Correlated fluctuations in luminosity distance and the importance of peculiar motion in supernova surveys
183 citations recorded by the source corpus.
Large scale structure introduces two different kinds of errors in the luminosity distance estimates from standardizable candles such as supernovae Ia (SNe)--a Poissonian scatter for each SN and a coherent component due to correlated fluctuations between different SNe. Increasing the number of SNe helps reduce the first type of error but not the second. The coherent component has been largely ignored in forecasts of dark energy parameter estimation from upcoming SN surveys. For instance it is commonly thought, based on Poissonian considerations, that peculiar motion is unimportant, even for a low redshift SN survey such as the Nearby Supernova Factory (SNfactory; z=0.03-0.08), which provides a useful anchor for future high redshift surveys by determining the SN zero point. We show that ignoring coherent peculiar motion leads to an underestimate of the zero-point error by about a factor of 2, despite the fact that SNfactory covers almost half of the sky. More generally, there are four types of fluctuations: peculiar motion, gravitational lensing, gravitational redshift and what is akin to the integrated Sachs-Wolfe effect. Peculiar motion and lensing dominates at low and high redshifts, respectively. Taking into account all significant luminosity distance fluctuations due to large scale structure leads to amore » degradation of up to 60% in the determination of the dark energy equation of state from upcoming high redshift SN surveys, when used in conjunction with a low redshift anchor such as the SNfactory. The most relevant fluctuations are the coherent ones due to peculiar motion and the Poissonian ones due to lensing, with peculiar motion playing the dominant role. We also discuss to what extent the noise here can be viewed as a useful signal, and whether corrections can be made to reduce the degradation.« less
Subfields: Astronomy and Astrophysics
View Paper: https://www.semanticscholar.org/paper/c9d219f8c9b8345f3fba3966c0ae48ef7fa936cb
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In Astronomy and Astrophysics
Citations in the corpus
- FIRST-YEAR SLOAN DIGITAL SKY SURVEY-II SUPERNOVA RESULTS: HUBBLE DIAGRAM AND COSMOLOGICAL PARAMETERS (2009, methodology): “It is not a good approximation for the nearby SN sample on both theoretical (Hui & Greene 2006; Cooray & Caldwell 2006) and observational (Neill et al. 2007) grounds.”
- The Complete Light-curve Sample of Spectroscopically Confirmed SNe Ia from Pan-STARRS1 and Cosmological Constraints from the Combined Pantheon Sample (2017, background): “The systematic uncertainty of the coherent flow corrections should account for covariance between the velocities of the SN host galaxies (Hui & Greene 2006).”
- Observational Constraints on the Nature of Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey (2007, background): “While SN Ia cosmology is not dependent on the value ofH0, it is sensitive to deviations from a homogeneous Hubble flow and these regional velocity fields may limit our ability to estimate properties of dark energy, as emphasized by Hui & Greene (2006) and by Cooray & Caldwell (2006).”
- SUPERNOVA CONSTRAINTS AND SYSTEMATIC UNCERTAINTIES FROM THE FIRST THREE YEARS OF THE SUPERNOVA LEGACY SURVEY (2011, methodology): “Peculiar Velocities, zcut, and the “Hubble Bubble” Hui & Greene (2006) discuss methods to calculate the correlated uncertainty in SN luminosity distances due to peculiar velocities given a survey geometry and radial selection function.”
- (An)isotropy of the Hubble diagram: comparing hemispheres (2007, background): “2006a; Hui & Greene 2006; Weinhorst 2006; Cooray & Caldwell 2006; Haugbølle et al. 2006; Neill et al. 2007; Wang 2007; Hannestad et al. 2007, Gordon et al. 2007)], 3. to search for systematic errors in the observations and their analysis (Kolatt & Lahav 2001, Gupta et al. 2007).”
- Consistently large cosmic flows on scales of 100 h−1 Mpc: a challenge for the standard ΛCDM cosmology (2008, background): “…very large scale structures and that this in turn has implications for the impact of such structures as a ‘foreground’ for calibrating SNe (Cooray & Caldwell 2006; Hui & Greene 2006; Neill et al. 2007; Abate & Lahav 2008) and for its effects on the CMB such as the ISW effect (Fosalba & Doré 2007).”
- A 3% SOLUTION: DETERMINATION OF THE HUBBLE CONSTANT WITH THE HUBBLE SPACE TELESCOPE AND WIDE FIELD CAMERA 3 (2011, methodology): “Hui & Greene (2006) point out that the peculiar velocities of SN Ia hosts and their correlations can produce an additional systematic error in the determination of the SN Ia m–z relation used for cosmography.”
- A REDETERMINATION OF THE HUBBLE CONSTANT WITH THE HUBBLE SPACE TELESCOPE FROM A DIFFERENTIAL DISTANCE LADDER (2009, background): “A number of authors (Hui & Greene 2006; Cooray & Caldwell 2006) have shown that coherent flows like a Hubble bubble are likely to induce bias at lower redshifts, and we maintain our view that it is better to restrict our analysis to z > 0.023 and avoid this possible bias.”
- Evidence for anisotropy of cosmic acceleration (2018, result): “The effect of peculiar velocities on SNe Ia cosmology has been discussed earlier (Hui & Greene 2006; Davis et al. 2011), however these studies relied on covariances that apply to Copernican observers.”