1. JWST Science Policy & Science Parallels
Neill Reid (SMO)
ESAC
29 September 2016
Space Telescope Science Institute
JSTAC: April 29, 2014

2. Context JWST was conceived as a “prime-only” observatory
Instrument operations in parallel mode were envisaged as only available for internal calibration measurements
Operating two or more instruments in parallel mode
Supports the goal of maximising JWST’s scientific productivity
Implementation supported by SWG and JSTAC
JWSTMO submitted a proposal to the JWST Project requesting additional resources to implement science parallels
The proposal was accepted by the Project
Additional resources have been provided to support implementation
Science policy decisions have been taken to specify the availability of parallel observations in Cycle 1
ESAC: September

3. definitions
ESAC: September

4. Coordinated parallels
In programs with coordinated parallels, all observations contribute to a single, coherent science program
Fully achieving the science goals outlined in the proposal requires observations with all instruments specified in the proposal
The observing parameters of the coordinated parallels are taken into account in developing the observing schedule
Observations are submitted as a single proposal
APT templates will be developed for JWST
Coordinated parallels are common with HST
In particular, imaging programs routinely combine ACS/WFC3 for multi-wavelength imaging
ESAC: September

5. Examples: Frontier Fields & other deep field surveys
Blank field
WFC3+ACS
Orion imaging survey
(PI: Robberto, Cycle 13)
Cluster
ACS+WFC3
ESAC: September

6. Pure parallels
Pure parallel observations constitute stand-alone science programs that are crafted to take advantage of scheduling opportunities offered by unrelated, independent prime science programs
Pure parallels increases the science return by adding new science
Observing parameters are set based on the scheduling requirements of the prime program; pure parallels do not influence those requirements
Pure parallel programs have been most effective scientifically as coherent programs run by associated science teams
Observations are submitted as a separate, stand-alone program
Standard APT templates for JWST
Parallel programs are matched against suitable prime programs once those programs are fully defined and LRP-ready
ESAC: September

7. Pure parallels on HST
Initially, pure parallel programs were matched against prime programs using a automated scheduling algorithm – almost exclusively imaging
Initially relatively successful, leveraging WFPC2 imaging (eg Medium Deep Survey)
Default ACS parallel program introduced in Cycle 11 to fill out schedule
Diminishing science return relative to prime with completion of prime imaging programs, eg GOODS
Pure parallel programs on hiatus from Cycle 13
Wear and tear coupled with limited science impact
Pure parallels reintroduced post-SM4
Explicit effort made to optimise opportunities
TAC-selected programs matched manually against prime programs (primarily COS, including COS GTO programs) with the PIs working in conjunction with Institute staff
ESAC: September

8. Examples: Medium Deep Survey - WFPC2
The Brightest of Reionising Galaxies – WFC3-IR direct
WFC3 Infrared Spectroscopic Parallel Survey – WFC3-IR grism
ESAC: September

9. Implementation & Policies
ESAC: September

10. APT Coordinated Parallel GUI
Coordinated parallel observations will be specified via observing templates in APT
Templates optimise the observing scheme (dithers, filter changes, etc) for both instruments

11. Pure Parallel Observations
Pure parallel observations are matched against observations from multiple approved programs (i.e. post-TAC)
Pure parallels may not affect the observing scheme of the prime observation
SWG: July

12. Implementation Status
As of September :
All two-instrument pure-parallel combinations will be available for Cycle 1
Instrument combinations for coordinated parallels have been prioritised by STScI, working in conjunction with the SWG. Top 5 priorities are:
NIRCam Imaging + MIRI Imaging (*)
NIRCam Imaging + NIRISS WFSS (*)
MIRI Imaging + NIRISS WFSS (*)
NIRSpec MOS + NIRCam Imaging (TBD)
NIRCam Imaging + NIRISS Imaging (*)
Coordinated parallel templates for at least 4 combinations (*) will be available by the start of the APT GTO proposal preparations for Cycle 1.
The remaining coordinated parallel templates (incl. 3-instrument coordinated parallels) will be implemented prior to launch and will be available in Cycle 2.
ESAC: September

13. Policies
All parallel observations are limited to two instrument combinations in Cycle 1
Coordinated parallels will be available to GO and GTO proposers from Cycle 1
Instrument combinations will be limited to those specified in the Calls for Proposals for each cycle
GTO and GO (including DD-ERS) proposers will have access to the same options in each cycle
The science case for GO coordinated parallels will be assessed by the TAC
The science case for GTO coordinated parallels will be assessed by an review panel reporting to NASA HQ and the STScI Director
Coordinated parallels will carry the same exclusive access period as the prime observations
GO Pure Parallel programs will be available in Cycle 1
All instrument combinations will be available unless specifically excluded in the Cycle 1 GO Call for Proposals
Pure parallel observations may not interfere with prime observations
Some prime observations (e.g. exoplanet transit, coronagraphy) may not be available for pure parallel programs
All pure parallel observations will have zero exclusive access period (ie non-proprietary datasets)
ESAC: September

14. Summary
Science parallels will be implemented for a limited subset of instrument combinations for both GO and GTO programs in JWST Cycle 1
Coordinated parallel programs will be reviewed and assessed by the TAC (GO programs) or an independent review committee (GTO programs)
Pure parallel programs are available as GO programs and the data will have no proprietary period
ESAC: September