Transcript The 2dF Galaxy Redshift Survey

(I) Neutrino Masses from LSS
(I) Neutrino Masses from the CMB
(III) The Dark Energy Survey
Ofer Lahav
University College London
Concordance Cosmology
 SN Ia
 CMB
 LSS – Baryonic
Oscillations
 Cluster counts
 Weak Lensing
 Integrated Sachs Wolfe
Physical effects:
* Geometry
* Growth of Structure
Massive Neutrinos and Cosmology
* Why bother? – absolute mass, effect on other parameters
* Brief history of ‘Hot Dark Matter’
* Limits on the total Neutrino mass from cosmology within CDM
M < 1 eV
* Mixed Dark Matter?
* Non-linear power spectrum and biasing – halo model
* Combined cosmological observations and laboratory experiments
Brief History of
‘Hot Dark Matter’
* 1970s : Top-down scenario with massive neutrinos (HDM) –
Zeldovich Pancakes
* 1980s: HDM - Problems with structure formation
* 1990s: Mixed CDM (80%) + HDM (20% )
* 2000s: Baryons (4%) + CDM (26%) +Lambda (70%):
But now we know HDM exists!
How much?
Globalisation and
the New Cosmology
 How is the New Cosmology affected by
Globalisation?
 Recall the Cold War era:
Hot Dark Matter/top-down (East)
vs. Cold Dark Matter/bottom-up (West)
 Is the agreement on the `concordance model’ a
product of Globalisation?
OL, astro-ph/0610713
From Great Walls to
Neutrino Masses
Neutrinos decoupled when they were still
relativistic, hence they wiped out structure
on small scales
k > knr = 0.026 (m /1 eV)1/2 m1/2 h/Mpc
Colombi, Dodelson, &
Widrow 1995
CDM+HDM
WDM
Massive neutrinos mimic
a smaller source term
CDM
Neutrino properties
The number of neutrino species N affects
the expansion rate of the universe, hence BBN.
BBN constraints N between 1.7 and 3 (95% CL)
(e.g. Barger et al. 2003).
From CMB+LSS+SN Ia, N =4.2+1.2-1.7 (95% CL)
(Hannestad 2005)
We shall assume N =3
Electron, muon and tau neutrinos
Eigen states m1, m2, m3
112 neutrinos per cm3
 h2 = M/(94 eV)
Neutrino Mass Hierarchy
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Absolute Masses of Neutrinos
Based on
measured
squared mass
differences
from solar and
atmospheric
oscillations
Assuming
m1 < m2 < m3
E & L, NJP 05
What could cosmic probes tell
us about Neutrinos and Dark
Energy?
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
The Growth factor: degeneracy
of Neutrinos Mass and Dark
Energy
QuickTime™and a
TIFF(Uncompressed) decompressor
are needed to see this pi cture.
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Qui ckTime™ and a
TIFF ( Uncompressed) decompressor
are needed to see this pi cture.
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Kiakotou, Elgaroy, OL
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
DP(k)/P(k)
= -8  /m
Not valid on
useful scales!
Quic kTime™ and a
TIFF ( Unc ompres s ed) dec ompr ess or
are needed to s ee this pic ture.
Kiakotou, Elgaroy, OL
2007, astro-ph 0709.0253
Weighing Neutrinos with
2dFGRS
 = 0.05
0.01
0.00
 Free streaming effect:
/m < 0.13
Total  mass M< 1.8 eV
 0.001 <  < 0.04
(Oscillations) (2dF)
 a Four-Component
Universe ?
Elgaroy , Lahav & 2dFGRS team,
astro-ph/0204152 , PRL
What do we mean by
‘systematic uncertainties’?
• Cosmological (parameters and priors)
• Astrophysical (e.g. Galaxy biasing)
• Instrumental (e.g. ‘seeing’)
Degeneracy of neutrino mass
n= 0.9
n=1.0
Prior 0< m<0.5
n= 1.1
Biasing vs. neutrino mass
Pg(k) = b2(k) Pm(k)
b(k) = a log(k) + c
a
---- SAM for
L>0.75 L*
Total neutrino mass
Elgaroy & Lahav , JCAP, astro-ph/030389
Weak Lensing is promising
M
Abazajian & Dodelson (2003)
also Hannestad et al. 2006
Non-linear P(k) with massive neutrinos
Abazajian et al. (astro-ph/0411552)
modeled the effects of neutrino infall
into CDM halos
and incorporated it in the halo model.
The effect is small: DP(k)/P(k) » 1%
at k » 0.5 h/Mpc for M » 1 eV
Future work : high-resolution simulations
with CDM, baryons and neutrinos
CMB with massive 
M =0.3, 0.9, 1.5, 6.0 eV
Fixed cdm = 0.26
E&L 2004
Neutrinos masses and the CMB
If znr > zrec

 h2 > 0.017 (i.e. M > 1.6 eV)
Then neutrinos behave like matter this defines a critical value in CMB features
* Ichikawa et al. (2004 )
from WMAP1 alone  M < 2.0 eV
* Fukugita et al. (2006)
from WMAP3 alone  M < 2.0 eV
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Normalization vs neutrino mass
using WMAP alone +
concordance model
Is CMB polarisation useful
for neutrino mass?
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Not directly,
but reduces degeneracy with
the reionization optical depth
Fukugita, Ichikawa,
Kawasaki, OL, astro-ph/0605362
Ratio of bulk flows with massive
neutrinos  =0.04
Data
Deriving Neutrino mass from
Cosmology
2dF (P01)
WMAP+LSS+SN
…
2dF (C05)+CMB
BAO+CMB+LSS
+SN
Ly- + SDSS+
WMAP+…
WMAP alone
Elgaroy, OL et al.02
Spergel et al. 06
M = S mi
< 1.8 eV
< 0.68 eV
Sanchez et al. 05
Goobar et al. 06
< 1.2 eV
< 0.62 eV
Seljak et al. 04
< 0.17 eV
Ichikawa et al. 04
Fukugita et al. 06
< 2.0 eV
Authors
All upper limits 95% CL, but different assumed priors !
Forecasting Neutrino mass from
Cosmology
Data
Authors
High-z galaxy Takada et al. (2006)
surveys +
Planck
error
0.03-0.06 eV
High-z galaxy Hannestad & Wong
surveys +
(2007)
Planck
SKA + Planck Abdalla &
Rawlings(2007)
0.05 eV
Note different error definitions and assumed priors !
0.05 eV
Combined Cosmology
& Terrestrial Experiments
Fogli et al.
Hep-ph/0408045
Combining KATRIN+CMB (Host, OL, Abdalla & Eitel 2007) =>> Ole’s talk
Neutrinos - Summary
* Redshift surveys (+ CMB) M < 0.7-1.8 eV
Ly- (+ CMB+LSS)
M < 0.17 eV
* Within the -CDM scenarios, subject to
priors.
* Alternatives: MDM ruled out.
* Future: errors down to 0.05 eV
using SDSS+Planck,
and weak gravitational lensing of background
galaxies and of the CMB.
Resolve the neutrino absolute mass!
Baryon Wiggles as Standard Rulers
Imaging Surveys
Survey
Sq. Degrees
Filters
Depth
CTIO
75
1
shallow
published
VIRMOS
9
1
moderate
published
COSMOS
2 (space)
1
moderate
complete
DLS (NOAO)
36
4
deep
complete
Subaru
30?
1?
deep
2005?
observing
CFH Legacy
170
5
moderate
2004-2008
observing
RCS2 (CFH)
830
3
shallow
2005-2007
approved
VST/KIDS/
VISTA/VIKING
1700
4+5
moderate
2007-2010?
50%approved
DES (NOAO)
5000
4
moderate
2008-2012?
proposed
Pan-STARRS
~10,000?
5?
moderate
2006-2012?
~funded
LSST
15,000?
5?
deep
2014-2024?
proposed
9
deep
2013-2018?
proposed
4+5
moderate
2010-2015?
proposed
2+1?
moderate
2012-2018?
proposed
VST/VISTA
1000+
(space)
5000?
DUNE
20000? (space)
JDEM/SNAP
Dates
Status
Y. Mellier
DUNE: Dark UNiverse
Explorer
Mission baseline:
• 1.2m telescope
• FOV 0.5 deg2
• PSF FWHM 0.23’’
• Pixels 0.11’’
• GEO (or HEO) orbit
Surveys (3-year initial programme):
• WL survey: 20,000 deg2 in 1 red broad band,
35 galaxies/amin2 with median z ~ 1, ground
based complement for photo-z’s
• Near-IR survey (J,H). Deeper than possible
from ground. Secures z > 1 photo-z’s
• SNe survey: 2 x 60 deg2, observed for 9
months each every 4 days in 6 bands, 10000
SNe out to z ~ 1.5, ground based spectroscopy
Photometric redshift
• Probe strong
spectral features
(4000 break)
• Difference in flux
through filters as the
galaxy is redshifted.
*Training on ~13,000 2SLAQ
*Generating with ANNz
Photo-z for ~1,000,000 LRGs
MegaZ-LRG
z = 0.046
Collister, Lahav,
Blake et al.,
astro-ph/0607630
Baryon oscillations
Blake, Collister, Bridle & Lahav; astro-ph/0605303
The Dark Energy Survey
• Study Dark Energy using
4 complementary techniques:
Blanco 4-meter at CTIO
I. Cluster Counts
II. Weak Lensing
III. Baryon Acoustic Oscillations
IV. Supernovae
•
Two multi-band surveys
5000 deg2 g, r, i, z
40 deg2 repeat (SNe)
•
Build new 3 deg2 camera
and data management system
Survey 2010-2015 (525 nights)
Response to NOAO AO
300,000,000 photometric redshifts
The DES Collaboration
Fermilab: J. Annis, H. T. Diehl, S. Dodelson, J. Estrada, B. Flaugher, J. Frieman,
S. Kent, H. Lin, P. Limon, K. W. Merritt, J. Peoples, V. Scarpine, A. Stebbins,
C. Stoughton, D. Tucker, W. Wester
University of Illinois at Urbana-Champaign: C. Beldica, R. Brunner, I. Karliner,
J. Mohr, R. Plante, P. Ricker, M. Selen, J. Thaler
University of Chicago: J. Carlstrom, S. Dodelson, J. Frieman, M. Gladders,
W. Hu, S. Kent, R. Kessler, E. Sheldon, R. Wechsler
Lawrence Berkeley National Lab: N. Roe, C. Bebek, M. Levi, S. Perlmutter
University of Michigan: R. Bernstein, B. Bigelow, M. Campbell, D. Gerdes, A. Evrard,
W. Lorenzon, T. McKay, M. Schubnell, G. Tarle, M. Tecchio
NOAO/CTIO: T. Abbott, C. Miller, C. Smith, N. Suntzeff, A. Walker
CSIC/Institut d'Estudis Espacials de Catalunya (Barcelona): F. Castander, P.
Fosalba, E. Gaztañaga, J. Miralda-Escude
Institut de Fisica d'Altes Energies (Barcelona): E. Fernández, M. Martínez
CIEMAT (Madrid): C. Mana, M. Molla, E. Sanchez, J. Garcia-Bellido
University College London: O. Lahav, D. Brooks, P. Doel, M. Barlow, S. Bridle,
S. Viti, J. Weller
University of Cambridge: G. Efstathiou, R. McMahon, W. Sutherland
University of Edinburgh: J. Peacock
University of Portsmouth: R. Crittenden, R. Nichol, R. Maartnes, W. Percival
University of Sussex: A. Liddle, K. Romer
plus postdocs and students
The Dark Energy Survey UK Consortium
(I) PPARC funding:
O. Lahav (PI), P. Doel, M. Barlow, S. Bridle, S. Viti, J. Weller (UCL),
R. Nichol (Portsmouth), G. Efstathiou, R. McMahon, W. Sutherland (Cambridge)
J. Peacock (Edinburgh)
Submitted a proposal to PPARC requesting £ 1.7M for the DES optical design.
In March 2006, PPARC Council announced that
it “will seek participation in DES”.
PPARC already approved £220K for current R&D.
(II) SRIF3 funding:
R. Nichol, R. Crittenden, R. Maartens, W. Percival (ICG Portsmouth)
K. Romer, A. Liddle (Sussex)
Funding the optical glass blanks for the UCL DES optical work
These scientists will work together through the UK DES Consortium.
Other DES proposals are under consideration by
US and Spanish funding agencies.
DES Forecasts: Power of Multiple
Techniques
Assumptions:
Clusters:
8=0.75, zmax=1.5,
WL mass calibration
w(z) =w0+wa(1–a)
BAO: lmax=300
WL: lmax=1000
(no bispectrum)
Statistical+photo-z
systematic errors only
Spatial curvature, galaxy bias
marginalized,
Planck CMB prior
Factor 4.6 improvement over Stage II
DETF Figure of
Merit: inverse
area of ellipse
68% CL
DES z=0.8 photo-z shell
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
M
0.0 eV
0.4
0.9
1.7
Back of the envelope: improved by sqrt (volume) => Sub-eV from DES
(OL, Abdalla, Black; in prep)
DES and a Dark Energy Programme
•
* 4-5 complementary probes
•
* Survey strategy delivers substantial DE science after 2
years
•
* Relatively modest (~ $20-30M), low-risk, near-term
project with high discovery potential
•
* Synergy with SPT and VISTA on the DETF Stage III
timescale
•
* Scientific and technical precursor to the more ambitious
Stage IV Dark Energy projects to follow: LSST and
JDEM
Some Outstanding Questions:
* Vacuum energy
(cosmological constant, w= -1.000 after all ?)
* Dynamical scalar field ?
* Modified gravity ?
* Why /m = 3 ?
* Non-zero Neutrino mass < 1eV ?
* The exact value of the spectral index: n < 1 ?
* Excess power on large scales ?
* Is the curvature zero exactly ?