ciber: launched! february 25, 2009 at 3:45 am

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