Name: Luis Campusano

Institution: DAS/ Univers. de Chile

e-mail: luis(no-spam)das.uchile.cl

Partner Contry: CHI

Science Meeting: Yes

User Meeting: Yes

NGO Staff Meeting: Yes

Presentation: Yes

Format: Poster

Title: Spectroscopic confirmation of a z ~ 0.8$ galaxy structure traced by quasars and Mg II absorbers

Co-author: Ilona K. Sochting,1 Chris P. Haines,2 Roger G. Clowes,3 Gerard M. Williger,4 Matthew Graham,5 David Valls-Gabaud,6 Olga Kuhn.

Co-authors' Institutions: 1 Astrophysics, University of Oxford, Keble Road, OX1 3RH, UK (e-mail: iks@astro.ox.ac.uk) 2 Observatorio Astronomico Capodiamonte, Italy 3 Department of Computing, University of Central Lancashire, Preston, PR1 2HE, UK 4 Caltech, USA 5 Observatoire Midi-Pyrinees, France 6 NOAO, USA

Abstract:

We report the results of the spectroscopic investigation of a z ~ 0.8 structure traced by quasars, MgII absorbers and an excess of I - K ~ 3.4 galaxies. Using a single mask in GMOS at Gemini South, low resolution spectra were obtained for 19 field galaxies in a random 5' X 5' field within this ~ 3.5 X 3 deg2; or ~ 120 X 100h-2Mpc2 structure. Using generous selection criteria of I - K > 3.0$ and I < 21.2, slitlets have been allocated to 11 targets, and further 8 targets were added serendipitously to fill out the mask. Despite the very relaxed constraines and apparent lack of any z ~ 0.8 galaxy clusters within our GMOS field, we detected a clear peak in the redshift distribution at z = 0.784. The detection is significant at level and coinside with the redshift of previously reported structure traced by quasars and MgIIs aborbers. Our results confirm the existance of a galaxy excess reported previously as a possible ``sheet'' like structure at z ~ 0.8.