CIBER estimates of the Absolute ZL Foreground Intensity through Fraunhofer Absorption Line Spectroscopy Phil Korngut Caltech NIR Background II, Munich Jun 1st, 2015
CIBER estimates of the Absolute ZL Foreground Intensity through Fraunhofer Absorption Line Spectroscopy Cosmologically pertinent results are currenty awaiting publication. Details of the technique will be discussed as implemented by CIBER.
Relative Brightness of Zodi and EBL Outdated EBL plot, (sorry if your measurements are not shown) Assume the brightest EBL reported and faintest ZL reported.
Relative Brightness of Zodi and EBL Outdated EBL plot, (sorry if your measurements are not shown) Zodi at NEP Assume the brightest EBL reported and faintest ZL reported.
Relative Brightness of Zodi and EBL Outdated EBL plot, (sorry if your measurements are not shown) Zodi at ecliptic lat = 10deg Zodi at NEP Assume the brightest EBL reported and faintest ZL reported.
DIRBE Annual Modulation 25um Animation from Ned Wright Pyo et al 2012 using Akari Kelsall and Wright DIRBE models are geometric and time/position dependent Difference in Absolute Photometry measurements is predominantly Foreground Model
Alternate Method of absolute ZL Estimation independent of Geometry Joseph von Fraunhofer (6 March 1787 7 June 1826) CaII 8542A line Line depth Short of ~2microns, the ZL is reflected Solar Spectrum with well characterized Absorption features.
Alternate Method of absolute ZL Estimation independent of Geometry Joseph von Fraunhofer (6 March 1787 7 June 1826) CaII 8542A line Isotropic EBL Line depth Short of ~2microns, the ZL is reflected Solar Spectrum with well characterized Absorption features.
Alternate Method of absolute ZL Estimation independent of Geometry Joseph von Fraunhofer (6 March 1787 7 June 1826) CaII 8542A line Isotropic EBL Line depth Line depth Sum Short of ~2microns, the ZL is reflected Solar Spectrum with well characterized Absorption features.
Previous Application of Fraunhofer Line Measurements to EBL Bernstein et al 2002 Measurements From the Ground Airglow Lines Credit: NASA/ Atmospheric Extinction Atmospheric scattering Many systematics can be avoided by doing this measurement from Space!
Previous Application of Fraunhofer Line Measurements to EBL Bernstein et al 2002 Measurements From the Ground Airglow Lines Credit: NASA/ Atmospheric Extinction Atmospheric scattering Many systematics can be avoided by doing this measurement from Space!
The CIBER Collaboration John Battle Jamie Bock Viktor Hristov Alicia Lanz Phil Korngut Peter Mason Michael Zemcov Asantha Cooray Joseph Smidt Yan Gong Chang Feng Toshiaki Arai Shuji Matsuura Kohji Tsumura Takehiko Wada Yosuke Onishi Mai Shirahata Toshio Matsumoto Dae Hee Lee Uk Won Nam Min Gyu Kim Keith Lykke Steve Brown Allan Smith
Design Requirements for a Space-based Fraunhofer line Spectrometer, $$$ Large apertures or lots of time in space is expensive Make very large pixels ZL Brightness and Line width R ~ 1000 sufficient for 854.2nm CaII line Use a sounding rocket
The Narrow Band Spectrometer 256x256 HgCdTe PICNIC array made by Teledyne.
The Narrow Band Spectrometer λ δθ = 8.5deg Instantaneous FOV =72.25 deg^2 Pixel size = 2 256x256 HgCdTe PICNIC array made by Teledyne.
The Narrow Band Spectrometer λ δθ = 8.5deg Instantaneous FOV =72.25 deg^2 Pixel size = 2 256x256 HgCdTe PICNIC array made by Teledyne.
CIBER s approach to the NIR EBL R Wide = 20 field Spectrometer (2.5x2.5deg) from Dual 800nm band to imager 2000nm (1.1um and 1.6um to (Measure measure spatial the Absolute R = fluctuations 1200 Intensity Spectrometer in the Spectrum background) to Measure of the the Zodiacal EBL) foreground via the 854.2nm CaII Fraunhofer line
Co-mounted in a LN2 Cryostat
Absolute NBS Calibration with the NIST SIRCUS Laser
Absolute NBS Calibration with the NIST SIRCUS Laser
CIBER Flight History -Flown 3 times from 2010 to 2012 on a BBIX 2 stage rocket. -Flight 4 on a four stage BBXII rocket.
Field Selection to Sample Parameter Space 9 Fields over 3 flights (6 independent) Bootes Elat-30 Elat-10 SWIRE NEP
Narrow Band Spectrometer Data Reduction Raw Single field NBS Image Ideal ZL CaII image Subtract Dark Current Template and mask outlier regions.
Narrow Band Spectrometer Data Reduction Single field NBS Image Dark Current, Flat field, Bad pixels masked Ideal ZL CaII image
Narrow Band Spectrometer Data Reduction Single field NBS Image Dark Current, Flat field, Bad pixels masked Ideal ZL CaII image Smoothed for Ease of Viewing only Register Astrometry & Create synthetic image based on 2mass stars
Narrow Band Spectrometer Data Reduction Single field NBS Image Dark Current, Flat field, Bad pixels masked Ideal ZL CaII image Binned By Wavelength Results as of Austin Meeting
Modelling all of the components required for Accurate ZL Estimates What we measure What we want Zodiacal Light Diffuse Galactic Light amplitude Stellar Light EBL, Airglow resid, Dark Current Resid etc. Spatial Distribution Effective CaII absorption profile of the component
Modelling all of the components required for Accurate ZL Estimates
Modelling all of the components required for Accurate ZL Estimates For CaII depth in ISL to first order use Lehtinen and Mattila 2013 ISL model Δλ = 1nm Approximately Solar and stable at our Glats at Δλ = 1nm
Modelling all of the components required for Accurate ZL Estimates Rely on Ancillary all-sky catalog (DSS-i2 (880nm)) et astrometry and perform a Sub-pixel stack to measure PSF enerate Model Star Template Including CaII NBS Measured Star Field (NEP)
Modelling all of the components required for Accurate ZL Estimates Rely on Ancillary all-sky catalog (DSS-i2 (880nm)) et astrometry and perform a Sub-pixel stack to measure PSF enerate Model Star Template Including CaII Mask Model Remnant Contribution Generate a mask removing pixels brighter than t from stars brighter than M in a catalog based model map
Modelling all of the components required for Accurate ZL Estimates Average correlation slope is 1.0 +- 0.1 for whole model
Modelling all of the components required for Accurate ZL Estimates
Modelling all of the components required for Accurate ZL Estimates With an 8.5 degree FOV the ZL is not uniform and gradient is important Shape of Free parameter in Fit
Fit For the ZL amplitude Low Ecliptic Lat DGL ISL DGL+ISL DGL+ISL+ ZL(free) Data 1D Spectra Data ISL+DGL Total Fit
Fit For the ZL amplitude Large Relative Contamination DGL ISL DGL+ISL DGL+ISL+ ZL(free) Data 1D Spectra Data ISL+DGL Total Fit
Best Fit Spectra For the Whole Sample Mean subtracted shown on same scale
Conclusions -Look for NBS paper soon with ZL model tests! -Going to space for this measurement avoids atmospheric systematics. -Large pixel size and FOV allows for detection in short exposures, but allows for other systematics. - Absolutely calibrated satellite mission could make excellent measurements.