How are the GTO teams implementing their coronagraph programs? is - - PowerPoint PPT Presentation

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How are the GTO teams implementing their coronagraph programs? is - - PowerPoint PPT Presentation

May 30, 2023 258 likes •938 views

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

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How are the GTO teams implementing their coronagraph programs?

Laurent Pueyo, Chris is Stark, Marshall Perrin, Remi Soummer.

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How are the GTO teams implementing their coronagraph programs?

Laurent Pueyo, Chris

is Stark, Marshall

Perrin, Remi Soummer.

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3 Tools You Will Want for Coronagraphic Observation Planning

JWST Exposure Time Calculator (ETC) JWST Coronagraph Visibility Tool (CVT) Astronomer’s Proposal Tool (APT)

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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)
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Step 1: JWST Corongraph Visibility Tool (CVT)

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Allowable JWST Orientations

Solar elongations from 85° – 135°

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Rotating about Sun axis forms stripe on ecliptic sphere

Creating a PA Visibility Tool

Allowable JWST Orientations

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Visibility Depends on Ecliptic Latitude 2 Semi-Annual Viewing Blocks 1 Annual Viewing Block Continuous Viewing Zone

Creating a PA Visibility Tool

V3 PA varies over the course of a viewing block

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Allowable JWST Orientations

Solar elongations from 85° – 135°, V1 roll angles range from ±3.5° to ±7°

±7° ±3.5°

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Example of 1 Annual Viewing Block

HD 10647 Wide range of possible PAs

Observable Window Solar Elongation Allowed PAs

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Example of 2 Semi-annual Viewing Blocks

HD 141569

~14° ~7°

Limited range of PAs, larger roll dither allowed at elongation ~ 135°

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Step 1: JWST Corongraph Visibility Tool (CVT) Example

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Step 2: JWST Exposure Time Calculator (ETC)

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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

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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.

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Step 2: JWST Exposure Time Calculator (ETC) Example

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Step 3: Astronomer’s Proposal Tool (APT)

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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

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  • 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:

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Guidelines to Follow:

  • 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!
  • 2. Thou shalt observe a reference star to measure the PSF

(for PSF subtraction by the pipeline)

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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

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Guidelines to Follow:

  • Reduces PSF changes between science and reference observations;

higher contrast

  • Science target & reference must be simultaneously visible
  • 3. Thou shalt make these a non-interruptible sequence.
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The Basic Coronagraphic Sequence

Obs ¡# ¡ Target ¡ Roll ¡ Inst ¡ Mask ¡ Filter ¡ 1 ¡ Science ¡ θ0 2 ¡ Science ¡ θ0 ¡+ ¡Δθ 3 ¡ Reference ¡ N/A ¡

Non-interruptible

Figure credit: M. Perrin

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A Multi-Filter Coronagraphic Sequence

Obs ¡# ¡ Target ¡ Roll ¡ Inst ¡ Mask ¡ Filter ¡ 1 ¡ Science ¡ θ0 NIRCam ¡ 210R ¡ F182M, ¡ F210M ¡ 2 ¡ Science ¡ θ0 ¡+ ¡Δθ NIRCam ¡ 210R ¡ F182M, ¡ F210M ¡ 3 ¡ Reference ¡ N/A ¡ NIRCam ¡ 210R ¡ F182M, ¡ F210M ¡

Non-interruptible

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A Multi-Instrument Coronagraphic Sequence

Obs ¡# ¡ Target ¡ Roll ¡ Inst ¡ Mask ¡ Filter ¡ 1 ¡ Science ¡ θ0 NIRCam ¡ 210R ¡ F182M ¡ 2 ¡ Science ¡ θ1 MIRI ¡ LYOT ¡ F2300C ¡ 3 ¡ Science ¡ θ0 ¡+ ¡Δθ NIRCam ¡ 210R ¡ F182M ¡ 4 ¡ Science ¡ θ1 ¡+ ¡Δθ MIRI ¡ LYOT ¡ F2300C ¡ 5 ¡ Reference ¡ N/A ¡ NIRCam ¡ 210R ¡ F182M ¡ 6 ¡ Reference ¡ N/A ¡ MIRI ¡ LYOT ¡ F2300C ¡

Non-interruptible

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A Multi-Epoch Coronagraphic Sequence

Obs ¡# ¡ Target ¡ Roll ¡ Inst ¡ Mask ¡ Filter ¡ 1 ¡ Science ¡ θ0 NIRCam ¡ SWB ¡ F210M ¡ 2 ¡ Science ¡ θ0 ¡+ ¡Δθ NIRCam ¡ SWB ¡ F210M ¡ 3 ¡ Reference ¡ N/A ¡ NIRCam ¡ SWB ¡ F210M ¡ 4 ¡ Science ¡ θ1 NIRCam ¡ SWB ¡ F210M ¡ 5 ¡ Science ¡ θ1 ¡+ ¡Δθ NIRCam ¡ SWB ¡ F210M ¡ 6 ¡ Reference ¡ N/A ¡ NIRCam ¡ SWB ¡ F210M ¡ Non-interruptible Non-interruptible

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How about performances?

Contrast limits due to thermal drifts. Contrast limits due to pointing. Observing efficiency.

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McElwain et al., this conference ¡

Contrast limits due to thermal drifts.

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McElwain et al., this conference ¡

Contrast limits due to thermal drifts.

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McElwain et al., this conference ¡

Contrast limits due to thermal drifts.

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Lajoie et al., 2016 ¡

Contrast limits due to pointing.

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Lajoie et al., 2016 ¡

Contrast limits due to pointing.

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Lajoie et al., 2016 ¡

Contrast limits due to pointing.

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Lajoie et al., 2016 ¡

Contrast limits due to pointing.

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Lajoie et al., 2016 ¡

Contrast limits due to pointing.

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Lajoie et al., 2016 ¡

Contrast limits due to pointing.

  • Proc. of SPIE Vol. 9143 91433V-5
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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

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Observing Efficiency: timing

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Observing Efficiency: timing

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Observing Efficiency: timing

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Observing Efficiency: timing

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Observing Efficiency: timing

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Observing Efficiency: ordering

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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
  • bservations. 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.