Telescope and Instrument Performance
Summary (TIPS)
16 Jan 2003
AGENDA
1. Type 1a SuperNovae
2. JWST’s NIR Detectors
Adam Riess
Bernie Rauscher
Adam G. Riess
Space Telescope Science Institute
How (we think) Nature makes a SN Ia
•
•
•
•
Homogeneity: 1.4 Mo, 1051 ergs
Negligible hydrogen, lots of IME
Mature progenitors
Models (delayed-detonation) good fit to observations
“Standard” Candles
dust
Bright=near
dim=far
dim & red=closer!
Expansion History of the Universe
(redshift)
,Ω
,Ω
,Ω
(Distance)
M
M
M
<1
=1
>1
Mass is
destiny
The Accelerating Universe
By 1998 two teams measured ~100 SNe Ia at 0.01 <z<1.0 Surprise!
The Universe is accelerating, propelled by dark energy.
High-z
SCP
Searching for the Epoch of
…a required feature of a mixed dark matter/dark energy Universe
ρ
M
ρΛ
=
ρ
M ,0
ρΛ
(1 + z ) 3
ρ
M
z
ρΛ
0.0
0.4
0.8
1.2
1.7
0.4
1.0
2.3
4.3
8.0
Searching for the Epoch of
ρ
M
ρΛ
=
ρ
M ,0
ρΛ
ρ
(1 + z ) 3
M
z
ρΛ
0.0
0.4
0.8
1.2
1.7
0.4
1.0
2.3
4.3
8.0
Our current goal: 6-8 SNe Ia at 1.2<z<1.8
“Difficulty”
∝
(1 + z )
6
Or why its so hard to find type Ia supernovae at z>1.2
Effect
geometrical dilution
Factors of (1+z)
2
redshift of energy density
1
dilation of integration time
1
Decline of SN Ia SED
~0.9-1.0 µ
~1
Decline in QE of detectors
~0.9-1.0 µ
~1
Total=
6 than at z=0.5 (a.k.a., 1998)
Finding SNe Ia at 1.2<z<1.8 is 10 to 40 times harder
The GOODs ACS Treasury Program and
The Hubble Higher-z Supernova Search Team
“A Higher-z Supernova Search Piggybacking on the
ACS Survey”
134 orbits ToO
Riess (STScI)
Strolger (STScI)
for 6-8 SNe Ia
Tonry (UH)
at 1.2<z<1.8
Filippenko (UCB)
Kirshner, (CfA)
Challis, (CfA)
Casertano, (STScI)
Dickinson (STScI)
Giavalisco (STScI)
Ferguson (STScI)
399 orbits
of deep imaging
for extragalactic
studies
Searching for SNe Ia with ACS
5 z-band epochs, spaced by 45 days, simultaneous v,i band, 120 tiles
CDFS=08/02-02/03
HDFN=11/02-05/03
What we are finding…
~5-6 SNe per search epoch (~0.3 SNe/ACS pointing)
~1/2 type Ia, ~1/2 core-collapse, 0.3<z<1.8, <z>=1
SN Color Differences
cit
i
f
de
V
aU
I
SN
i
v
Most Common SN types: type Ia and type II
z
Color Discrimination
Our first higher-z SN Ia, Aphrodite
Aphrodite (1<z<1.5)
ACS F850lp
ACS grism spectrum
NICMOS F110W
viz
The Rise and Fall of Aphrodite
Oct
Oct
20
Nov
Aug
Oct
Sept
Oct
Nov
Oct517
30
31
1110
25
22
Our Second Higher-z SN Ia, Thoth
Epoch 2
Epoch 3
Epoch 3-2
red, elliptical
host
Keck
VLT
z=1.3
Our Third Higher-z SN Ia, Nanna
Epoch 1
Epoch 2
OII, Keck
difference
And Some Even More Distant…
Athena: phot-z: 1.8<z<2.2
Colors, mag SN Ia at z~1.8
Osiris: Colors, mag
SN Ia at 1.5<z<1.8
ACS f850lp
viz
We are off to a great start…results coming soon to a journal near you…
Dilution of Light or Gravity Depends on
the Number of Dimensions Either “Sees”
Number of Dimensions
Intensity/Distance Law
1
Independent of Distance
(I ~ 1/R0)
2
Reciprocal of Distance
I ~ 1/R1
3
Inverse Square Law
I ~ 1/R2
Essential component of String Theory: photons move in 3 dimensions,
Gravitons leaks into 5,10 or 11 D long-range decay of gravity (Dvali et al 2001)
The Future Is Bright for SNe Ia!
•New tests of the new cosmology (searching for past
deceleration)
•Deeper understanding of SNe Ia (progenitors)
•Probing the nature of Dark Energy
The End
JWST's Near-Infrared Detectors:
Ultra-Low Background Operation and Testing
And coming soon!
Bernie Rauscher, Don Figer, Mike Regan, Sito Balleza, Robert
Barkhouser, Eddie Bergeron, Gretchen Greene, Ernie Morse, Steve
McCandliss, Russ Pelton & Tom Reeves
16 January 2003
STScI TIPS
1
Outline
• What is a Near-Infrared Array Detector?
• JWST Science Drivers
• Detector Requirements
• Detector testing at STScI/JHU
• Optimal Use
• Summary
16 January 2003
STScI TIPS
2
JWST’s IR Arrays are “Hybrid” Sensors
• PN junctions are “bump
bonded” to a silicon
readout multiplexer
(MUX).
• Silicon technology is
more advanced than
other semiconductor
electronics technology.
• The “bump bonds” are
made of indium.
16 January 2003
STScI TIPS
3
JWST Needs Very Good Near Infrared Detectors!
•
Completing the JWST Design
Reference Mission “on time”
requires background limited nearinfrared (NIR) broadband imaging
1.E+02
Sunshield
•
•
•
Zodiacal light is the dominant
background component in the NIR
The total NIR detector noise
requirement is therefore =10 erms in a t=1000 seconds exposure.
NIRSpec will probably be
detector noise limited. The total
noise goal is =3 e- rms per 1000
seconds exposure
Signal [e-/sec/pix]
1.E+01
JWST requirement
1.E+00
JWST goal
1.E-01
R=5
1.E-02
Zodiacal Light
1.E-03
R=1000
1.E-04
0.1
1
10
Wavelength [µm]
16 January 2003
STScI TIPS
4
JWST Near Infrared (NIR)
Detector Requirements
Parameter
Detector Noise per image
Read Noise (nFowler≤16)
Dark Current
QE
0.6 µm < λ < 1.0 µm
1.0 µm < λ < 5.0 µm
Pixel-to-pixel uniformity
Operability
Latent Image
Fill Factor
Radiation Immunity
Frame Time
Temperature
MTF
a
Requirement
−
Status
Goal
InSb
−
−
HgCdTe
−
9 e RMS
2.5 e RMS
10.8 e RMS
NR
NR
NR
NR
10.6 e RMS
−
0.004 e /s
4.6 e RMS
−
0.02 e /s
≥70%
≥90%
≥95%
unknown
>80%
~10%
NA
<0.5%
>98
unknown
<12s
in range
unknown
unknown
95%
~74%
>80%
~10%
~74%
NA
<0.5 %
>98%
unknown
<12 s
in range
unknown
≥80%
TBD
≥98%
∼0.1%
>95%
<4% inop EOM
12 s
30 K < T < 37 K
0.53
TBD
≥99.5%
0
100%
no effect
<12 s
allow ±2 K
>0.53
−
6.7 e RMS
−
Assumes 1000 second exposure and quadrature sum of read noise and shot noise from dark current.
16 January 2003
STScI TIPS
5
Detector Testing at STScI/JHU:
Independent Detector Testing Laboratory
16 January 2003
STScI TIPS
6
Past and present personnel
Eddie Bergeron
Data Analyst
Tom Reeves
Lab Technician
Robert Barkhouser
Optical Engineer
Mike Telewicz
Intern
Bernie Rauscher
Project Scientist
Utkarsh Sharma
Graduate Student
Gretchen Greene
Mechanical Engineer
Steve McCandliss
JHU Lead
Ernie Morse
Data Analyst
Monica Rivera
Intern
Scott Fels
Intern
Don Figer
Director
Russ Pelton
Technician
Sito Balleza
Systems Engineer
Mike Regan
System Scientist
16 January 2003
STScI TIPS
7
IDTL Experiments
 Read noise
 Conversion Gain
 Dark current
• Linearity
 Electronic Gain
 Latent charge (persistence)
• Relative and Absolute Quantum efficiency (QE)
• Intra-pixel sensitivity
16 January 2003
STScI TIPS
8
Dark Current
•
Lowest measured dark current is ~0.006 e−/s/pixel.
16 January 2003
STScI TIPS
9
IDTL Measurements: Read Noise
•
Read noise is ~10 e− for Fowler-8. (system read noise is ~2.5 e−)
16 January 2003
STScI TIPS
10
IDTL Measurements: Conversion Gain
Per correlated
double sample
16 January 2003
STScI TIPS
11
IDTL Test System
Hawaii Shirt
Hawaii Detector
16 January 2003
STScI TIPS
12
Then & Now
November 2000
November 2002
16 January 2003
STScI TIPS
13
IDTL First Light Images
Raytheon ALADDIN
Jan. ‘01 (MUX)
16 January 2003
Rockwell HAWAII-1R
Feb. ‘02 (MUX)
Apr. ‘02 (SCA)
Rockwell HAWAII-1RG
Jun. ‘02 (MUX)
Raytheon SB-304
Rockwell HAWAII-2RG
Nov. ‘02 (MUX)
Jan. ‘03 (MUX)
STScI TIPS
Jul. ‘02 (SCA)
14
IDTL Test System
Leach II Controller Electronics
Dewar
Entrance
Window
Vacuum Hose
He Lines
16 January 2003
STScI TIPS
15
Detector Readout System
T=30-50 K
Unix Instrument
Control Computer
Warm Harness
COTS Leach II IR
Array Controller
T~293 K
Cryogenic Harness
JWST SCA
16 January 2003
Detector Customization
Circuit
STScI TIPS
16