The DEEP2 Redshift Survey

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.


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


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.


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


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….


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


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


Redshift Distribution of DEEP2 Survey


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, ….


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


Redshift Maps in 4 Fields: z=0.7-1.3

Cone diagram of 1/12 of the full DEEP2 sample


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


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.


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


By combining area with depth, AEGIS allows us to study rare objects in detail…

B. Gerke, JN et al. 2006, AEGIS ApJL, Accepted


Like a spectroscopically identified, dual AGN at z=0.7

H

[OIII] 4959

[OIII]5007

/ z

posi

tion


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


• 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

The DEEP2 Redshift Survey

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