granada, october 2007 marc davis uc berkeley the deep2 redshift survey
TRANSCRIPT
Granada, October 2007
Marc Davis
UC Berkeley
The DEEP2 Redshift Survey
The DEEP2 Collaboration
U.C. Berkeley
M. Davis (PI)
D. CrotonD. Croton
M. Cooper
B. Gerke
R. Yan
U.C. Santa Cruz
S. Faber (Co-PI)
D. Koo
P. Guhathakurta
U.C. Santa Cruz
D. Phillips
S. Kassin
K. Noeske
A. Metevier
L. Lin
N. Konidaris
G. Graves
J. Harker
Other InstitutionsJ. Newman (LBNL)
A. Coil (Arizona)C. Willmer (Arizona)B. Weiner (Arizona)R. Schiavon (UVA)
C. Conroy (Princeton)N. Kaiser (Hawaii)
D. Finkbeiner(Harvard)
A. Connolly (Pitt.)
The DEEP2 Galaxy Redshift Survey used the DEIMOS spectrograph at the Keck II telescope to study both galaxy
properties and large-scale structure at z~1.
Granada, October 2007
DEEP2 has been made possible by DEIMOS, a new instrument on Keck II
DEIMOS:
• PI: Faber
• wide-field multiplexing (up to 160 slitlets over a 16’x4’ field)
• high resolution (R~5000)
• spectral range (~2600 Å at highest resolution)
• CCD array of 8k x 8k
Optics are key to the success of DEIMOS
Complex design by Harlan Epps
Brilliant work by Dave Hilyard
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DEEP2 pre-selects high-z galaxies using observed
colors
DEEP2 mask selection
Targeted galaxies are enclosed with white curves
Solid slits are objects selected on a given mask.
dotted and dashed lines are galaxies from neighboring masks.
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DEEP2 slitmask spectroscopy
Using custom-milled slitmasks with DEIMOS we obtained spectra of ~150 targets at a time. A total of 400 slitmasks was required for the survey; we tilted slits up to 30 degrees to obtain rotation curves.
position
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AEGIS: the All-wavelength Extended Groth Strip International Survey
Spitzer MIPS, IRAC
DEEP2 spectra and Caltech/JPL Ks imaging
HST/ACSV,I (Cycle 13)
DEEP2/CFHTB,R,I
GALEX NUV+FUV
Chandra & XMM:XMMChandra (1.6Ms)
Plus VLA (6 & 21 cm), SCUBA, etc….
Granada, October 2007
X-ray analysis - detection and photometry
• P.Nandra et al.• Each square has integration
time of 200 ksec• Source selection and
photometry by own method– Elliptical shaped PSFs
• All data will be released in August, 2007
1.6 Ms
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A Redshift Survey at z=1:• 3 sq. degrees • 4 fields (0.5o x <2o)• 80 Keck nights, one-hour exposures to RAB=24.1• primarily z~0.75-1.4 (pre-selected using BRI photometry)• 47,000 unique redshifts, error ~30 km/s• ~5·106 h-3 Mpc3
• 1200 l/mm: ~6500-9200 Å• 1.0” slit: FWHM 68 km/s• z=0.7-1.4 spans lookback time ~6.0 - 8.0 Gyr ago• Within DEEP2 we are surveying 2.5 Gyr or ~20% of the history of the Universe, and SDSS/2dF comparisons give ~3x this baseline
Granada, October 2007
Redshift Distribution of DEEP2 Survey
Granada, October 2007
DEEP2 Status Update
• DEEP2 began observations in July 2002.
• Observations are now >99% finished, with >49k spectra in hand and 3 of 4 fields completed.
• Follow-up observations have begun.
•ALL the data is already public:
http://deep.berkeley.edu/DR4
• The catalog and 2d spectra is all available, and others are releasing Chandra, Spitzer, GALEX, HST, ….
Granada, October 2007
Brian F. Gerke
Evrard et al. 02Hubble volume simulations
ΛCDMτCDM
o 1015 Mo
* 10 14.5-15Mo
. 1014-14.5 Mo
Ω=1 Ω=0.3,ΩΛ=0.7
Cluster abundance depends on cosmology
Granada, October 20072PIGG:Eke et al 2004
DEE
P2: G
erke
et a
l 200
5
z=0.75
z=1.0
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Redshift Maps in 4 Fields: z=0.7-1.3
Cone diagram of 1/12 of the full DEEP2 sample
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Galaxy groups in DEEP2
, zposition
•Overdensities identified in redshift space.
•Use the VDM algorithm of Marinoni et al. (2002).
•Group in early DEEP2 data s~250 km/sec
Granada, October 2007
DEEP2 Group Catalog
Gerke et al. 2005, astro-ph/0410721
Shown are groups for 3 fields --length of ellipse proportional to velocity dispersion
Groups with >350 km/s
Why search for groups in DEEP2?•Apparent abundance of groups: dN(,z)/dzd Provides a useful test of dark energy eq. of state (Newman et al, 2002)
•differences in the volume element varies by 3x between w=0 and w=-1
•For groups of modest-mass, the evolution of dispersion is 2nd order
•Heavy black curve is ΩT=.3 DEIMOS took ~7 years to build; at time of designing science expt. ΩT was still undetermined, and DE was not discussed.
Granada, October 2007
Brian F. Gerke
Projected constraints
Computed with DM halos in simulated DEEP2 and 2dF light cones, constructed from the Millennium Run.
In each panel, the suppressed parameter is held fixed.
input cosmology
DEEP2 Cluster Counts
•DEEP2 survey counted ~300 groups•Velocity dispersion measured in each case•Counts of N(, z) is a strong test of w•Have not got mock catalogs with the evolving color selection, making it difficult to proceed•B. Gerke will have results out “soon”
Measuring Kaiser infall in (rp,)
•The blue galaxies show fully developed coherent infall pattern on scales >5 Mpc, as expected.
•The red galaxies have very extended fingers of god, as expected.
Coil et al, 2008
Kaiser infall, MOCKS
Millenium mocks, not a bad approximation
Coil et al, 2008
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By combining area with depth, AEGIS allows us to study rare objects in detail…
B. Gerke, JN et al. 2006, AEGIS ApJL, Accepted
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Like a spectroscopically identified, dual AGN at z=0.7
H
[OIII] 4959
[OIII]5007
/ z
posi
tion
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HST reveals a fairly-normal early-type host
Rotation Curves of 88 galaxies with HST and DEIMOS’s Spatial Resolution
•Study evolution of Spirals
Metevier et al, 2007, in process
Ly-alpha emission seen in many slits
•Slits are 1” long, more than 50% blank field, giving > 1 sq arcminute for deep search, 3 < z < 6
•Searching by “eye” for asymmetric emission lines
•So far they have searched ~20% of fields and found 9 clean systems
Sawicki et al, in preparation
Granada, October 2007
• DEEP2 observations are >99% done
•Work not yet published is study of galaxy clustering
• DR4 has occurred this August: http://deep.berkeley.edu/DR4
• AEGIS ApJL special issue
• Way too many new results to cover in one talk!
•A Spectroscopic survey has many followups!
Conclusions on DEEP2