The key for probing galaxy evolution: relating luminous matter in galaxies to their dark environments

• Applicants: Professor Dr. Peter Schneider; Dr. Stella Seitz
• Subject Area: Astrophysics and Astronomy
• Term: from 2005 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5448834

• Final Report Year: 2012

Final Report Abstract

Dark Matter governs the formation and evolution of galaxies, as well as their dynamical properties at scales > 10 kpc. We analyzed the Galaxy-Galaxy Lensing signal in several multi-band wide-field surveys, starting from the reduction of preprocessed raw data, creation of multi-band catalogues, estimation of photometric redshifts and creation of shear catalogues. Concerning the technical aspects, we have developed and optimized methods for the efficient reduction of very large data sets, quality control, photometric redshifts and shear measurements. We have quantified the GGL signal in all of our datasets and interpreted these results in the framework of theoretical models. Among other results, we calibrated the galaxy-mass scaling relations over a broad magnitude range, and we verified the considerably higher mass-to-light ratio of early-type galaxies compared to late-types. We have obtained the first-ever measurement of the galaxy-galaxy-galaxy lensing signal, which opens a new door for using higher-order mass-galaxy correlations to test galaxy evolution models.

Publications

• (2006): Weak lensing measurements of dark matter halos of galaxies from COMBO-17. In: A&A 455 (2), S. 441–451
  Kleinheinrich, M., Schneider, P., Rix, H.-W., et al.
  
• (2007). GaBoDS: The Garching-Bonn Deep Survey-VI. Probing galaxy bias using weak gravitational lensing. Astronomy & Astrophysics, 461(3), 861-879
  Simon, P., Hetterscheidt, M., Schirmer, M., et al.
  
• (2008). First detection of galaxy-galaxy-galaxy lensing in RCS-A new tool for studying the matter environment of galaxy pairs. Astronomy & Astrophysics, 479(3), 655-667
  Simon, P., Watts, P., Schneider, P., et al.
  
• (2009). CARS: the CFHTLS-Archive-Research Survey-I. Five-band multi-colour data from 37 sq. deg. CFHTLS-wide observations. Astronomy & Astrophysics, 493(3), 1197-1222
  Erben, T., Hildebrandt, H., Lerchster, M., et al.
  
• (2009). Relative clustering and the joint halo occupation distribution of red sequence and blue-cloud galaxies in COMBO-17. Monthly Notices of the Royal Astronomical Society, 398(2), 807-831
  Simon, P., Hetterscheidt, M., Wolf, C., et al.
  
• (2010). Bias-free shear estimation using artificial neural networks. The Astrophysical Journal, 720(1), 639
  Gruen, D., Seitz, S., Koppenhoefer, J. & Riffeser, A.
  
• (2011). Probing the dark-matter halos of cluster galaxies with weak lensing. Astronomy & Astrophysics, 531, A169
  Pastor Mira, E., Hilbert, S., Hartlap, J. & Schneider, P.
  
• (2011): Estimate of dark halo ellipticity by lensing flexion. In: A&A 528, A52
  Er, X. & Schneider, P.
  
• (2012): Towards an understanding of third-order galaxy-galaxy lensing. In: A&A 548, A102
  Simon, P., Schneider, P. & Kübler, D.
  
• (2008). Photometric redshifts for the CFHTLS-Wide
  Brimioulle, F., Lerchster, M., Seitz, S. et al.