshop
Green Bank Telescope • Largest & most sensitive steerable single dish in the world (100 m) • Unblocked aperture for superbly clean optical path Use of an edge-on WD/pulsar binary (PSR J1614-2230) to measure of the mass of the WD and pulsar using the Shapiro delay of the ms pulsar (Demorest et al 2010).
Expanded Very Large Array • 27 x 25m diameter radio telescopes • Interferometric baselines to 35 km • Arcsec imaging • Major upgrade enhances sensitivity by >10 and greatly expands spectroscopic capabilities Recent example of an image of a radio galaxy (Her A) obtained by the EVLA (Cotton et al 2011).
Very Long Baseline Array Ten 25m diameter radio telescopes Interferometric baselines to 8,600 km Highest resolution imaging telescope; sub-milliarcsecond resolution Highest precision astrometric telescope: 10 μsec precision now! Key Science Project emphasis
Atacama Large Mm/submm Array • A global partnership to deliver a transformational millimeter/submillimeter interferometer • North America (US, Canada, Taiwan) • Europe (ESO) • East Asia (Japan,Taiwan) • 5000m (16,500 Ft) site in Chilean Atacama desert • Main Array: 50 x 12m antennas • + Total Power Array 4 x 12m • + Atacama Compact Array (ACA): smaller array of 12 x 7m antennas • Call for early science: proposals due June 30 NSF Large Facilities Workshop
Challenge • How does the Observatory meet its mission to enable the best science by the astronomical community on NRAO telescopes? • For example, this semester: • EVLA: 2880 hrs • GBT: 3600 hrs • VLBA: 1040 hrs This resource, time on the most powerful telescopes of their kind, must be allocated using a process that the community has confidence in; that is transparent, fair, and nimble enough to respond to changing scientific developments. NSF Large Facilities Workshop
Until Recently • Proposals submitted for each telescope separately on a trimester basis (VLA configuration cycle). • Each proposal was reviewed anonymously by ~5 referees • The results were collated and reviewed by a Proposal Selection Committee, one for the VLA/VLBA, one for the GBT • Dispositions were sent to the proposers • Appeals were handled through the Director NSF Large Facilities Workshop
Motivation for Reform • To provide the wider scientific community with greater ownership of, and responsibility for, the science addressed by NRAO facilities. • To decouple the proposal cycle from operational considerations (e.g., the EVLA configuration cycle) in order to encourage users to be solely motivated by science imperatives. • To bring the proposal cycle into better alignment with other ground based facilities and space missions. • To enhance the simplicity, transparency, and accountability of the proposal handling and time allocation process. NSF Large Facilities Workshop
Background • “Selecting and Scheduling Observing Proposals at NRAO Telescopes” (Hogg 2006, in Organizations and Strategies in Astronomy, ASSL 343, Springer) • The evolution of the NRAO toward a panel-based proposal review and time allocation system on a semester cycle can be traced through recommendations by the Users Committee starting in 2006. • These were consolidated in a framework document in Jan 2009. • 2009 UC Report: “The UC recommends a transition from the current individual referee reports to panel reviews by telecon, with the final TAC being a smaller face-to-face meeting.” NSF Large Facilities Workshop
Proposal Evaluation & Time Allocation(effective 1 Feb 2011) The key changes are: • Two calls for proposals a year rather than three • - From Feb 1, Jun 1, & Oct 1 • - To Feb 1 & Aug 1 • A unification of • - Proposal submission • - Proposal evaluation • - Time allocation • Associated policy changes NSF Large Facilities Workshop
Proposal Submission • Single web portal and helpdesk for all NRAO telescopes: GBT, EVLA, VLBA, ALMA (goal) • Consolidation of documentation and tools for proposal submission (underway) • PST will support one proposal for use of one or more of GBT, EVLA, and VLBA • ALMA proposal submission requires the use of the ALMA OT (for the foreseeable future) NSF Large Facilities Workshop
Proposal Types • Regular proposals: proposals that request <200 hrs total observing time on the GBT, EVLA, and/or VLBA/HSA. • Large proposals: proposals that request >200 hrs total observing on the GBT, EVLA, and/or VLBA/HSA. • Triggered proposals: proposals for pre-planned observations of transients whose event times are unknown a priori; well-defined triggering criteria are required. • All three types of proposal may request time on more than one NRAO telescope and/or an NRAO telescope with an external telescope or mission. These are referred to as joint proposals. NSF Large Facilities Workshop
Proposal Types • One other type of proposal (really two) is available and may be submitted at any time: • Director’s Discretionary Time: proposals for • - Targets of Opportunity or • - Exploratory Time for high risk/high yield projects. • It is anticipated that up to 5% of the observing time available on each telescope will be reserved for DDT proposals. NSF Large Facilities Workshop
Proposal Evaluation • Proposal review is panel-based • Members are all external to the Observatory and bring broad expertise to bear on program evaluation • There are 8 Science Review Panels (SRPs) corresponding to 8 science categories • Each SRP comprises a Chair and 5 members. • Each SRP member independently reviews proposals that fall within the SRP purview based on their science merit • The Chair does not review proposals except for those on which a panel member is conflicted • PI/co-I and institutional conflicts are captured automatically; all others are self-declared • SRP then meets via telecon to discuss and produce final ranking of proposals based on scientific merit M27 (Dumbbell nebula) NSF Large Facilities Workshop
Science Categories • SSP – Solar system, stars, planetary systems: Sun, planets, comets, IPM; exoplanets; main sequence stars; active stars; stellar winds; AGB & post-AGB stars; Pne • ETP – Energetic transients and pulsars: X-ray binaries, cataclysmic variables, novae, supernovae, gamma-ray bursts, pulsars • SFM – Star formation: young stellar objects; protostars; jets, outflows; T Tauri stars; circumstellar disks; protoplanetary systems; astrochemistry • ISM – Interstellar medium: galactic HI & OH; ISM magnetic field; SNRs; HII regions; astrochemistry • NGA – Normal galaxies, groups, and clusters: disk emission; star formation; magnetic fields; galactic winds; starbursts; ULIRGS; intracluster emission • EGS – Extragalactic structure: galaxy structure; galaxy kinematics; chemistry and dynamics; gas in galaxies • AGN – Active galactic nuclei: Seyferts; low-luminosity AGN; H2O megamasers; CSOs; radio galaxies; blazars; quasars; environmental interactions • HIZ – High redshift and source surveys: High-Z objects; extragalactic source surveys; galaxy formation; gravitational lenses; CMB; early universe NGC 1365 NSF Large Facilities Workshop
Time Allocation • Each SRP Chair is also a member of the Time Allocation Committee (TAC) • The TAC meets f2f twice a year to: • Merge the SRP rankings • Discuss and rank large proposals • Assess input from technical reviews • Recommend time allocations for the GBT, EVLA, and VLBA • Assign scheduling priorities (A, B, C, and reject) • Nominate outstanding programs for KSP designation • The NRAO Director, OSO Head, SAA Head, and site Directors meet to review and approve TAC recommendations and to select Key Science Projects as appropriate. NSF Large Facilities Workshop Rho Ophiuchi
Data Policy • Regular and triggered proposals: 12 months • Large proposals: up to 12 months, proposers encouraged to release data sooner • DDT proposals: case by case assessment*, but no more than 6 months * Including waiving the proprietary entirely NSF Large Facilities Workshop NGC 4911
Non-disclosure/Conflicts of Interest • Policy must apply to those privy to confidential information, data, and ideas: • Members of SRPs • Members of the TAC • NRAO staff involved in proposal handling, TAC support, scheduling • NRAO personnel involved in Director's Review of TAC recommendations • Policy must be compliant with AUI and NSF policy on scientific misconduct Arp 188 NSF Large Facilities Workshop
Summary • The NRAO has moved to a semester based cycle for proposal submission • A panel-based proposal review system has been adopted that retains the attractive features of independent review • The TAC meets face to face to make recommendations regarding scheduling priorities and time allocations • The TAC also considers large proposals • Recommends KSP to Director • Director’s Review of TAC recommendation concludes the process NSF Large Facilities Workshop
Thanks! NSF Large Facilities Workshop
NRAO in the Coming Decade Transformative science opportunities with ALMA, EVLA, GBT, VLBA Unified user support for all astronomers NRAO facilities complementary to NOAO, Gemini, JWST, LSST, GSMT,… Planning for the futurewith the community Astro2010 Decadal Survey recommendations Frequency Agile Solar Radiotelescope North American Nanohertz Observatory for Gravitational Waves Precision Array to Probe the Epoch of Reionization R+D for next-generation facilities
Key Science Projects • An NRAO Key Science Project designation is intended to identify those projects that are timely, fundamental, and will have a significant science impact on the wider astronomy and astrophysics communities. • NRAO offers KSP observation planning support, provides data quality assurance, and post-observing consultation and support to assist in the timely reduction, analysis, and dissemination of data. • The NRAO will work with Key Science Project teams to support non-standard observing modes and calibration techniques as needed. • Possible additional support through student/visitor programs NSF Large Facilities Workshop
Key Science Projects • KSP are currently nominated by the TACs and approved by the Director’s Review. • A modified selection process will be implemented with the new proposal handling process: • Proposal submission includes request for consideration as KSP • Proposal specifies resources required • KSP recommendation made by TAC and approved by DR • Per PASEO recommendation NRAO will move toward Legacy Programs NSF Large Facilities Workshop