massive sze-selected clusters from the atacama cosmology

CL2010, IPMU July 2 2010

Massive SZE-selected clusters from the Atacama Cosmology Telescope

Felipe Menanteau (Rutgers)and the ACT collaboration

(Menanteau et al. 2010, in arXiv:1006.5126)


Outline

• Why Clusters and the SZ Cluster Selection.

• Optical Identification of SZ-selected clusters

• The observed “purity” of the ACT SZ-sample.

• Conclusions


Why Clusters?

• Clusters are relatively simple objects

• The number of massive, collapsed systems gives us a handle on the

density ( !M) and RMS ("8) of the matter distribution (and dark energy too)

• SZE is redshift independent

• SZE integrated Y parameter is tightly correlated with cluster mass

Y = (!

yd!)d2A(z)


SZE Signature (Observable)Hot electron gas

imposes a unique

spectral signature

NO SZ Contribution in Central Band

(Credit: Neelima Seghal) 1.4°x 1.4°

145 GHz

decrement



imposes a unique

spectral signature



145 GHz

decrement220 GHz

null



imposes a unique

spectral signature



145 GHz

decrement220 GHz

null

270 GHz

increment


ACT: Atacama Cosmology Telescope

• Next to the ALMA site @ 5200 meter elevation


Sky CoverageSky Coverage!

ACT observes in the south (ACT strip at -55o) and at the equator (includes SDSS Stripe 82) !

ACT Survey Coverage

2007

2008

2009 Stripe 82

ACT Range BOSS

BCS

Masked

Tobias A. Marriage Fall 2009


2008 ACT coverage

Marriage et al. (2010)


• 2 nights at Blanco/MOSAICII - both nights lost to poor weather (Aug 18, 2009)

• 4 nights at NTT/EFOSC2 - 3 photometric nights, seeing 0.6”-1.0” (Oct 25, 2009)

• 4 night at SOAR/SOI - 4 photometric nights, seeing 0.6”-1.0” (Dec 12)

• g: 270 s, r:360 s and i: 1100s, (~30 min/cluster)

• 12-15 candidates per night -- fast readout times!!

Optical Follow-up: Purity of the ACT SZ Cluster Sample

In March 2009, we proposed as (NOAO/ESO/CNTAC) to determine the recovery fraction of real clusters from a large sample ACT SZE decrements at 148 GHz as a function of SNR.









Cluster









NTT/La Silla









SOAR/Pachón

NTT/La Silla


“Testing the Selection Function of Galaxy Clusters in the New SZE Surveys”

r-band brightness of E galaxiesExpected cluster distribution

Tinker et al (2008) mass function

Cluster Identification (Proposed)


Cluster Identification (Recovered)

Recovery fraction of early-type galaxies with r1/4 (de Vaucouleurs) profiles for actual SOAR and NTT observing conditions

Magnitude limits determined from simulation Galaxy i-band apparent magnitude as function of redshift


How far can we see?• Simulate on lower signal NTT observations

Take image of one of the new real clusters, mask out stars and other non-cluster galaxies, scale g, r, i data in brightness (DL)

and size (DA) and evolution for range of redshifts, add scaled

image to another “blank field” image.

Blank Field/Noise ACT Cluster

+

z=0.59


Cluster Simulationz=0.60

6 Menanteau et al.

Table 2ACT 2008 clusters

ACT Descriptor R.A. (J2000) Dec. (J2000) Redshift SNR Alt Name

ACT-CL J0145-5301 01:45:03.6 -53:01:23.4 0.118 a 4.7 (4.0) Abell 2941ACT-CL J0641-4949 06:41:37.8 -49:46:55.0 0.146 b 4.9 (4.9) Abell 3402ACT-CL J0645-5413 06:45:29.5 -54:13:37.0 0.167 a 7.1 (7.1) Abell 3404ACT-CL J0638-5358 06:38:49.4 -53:58:40.8 0.222 a 10.6 (10.0) Abell S0592ACT-CL J0516-5430 05:16:37.4 -54:30:01.5 0.294 c 5.2 (4.7) Abell S0520/SPT-CL J0516-5430ACT-CL J0658-5557 06:58:33.1 -55:57:07.2 0.296 d 11.6 (11.5) 1E0657-56 (Bullet)ACT-CL J0245-5302 02:45:35.8 -53:02:16.8 0.300 e 8.3 (9.1) Abell S0295ACT-CL J0217-5245 02:17:12.6 -52:44:49.0 0.343 f 4.5 (4.1) RXC J0217.2-5244ACT-CL J0237-4939 02:37:01.7 -49:38:10.0 0.40± 0.05 4.9 (3.9)ACT-CL J0707-5522 07:07:04.7 -55:23:08.5 0.43± 0.06 4.2 (. . .)ACT-CL J0235-5121 02:35:45.3 -51:21:05.2 0.43± 0.07 5.7 (6.2)ACT-CL J0330-5227 03:30:56.8 -52:28:13.7 0.440 g 7.4 (6.1) Abell 3128(NE)ACT-CL J0509-5341 05:09:21.4 -53:42:12.3 0.461 h 4.4 (4.8) SPT-CL J0509-5342ACT-CL J0304-4921 03:04:16.0 -49:21:26.3 0.47± 0.05 5.0 (3.9)ACT-CL J0215-5212 02:15:12.3 -52:12:25.3 0.51± 0.05 4.8 (4.9)ACT-CL J0438-5419 04:38:17.7 -54:19:20.7 0.54± 0.05 8.8 (8.0)ACT-CL J0346-5438 03:46:55.5 -54:38:54.8 0.55± 0.05 4.4 (4.4)ACT-CL J0232-5257 02:32:46.2 -52:57:50.0 0.59± 0.07 5.2 (4.7)ACT-CL J0559-5249 05:59:43.2 -52:49:27.1 0.611 i 5.1 (5.1) SPT-CL J0559-5249ACT-CL J0616-5227 06:16:34.2 -52:27:13.3 0.71± 0.10 6.3 (5.9)ACT-CL J0102-4915 01:02:52.5 -49:14:58.0 0.75± 0.04 8.8 (9.0)ACT-CL J0528-5259 05:28:05.3 -52:59:52.8 0.768 h 4.7 (. . .) SPT-CL J0528-5300ACT-CL J0546-5345 05:46:37.7 -53:45:31.1 1.066 h 7.2 (6.5) SPT-CL J0546-5345

Note. — R.A. and Dec. positions denote the BCG position in the optical images of the cluster. The SZE positionwas used to construct the ACT descriptor identifiers. Clusters with uncertainty estimates on their redshifts are thosesystems for which only photometric redshifts are available from the NTT and SOAR gri imaging. The values of SNRin parentheses are the current values from Marriage et al. (2010), while the others are the ones used in this studya spec-z from de Grandi et al. (1999)b spec-z from Jones et al. (2009)c spec-z from Guzzo et al. (1999)d spec-z from Tucker et al. (1998)e spec-z from Edge et al. (1994)f spec-z from Bohringer et al. (2004)g spec-z from Werner et al. (2007)h spec-z from Infante et al. (2010)i spec-z from High et al. (2010)

For a few of these we obtained new NTT/SOAR gri ob-servations in order to calibrate our photometric redshiftand to test our identification procedure; however, for themost part these were avoided and we relied on publicarchival imaging and on data from other existing pro-grams to compare with the SZE sources.

AS0295 and AS0592 are included among the low red-shift SZE clusters reported by Hincks et al. (2009) andare the focus of a separate observing program by ourgroup (09B-0389, PI:Hughes) aimed at obtaining weaklensing masses using deep V and R observations. Thesewere obtained using the MOSAIC camera on the Blanco4-m telescope on January 9, 2010 under photometric con-ditions.

1E0657!56 (the Bullet Cluster) has been extensivelyobserved at di!erent wavelengths. Here we show theoptical observations of the cluster central region takenwith the Advanced Camera for Surveys aboard the Hub-ble Space Telescope (HST) (GO:10200, PI:Jones andGO:10863, PI:Gonzalez) using the F606W (V ), F814W(I) and F850LP (z) filters which were taken from theHST archive27.

For RXCJ0217.2!5244 we used our own pipeline toprocess raw V (720s) and R (1200s) images obtained from

27 http://archive.stsci.edu/

the ESO archive28 (70.A-0074-A, PI:Edge) utilizing theSUSI camera on the NTT on Oct 7 and 12, 2002.

A fraction of the area covered by ACT overlaps withthe 41 deg2 griz imaging from the CTIO 4-m telescopeMOSAIC camera on the 05hr field from the SouthernCosmology Survey (Menanteau et al. 2010). We usedthese data to search for optical identification of SZE clus-ter candidates in the region to avoid re-targeting with theNTT and SOAR telescopes.

4. RESULTS

4.1. The ACT SZE Cluster SampleOur analysis has resulted in a sample of 23 optically-

confirmed SZE clusters selected from 455 square-degreesof ACT data between 0.1 < z < 1.1. Nine of theseclusters, such as 1E0657!56 (the Bullet Cluster), AbellS0592, and Abell 3404 are well known and appear at lowredshift (z < 0.4); and four systems in our sample havebeen reported as SZE-selected clusters by SPT in theirarea overlapping with the ACT coverage. Three of thesesystems (ACT-CL J0509!5341, ACT-CL J0528!5259,and ACT-CL J0546!5345) were originally reported asSZE-selected clusters by Staniszewski et al. (2009), withoptical and X-ray properties subsequently studied by us

28 http://archive.eso.org/


The ACT-SZ cluster sample

from Menanteau et al (2010), arXiv:1006.5126

6 Menanteau et al.












4. RESULTS







(9) known

6 Menanteau et al.












4. RESULTS







(10) new

6 Menanteau et al.












4. RESULTS







(14) SZ discovered


Menanteau et al. (2010) in prep Menanteau et al. (2010) in prep

Some Previously Know Clusters


ACT-J0658-5557, z=0.296(Bullet Cluster)

Menanteau & Hughes (2009)



Menanteau et al. (2010) in prep Menanteau et al. (2010) in prep



Menanteau & Hughes (2009) Menanteau et al. (2010) in prep

SZ-discovered Clusters


(A3128-NE)

Menanteau et al. (2010) in prep Menanteau et al. (2010) in prepMenanteau et al. (2010) in prep



Menanteau et al. (2010) in prep Menanteau et al. (2010) in prepMenanteau et al. (2010) in prep



Strong Lensing(examples)

- 7/23 clusters show strong lensing arcs- 3 of these have already reported

• Purity = Nreal/Nobserved

• 100% purity for SNR>5.6 (10 clusters)

• 80% purity at SNR>5.1

• Observed 100% of SNR>4.8 cluster candidates (dashed line)CL2010, IPMU July 2 2010

Purity of the ACT cluster sample


Cluster Redshift Distribution

(uses Tinker et al. 2008 mass function)




Full sample (23)




Full sample (23)

Pure Sample (10)




Full sample (23)

Pure Sample (10)

We see no z>1.1 clusters M>1x1015Mo !


Clusters X-ray Properties ChandraXMM-NewtonRASS knownRASS new

Reiprich & Bohringer (2002)

X-ray temperatures T~ 5-14 keV (from Chandra/XMM-Newton)


Clusters X-ray Properties ChandraXMM-NewtonRASS knownRASS new

Reiprich & Bohringer (2002)

X-ray temperatures T~ 5-14 keV (from Chandra/XMM-Newton)

ACT-CL 0546-5345(SPT-CL 0546-5345)

The most massive cluster z>1?



VLT/FORS2 R,I bandsInfante et al. in prep (2010)



VLT/FORS2 R,I bandsInfante et al. in prep (2010)


arc

LX(0.1! 2.4 keV) = 8.66+0.38!0.36 " 1044erg s!1

M200 ! 1" 1015 M!

M200 ! 4" 3# 1015M!(zsource = 2" 3)


The most massive cluster at z>1?

• VLT FORS2 (Dec 2009) observations of 40 members

Te = 8.16+1.35!1.06 keV

M200 = 1.22± 0.26! 1015M!

!v = 1089.3± 56km s!1

ACT-CL J0546 !5345 (or SPT-CL 0547-5345) @ z=1.0656 ± 0.0004

• Chandra public archival data (57.1 ks exposure)


Summary• 23 confirmed clusters (BCG and red sequence) from 455 sq-

deg, between 0.12<z<1.06

• All are very rich systems; some with strong lensing arcs

• More than half are new SZE clusters with photometric redshifts from 0.4 to 0.8.

• Purity falls sharply for SNR < 5.0, 100% purity for SNR>5.7

• We see no massive clusters (>1e15Mo) above z=1.1

• We have one of the first redshift-independent sample of galaxy clusters selected via the SZ effect to be used in cosmology.

• Follow-up: 2010B: 5 Gemini/GMOS + 2 VLT/FORS,

• 54hrs warm Spitzer/IRAC (3.6um and 4.5um)

massive sze-selected clusters from the atacama cosmology

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