S cience Case 5: Planning a Deep NIRCam S urvey Building the APT - - PowerPoint PPT Presentation

S cience Case 5: Planning a Deep NIRCam S urvey

Building the APT file

Martha Boyer S TS cI, NIRCam Team

0.0 0.2 0.4 0.6 0.8 1.0 5 10 15 20 25 30 0.5 2.5 4.5 Transmission Fν Wavelength (microns)

Data Required:

“ Deep, multicolor imaging to provide galaxy samples including mid-infrared data to help with accurate mass estimations and increase discovery space” –

• M. Rieke
• ~46 sq. arcmin with NIRCam
• MIRI imaging in parallel
• Deep integrations (~20-40 ksec)
• 4 NIRCam S

W filters, 5 NIRCam LW filters, and 1 MIRI filter

• S

ubpixel dithers and larger dithers to cover detector gaps

S t art a JWS T proposal Proposal Information Page

• Title
• Abstract
• Categories
• Keywords
• PDF proposal file

Tot al proposal t ime displayed here

Creat e a New Fixed Target if your t arget is not in S imbad, NED, et c.

Target: 03 32 42.694, -27 47 59.66

Create a New Fixed Target

Y es

High-redshift galaxies Galaxy

Creat e a New Observat ion Folder

Inside Observation 1

The top half of the Observation 1 window is General Information.

• As you choose Instruments and templates, new options appear.
• Note that when you give this observation a Label, the name also changes

in the sidebar.

• Greyed areas show information about visits & observation time
• Data volume is also displayed

Inside Observation 1

Offsets (dithers, mosaic slews) larger than the ‘ visit splitting distance’ require acquisition of a new guide star, creating additional overheads.

Inside Observation 1

The bottom half of the Observation 1 window is Instrument Setup. The prime instrument is the first tab, followed by the parallel instrument

Image credit: Dan Coe

Image credit: Dan Coe

Primary Dithers for covering detector gaps Three sizes:

– INTRASCA: Obj ects smaller than the individual S

CA detectors

• (<50” or <100” for short or long wavelength observations, respectively)
• Only available for Module B

– INTRAMODULE: Obj ects smaller than the individual module

• (<110” )

– FULL: Large fields without gaps, including mosaics

Image credit: P . Goudfrooij

Coordinated Parallel S ubpixel Dithers

• Different instrument orientations and

plate scales

• Patterns keep pixel phases ‘ ideal’ to

within 0.05 pix for parallel instruments.

– Exception: MIRI at >12 µm (well sampled

anyway)

S hort and Long wavelength channels observed simultaneously.

• S

everal competing factors:

– Longer integrations to reduce overheads – S

horter integrations to reduce cosmic-ray hit effects

– Co-added data to reduce data downlink

Inside Observation 1

Inside Observation 1

Arc Min Arc Min 75 ksec / filter 37.5 ksec / filter

2x2 mosaic, with some overlap to cover the gap between the modules

NIRCam MIRI

S et the position angle restriction

Add a new filter to the observation S W F090W F200W F150W F115W F115W LW F410M F335M F444W F277W F356W F770W for all MIRI observations

This observing strategy exceeds the data limit for a single visit. The limit is 58 GB/visit JWS T will downlink data in 4-hour contacts, occurring twice per day, approximately 12 hours apart. In one contact, JWS T can transmit 28.2 GB of recorded science data. The onboard S

• lid S

tate Recorder can hold at least 58.8 GB. As such, if a contact is missed, science observations can continue without filling the recorder, and the ground can catch up on the next contact. For opt imal schedulabilit y, keep visit s below 28.2 GB dat a volume.

Three ways around the data limit issue for these observations:

• Creat e a ‘ manual’ mosaic, where you define 4 different t arget s at

each t ile posit ion & build each t ile observat ion separat ely.

• Create a mosaic for every filter setup.
• Create a single target, but set up 4 different observations where

each one includes an offset that mimics a mosaic. S ci Case #5

SW Filter LW Filter

• Approx. Depth

F090W F410M 42 ksec F200W F335M 25 ksec F150W F444W 42 ksec F115W F277W 33 ksec F115W F356W 25 ksec

All observat ions image wit h t he F770W filt er in parallel

SW Filter LW Filter

• Approx. Depth

F090W F410M 42 ksec F200W F335M 25 ksec F150W F444W 42 ksec F115W F277W 33 ksec F115W F356W 25 ksec

All observat ions image wit h t he F770W filt er in parallel

Observation Groups /Int Integrat ions /Exp NIRCam Imaging Duration (sec) Groups /Int Integrat ions /Exp MIRI Imaging Duration (sec) Data Volume (MB) DeepTrial410M #1 7 2 24741 248 4 24777 35,672 DeepTrial410M #2 5 2 17010 227 3 17010 25,256 DeepTrial335M ** 7 3 24738 248 6 24780 35,672 DeepTrial444W #1 7 2 24741 248 4 24777 35,672 DeepTrial444W #2 5 2 17010 227 3 17010 25,256 DeepTrial277W ** 7 4 32988 247 8 32904 47,435 DeepTrial356W ** 7 3 24738 248 6 24780 35,672

**These have 2-point subpixel dithers instead of 3-point subpixel dithers

• Duplicate this observation folder 3x to create 4 ‘ mosaic’ tiles.
• S

elect the correct target for each observation folder

• S

et the correct P A range for each observation folder

• Link observations to make sure they’ re observed with the same P

A

• ‘ S

ame P A Link’ under S pecial Requirements Target 1: 03 32 42.694, -27 47 59.66 Target 2: 03 32 44.668, -27 47 3.47 Target 3: 03 32 34.263, -27 47 3.77 Target 4: 03 32 36.528, -27 46 9.54 OR, Target 1 + Offsets:

ΔX ~ 70” ΔY ~ 100”

Run S mart Accounting to reduce overheads Explore various diagnostics:

• Visit Coverage = CVS

file with pointing info

• Polygons, P

As, etc.

• Pointing File = text file demonstrating

exposure sequence and dither steps

• Times File = text file with overheads
• Smart Accounting = text file showing
• verhead improvements