TIPS/JIM
September 15, 2011
Agenda:
INS Division News (Danny Lennon)
JWST Update (Massimo Stiavelli)!
Introducing JWSTʼs NIRISS: The Near Infrared Imager and Slitless
Spectrograph (Alex Fullerton)!
Updated Results from the COS Spectroscopic Sensitivity Monitoring
(Rachel Osten)!
Flux Dependent Non-Linearity in NIR Detectors: The Evil Twin of
Persistence (Mike Regan)!
!
Next TIPS/JIM: October 20, 2011
INS News Staffing:
John Debes (ESA/AURA) has joined the COS/STIS team.
Miscellaneous:
The INS picnic will be held on Saturday, October 15th at Oregon Ridge Park
HST:
Instrument teams are in the process of seeking MO approval for C19 calibration proposals.
...and in reviewing C19 proposals. Planning windows are out.
SSR1 anomaly - corrected - no data lost!
JWST:
Webinar set for Sep 21st at 2pm. Access for STScI staff available in the auditorium.
..see Massimo's talk.
TIPS/JIM
September 15, 2011
Agenda:
INS Division News (Danny Lennon)
JWST Update (Massimo Stiavelli)!
Introducing JWSTʼs NIRISS: The Near Infrared Imager and Slitless
Spectrograph (Alex Fullerton)!
Updated Results from the COS Spectroscopic Sensitivity Monitoring
(Rachel Osten)!
Flux Dependent Non-Linearity in NIR Detectors: The Evil Twin of
Persistence (Mike Regan)!
!
Next TIPS/JIM: October 20, 2011
JWST Status!
Massimo Stiavelli, !
September 15th,
2011!
Space Telescope Science Institute
Agenda!
!
n
n
n
n
TFI à NIRISS see Alexʼ presentation!
STScI Progress!
Funding!
SWG at STScI!
!
!
Progress at STScI!
!
n
On-board Script System !
u
n
Proposal Planning System (see slides)!
u
u
u
n
u
Birth of NIRISS!
MIRI cryovac completed!
Telescope Team!
u
!
!
WEx passed internal acceptance test!
Web Instrument Team!
u
n
Completed support for APT Guide Star use cases!
Completed support for mosaics MSA dithers !
Completed FOV tool!
WFS&C!
u
n
Successfully completed MIRI Roadshow test. Javascript flawless!!
WebbPSF available!
Visualizing Candidate Guide Stars in
APT!
Candidate Guide Star
Sets
--------------------------------
Each Green Circle is a
candidate Guide Star Set. Click on them to see
candidate guide stars
9/19/11
+ V3
4
Visualizing Candidate Guide Stars in
APT Adjusting Orient!
Candidate Guide Star
Sets
--------------------------------
Each Green Circle is a
candidate Guide Star Set. Click on them to see
candidate guide stars
9/19/11
+ V3
5
Adding a 3x3 Mosaic!
+ V3
9/19/11
6
Adjusting a 3x3 Mosaic!
+ V3
9/19/11
7
Visualizing the adjusting a 3x3 Mosaic!
+ V3
9/19/11
8
Visit Scheduling System FOV Tool!
Request Phase for
Guide Stars – Shown
here
-----------------------------
This phase identifies
candidate guide stars.
White outline is the SIAF
definition.
Blue outline is the usable
region of guider
accounting for pointing
uncertainty after slew.
Yellow dots are candidate
guide stars.
Blue dots are bad regions
in the guider.
Select Phase for Guide
Stars- Not shown here -------------------------------
After a visit is on a short
term scheduled, we know
the time and V3PA angle.
We then select the guide
stars and reference stars
9/19/11
for OSS. + V3
Projection of Celestial North Vector Projection of Sun Vector + V2
Target & 4-point Dither
Can click on
target, dithers,
guide stars, etc.,
for more info 9
Funding!
n
Still not determined. US Senate CSJ subcommittee funds JWST
at the funding level needed for the 2018 launch date.!
u
Assuming this is preserved in the final vote, the final budget will need to be
decided at the House-Senate conference.!
n
Several expressions of support. Most recently 1400 European
Astronomers sent a letter to the head of the OSTP, Holdren.
Professional societies with membership exceeding 85,000 have
also expressed support. !
n
A lot of misinformation (or disinformation) on the web. To help
solve this there will be a webinar on Wednesday 21th at 2pm.
Speakers: Matt M., Rick Howard and Eric Smith (HQ), John
Mather, Julianne Dalcanton and Roberto Abraham.!
!
SWG at STScI!
n
n
!
!
!
There will be a SWG Meeting at STScI on Sept 20th and 21st.!
Agenda still being prepared.!
TIPS/JIM
September 15, 2011
Agenda:
INS Division News (Danny Lennon)
JWST Update (Massimo Stiavelli)!
Introducing JWSTʼs NIRISS: The Near Infrared Imager and Slitless
Spectrograph (Alex Fullerton)!
Updated Results from the COS Spectroscopic Sensitivity Monitoring
(Rachel Osten)!
Flux Dependent Non-Linearity in NIR Detectors: The Evil Twin of
Persistence (Mike Regan)!
!
Next TIPS/JIM: October 20, 2011
Introducing JWST’s NIRISS:
The Near InfraRed Imager & Slitless Spectrograph
Alex Fullerton
STScI / HIA
TIPS/JIM
2011 September 15
The Tunable Filter Imager (TFI)
TIPS / JIM
Presenter
Title
2004 May 20
Nelan
JWST FGS SRR (April 7, 2004)
2005 March 17 Fullerton
Overview of Calibration Activities for the JWST
FGS-TFI
2005 May 19
Fullerton
FGS Tunable Filter Imager: Updates from PDR
2006 June 15
Fullerton
“Phase C” Design of the JWST/FGS Tunable Filter
Imager
2008 Sept. 18
Fullerton
The Tunable Filter Imager Passes its CDR[s]
2010 Sept. 16
Sivaramakrishnan The Non-Redundant Mask on JWST
2010 Nov. 18
Sivaramakrishnan
2011 March 17 Chayer
TIPS/JIM
2011 September 15
Non-Redundant Tilts (NRT): A Fallback Coarse
Phasing Method for JWST Using TFI
JWST FGS & TFI Cryovac Risk Mitigation Tests
TFI Lessons Learned
#1: Cryogenic etalons are tricky.
July 20, 2011:
Wave good-bye to TFI.
Say hello to NIRISS.
Near InfraRed Imager & Slitless Spectrograph
TIPS/JIM
2011 September 15
Design Considerations for NIRISS
Ø  Maintain capability to address core TFI Science
•  “First Light”
•  Exoplanets
Emphasis of nascent GTO Programs
Ø  Minimize technical risk
•  Schedule is a (big) issue
•  Cost is a (big) issue
Ø  Simplify operations
TIPS/JIM
2011 September 15
“Scope” is the only adjustable parameter
available to CSA Program Management.
Helps the S&OC (i.e., us) a bit.
Observing Modes
TFI
Narrow-Band Imaging
R~100; tunable 1.5 – 2.6 & 3.0 – 5.0 microns
Coronagraphic Imaging
R~100; tunable 3.0 – 5.0 microns
Sparse-Aperture Interferometric Imaging
R~100; tunable 3.0 – 5.0 microns
NIRISS
Wide-Field Slitless Spectroscopy
R~ 150; 1.0 – 2.5 microns
XXXXXXXXXXXXXXXXX
Sparse-Aperture Interferometric Imaging
Fixed medium-band filters
Single-Object Slitless Spectroscopy
R~700; 0.7 – 3.0 microns
Broad-Band Imaging
Fixed filters; 1 – 5 microns
TIPS/JIM
2011 September 15
Optical Layout of the TFI
2048×2048 HgCdTe
5.2 micron cut-off
18 micron pixels
TIPS/JIM
2011 September 15
Optical Layout of NIRISS
2048×2048 HgCdTe
5.2 micron cut-off
18 micron pixels
TIPS/JIM
2011 September 15
Elements in the NIRISS Dual Wheel
Pupil Wheel
Filter Wheel
OPEN
[1]
OPEN
[1]
G700XD
[2]
F158M
[9]
MASKNR
[3]
G150H
[2]
F140M
[8]
F200W
[4]
F090W
[7]
F150W
[5]
TIPS/JIM
2011 September 15
F115W
[6]
G150V
[9]
F480M
[3]
F277W
[8]
F430M
[4]
F356W
[7]
F380M
[5]
F444W
[6]
Wide-Field Slitless Spectroscopy
Pupil Wheel
Filter Wheel
OPEN
[1]
OPEN
[1]
G700XD
[2]
F158M
[9]
MASKNR
[3]
G150H
[2]
F140M
[8]
F200W
[4]
F090W
[7]
F150W
[5]
TIPS/JIM
2011 September 15
F115W
[6]
G150V
[9]
F480M
[3]
F277W
[8]
F430M
[4]
F356W
[7]
F380M
[5]
F444W
[6]
Slitless Spectroscopy with Two Orthogonal Grisms •  A spectrum for every source in the field of view. NIRISS is CompeAAve With NIRSpec Bad Good Sparse-Aperture Interferometric Imaging
Pupil Wheel
Filter Wheel
OPEN
[1]
OPEN
[1]
G700XD
[2]
F158M
[9]
MASKNR
[3]
G150H
[2]
F140M
[8]
F200W
[4]
F090W
[7]
F150W
[5]
TIPS/JIM
2011 September 15
F115W
[6]
G150V
[9]
F480M
[3]
F277W
[8]
F430M
[4]
F356W
[7]
F380M
[5]
F444W
[6]
Sparse-­‐aperture interferometry with NIRISS pushes the angular resoluAon of JWST to its limit Bright planets goal Faint planets Beichman et al 2010 ²
Filter Set (3) for Use With MASKNR OpAmized for constraining temperature and mass. Single-Object Slitless Spectroscopy
Pupil Wheel
Filter Wheel
OPEN
[1]
OPEN
[1]
G700XD
[2]
F158M
[9]
MASKNR
[3]
G150H
[2]
F140M
[8]
F200W
[4]
F090W
[7]
F150W
[5]
TIPS/JIM
2011 September 15
F115W
[6]
G150V
[9]
F480M
[3]
F277W
[8]
F430M
[4]
F356W
[7]
F380M
[5]
F444W
[6]
G700XD design Slitless cross-­‐dispersed 0.6-­‐3.0 μm spectroscopy weak cylindrical surface 3-D SKETCH
(not to scale)
GRISM
γ
m=3 Φ
PRISM
m=2 Ruled area
²
²
²
R∼700 dispersion with grism along V2 Low dispersion with prism along V3, to separate orders Weak cylindrical lens on front side of prism to induce a defocus along V3 m=1 m=0 SchemaAc of Transit and Eclipse Science Seager & Deming (2010, ARAA, 48, 631) Transit Measure size of planet 10-­‐2 See starlight transmi\ed through planet atmosphere 10-­‐4 Eclipse Learn about atmospheric Planet thermal circulaAon from thermal emission appears phase curves and disappears 10-­‐3 17 Transit Spectrum of Habitable “Ocean Planet” NIRISS G700XD perfectly suited for such challenging programs. The water vapor features below have a depth of 50 parts per million. NIRISS wavelength range 0.6 μm 2.5 μm Broad-Band Imaging - Blue
Pupil Wheel
Filter Wheel
OPEN
[1]
OPEN
[1]
G700XD
[2]
F158M
[9]
MASKNR
[3]
G150H
[2]
F140M
[8]
F200W
[4]
F090W
[7]
F150W
[5]
TIPS/JIM
2011 September 15
F115W
[6]
G150V
[9]
F480M
[3]
F277W
[8]
F430M
[4]
F356W
[7]
F380M
[5]
F444W
[6]
Broad-Band Imaging - Red
Pupil Wheel
Filter Wheel
OPEN
[1]
OPEN
[1]
G700XD
[2]
F158M
[9]
MASKNR
[3]
G150H
[2]
F140M
[8]
F200W
[4]
F090W
[7]
F150W
[5]
TIPS/JIM
2011 September 15
F115W
[6]
G150V
[9]
F480M
[3]
F277W
[8]
F430M
[4]
F356W
[7]
F380M
[5]
F444W
[6]
NIRISS SensiAvity vs NIRCam NIRISS with spare NIRCam filter filter
Good In general , NIRISS is more sensi@ve than NIRCam. Summary
NIRISS is coming!
Capable instrument
Complements & Extends near-IR capability of JWST
Straightforward to operate*
First Light: Lyman alpha emitters (10< z<13) ; photometric redshifts
High-resolution imaging: exoplanet imaging and characterization
Spectroscopy of transiting exoplanet atmospheres (including H2O, CO2 features…)
* Grisms / aperture mask introduce complexity on the “back end”.
TIPS/JIM
2011 September 15
TIPS/JIM
September 15, 2011
Agenda:
INS Division News (Danny Lennon)
JWST Update (Massimo Stiavelli)!
Introducing JWSTʼs NIRISS: The Near Infrared Imager and Slitless
Spectrograph (Alex Fullerton)!
Updated Results from the COS Spectroscopic Sensitivity Monitoring
(Rachel Osten)!
Flux Dependent Non-Linearity in NIR Detectors: The Evil Twin of
Persistence (Mike Regan)!
!
Next TIPS/JIM: October 20, 2011
Updated Results
from the COS
Sensitivity
Monitoring Program
Rachel Osten
TIPS/JIM Sept. 15 2011
Wednesday, September 14, 2011
Outline
Recap
COS FUV spectroscopic sensitivity
trends in 2010
trends in 2009
}
subject of 2 ISRs; Osten
et al. 2010,2011
trends in 2011
COS NUV spectroscopic sensitivity in
2010 & 2011
Wednesday, September 14, 2011
COS sensitivity trends circa June
2010
NUV: bare Algratings (G225M,
G285M) declining
[~expected]
FUV: all gratings
showing gratingsegment-, λdependent
declines
[unexpected]
Osten et al. COS ISR 2010-15
Wednesday, September 14, 2011
Anomaly Review Board convened to
study the FUV sensitivity decline
Is the sensitivity loss localized? no
Is the XDL detector gain sag causing
sensitivity decline? no
Does the voltage affect sensitivity? no (~1%)
Likely suspect: degradation of quantum
efficiency of CsI photocathode of the FUV
detector, due possibly to water vapor
outgassing initially, followed by exposure to
atomic oxygen
Wednesday, September 14, 2011
Trends in 2010
Developments:
1. Change in temporal
trend occurring
around 2010.2
2. Refinement of
analysis allowing
for slopes to be
computed over
finer wavelength
bins
3. change in default
pulse height
filtering
Wednesday, September 14, 2011
Osten et al. COS ISR 2011-02
Apparent Dependence of
Sensitivity Decline on Pulse
Height Threshold
[black] events
with PHA (4,30)
[blue] events
with PHA (2,30)
Proffitt et al. COS ISR in prep.
Wednesday, September 14, 2011
change to PHA
minimum of 2 on
Dec. 22, 2010:
sensitivity
decline still
occurring
FUV Sensitivity Declines
prior to 2010.2
Osten et al. COS ISR 2011-02
Wednesday, September 14, 2011
FUV Sensitivity Declines
after 2010.2
for data
taken up
through
the end
of Dec.
2010
Osten et al. COS ISR 2011-02
Wednesday, September 14, 2011
FUV Sensitivity Trends
Implemented in TDS Reference
File Delivered March 18, 2011
testing of reference file
showed relative fluxes
corrected to ±3% (G140L),
±2% (M modes)
systematic behavior when
comparing pipeline fluxes
to reference spectra;
calibration apparently off
by > 5% in some places (2%
claimed for M modes; Massa
et al. 2010)
reference spectrum=model for LDS749B, STIS
spectrum for WD0947+857, WD0320-539
Osten et al. COS ISR 2011-02
Wednesday, September 14, 2011
short λ end may implicate
flux calibration of STIS
(<1160 Å)
Solving a Conundrum
Initial FUV absolute flux calibration of
COS was done using LDS749B, a DB WD
primary standard
Massa et al. (COS ISR 2010-02) reported an
apparent inconsistency when comparing the
fluxes of two other standard stars
observed during SMOV with LDS749B
More recent testing shows no apparent
inconsistency in standard stars, but does
reveal systematic offsets between pipeline
flux calibration and reference spectra
Wednesday, September 14, 2011
from SMOV observations,
LDS749B appeared brighter/
other standards fainter
mean=1.0351±0.0033
G160M grating; Massa et al. COS ISR 2010-02
ratio of net spectra divided by ratio of
models
expect agreement to be better than 2.8%
Wednesday, September 14, 2011
Evidence for an even steeper
initial decline?
Sensitivity(λ,t)=
S(λ)* r(λ,t)
S=absolute flux
calibration, r=relative
sensitivity, assumed to be
continuous
(1610-1770 Å)
Osten et al. COS ISR 2011-02 (1410-1580 Å)
extend observations of
LDS749B backward to
include initial high
voltage observation
offset of r(λ,t) at time
of abs. flux calibration
may explain some of the
observed discrepancies in
flux. calibration
the initial outgassing may
have been steeper than
previously thought
Wednesday, September 14, 2011
★=WD1057+719 (relative sensitivity)
▲=LDS749B (▲=LDS749B at high voltage)
T=‟tied” observation of WD1057+719/
LDS749B
" = time of absolute flux calibration
observations of LDS749B
Recent FUV
Sensitivity Trends
Wednesday, September 14, 2011
Recent FUV
Sensitivity Trends
Wednesday, September 14, 2011
Recent FUV
Sensitivity Trends
Wednesday, September 14, 2011
Recent FUV
Sensitivity Trends
Wednesday, September 14, 2011
Recent FUV
Sensitivity Trends
Wednesday, September 14, 2011
Recent FUV
Sensitivity Trends
Wednesday, September 14, 2011
Recent FUV
Sensitivity Trends
Wednesday, September 14, 2011
Recent FUV
Sensitivity Trends
Wednesday, September 14, 2011
Recent FUV
Sensitivity Trends
Wednesday, September 14, 2011
Another break?
A suggestive downturn in early 2011
being investigated; assuming this is
another break. . .
Wednesday, September 14, 2011
Observation
9/11/01!
Another break?
Wednesday, September 14, 2011
COS NUV Sensitivity
Trends
G230L, G185M
slight increase
in sensitivity <
2150 Å (possibly
also in STIS)
evolution of λdependence to
G285M relative
sensitivity
less of a
decrease for
G225M <2150 Å
Wednesday, September 14, 2011
solid lines show values in current reference
file; reference file to be updated
Recent STIS Trends
Wednesday, September 14, 2011
Conclusions
Temporal trends of COS FUV sensitivity
continue to evolve; stay tuned
Evidence of an initial, unrecognized
steep outgassing
FUV flux calibration now recognized to
be grating-, cenwave-, and FP-POS
dependent
NUV bare Al gratings continuing
decline, MgF2-coated gratings slight
increase in sensitivity at short λs
Wednesday, September 14, 2011
TIPS/JIM
September 15, 2011
Agenda:
INS Division News (Danny Lennon)
JWST Update (Massimo Stiavelli)!
Introducing JWSTʼs NIRISS: The Near Infrared Imager and Slitless
Spectrograph (Alex Fullerton)!
Updated Results from the COS Spectroscopic Sensitivity Monitoring
(Rachel Osten)!
Flux Dependent Non-Linearity in NIR Detectors: The Evil Twin of
Persistence (Mike Regan)!
!
Next TIPS/JIM: October 20, 2011
Flux Dependent Non-Linearity:
The Evil Twin of Persistence
Mike Regan, Kevin Lindsay, Eddie
Bergeron, Rachel Anderson
Photons captured in the depletion region
yield an electron/hole pair.
As charge accumulates, the depletion region gets
smaller exposing empty traps to free charge.
After a reset trapped electrons and holes
are left in the depletion region.
During the next exposure the electrons/holes
decay from the traps and are seen as an
increase in the voltage.
But what happens during the
original exposure?
During an exposure traps capture charge
decreasing the observed voltage.
This model makes several
predictions.
•  Flat field response will be lower at low
fluxes in high trap regions.
•  Detector bias changes that decrease
the size of the depletion region will
induce “negative persistence”.
•  Slopes after cosmic rays will be lower.
Trap Density Map in our “Beautiful”
Device.
Flat Fields
The Ratio of high and low flux flat fields shows a
difference in the high trap region.
Flux ratio
was a
factor of
60.
Bias change to decrease
depletion region
The measured slopes on the device are
negative after we change the bias.
The negative observed rates decay away
just like persistence.
Cosmic Rays
The slope after a cosmic ray is lower and is
proportional to the magnitude of the CR
Conclusions
•  The model matches all the
observations.
•  The observed QE is a function of the
flux -> Flux dependent QE
•  Determining slopes when there is a
cosmic ray is not simple (as I thought
before).