# Presentation: 454805

## CIBER: The Cosmic Infrared Background ExpeRiment

- John Battle
- Jamie Bock (PI)
- Andrew Lange
- Ian Sullivan
- Mike Zemcov
**UC San Diego**
**Brian Keating**
- Tom Renbarger
**UC Irvine**
- Asantha Cooray

**CIBER: *****The Cosmic Infrared Background ExpeRiment***
***“******Blasting into the Thermosphere to study Stromgren-spheres”***

**ISAS / JAXA**
- Toshio Matsumoto
- Shuji Matsuura
- Kohji Tsumura
- Takehiko Wada
**Nagoya U.**
- Mitsunobu Kawada
- Toyoki Watabe
**KASSI**
- Dae-Hee Lee
- Soojong Pak

## The first starlight

## CMB probes of reionization

- The amplitude of the first peak of the CMB EE power spectrum depends on the optical depth for CMB photons to reionization.

- See Fan, Carilli, and Keating ARAA (2006)

- WMAP (2006)

## How can you detect the first stars?

- Cooray

## CIBER will answer three main questions

**1.**** Is the background reported by IRTS real?**

**2.**** Is there a Lyman cutoff feature around 1 μm?**

**3.**** If the IRTS reported background is not real, then is there a detectable diffuse extragalactic background from the first stars?**

- Cooray

## CIBER:  Probing the First-Light IR Background

**Low-Resolution Spectrometer**
-  = 0.8 – 2.0 m, / ~ 20
-  Search for Ly cutoff feature
-  Measure Zodiacal color

**     ****Wide-Field Imagers**
-  = 0.9 m & 1.6 m
-  Probe Spatial Fluctuations

** ****Narrow-Band Spectrometer**
-  = 0.8542 m
-  Measure Zodiacal intensity

- Direct Zodiacal
-  Measurement!!

## The CIBER Payload

- Nike Black Brandt rocket

- (Low-resolution
-  spectrometer
-  blocked from view.)

## The CIBER Instrument Suite

**The CIBER Instrument Suite**

**I-band Imager**
** ****(0.8-1.2 ****μ****m)**

**H-band Imager**
** ****(1.2-2.0 ****μ****m)**

**Narrow-band**
**Spectrometer**

**Low-resolution**
**Spectrometer**

**Cold Plate**
**  ****(350 mm**
**     ****diam.)**

## CIBER: The Cosmic Infrared Background Experiment

**Dual wide-field imagers (blue) **
**λ****=**** 0.9, 1.6 ****μ****m****	****	****λ****/****Δ****λ****=2**
**2  x 2   FOV ****	****	****7” pixels. **
**Narrow-Band Spectrometer (orange)**** **
**λ****= 0.8542 ****μ****m (Ca ****II****)****	****λ****/****Δλ****=1000**
**8  x 8  FOV ****	****	****120” pixels.**
**Low-Resolution Spectrometer (red)**
**λ****=**** ****0.7 - 1.8 ****μ****m.****	****	****λ****/****Δλ****=20**
**6  x 6  FOV****	****	****80” pixels**

**o**

**o**

**o**

**o**

**o**

**o**

## Low-Resolution Spectrometer (LRS)

- Low-Resolution
- Spectrometer sensitivity after 50s

- TeV blazar absorption spectra set an upper limit on the EGB (Aharonian et. al. 2005)

**The LRS can detect the IRTS background without any foreground subtraction**
***The LRS will be the first instrument to span the entire 0.7 – 1.8 μm range ***

- Cooray

## NBS

**Narrow-Band Spectrometer **measures the absolute intensity of the Zodiacal brightness using the reflected Ca II 854.2 nm Fraunhofer absorption line.
- The excess IRB reported by DIRBE and IRTS could be explained by a 20 % error in the DIRBE Zodiacal dust model.
- Compact imaging spectrometer detects the integrated Ca II 854.2 nm line strength.
- High sensitivity measures the absolute Zodiacal brightness to  < 1 % in 6 fields.
- Control systematic errors associated with the instrument to 3 % in order to compare with DIRBE J-band.

- Dust

## Measuring the ZL with the NBS

- Narrow-band filter

- λ

- λ

- λ

- 2

- 1

- 0

- ZL model uncertainties: Currently set limit on absolute brightness measurements of the IR background
- ZL is expected to have a solar spectrum, including absorption features

- Ca II

## Dual wide-field imagers

- The H-band imager should detect the fluctuations seen by Spitzer with high signal to noise.
- The I-band imager provides a robust null check of detected fluctuations.

- The two imagers have the same optics

- Cooray

## Cryostat and telescope mount: fabricated!

## Two Imagers...Inspired by CMB:

***Two Imagers...Inspired by CMB:***
- Wide 2o field eliminates mosaicing artifacts
- Two spectral bands discriminate first-light fluctuations from foregrounds.
- Spatial resolution of 7" deeply removes galaxy clustering and shot noise.
- High sensitivity probes significantly deeper than the fluctuations reported by Spitzer and the IRTS.

## CIBER has an extremely wide F.O.V.

- North Ecliptic Pole

- SWIRE Elais N1

- Akari

- Spitzer

**Spitzer field of view**

**Akari field of view**

**Spitzer field of view**

**CIBER has an *****extremely***** wide F.O.V.**

**Low-Resolution Spectrometer **searches for the Lyman cutoff signature of reionization in the IRB.
- At the IRB level reported by the IRTS, such a bright feature would be apparent without any foreground subtraction.
- It will also measure the Zodiacal color.
- Absolute grating spectrometer measures in the spectrally unexplored 0.7 – 1.8 mm range between IRTS and HST.

**CIBER Instruments and Cryostat**

- Narrow  Band Spectrometer

- Low Res Spectrometer

- Imager, One of Two

## Detectors

- The 10242 detector arrays provide background-limited performance.
- Our HAWAII-1 engineering-grade array from Rockwell shows negligible dark current and high quantum efficiency.
- Use an off-chip JFET follower to eliminate multiplexer glow.
- In order to minimize dark current associated with temperature drifts, the array is mounted on a thermally isolated stage, which is monitored with sensitive dc-stabilized thermometry and thermally regulated.
- A cold shutter placed just above the array allows us to record dark frames prior to launch, and on ascent and descent.  The shutter is similar to the NITE shutter, designed to minimize stray-light leakage.

- Quantum efficiency (QE)
- Blue QE=0.60
- Red QE=0.54

**HAWAII-1 HgCdTe arrays used for the two imagers**

## Launch windows

- Solar elongation between 64 and 124 degrees for all science fields, to allow direct comparison with DIRBE

- Science fields at least 55 degrees above horizon, and sun at least 5 degrees below horizon

- Science fields at least 55 degrees above horizon, and moon below horizon

## Nike Black Brandt: Sounding Rocket

## CIBER flight events

| Event | time (sec) | Altitude (km) | Range (km) | Velocity (mps) |
| --- | --- | --- | --- | --- |
| Rail release | 0.6 | 1.2 | 0.0 | 44 |
| Terrier Burnout | 6.2 | 3.2 | 0.1 | 620 |
| Black Brant Ignition | 12.0 | 6.4 | 0.3 | 496 |
| Canard Decouple | 18.0 | 10.0 | 0.4 | 734 |
| Black Brant Burnout | 44.4 | 52.4 | 2.7 | 2557 1.5 miles/sec |
| Despin | 60.0 | 91.0 | 4.8 | 2406 |
| Payload Separation | 65.0 | 102.9 | 5.5 | 2358 |
| 250 km Upleg | 138.1 | 250.0 | 15.4 | 1683 |
| Apogee | 329.1 | 409.0 | 40.2 | 138 |
| 250 km Downleg | 520.1 | 250.0 | 65.0 | 1683 |
| Ballistic Impact | 635.3 | 1.2 | 80.2 | 1702 |
| Chute Deploy | 725.2 | 4.9 | 80.2 | 103 |
| Payload Impact | 957.4 | 1.2 | 80.2 | 11 |

## CIBER Fields (in ecliptic coordinates)

**Recovery**

## Timeline

- 2007- 	**The four telescopes have been fabricated. **
- The cryostat is finished and works great.
- Focus and vibe testing of optics is complete.
- Optics perform very well and meet preliminary vibe goals.
- Calibration and testing in the lab
- Spectral calibration of NBS,
- In flight calibration
- flat field testing
- Collimation
***All happening now and will finish this summer.***
- 2008-	May: first launch
- 	followed by refurbishment of payload.
- 	First flight data analysis.
- 2009-	February: first chance for second launch.

## Acknowledgements

**Jamie Bock (JPL CIBER PI; slides)**
**Asantha Cooray (UC Irvine; theoretical models and slides)**
**Ian Sullivan (Caltech Graduate Student; Mech design and slides)**
**Michael Zemcov (Lead Caltech & JPL Postdoc; Testing, Integration)**
**Tom Renbarger (UCSD Postdoc; NBS & Drawings)**
**Pete Mason (Caltech 1950, Cryo Wiz)**
**John Battle & Viktor Hristov (JPL; Electronics Pros)**
**Mike Rezin (UCSD; Electronics Shop Genius)**
**ISAS Team (T. Matsumoto et al, Rocketeers)**
**UCSD COSMOS and NASA (E/PO Support)**