Mapping the Cosmic Web with the largest all-sky surveys
Abstract
Our view of the low-redshift Cosmic Web has been revolutionized by galaxy redshift surveys such as 6dFGS, SDSS and 2MRS. However, the trade-off between depth and angular coverage limits a systematic three-dimensional account of the entire sky beyond the Local Volume (z < 0.05). In order to reliably map the Universe to cosmologically significant depths over the full celestial sphere, one must draw on multiwavelength datasets and state-of-the-art photometric redshift techniques. We have undertaken a dedicated program of cross-matching the largest photometric all-sky surveys - 2MASS, WISE and SuperCOSMOS - to obtain accurate redshift estimates of millions of galaxies. The first outcome of these efforts - the 2MASS Photometric Redshift catalog (2MPZ, Bilicki et al. 2014a) - has been publicly released and includes almost 1 million galaxies with a mean redshift of z=0.08. Here we summarize how this catalog was constructed and how using the WISE mid-infrared sample together with SuperCOSMOS optical data allows us to push to redshift shells of z~ 0.2 -0.3 on unprecedented angular scales. Our catalogs, with ~ 20 million sources in total, provide access to cosmological volumes crucial for studies of local galaxy flows (clustering dipole, bulk flow) and cross-correlations with the cosmic microwave background such as the integrated Sachs-Wolfe effect or lensing studies.
- Publication:
-
The Zeldovich Universe: Genesis and Growth of the Cosmic Web
- Pub Date:
- October 2016
- DOI:
- 10.1017/S1743921316009753
- arXiv:
- arXiv:1408.0799
- Bibcode:
- 2016IAUS..308..143B
- Keywords:
-
- catalogs;
- surveys;
- galaxies: distances and redshifts;
- techniques: photometric;
- methods: data analysis;
- (cosmology:) large-scale structure of universe;
- cosmology: observations;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- Proceedings of IAU Symposium 308 "The Zeldovich Universe: Genesis and Growth of the Cosmic Web", 23-28 June 2014, Tallinn, Estonia