Peculiar-velocity cosmology with Types Ia and II supernovae

Abstract

We present the Democratic Samples of Supernovae (DSS), a compilation of 775 low-redshift Type Ia and II supernovae (SNe Ia & II), of which 137 SN Ia distances are derived via the newly developed snapshot distance method. Using the objects in the DSS as tracers of the peculiar-velocity field, we compare against the corresponding reconstruction from the 2M++ galaxy redshift survey. Our analysis -which takes special care to properly weight each DSS subcatalogue and cross-calibrate the relative distance scales between them -results in a measurement of the cosmological parameter combination 𝑓 𝜎 8 = 0.390 +0.022 −0.022 as well as an external bulk flow velocity of 195 +22 −23 km s −1 in the direction (ℓ, 𝑏) = (292 +7 −7 , −6 +5 −4 ) deg, which originates from beyond the 2M++ reconstruction. Similarly, we find a bulk flow of 245 +32 −31 km s −1 toward (ℓ, 𝑏) = (294 +7 −7 , 3 +6 −5 ) deg on a scale of ∼ 30 ℎ −1 Mpc if we ignore the reconstructed peculiar-velocity field altogether. Our constraint on 𝑓 𝜎 8 -the tightest derived from SNe to date (considering only statistical error bars), and the only one to utilise SNe II -is broadly consistent with other results from the literature. We intend for our data accumulation and treatment techniques to become the prototype for future studies that will exploit the unprecedented data volume from upcoming wide-field surveys.

The growth of density perturbations in the last $\sim$10 billion years from tomographic large-scale structure data

“…At redshifts z 1 further information could be gained by combining these data with infrared data such as unWISE [7,116] or radio continuum data [117,118]. Finally, other high-precision probes of growth, such as redshift-space distortions and peculiar velocity surveys [119,120], should allow us to constrain the growth history at least at the same level as tomographic data, and therefore it is worth developing methods to combine these measurements in a consistent way. We use only DES data as a worst case scenario where the last node remains unconstrained.…”

The Sloan Digital Sky Survey Peculiar Velocity Catalogue

“…More recently, the advent of large redshift surveys of nearby galaxies, such as the 2MASS Redshift Survey (Huchra et al 2012), Sloan Digital Sky Survey (SDSS; York et al 2000), 6dF Galaxy Survey (Jones et al 2004), and the Arecibo Legacy Fast ALFA Survey (Giovanelli et al 2005) have enabled the creation of large, homogeneous peculiar velocity sub-samples. Studies using peculiar velocities have hence seen a resurgence, including in the areas of cosmography (Springob et al 2014;Tully et al 2014;Graziani et al 2019), measurements of the bulk flow and low-order velocity moments (Watkins et al 2009;Feldman et al 2010;Ma & Scott 2013;Scrimgeour et al 2016;Qin et al 2018Qin et al , 2019aQin 2021;Qin et al 2021); testing ΛCDM and General Relativity via the velocity correlation function or power spectrum (Johnson et al 2014;Huterer et al 2017;Howlett et al 2017;Adams & Blake 2017;Howlett 2019;Qin et al 2019b; Adams & Blake 2020); and fitting cosmological parameters and the external tidal field using reconstructions of the velocity field from galaxy redshifts (Carrick et al 2015;Boruah et al 2020b;Said et al 2020;Lilow & Nusser 2021;Stahl et al 2021). Furthermore, in the era of the Hubble tension (e.g., Verde et al 2019), the importance of robust and accurate peculiar velocity measurements for correcting low-redshift distance measurements from Type Ia supernovae and gravitational waves has come to the forefront (Scolnic et al 2014;Guidorzi et al 2017;Howlett & Davis 2020;Boruah et al 2020a).…”

Cosmic Flow Measurement and Mock Sampling Algorithm of Cosmicflows-4 Tully-Fisher Catalogue

“…In previous work, the bulk and shear moments are commonly measured using two different methods: maximum likelihood estimation (MLE, Kaiser 1988); minimum variance (MV) estimation (Watkins et al 2009;Feldman et al 2010). The measurements generally agree so far with the Λ cold dark matter model (ΛCDM) prediction (Kaiser 1988;Staveley-Smith & Davies 1989;Jaffe & Kaiser 1995;Nusser & Davis 1995;Parnovsky et al 2001;Nusser & Davis 2011;Turnbull et al 2012;Ma & Scott 2013;Ma & Pan 2014;Hong et al 2014;Scrimgeour et al 2016;Qin et al 2018Qin et al , 2019bBoruah et al 2020;Qin 2021;Stahl et al 2021).…”