of the universe!

Smithsonian Astrophysical Observatory University of Texas, Austin

Lockheed Martin

Cosmic Inflation Probe will characterize the physics underlying inflation by precisely measuring the power

spectrum of matter density fluctuations in the present-day universe.

The experiment involves a survey of the galaxy distribution over 140 sq. degrees from z=3 to 6.5 using H as the tracer.

The CIP mission has an extremely simple instrument design and mission plan.

The team includes SAO, UT, and Lockheed-Martin who are currently carrying out a NASA funded study

Eiichiro’s Part:

Cosmological Motivation

Observable Consequences of Inflation

How CIP will measure the inflaton potential

Dan’s Part:

Instrument Design

Mission Plan

Data Analysis and Auxiliary Science

Cosmology - Exciting, but Embarrassing Situation

Recent, very successful determinations of the cosmological parameters have

revealed that we don’t understand most

of the universe!

How much we don’t know about the universe

~10^-34 sec Inflation Dark Energy I

<30,000 yrs Radiation Era Radiation

<8 billion yrs Matter Era Dark Matter

<now Dark Energy Era Dark Energy II

Log(Time)

Four Big Questions in Cosmology

The nature of dark matter



What are they? How many of them?

The nature of dark energy



What is it?



Modification to gravity? Another form of energy?

The origin of baryons



Physics of Baryogenesis?

The physics of inflation



Did it happen at all?



If so, how did it happen? What powered inflation?

LHC

CIP

Why Inflation?

Inflation saves the Big Bang Model

• The isotropy of the cosmic background radiation (T/T ~ 10^-5 ).

• The flatness of the universe (_ =1).

• The origin of cosmic structure.

By exponentially expanding a small region, Inflation

naturally solves several problems not addressed by the

Big Bang model:

Observe Inflation

Inflation generates primordial fluctuations in spacetime.

(a) Fluctuations inherited in radiation



Cosmic Microwave Background

 Temperature Anisotropy

 Polarization Anisotropy

(b) Fluctuations inherited in matter



Dark Matter Distribution (Gravitational Lensing)



Galaxy Distribution (Redshift Surveys)



Gas Distribution (Lyman-alpha clouds)

(c) Fluctuations in spacetime itself



Primordial Gravitational Waves

INFLATION

Inhomogeneous Homogeneous

x 100,000

Inside Horizon Exit Horizon

Enter Horizon Fluctuations conserved

outside the Horizon

Direct probe of physics of Inflation!!

Observe Inflation

Inside Horizon V()

V()

galac

tic size

COBE

Different wavelengths

measure different locations of V()

Need to cover a wide range of .





Andrei Linde

The number of papers whose title

contains “inflation” (as of today): 119



New Inflation (1981, cited 1405 times)



Chaotic Inflation (1983, cited 852 times ）



Hybrid Inflation (1994, cited 424 times ）

Dr. Inflationary Universe Dr. Inflationary Universe

But, which model is right?

Approaching the

Inflationary Paradigm

0

order test: did inflation happen?

1.

Is the observable universe flat?

2.

Are fluctuations Gaussian?

3.

Are fluctuations nearly scale independent?

4.

Are fluctuations adiabatic?

1

order test: which model is right?

1.

Deviation from Gaussianity?

2.

Deviation from scale independence?

3.

Deviation from adiabaticity?

Did Inflation Happen?

Flatness ( 

= 1): 

= 1.02 ± 0.02 Gaussianity ( ƒ

~1): -58 < ƒ

< 134

Scale invariance ( n

~1): n

= 0.99 ± 0.04

Adiabaticity (  T/T=(1/3)*  ): deviation <

30%

  ^{x   }

  ^{x   f}

^

  ^{x }



1 3

  k

k

Spergel, Verde, Peiris, Komatsu et al. (2003)

Komatsu et al. (2003)

Spergel, Verde, Peiris, Komatsu et al. (2003)

Peiris, Komatsu et al. (2003)

Dev. from Scale Invariance

Different wave- numbers probe different parts of potential.

We need to cover many decades in wave-number to

determine the shape of potential

 Require a variety of probes.

The Current State-of-the-Art

V(











Toward “the” Inflation Model

What is necessary?



More accurate measurements of P(k)

 Not just statistical error! Minimum systematic error



Sample more k-modes

One solution = A galaxy survey at high-z



Why high-z? Less non-linear power!

As the universe ages, gravitational effects distort initial power spectrum on increasingly larger scales

• At z=6, non-linear contribution at k=1 Mpc^-1 is about 15%.

All we care about is the position of galaxies

Different mass selections merely change the overall normalization, preserving the shape of the power spectrum.

Bias is a measure of the degree to which galaxies follow the dark matter distributi on

• Linear bias affects only the overall nor malization and not the shape; thus no aff ect on the inflation constraints

• CIP overlaps strongly with both CMB and Ly studies, providing an accurate b ias estimate

CIP will nail it!

V(











Achieving 1% accuracy drives the observing strategy

Science Drivers:

To best constrain inflation and overlap with CMB, need adequate statistics on scales from 1 Mpc to 100 Mpc

Achieving 1% accuracy drives the observing strategy

Science Drivers:

To best constrain inflation and overlap with CMB, need adequate statistics on scales from 1 Mpc to 100 Mpc

Achieving 1% accuracy drives the observing strategy

Science Drivers:

To best constrain inflation and overlap with CMB, need adequate statistics on scales from 1 Mpc to 100 Mpc

H is an ideal line due to its strength

CIP design stresses simplicity

No moving parts in the instrument (other than an ejectable telescope cover and a one-time-use secondary mirror focus mechanism).

•

background through proven passive cooling techniques).

•

•

CIP is stationed at L2 to achieve proper passive cooling.

CIP in Delta II

CIP fits inside the fairing of a standard-issue Delta launch vehicle.

Almost all the hardware has been flown before.

Mission Cost Summary

Smithsonian Astrophysical Observatory*

University of Texas Lockheed-Martin

SAO CIP Contract Delta Launch Vehicle (GFE)

CIP Total Program Total Allowable Costs

Contingency

$ 43.3 10.1 385.0

$ 438.4 80.0

$ 518.4 670.0

$ 151.6 FY04

$M

* Includes $14.5 M in SAO burden on subcontracts

Observation Design

• Survey Volume: 140 sq deg overlaps with CMB

• Spectral Resolution: need to resolve 1 Mpc in redshift space at z = 6, implying resolving power > 200

• z range: need high-z in order to overcome non-linearity and bias; also need broad z-range to watch and calibrate non- linear effects: 3 < z < 6.5 is ideal.

• Spectral coverage: is the only viable option in order to get enough objects. At 3 < z < 6.5, this implies spectral coverage of 2.55

• Flux limit: to get accurate power spectrum requires source densities of around 10 per sq. arcmin. At z = 6, this is

reached at star formation rates of 6 M_sun/year, or flux_H=1.9 x 10^-14 ergs/m²/s (based both on direct observations and

theoretical predictions).

• Telescope and Exposure time: 11.5 hour exposure with a 1.8-m space-based telescope operating for 2 years will reach these limits. Not possible from the ground.

As the earth goes around the sun, the dispersion direction rotates on the sky:

x y

x y

 z

As we map the sky repeatedly over

3 months, we build up a set of spectra showing intensity in the x,y, plane.

We transform to the x,y,z plane.

High-z galaxies Stars

Nearby galaxies Dispersed

Noise added Median filtered After 10 rotations Spectrum

Extracting the data 1’ x 1’

The CIP Study Team is Small but Very Active

CfA: PI Gary Melnick (SWAS PI) Giovanni Fazio (IRAC PI)

Volker Tolls (SWAS Project Scientist) UT : Eiichiro Komatsu, Karl Gebhardt,

Volker Bromm, Dan Jaffe

Lockheed: Bob Woodruff (HST Corrective Optics) + cast of many

Helpful consultation from many, special mention: Daniel Eisenstein, Paul Shapiro

Ancillary Science

• Star Formation History: CIP will measure SFR for over 10 million galaxies fro m 3<z<6.5, providing unprecedented numbers on the star formation history of t he universe.

• Dark Energy: CIP will measure the baryonic oscillations (the counterpart to th e CMB fluctuations) at high-z. If dark energy is important there (i.e., not a cosm ological constant), CIP will be in the unique position to provide the only measur e of dark energy at high-z.

• Neutrino Mass: CIP will measure the total mass of all neutrinos down to ~0.2 eV (current limit is 0.7eV), but can greatly improve this if bias is well understoo d (comparison to simulations).

• Brown Dwarfs: CIP will take R=200 2.5-5 m spectra of a significant sample of cool brown dwarfs.

• Supernovae: CIP will measure the same spot on the sky with one hour expos ures spaced by one month, which is excellent cadence for SNe. In 140 sq deg, CIP will find hundreds of Type Ia SNe with IR spectra.

• Extreme Objects: CIP will find the highest redshift objects, the highest star for ming objects, the pure-emission line objects, etc.

(Built without torquing instrument or mission)

Current Status and where we go from here.

What if this happens?

CIP will take R=200 2.5-5 m spectra of a significant sample of cool brown dwarfs.

Over the 140 square degree field, CIP will take S/N=10 spectra of brown dwarfs down to L=21. The spectral range includes important features of H₂O and CH₄.

Brown Dwarf Survey Parameters Spectral

Type

Absolute L’

D_max (pc)

Survey Volume (10⁶ pc³)

L3 10.5 1200 430

L5 11 1000 250

L8 11.5 800 120

T6 13.5 320 8

T9 14.5 200 2

Data from Golimowski et al. (2004)

Will gravitational effects confuse the results?

Galaxy Bias

Bias is a measure of the degree to which galaxies follow the dark matter distribution

• Linear bias affects only the overall

normalization and not the shape; thus no affect on the inflation constraints

• CIP overlaps strongly with both CMB and Ly

studies, providing an accurate bias estimate

Galaxy Bias

Non-Linear Power

As the universe ages, gravitational effects distort initial power spectrum on increasingly larger scales

• At z = 6, non-linear contribution at k = 1 Mpc^-1 is about 15%. All CIP inflation constraints use k<0.5 where the non-linear contribution is negligible

Bias is a measure of the degree to which galaxies follow the dark matter distribution

• Linear bias affects only the overall

normalization and not the shape; thus no affect on the inflation constraints

• CIP overlaps strongly with both CMB and Ly

studies, providing an accurate bias estimate

Will gravitational effects confuse

the results?

Redshift Space Distortion

Since we are measuring redshifts, the measured clustering length of gal axies in z-direction will be affected by peculiar velocity of galaxies.

 This is the so-called “redshift space distortion”.

Angular direction is not affected at all by this effect.

In the linear regime, the clustering length in z-direction appears shorter than actually is.

 This is not the “finger-of-god”! The finger-of-god is the non-linear effect.

The distortion pattern can be calculated and corrected exactly using line ar theory.

 As a bonus, the amplitude of the distortion give us an estimate of bias!

z direction

angular direction No peculiar motion Peculiar motion

REDSHIFT IDENTIFICATION

• At z = 5, we get about 4000 A of rest spectum.

• Thus, we will often have more than Hfor identification.

• Confusion with bluer lines will only be with extreme objects: z > 8 objects with only O[II] or O[III] lines.

• NII is often present in star forming regions, and CIP does have resolution to see that complex around H

• Ly is only an issue for z > 20 objects!

• Confusion with lines redder than His only from nearby galaxies, but these will be easy to ID from the Br series and their obvious continuum.

• Ground based imaging survey will provide photo-z’s

CIP will easily identify redshifts, with less than 1%

contaminates (has negligible effect on statistics).

SPACECRAFT VERIFICATION

TESTS SPACECRAFT

ASSEMBLY COMPLETE

OPTICAL TELESCOPE

ASSEMBLY COMPLETE

FPA CRYOGENIC CHARACTER-

IZATION TESTS FPA

FABRICATION COMPLETE

FPA CRYOGENIC ACCEPTANCE

TESTS

• S/C STRUCTURE

• POWER SYSTEM

• THERMAL CONTROL SYSTEM

• POINTING CONTROL SYSTEM

• C&DH SYSTEM

• FPA CONTROL ELECTRONICS

• COMMUNICATIONS SYSTEM

• PROPUSLION SYSTEM

• FLIGHT SOFTWARE

• INTERFACE CHECKS

• STATIC LOAD/

MODAL TEST

• BAKE OUT

• FUNCTIONAL TESTS

• EMC

• COMPATS/I/F CHECK

INSTALL FPA IN OTA

OTA FULL- APERTURE TEST AND CALIBRATION DELTA CHAMBER

• FPA DETECTION OF SPECTRA FOR NUMEROUS FIELDS

• VACUUM, OTA <100K

• FPA AT OPERATIONAL TEMPERATURE

• OTA VERTICAL INTEGRATE AND ALIGN S/C, OTA AND SOLAR PANELS

OBSERVATORY VERIFICATION

TESTS

• BASELINE FUNCTIONAL

• EMC/MAGNETIC SURVEY

• JITTER/DYNAMIC TEST/MODAL TEST

• ACOUSTIC/PYROSHOCK TEST

• POST-TEST FUNCTIONAL

OBSERVATORY TV/TB TESTS

OBSERVATORY FULL- APERTURE SYSTEM TESTS

OBSERVATORY POST-TV/TB

TESTS

OBSERVATORY PREP AND

SHIP DELTA CHAMBER

• TEMPERATURE CYCLING AND EXTREMES

• THERMAL BALANCE

• OBSERVATIORY FUNCTIONALS

• MISSION SCENARIOS TESTS

DELTA CHAMBER

• CIP ILLUMINATED BY SUBAPERTURE

• VACUUM, OTA < 100K

• FPA AT OPERATIONAL TEMPERATURE

• FPA DETECTION SPECTRA CHECKS

• OBSERVATIORY FUNCTIONAL TESTS

• MISSION SCENARIOS TESTS

• ETE COMPATS TEST

• LAUNCH REHERSAL

LOCKHEED-MARTIN ROCKWELL AMES

CIP ATLO TEST FLOW CHART 1/6/05

NOTE: Grating, Tertiary and FPA are mounted on OTA structure.

INSTALL OTA SHROUD

LAUNCH SITE CHECKOUT

LAUNCH

KSC FROM OTA TEST FLOW