Upload
suchin
View
48
Download
2
Tags:
Embed Size (px)
DESCRIPTION
Will the Dark Energy Survey measure neutrino masses? http://www.darkenergysurvey.org. Outline DES: what is it and update + probes used Neutrino masses from DES. The Dark Energy Survey (DES). Proposal: Perform a 5000 sq. deg. survey of the southern galactic cap - PowerPoint PPT Presentation
Citation preview
Will the Dark Energy Survey measure neutrino masses? http://www.darkenergysurvey.org
OutlineDES: what is it and
update + probes usedNeutrino masses from
DES
The Dark Energy Survey (DES)Proposal:
◦ Perform a 5000 sq. deg. survey of the southern galactic cap
◦ Measure dark energy with 4 complementary techniques
New Instrument:◦ Replace the PF cage
with a new 2.2 FOV, 520 Mega pixel optical CCD camera + corrector
Time scale:◦ Instrument Construction
2008-2011Survey:
◦ 525 nights during Oct.–Feb. 2011-2016
◦ Area overlap with SPT SZ survey and VISTA VHS
Use the Blanco4m Telescope at the Cerro TololoInter-American Observatory (CTIO)
The DES Collaborationan international collaboration of ~100 scientists from ~20 institutions
US: Fermilab, UIUC/NCSA, University of Chicago,LBNL, NOAO, University of Michigan, University of Pennsylvania, Argonne National Laboratory, Ohio State University, Santa-Cruz/SLAC Consortium
Observatorio Nacional, CBPF,Universidade Federal do Rio de Janeiro, Universidade Federal do Rio Grande do Sul
Brazil Consortium:
UK Consortium:UCL, Cambridge, Edinburgh, Portsmouth, Sussex, Nottingham
Spain Consortium:CIEMAT, IEEC, IFAE
CTIO
DES Organization
SupernovaeB. NicholJ. Marriner
ClustersJ. MohrT. McKay
Weak LensingB. JainS. Bridle
Galaxy ClusteringE. GaztanagaW. Percival
Photometric RedshiftsF. CastanderH. Lin
SimulationsA. KravtsovA. Evrard
TheoryW. HuJ. Weller
Strong LensingE. Buckley-GeerM. Makler
Galaxy EvolutionR. WechslerD. Thomas
QSOsR. McMahonP. Martini
Milky WayB. SantiagoB. Yanny
11 Science Working Groups
Over 100 scientistsfrom the US, UK, Spain and Brazil
The DES Instrument: DECam DECam Focal Plane
3 sq. deg. field of view (~ 0.5 meter diameter focal plane)62 2kx4k Image CCDs: 520 MPix8 2kx2k Alignment/focus CCDs4 2kx2k Guide CCDs
The 5 lenses are now being polished
C2
Polishing & coating coordinated by UCL (with 1.7M STFC funding)
C1
Design: 5 lensesLargest is~ 1m diameterSmallest is ~ 0.5m
Polishing started in May 2008 Est. Delivery May 2010
DES CCDs 62 2kx4k fully
depleted CCDs: 520
Megapixels Excellent red
sensitivity Developed by
LBNL
0
10
20
30
40
50
60
70
80
90
100
300 400 500 600 700 800 900 1000 1100Wavelength (nm)
Qua
ntum
Eff
icie
ncy
(%)
Thinned CCD Deep DepletedLBNL high resistivity
Full size prototype imager used for integration testing out at Sidet (Fermilab)
9
DECam parts in Fabrication: Shutter
Bonn University and Argelander Institute in Germany is making the DES Shutter
Opening is ~ 600mm diameter
The DECam Shutter is the largest ever (so far)
Earthquake!!!No damage to
telescopeGiven that and
timeline of CCD’s and corrector -> first light should be late next year
Dark Energy Science Program
Four Probes of Dark EnergyGalaxy Clusters
• clusters to z>1• SZ measurements from SPT• Sensitive to growth of structure and geometry
Weak Lensing• Shape measurements of 300 million galaxies • Sensitive to growth of structure and geometry
Large-scale Structure• 300 million galaxies to z = 1 and beyond• Sensitive to geometry
Supernovae• 15 sq deg time-domain survey• ~3000 well-sampled SNe Ia to z ~1• Sensitive to geometry
Plus QSOs, Strong Lensing, Milky Way, Galaxy Evolution
Synergy with VISTADES recovers V in VISTA!DES will provide the visible and Vista the IR counterpart
DES grizDES10 Limiting Magnitudes g 24.6 r 24.1 i 24.0 z 23.9
+2% photometric calibrationerror added in quadrature
Galaxy Photo-z Simulations
+Developed improved Photo-z & Error Estimates and robust methods of outlier rejectionCunha, Lima, Frieman, Lin and Abdalla, Banerji. Lahav
Z 23.8Y 21.6
+VHS DES griZY +VHS JHKs onESO VISTA 4-menhances science reach
*Vista Hemisphere Survey
J 20.3H 19.4Ks 18.3
ANNz; low depth survey: trainingsets in place
DES Forecasts: Power of Multiple Techniques
Assumptions:Clusters: 8=0.75, zmax=1.5,WL mass calibration
BAO: lmax=300WL: lmax=1000(no bispectrum)
Statistical+photo-z systematic errors only
Spatial curvature, galaxy biasmarginalized,Planck CMB prior
w(z) =w0+wa(1–a) 68% CL
geometric
geometric+growth
DETF Figure of Merit: inversearea of ellipse
Stage II notincluded here
DES will also constrain the neutrino mass
We have made simulations for this with Des photometric redshifts
We have also measured this from the current SDSS survey. (cosmological results presented by Thomas Tues.)
I will go through the assumptions and present the forecasts.
Neutrinos as Dark Matter• Neutrinos are natural DM candidates
• They stream freely until non-relativistic (collisionless phase mixing) Neutrinos are HOT Dark Matter• First structures to be formed when Universe became matter -dominated
• Ruled out by structure formation CDM
eV 46 m 1 Ω eV 93.2m
hΩi
iνi
i2
ν
MpceV 30m 41
-1
ν
Neutrino Free Streaming
F
b, cdm
n
Measuring the clustering with Photo-z
Photo-z distribution
Looking at techniques in real data:The 2SLAQ & MegazLRG. (Pathfinder with DES)
2SLAQ galaxies selected from the SDSS survey. Mainly red galaxies at redshift ranging from 0.4 to 0.7.
Even though photo-z are good for LRG given large 4000A break different techniques give different accuracies
13000 galaxies from 2SLAQ. ~8000 for training ~5000 to calibrate the histogram
Abda
lla e
t al 0
8
DES+VISTA would improve photo-z by a factor of 2 for z> 1What is the effect on WL, BAO, SNIa Science?
Banerji, Abdalla, OL & Lin 0711.1059
DES (5 filters) vs. DES+VISTA(8 filters)
Already seen earlier this weekThomas et al. 0911.5291
WMAP red: bound is ~1.3eV. (all 95%)+ BAO+SNe: blue 0.69eV + MegaZ : yellow 0.65eV + BAO+SNe+MegaZ+HST: green 0.28eV
Neutrino mass from DES+Planck
Lahav, Kiakotou, Abdalla and Blake(0910.4714)DES + Planck 5 times more constraining than WMAP + MegaZDES will have many galaxy types (~30 or so) to do this experiment -> important for galaxy bias
Two simulations used:Input: Mn =0.05 eV and 0.25eV
Error: 0.12 eV 95% (Only DES + Planck) on both simulations. Without any further data (BAO, SNe, clusters, etc…)
Total Neutrino Mass DES vs. KATRIN Mn< 0.1 eV Mn < 0.6 eV
t
Goal: 0.05 eVOther cosmological probes of the neutrino mass: weak lensing, CMB lensing, etc…
ConclusionsDES under construction:
◦ Lenses being polished◦ CCD’s being tested◦ Should have first light late next year
Science predicts a increase in our knowledge in w0-wa plane
Also increase in our knowledge in the neutrino mass:◦ Same experiment done on SDSS LRG’s
m_nu < 0.28eV◦ For DES m_nu < 0.12eV with Planck only.◦ All these have to be taken with a pinch of salt…
but…