How are the GTO teams implementing their coronagraph programs? is Stark , Marshall Perrin, Laurent Pueyo, Chris Remi Soummer.
How are the GTO teams implementing their coronagraph programs? Laurent Pueyo, Chris is Stark, Marshall Perrin, Remi Soummer.
3 Tools You Will Want for Coronagraphic Observation Planning JWST Exposure Time Calculator (ETC) JWST Coronagraph Visibility Tool (CVT) Astronomer’s Proposal Tool (APT)
3 Tools You Will Want for Coronagraphic Observation Planning Recommended Sequence: 1. JWST Coronagraph Visibility Tool (CVT) 2. JWST Exposure Time Calculator (ETC) 3. Astronomer’s Proposal Tool (APT)
Step 1: JWST Corongraph Visibility Tool (CVT)
Allowable JWST Orientations Solar elongations from 85° – 135°
Creating a PA Visibility Tool Allowable JWST Orientations Rotating about Sun axis forms stripe on ecliptic sphere
Creating a PA Visibility Tool Visibility Depends on Ecliptic Latitude V3 PA varies over the course of a viewing block Continuous Viewing Zone 1 Annual Viewing Block 2 Semi-Annual Viewing Blocks
Allowable JWST Orientations Solar elongations from 85° – 135°, V1 roll angles range from ±3.5° to ±7° ±3.5° ±7°
Example of 1 Annual Viewing Block HD 10647 Wide range of possible PAs Allowed PAs Observable Window Solar Elongation
Example of 2 Semi-annual Viewing Blocks HD 141569 Limited range of PAs, larger roll dither allowed at elongation ~ 135° ~7° ~14°
Step 1: JWST Corongraph Visibility Tool (CVT) Example
Step 2: JWST Exposure Time Calculator (ETC)
Step 2: JWST Exposure Time Calculator (ETC) The ETC not yet a full coronagraph simulator with all bells and whistles... If that is what you want go here: https://github.com/kvangorkom/pandeia-coronagraphy
Step 2: JWST Exposure Time Calculator (ETC) Key questions the ETC addresses for now: Will I be able to see an astrophysical source is my PSF subtraction is “perfect”?E.g. what is the photon noise on the speckles. Will I saturate? These are the two questions that depend on exposure time.
Step 2: JWST Exposure Time Calculator (ETC) Example
Step 3: Astronomer’s Proposal Tool (APT)
Guidelines to Follow: 1. Thou shalt observe your science target at 2 roll angles, differing by at least one degree (a “roll dither”) 2. Thou shalt observe a reference star to measure the PSF (for PSF subtraction by the pipeline) 3. Thou shalt make these a non-interruptible sequence. Figure credit: M. Perrin
Guidelines to Follow: 1. Thou shalt observe your science target at 2 roll angles, differing by at least one degree (a “roll dither”) Mitigates bad pixels in science image Rotates speckles wrt astrophysical scene
Guidelines to Follow: 2. Thou shalt observe a reference star to measure the PSF (for PSF subtraction by the pipeline) • Increases contrast by subtracting reference PSF from science image • Reference PSF star should be uncontaminated • Reference PSF should be close in spectral type (see supporting docs) • Reference PSF should be bright (shorter exposure time) • Reference PSF should be close to the science target (shorter slew time) • NOTE: Reference PSF observations are non-proprietary!
Guidelines to Follow: PSF spectral type selection guidelines: a future JDOX page Currently at http://www.starkspace.com/JWST_PSF_references.pdf Credi: Jarron Leisenring
Guidelines to Follow: 3. Thou shalt make these a non-interruptible sequence. • Reduces PSF changes between science and reference observations; higher contrast • Science target & reference must be simultaneously visible
The Basic Coronagraphic Sequence Figure credit: M. Perrin Non-interruptible Obs ¡# ¡ Target ¡ Roll ¡ Inst ¡ Mask ¡ Filter ¡ 1 ¡ Science ¡ θ 0 2 ¡ Science ¡ θ 0 ¡+ ¡ Δθ 3 ¡ Reference ¡ N/A ¡
A Multi-Filter Coronagraphic Sequence Obs ¡# ¡ Target ¡ Roll ¡ Inst ¡ Mask ¡ Filter ¡ Non-interruptible 1 ¡ Science ¡ NIRCam ¡ 210R ¡ F182M, ¡ θ 0 F210M ¡ 2 ¡ Science ¡ θ 0 ¡+ ¡ Δθ NIRCam ¡ 210R ¡ F182M, ¡ F210M ¡ 3 ¡ Reference ¡ N/A ¡ NIRCam ¡ 210R ¡ F182M, ¡ F210M ¡
A Multi-Instrument Coronagraphic Sequence Obs ¡# ¡ Target ¡ Roll ¡ Inst ¡ Mask ¡ Filter ¡ Non-interruptible 1 ¡ Science ¡ NIRCam ¡ 210R ¡ F182M ¡ θ 0 2 ¡ Science ¡ MIRI ¡ LYOT ¡ F2300C ¡ θ 1 3 ¡ Science ¡ θ 0 ¡+ ¡ Δθ NIRCam ¡ 210R ¡ F182M ¡ 4 ¡ Science ¡ θ 1 ¡+ ¡ Δθ MIRI ¡ LYOT ¡ F2300C ¡ 5 ¡ Reference ¡ N/A ¡ NIRCam ¡ 210R ¡ F182M ¡ 6 ¡ Reference ¡ N/A ¡ MIRI ¡ LYOT ¡ F2300C ¡
A Multi-Epoch Coronagraphic Sequence Non-interruptible Obs ¡# ¡ Target ¡ Roll ¡ Inst ¡ Mask ¡ Filter ¡ 1 ¡ Science ¡ NIRCam ¡ SWB ¡ F210M ¡ θ 0 2 ¡ Science ¡ θ 0 ¡+ ¡ Δθ NIRCam ¡ SWB ¡ F210M ¡ 3 ¡ Reference ¡ N/A ¡ NIRCam ¡ SWB ¡ F210M ¡ 4 ¡ Science ¡ NIRCam ¡ SWB ¡ F210M ¡ Non-interruptible θ 1 5 ¡ Science ¡ θ 1 ¡+ ¡ Δθ NIRCam ¡ SWB ¡ F210M ¡ 6 ¡ Reference ¡ N/A ¡ NIRCam ¡ SWB ¡ F210M ¡
How about performances? Contrast limits due to thermal drifts. Contrast limits due to pointing. Observing efficiency.
Contrast limits due to thermal drifts. McElwain et al., this conference ¡
Contrast limits due to thermal drifts. McElwain et al., this conference ¡
McElwain et al., this Contrast limits due to thermal drifts. conference ¡
Lajoie et al., 2016 ¡ Contrast limits due to pointing.
Lajoie et al., 2016 ¡ Contrast limits due to pointing.
Lajoie et al., 2016 ¡ Contrast limits due to pointing.
Contrast limits due to pointing. Lajoie et al., 2016 ¡
Contrast limits due to pointing. Lajoie et al., 2016 ¡
Contrast limits due to pointing. Lajoie et al., 2016 ¡ Proc. of SPIE Vol. 9143 91433V-5
Step 2: JWST Exposure Time Calculator (ETC) The ETC not yet a full coronagraph simulator with all bells and whistles... If that is what you want go here: https://github.com/kvangorkom/pandeia-coronagraphy
Observing Efficiency: timing
Observing Efficiency: timing
Observing Efficiency: timing
Observing Efficiency: timing
Observing Efficiency: timing
Observing Efficiency: ordering
Takeaways: - JWST Coronagraph planning takes time and attention to detail. Remember to check target visibility before diving in. - Tools have now been released, with GTOs using them to plan observations. Feedback will be included in further versions. - If you are interested in detailed performance simulations we will make our calculations public as we go along. We will not know everything until we get data. - When using APT, remember export .times and .smartaccounting files to optimize efficiency.
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