6dF Galaxy Survey Workshop Sydney Ophiuchus Supercluster and its Surroundings K. Wakamatsu, M.Nishida, M. Malkan, Q. Parker, W. Saunders, F. Watson

Ophiuchus cluster Discovered on Palomar Schmidt IV-N Plates (1981) during Our Hidden Globular Cluster Survey l=0.5° b=+9.3 °(Near the Galactic Center) A B =2.5 mag A rich cD cluster at cz=9000 km/s 2 nd brightest X-Ray cluster (after Perseus cluster in the sky) with kT=10 keV

Norma Ophiuchus x 5 luminous

Questions Basic Properties of the cluster e.g., velocity dispersion, angular extent Supercluster? A key cluster connected with wall structures? (SGL=173, SGB=44, cz= 9000 km/s) Massive enough to influence on the Great Attractor issue? Extensive studies in X-ray, but few in optical

Core of the Ophiuchus cluster in R-Band (Taken by Ebeling with UH 88-inch telescope)

1. Optical Galaxy Survey On SERC J-Sky Survey Films Eye survey with a binocular-type microscope We detected 4158 galaxies for 6 Schmidt fields (453,454,516,517,586,587) We Measured.Angular size > 4 arcsec.Magnitude Class 1 (bright) – 5(faint).Morphological types (S, E, compact, … )

● : MC 1 ● : MC 2 ● :MC 3 Distribution of Galaxies with magnitude classes

2. Identification to 2MASS Positional coincidence < 10 arcsec Among 4158 galaxies, 1471 objects are identified to 2MASS sources.

Cluster Core region 0.3 x 0.3 deg Galaxies missed in 2MASS are Marked with

Examples of 2MASS images 35 % of ours have 2MASS counterparts, 50 % of 2MASS sources have our counterparts

2Mass Identification Rate over Optical poorer bellow b<8°

2MASS Identification Rate for Optical Brightness Quite incomplete at optically faint galaxies

2MASS Identification Rate for Optical Angular Size Quite Incomplete at small-size galaxies

3. Redshift Survey with FLAIR II & 6dF Survey area: ☆ Ophiuchus cluster region ☆ Extending towords the Hercules cluster ☆ Crossing the Galactic Plane We put fibers more than 3000 targets 3800 < λ < 7500 (3.7 A/pixel) 3-4 hours for a field for low b Nice to detect H,K,G-lines with 6dF even for Ophiuchus galaxies

Target Galaxies for FLAIR & 6dF Redshift Survey Hercules cluster

Damaged Spectrum by a foreground star light

Damaged Spectrum by Galactic Emission Lines

Success rate for cz measuring

4. Structure of Ophiuchus cluster d< 1 deg d< 2 deg d< 3 deg d< 5 deg

A compact core & adjunct clusters

Mean cz : 9030 km/s Dispersion: 1000 km/s dispersion mean cz For galaxies 7,000 < cz < 10,500 km/s

5. Large Scale Structure around the Ophiuchus Cluster

A wall structure extends towards the Hercules supercluster

A wall connecting between Oph- and Her-superclusters Oph Her

Prominent peak around cz=9000 km/s=> Ophiuchus supercluster d< 5 deg d< 10 deg d< 15 deg d< 20 deg

A void extends to cz = 4,000 km/s

Future Works 1. A Deep Galaxy Survey with a Japanese telescope at SAAO 2MASS(1.3m) New(1.4m) exp. time (sec) scale (arcsec/pix) Photometry of galaxies => luminosity function 3. Large-scale structure with DR2

1.4m IR telescope at Sutherland, SAAO

Digital Sky Survey J,H, K Survey with the 1.4m telescope at SAAO Ophiuchus cluster (7’ x 7’)

Summary 1. Ophiuchus cluster has a large velocity dispersion as expected from its large X-ray luminosity 2. It accompanies several clusters within 6 deg, forming a supercluster 3. A wall structure extends toward the Hercules supercluster 4. A large void extends upto v = 4000 km/s

VIVA! April 26-27, 05 At Sydney 6dF Redshift Survey can go deep into the Galactic Plane

Few galaxies cz the Local Void A few galaxies cz Extension of the Local Void d< 30 deg