MOIRCS and FMOS for cluster studies

Ichi Tanaka

Astronomical Institute, Tohoku University

MOIRCSMOIRCS and and FMOSFMOS for cluster studiesfor cluster studies

Contents:

1. Intruduction and the current status of MOIRCS

2. MOIRCS and FMOS

3. Distant cluster studies as a target of FMOS-MOIRCS joint project

1.

Intruduction and Current Status of MOIRCS

MOIRCS:Multi-Object Infrared Camera and Spectrograph for Subaru

T. IchikawaT. Ichikawa

C. TokokuC. Tokoku

R. SuzukiR. Suzuki

Y. KatsunoY. Katsuno

T. NishimuraT. Nishimura

& K. Omata/ M. Konishi/ T. Yoshikawa et al.& K. Omata/ M. Konishi/ T. Yoshikawa et al.

F.O.V 4' × 7'

Observing Mode Imaging / MOS (cooled slits / Grizm)

Optimized wavelength 0.8 - 2.5 um

Spectral Resolution 500 ～ 1300 (2000) @ 0.5”slit

Detector HAWAII-2 (HgCdTe) 　 x 2

Pixel Size 18 um

Image Scale 0.117 arcsec/pixel

Readout noise / Q.E. <10e- (TBD) / ~60%

Slits about 50 slits per mask

Slit Capacity ~24

Expected effeciency Imaging: 0.34

Spectroscopy: 0.20

Limiting Magnitude Imaging （ 1 hr 、 S/N=10 ） 　　　 J=23.8, H=23.1, K=22.3

Spectroscopy （ R=500, 4 hr, S/N=5)

J=21.3, H=20.8, K=20.0

Performance of MOIRCS

(From GOODS 6hr Ks data)

Large FOV: CISCO versus MOIRCS

This is the MOIRCS view!

4' x 7'

Slit mask exchange unit

Main dewar

Support structure

Peripherals

opticsdetector

Suzuki et al. Subaru UM 2002

Components of MOIRCS

Support Structure/ Connector

Main Dewer

Optical Unit/ Bench/ Filter/ Grism

Slit Exchanging Unit

Peripherals

Detector

Inside is Cooled to 77K

The Design of MOIRCS --- dual camera & spectrograph system

LightMOS plate

exchanging unit

Front View

Side View

detector

Cooler

Cooler

Filters/Grism

Focal Plane

OPTICAL Rayout of MOIRCS

4 arcmin.

Unusable detector area (imaging)

~30 arcsec

Object on the center is devided

Imaging mode Spectrograph mode

Usable for Spectroscopy!

Cooled mask slot / robotic mask in-out mechanism

Max 50 slitlets / 24 masks available for a night

MOIRCS is the MOS in zJHK!

zJ R500 HK R500

Grisms: R=500 gratings for zJ / HK wavebands

R=1300 for J,H,K bands

Mask Dewar with the exclusive cooler (cooled to 150K)

can hold 24 slit masks

Linear Actuator

（ can handle 0.01mm accuracy ）

Gate Valve

Mask Dewar is detachable.

Useful for efficient mask exchange!

Slit Mask Exchanging Unit

◎Procedure1 ． Setting mask,

vacuuming, cool down

2 ． Rotate corrousel for selecting mask

3.Gate valve opens, grab a mask by robot arm

4. pick up a mask, rotate, set to the focal plane

5. Close Gate valve, start obs.

Room temperature test is successful

(~15minutes.)

Slit mask exchanging mechanism

First Light is soon.Current plan: early March, 2004

!!! MOIRCS Science Workshop: Feb. 27/28 in Sendai !!!

Registeration deadline … Jan. 31, 2004

A planned GT science will be intensively introduced and discussed on WS.

Contributions are greatly welcomed!

2.

MOIRCS and FMOSComparison

for scientific purpose

MOIRCS and FMOSFMOS: R=700 - 2400 zJH with OHS 400 in 30' FOV.

MOIRCS: R=500 - 1300 zJHK <50 in 4'x7' FOV.

FMOS … sparsely distributed targets => e.g. Field ObjectsMOIRCS … high density region => e.g. Clusters

ECHIDNA Rayout

MOIRCS and FMOS

FOCAS F.O.V.

Suprime-Cam F.O.V.

MOIRCS

FOV

FMOS: Good match to Suprime-Cam --- photo-z

MOIRCS: Good match to FOCAS --- optical spectroscopy

For General Field Survey

•MOIRCS & FOCAS … pensil beam survey for whole galaxies[rest optical spectra for all galaxies, but still large cosmic variance]

•FMOS & SpCam-WFCAM … much less cosmic variance[good for large-scale clustering, global cosmic SFR history, &

follow-up of the rare objects (sub-mm sources/ EROs/ AGNs) but needs a careful target selection by photo-z]

For Studies of Cluster environment… FMOS-MOIRCS joint observation is most efficient!

*** Only FMOS can do an efficient follow-up of SupCam 30'x30'data ***

3.

Distant Cluster Sudies as a Target of FMOS-MOIRCS Joint Project

Distant Clusters of Galaxies

Topic:

•Star-formation activities in cluster environment

•Large-scale clustering and star-formation

•Early-epoch of clusters

How the star-formation activities has ceased in clusters?

What is the relationship between the dynamical evolution of clusters and the galaxy evolution in clusters?

What properties do massive cluster galaxies have in their very young epoch?

•SFR measurement:

HHlines) …MOIRCS/FMOS

absorption (continuum for z>1 FMOS OHS!)

High density regions … MOIRCS (z>1); FOCAS(z<1)

Galaxies in the outskirts of clusters … FMOS

•Structure, cluster dynamics: often >10Mpc … FMOS! … no efficient way to do optical spectroscopy for faint

galaxies!

Complex cluster merger ・・・ < a few Mpc …MOIRCS

For understanding galaxy evolution in cluster environment …

A supercluster at z=0.54Connolly et al. (1996)

Suprime-Cam data by the PISCES project (Kodama et al.)

known clusters at z=0.54

Galaxies with photometric redshift~0.54Galaxies with pectroscopic redshift~0.54

CL 0016

A supercluster search for a large QSO group at z=1.1

Area A.

Area B.

Area C.

Our observed area by Suprime-Cam (i', z')

2 degrees

LQG10 … group of 23 QSOs at z~1.1 (Crampton et al. 1989) : LSS at z~1.1?Pilot works by Tanaka et al. (2000,2001), Yamada et al. (1997)

Results

Area A Area B

i’-z’ 　 color selection for old red glalaxies at z=1.1… some hint for superstructure associated with LQG10

Density enhancement mildly traces QSO distribution

Area A.

Area B.

Area C.

?

highest density peaks ・・・ MOIRCS/FOCAS is good

Others … only sparsely distributed

The whole structure / galaxy properies at the outskirts of clusters ==> ONLY FMOS can access!

Example of the hottest X-ray cluster RXJ 1347.5-1145

S-Z by Komatsu et al. (2001)

Redshift by Cohen &Kneib (2002)SupCam data by Miyazaki (private)

Substructure? 47 spectra … still not enough

Distant clusters …. More complex!

Examples of two clusters at z=0.8 Gioia et al. (1999)

PISCES project (Subaru press relase 2003)

Summary

• MOIRCS will soon achieve First Light (Workshop on 27-28 Feb.)

• FMOS, MOIRCS & Suprime-Cam can make up a good inter-collaborative project for intensive studies of cluster

environments at z>1.