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Full-Text Articles in Physical Sciences and Mathematics
Cosmology-Independent Estimate Of The Fraction Of Baryon Mass In The Igm From Fast Radio Burst Observations, Zhengxiang Li, He Gao, Jun-Jie Wei, Yuan-Pei Yang, Bing Zhang, Zong-Hong Zhu
Cosmology-Independent Estimate Of The Fraction Of Baryon Mass In The Igm From Fast Radio Burst Observations, Zhengxiang Li, He Gao, Jun-Jie Wei, Yuan-Pei Yang, Bing Zhang, Zong-Hong Zhu
Physics & Astronomy Faculty Research
The excessive dispersion measure (DM) of fast radio bursts (FRBs) has been proposed to be a powerful tool to study intergalactic medium (IGM) and to perform cosmography. One issue is that the fraction of baryons in the IGM, f IGM, is not properly constrained. Here, we propose a method of estimating f IGM using a putative sample of FRBs with the measurements of both DM and luminosity distance d L. The latter can be obtained if the FRB is associated with a distance indicator (e.g., a gamma-ray burst or a gravitational-wave event), or the redshift z of the FRB is …
The Dependence Of Intrinsic Alignment Of Galaxies On Wavelength Using Kids And Gama, Christos Georgiou, Harry Johnston, Henk Hoekstra, Massimo Viola, Konrad Kuijken, Benjamin Joachimi, Nora Elisa Chisari, Daniel J. Farrow, Hendrik Hildebrandt, Benne W. Holwerda, Arun Kannawadi
The Dependence Of Intrinsic Alignment Of Galaxies On Wavelength Using Kids And Gama, Christos Georgiou, Harry Johnston, Henk Hoekstra, Massimo Viola, Konrad Kuijken, Benjamin Joachimi, Nora Elisa Chisari, Daniel J. Farrow, Hendrik Hildebrandt, Benne W. Holwerda, Arun Kannawadi
Faculty Scholarship
The outer regions of galaxies are more susceptible to the tidal interactions that lead to intrinsic alignments of galaxies. The resulting alignment signal may therefore depend on the passband if the colours of galaxies vary spatially. To quantify this, we measured the shapes of galaxies with spectroscopic redshifts from the GAMA survey using deep gri imaging data from the KiloDegree Survey. The performance of the moment-based shape measurement algorithm DEIMOS was assessed using dedicated image simulations, which showed that the ellipticities could be determined with an accuracy better than 1% in all bands. Additional tests for potential systematic errors did …
Testing For Directionality In The Planck Polarization And Lensing Data, Majd Ghrear, Emory F. Bunn, Dagoberto Contreras, Douglas Scott
Testing For Directionality In The Planck Polarization And Lensing Data, Majd Ghrear, Emory F. Bunn, Dagoberto Contreras, Douglas Scott
Physics Faculty Publications
In order to better analyse the polarization of the cosmic microwave background (CMB), which is dominated by emission from our Galaxy, we need tools that can detect residual foregrounds in cleaned CMB maps. Galactic foregrounds introduce statistical anisotropy and directionality to the polarization pseudo-vectors of the CMB, which can be investigated by using the D statistic of Bunn and Scott. This statistic is rapidly computable and capable of investigating a broad range of data products for directionality. We demonstrate the application of this statistic to detecting foregrounds in polarization maps by analysing the uncleaned Planck 2018 frequency maps. For the …