Terapix Star Formation Region IC 1396, © 2002 CFHT
Minutes for the VIRMOS science meeting in Paris 2nd, 4rd of February 2006
by HJMCC - Updated February 24th, 2006

VIRMOS science meeting Paris

2nd, 3rd February 2005; IAP, Paris

Gianni Zamorani, Stephane Charlot, Gigi Guzzo, Alain Mazure, Giovanna Temporin, Alberto Cappi, Marco Scodeggio, Paolo Franzetti, Fabrice Lamaraeille, Jakob Welcher, Olga Cucciati, Silvian de la Torre, Baptiste Meneux, Angieska Pollo, Christophe Adami, Stephane Arnouts, Roberto Scaramella, Stephane Paltani (Thursday only), Thierry Contini, Allesendra Zanichelli, Paolo Cilegi, Sandro Bardelli, Angela Iovino, Bianca Garilli, Dario Maccagni, Henry Joy McCracken, Daniela Vergani, Olivier Le Fevre, Loretta Gregorini, Laurence Tresse, Marie Lemoine-Busserolle

Status of proposals

-  Ten hours has been awarded for the F14 field
-  F14: 7 pointings pre-imaging has arrived and has to be incorporated into the database
-  FORS proposal on the z 1.4 cluster didn't get any observations
-  SINFONI proposal was turned down; and all observations awarded time have been taken
-  The new OBs for the new large program on the deep field will have to be prepared in the next few weeks

Current status of data processing

WIDE survey status (Bianca, presentation)
-  Bottom line is there are 33 pointings still to be super-checked
-  Would like to finish these 40 pointings for the summer
-  Priority should be F22 and then F14
-  We still need to have supercheck weeks
-  Still need to have two independent checks by two independent people
-  Results were shown with 193 objects which were superchecked twice!

Supercheck weeks
-  13-17 February Toulouse
-  20-24 March Bologna
-  24-28 April Marseille
-  8-12 May Milan

AGNS, gianni
-  summary of AGN work
-  45% of the AGNs would have been missed by a similar selection

K-band data: Giovanna Temporin (presentation)
-  1 hour final exposure time at each stack location
-  Final stacked mosaic presented
-  68% data has an astrometric accuracy within 0.127''
-  overlapping pointings compared and magnitudes on the final stack compared with the existing pointings
-  1442 galaxies in this catalogue have measured z_spec with flags (2+),3,4
-  405 objects to K_vega<=19.0 with spectra (3+4)
-  in total there is 603 arcmin^2 in the new other
-  in total there is 741 objects (old and new area) with k_vega<=19.5

Kinematics of galaxies at 1.4
-  sub sample of 40 late type galaxies observed with SI
-  velocity gradient in galaxy at z 1
-  many maps presented; work is still in progress

VIPGI and redshift measurement tools (Bianca, presentation)
-  some work done on spectrophotometric calibration
-  some work done on the 'adjust first guess' procedure
-  new work on flat-field correction
-  If ESO agrees to return some guaranteed nights (say maybe ten nights!) to the consortium we might consider working on a FORS-compatible version of vipgi for the community
-  EZ development continues; demonstration presented
-  Much functionality available
-  how can we add functionality to this new tool beyond what has been provided in kbred? (question from OLF)
-  oLF suggests that 'bug lists' from KBRED be compiled

Thursday afternoon -- science presentations

density and environment (Olga, presentation)
-  complete for late type galaxies but not for early type galaxies
-  relative fraction of late and early types as a function of density contrast and redshift
-  the redshift bin 1.2-  also plots shown for luminosity function as a function of environment; late type galaxies have steeper slopes. These results seem to be different from SDSS which shows different in M* with a different slope
-  ACTION the density parameter must be added to the database

photometric redshifts (stephane)
-  delta-z(1+z) 0.03
-  stephane shows some plots which quantify the accuracy of the photometric redshifts
-  joint mask

-  changes to the database and catalogues should be clearly marked
-  the spectrophotometric catalogue needs to be added from the database

mass function (OLF, for Lucia)
-  new version of the mass function paper presented
-  stellar mass density as a function of redshift
-  mass function derivations
-  'downsizing' picture seen in the data which seems to be independent of star-formation history assumed in the data

k-rest frame LF (stephane)
-  some suggestions of a problem with swire photometric calibration (maybe it's up to around 15% off)
-  lf by type
-  from the lf function you can derive the nir luminosity and the stellar mass.
-  derived results seem independent of this calibration method

Luminosity function at high redshift (Stephane Paltani, presentation)
-  Use lf tool to compute luminosity functions
-  we use all flags, using the success rates found in the paper
-  m* and phi derived compared to Steidel values
-  much more efficient to compute the lf in 3 < z< 4
-  in this case the phi* is only three times smaller than Steidel
-  phi is very different at the bright end from Steidel
-  it might be possible to weight objects by their photometric properties
-  using this technique the 'cleaned' lf the phi-star is even lower, this case around a factor of two lower, but still different from the Steidel measurements

Clustering (Angieska, Gigi and Baptiste presentations here, here and here)
-  summary of the results in the papers
-  NEW: relative bias has been computed at fixed 1mpc scale
-  some hint of scale-dependent bias at high redshift

clustering (gigi, presentation)
-  there seems to be evidence of steepening slope at small separations (<<1h-1mpc))
-  Gigi summarises results of halo occupation models
-  vvds phot-zed xi-rp/pi compared with cosmos

Baptiste Meneux
-  Some plots shown with new catalogue extracted from the F22 field
-  Work needs to be done still with the masks
-  Baptiste, stephane and others will co-ordinate the preparation of the new masks

Friday 3rd February, Morning

Wide Data processing status (Bianca, presentation)
-  redshift distributions presented for each of the fields (10hr, 22hr, 14hr and 02hr)
-  there is a tail of objects extending up to z 1.5
-  distributions presented for all flags and flags 2-9
-  cone diagram for the wide survey presented; lots of large scale structure present
-  comparisons also made with GALLICS high resolution simulation

Next set of proposals
-  HST g,i proposal submitted
-  large program for four periods on the deep field underway
-  FORS cluster proposal will be resubmitted
-  discussion about resubmission of the wide survey: OLF suggests that the proposal be resubmitted with only two fields and larger contiguous area; discussion also about on-going XMM-LSS spectroscopic survey
-  discussion of swire / spitzer proposals
-  discussion of Herschel proposals

Clustering of VVDS/SWIRE (Sylvian de la Torre, presentation
-  clustering of vvds/swire data
-  compute wp in several redshift bins as a function of swire bins
-  higher correlation function amplitude found wrt the optically selected data

Structures in F02 (Christophe Adami, presentation)
-  discussion about various methods to find structures

Structures in F02 (Angela, presentation)
-  discussion about the structure found at z 1.5
-  presentation of various features in the data; significant numbers of concordant spectroscopic redshift
-  surrounded by a significant excess of galaxies have colours as red as early type galaxies at z 1.5
-  there is an excess of galaxies in this phot-zed range.

Spectrophotometric catalogues (Fabrice, presentation)
-  summary of the spectrophotometric catalogue
-  discussion of the spectrophotometric fitting tools; two tools under development
-  discussion of the mass / metallicity relation
-  some problems with low-z outliers, not sure if we understand their origins

Spectrophotometric uncertainties (Thierry, presentation)
-  uncertainties computed by using repeated spectroscopic measurements
-  errors are around 30%

Redshift of evolution of spectrophotometric parameters (Daniela Vergani, presentation)
-  dn(4000)/ew(oii) plane presented
-  this plane divided into two regions
-  composite spectra produced for these two types of galaxies
-  classification scheme divided into four
-  areal coverage can be important in comparing different surveys
-  many other results presented
-  work in progress: can morphological information be coupled with spectrophotometric properties?

Bimodality (Paolo Frazetti, presentation)
-  early / late distributions derived used u-v bimodal colour cut
-  try to understand the change in composition of the red peak
-  it seems the red peak contains a mix of galaxies, it is not composed exclusively of elliptical galaxies
-  applying bell selection we can retrieve the bell result
-  need to figure an 'ideal' identification for elliptical galaxies, but this will take some time!

Radio/swire identifications (Paolo Cilegi)
-  1054 sources, 604 with swire id
-  32 swire with no optical counterpart
-  in this data, radio flux / swire flux is not constant with photometric z, which has not been found before; need to understand these results before presenting them to the spitzer collaboration

list of papers (OLF, presentation)
-  olf suggests that we attempt to come up with an overall picture to try to explain what's going on
-  summary of papers in progress discussed
-  next meeting 29th, 30th May, location to be defined

-  summary of papers in progress

Agenda distributed by OLF before the meeting

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