Correlating the CMB with luminous red galaxies: The integrated Sachs-Wolfe effect
- Joseph Henry Laboratories, Jadwin Hall, Princeton University, Princeton, New Jersey 08544 (United States)
- Deptartment of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, New Jersey 08544 (United States)
- Apache Point Observatory, 2001 Apache Point Road, Sunspot, New Mexico, 88349-0059 (United States)
- Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)
We present a 2.5{sigma} detection of the Integrated Sachs-Wolfe (ISW) effect and discuss the constraints it places on cosmological parameters. We cross correlate microwave temperature maps from the Wilkinson microwave anisotropy probe (WMAP) satellite with a 4000 deg{sup 2} luminous red galaxy (LRG) overdensity map measured by the Sloan Digital Sky Survey. These galaxies have accurate photometric redshifts ({delta}z{approx}0.03) and an approximately volume limited redshift distribution from z{approx}0.2 to z{approx}0.6 well suited to detecting the ISW effect. Accurate photometric redshifts allow us to perform a reliable autocorrelation analysis of the LRGs, eliminating the uncertainty in the galaxy bias, and combined with the cross correlation signal, constrains cosmological parameters--in particular, the matter density. We use a minimum-variance power spectrum estimator that optimally weights the data according to expected theoretical templates. We find a 2.5{sigma} signal in the Ka, Q, V, and W WMAP bands, after combining the information from multipoles 2{<=}l<400. This is consistent with the expected amplitude of the ISW effect but requires a lower matter density than is usually assumed: the amplitude, parametrized by the galaxy bias assuming {omega}{sub M}=0.3, {omega}{sub {lambda}}=0.7, and {sigma}{sub 8}=0.9, is b{sub g}=4.05{+-}1.54 for V band, with similar results for the other bands. This should be compared to b{sub g}=1.82{+-}0.02 from the autocorrelation analysis. These data provide only a weak confirmation (2.5{sigma}) of dark energy but provide a significant upper limit: {omega}{sub {lambda}}=0.80{sub -0.06}{sup +0.03}(1{sigma}){sub -0.19}{sup +0.05}(2{sigma}), assuming a cosmology with {omega}{sub M}+{omega}{sub {lambda}}=1, {omega}{sub b}=0.05, {sigma}{sub 8}=0.9, and w=-1. The weak cross correlation signal rules out low matter density/high dark energy density universes and, in combination with other data, strongly constrains models with w<-1.3. We provide a simple prescription to incorporate these constraints into cosmological parameter estimation methods for ({omega}{sub M},{sigma}{sub 8},w). We find no evidence for a systematic contamination of ISW signal, either from galactic or extragalactic sources, but we do detect some large statistical fluctuations on smaller scales that could affect analyses without the template weighting.
- OSTI ID:
- 20711325
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 72, Issue 4; Other Information: DOI: 10.1103/PhysRevD.72.043525; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
Similar Records
THE INCIDENCE OF COOL GAS IN {approx}10{sup 13} M{sub sun} HALOS
THE SLOAN DIGITAL SKY SURVEY QUASAR LENS SEARCH. VI. CONSTRAINTS ON DARK ENERGY AND THE EVOLUTION OF MASSIVE GALAXIES