CIBER: Launched!February 25, 2009 at 3:45 am
The First Galaxies, Quasars, and Gamma-Ray Bursts
Ian SullivanJune 10, 2010
CIBER Collaboration
James BockViktor HristovAndrew LangeLouis Levenson
Peter MasonIan Sullivan
Michael Zemcov
Brian KeatingTom Renbarger
Toshio MatsumotoShuji MatsuuraKohji TsumuraTakehiko Wada
Dae Hee LeeUk Won Nam
Asantha Cooray
Formation of structure and galaxies
Trac & Cen 2007
z=9 z=8
z=7 z=6
Numerical Simulation of Reionization
Orange regions are ionized
Around z~10, UV radiation from the first stars and proto-galaxies caused the intergalactic medium of neutral Hydrogen to become ionized.
Current predictions are that these stars had mass M=30-300Msun
How can you detect the first stars?
Has the light from the first stars been detected?
TeV blazar absorption spectra set an upper limit on the EGB, but estimates of this limit vary
The diffuse background (yellow) appears much brighter than the sum of resolved galaxies (blue)
Dual wide-field Imagers λ= 1.0, 1.6 μmλ/Δλ=22o x 2o FOV 7” pixels.
CIBER: The Cosmic Infrared Background Experiment
Narrow-Band Spectrometer λ= 0.8542 μm (Ca II) λ/Δλ=10008o x 8o FOV 120” pixels
Low-Resolution Spectrometerλ= 0.7 - 1.8 μm.λ/Δλ=206o x 6o FOV80” pixels
Focal Plane Assemblies
Detector
Active thermal control stagePlunger
Bi-stable cold shutter
The shutter is actuated by two electromagnets
Each assembly is thermally isolated from the optics, and strapped to the LN2 tank with copper braid
Nose cone with parachute
Star tracker
Guidance system and gas reservoir
Telemetry
Experiment cryostat
Payload shutter door
• We observed 4 cosmological fields, 2 foreground assessment fields, and the star Vega for calibration of the NBS
• The cosmological fields are chosen to enjoy exceptional ancillary coverage to minimize point source contamination.
CIBER’s flight• Apogee is strongly sensitive to payload mass; CIBER achieved 335km with a 1060lb payload. • Total flight time was 15 minutes, including 6 minutes of observations
Imagers
Quantity 2009Flight
Units
I-band Imager (1.0 mm)
Responsivity 11.5 e- / mJ/m2srRead noise CDS 17 e-Dark Current 0.24 e-/sdnIn (1s)/pixel 43 nW/m2sr, 50 s
Array 1024x1024 HAWAII-1 (HgCdTe)
H-band Imager (1.6 mm)
Responsivity 18.7 e- / mJ/m2srRead noise CDS 14 e-Dark Current 0.28 e-/sdnIn (1s)/pixel 128 nW/m2sr, 50 s
Array 1024x1024 Hawaii-1 (HgCdTe)
Measuring fluctuations in the near-Infrared Background
Imagers: Fluctuations in the Near-Infrared Background
Sources from reionization should have a distinct spatial power spectrum
However, local galaxies dominate until they are removed to a low level
Science window
Low-Resolution Spectrometer (LRS)
Quantity 2009Flight
Units
Low-Resolution Spectrometer
Responsivity 10-65 e- / mJ/m2srRead noise CDS 25 e-Dark Current 0.5 e-/sdnIn (1s)/pixel 10-30 nW/m2sr, 50 s
Number of slits 5
Array 256x256 PICNIC (HgCdTe)
Measuring the absolute brightness of the near-Infrared Background
LRS: The absolute brightness of the Near Infrared Background
Low-ResolutionSpectrometer sensitivity after 50s
The LRS will be the first instrument to span the entire 0.7 – 1.8 µm range
Zodiacal Light spectrum with the LRS
•By itself, the LRS measures the shape of the spectrum of the Zodiacal Light
•Absolute calibration can be further improved in the future with the NBS
Tsumura et al 2010
Narrow-Band Spectrometer (NBS)Measuring the absolute brightness of the Zodiacal Light
Nar
row
-ban
d fil
ter
o
CosL λλλ
2
1
0
Quantity 2009Flight
Units
Narrow-Band Spectrometer
Responsivity 2.3 e- / mJ/m2srRead noise CDS 28 e-Dark Current <0.6 e-/sdnIn (1s)/pixel 87 nW/m2sr, 50 s
Resolution 1220 /l DlArray 256x256 PICNIC (HgCdTe)
• NBS design uses a narrow band filter tuned to a reflected CaII solar line to measure absolute intensity of ZL in each field.
• The wavelength across the array varies as o = i
cos
l=8540-8544nm
l=8536-8540nm
l=8532-8536nm
NBS: Absolute brightness of the Zodiacal Light
Modifications
All hardware modifications are complete for the second flight. These include:• New fixed baffles with Laser Black• Extended radiation shield above front plate• New shutter door black liner • All instruments moved inboard ¼”• Pop-up baffles for all instruments• New calibration lamp for the NBS• Strengthened suspension
Five more flights to come:• July 2010• February 2011• July 2011 – four-stage non-recoverable flight• Summer 2013 – first flight of CIBER2• Spring 2014
CIBE
R2