A5057274461- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Radio Astronomy Observations and Technology
- Computational Physics and Python Applications
- Astrophysics and Cosmic Phenomena
- Advanced Adaptive Filtering Techniques
- Astronomical Observations and Instrumentation
- Advanced Mathematical Theories and Applications
- Gamma-ray bursts and supernovae
- Advanced Measurement and Detection Methods
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Advancements in PLL and VCO Technologies
- Seismology and Earthquake Studies
- Control Systems and Identification
- Data-Driven Disease Surveillance
- Data Analysis with R
- CCD and CMOS Imaging Sensors
- Climate variability and models
- Dark Matter and Cosmic Phenomena
- Superconducting and THz Device Technology
- Relativity and Gravitational Theory
- Remote Sensing in Agriculture
- Blind Source Separation Techniques
Institute of Astronomy
2025
University of Cambridge
2018-2025
University of Manchester
2021-2023
University of Oxford
2016
We present a new cosmological analysis of the galaxy clusters in Planck MMF3 cosmology sample with cosmic microwave background (CMB) lensing calibration cluster masses. As demonstrated by Planck, detected via Sunyaev-Zel'dovich (SZ) effect offer powerful way to constrain parameters such as $\Omega_{\mathrm{m}}$ and $\sigma_8$. Determining absolute mass scale is, however, difficult, some recent calibrations have yielded constraints apparent tension $\Lambda$CDM model derived from power...
Lensing of the CMB is now a well-developed probe large-scale clustering over broad range redshifts. By exploiting non-Gaussian imprints lensing in polarization CMB, CORE mission can produce clean map deflections nearly full-sky. The number high-S/N modes this will exceed current maps by factor 40, and measurement be sample-variance limited on all scales where linear theory valid. Here, we summarise product discuss science that it enable. For example, summed mass neutrinos determined to an...
Abstract This paper discusses the science case for a sensitive spectro-polarimetric survey of microwave sky. Such would provide tomographic and dynamic census three-dimensional distribution hot gas, velocity flows, early metals, dust, mass in entire Hubble volume, exploit CMB temperature polarisation anisotropies down to fundamental limits, track energy injection absorption into radiation background across cosmic times by measuring spectral distortions blackbody emission. In addition its...
Combining galaxy cluster and void abundances breaks the degeneracy between mean matter density $\Omega_{\rm m}$ power spectrum normalization $\sigma_8$. In a first for voids, we constrain m} = 0.21 \pm 0.10$ $\sigma_8 0.95 0.21$ flat $\Lambda$CDM universe, using extreme-value statistics on claimed largest void. The Planck-consistent results detect dark energy with two objects, independently of other probes. Cluster-void studies also offer complementarity in scale, density, non-linearity -...
ABSTRACT We introduce the Planck SZiFi catalogues, a new set of 10 catalogues galaxy clusters detected through their thermal Sunyaev–Zeldovich (tSZ) signature. The are produced by applying cluster finder to PR3 temperature data down signal-to-noise threshold 5. They span three frequency channel combinations (100–857, 100–545, and 100–353 GHz) seven them constructed spectrally deprojecting Cosmic Infrared Background (CIB). This approach allows us, for first time in context finding, carefully...
Abstract This Science White Paper, prepared in response to the ESA Voyage 2050 call for long-term mission planning, aims describe various science possibilities that can be realized with an L-class space observatory is dedicated study of interactions cosmic microwave background (CMB) photons web. Our aim specifically use CMB as a backlight – and survey gas, total mass, stellar content entire observable Universe by means analyzing spatial spectral distortions imprinted on it. These result from...
ABSTRACT Galaxy clusters detected through the thermal Sunyaev–Zeldovich (tSZ) effect are a powerful cosmological probe from which constraints on parameters such as Ωm and σ8 can be derived. The measured cluster tSZ signal be, however, contaminated by Cosmic Infrared Background (CIB) emission, CIB is spatially correlated with field. We quantify extent of this contamination applying iterative multifrequency matched filter (iMMF) cluster-finding method to mock Planck-like data Websky...
This paper discusses the science case for a sensitive spectro-polarimetric survey of microwave sky. Such would provide tomographic and dynamic census three-dimensional distribution hot gas, velocity flows, early metals, dust, mass in entire Hubble volume, exploit CMB temperature polarisation anisotropies down to fundamental limits, track energy injection absorption into radiation background across cosmic times by measuring spectral distortions blackbody emission. In addition its exceptional...
class_sz is a versatile, robust and efficient code, in C Python, optimized to compute theoretical predictions for wide range of observables relevant cross-survey science the Stage IV era. The code public at https://github.com/CLASS-SZ/class_sz along with series tutorial notebooks ( https://github.com/CLASS-SZ/notebooks ). It will be presented full detail paper II. Here we give brief overview key features usage.
Multi-frequency matched filters (MMFs) are routinely used to detect galaxy clusters from CMB data through the thermal Sunyaev-Zeldovich (tSZ) effect, leading cluster catalogues that can be for cosmological inference. In order applied, MMFs require knowledge of cross-frequency power spectra noise in maps. This is typically estimated and taken equal data, assuming contribution tSZ signal detections negligible. Using both analytical arguments \textit{Planck}-like mock observations, we show...
As demonstrated by Planck , SPT, and ACT, the abundance of Sunyaev-Zeldovich-detected galaxy clusters across mass redshift is a powerful cosmological probe. Upcoming experiments such as Simons Observatory (SO) will detect over an order magnitude more objects than what previous have found, thereby providing unprecedented constraining potential. However, in for this potential to be realised, cluster detection analysis pipelines built understood much higher level accuracy has been date. Here we...
We introduce the Planck SZiFi catalogues, a new set of 10 catalogues galaxy clusters detected through their thermal Sunyaev-Zeldovich (tSZ) signature. The are produced by applying cluster finder to PR3 temperature data down signal-to-noise threshold 5. They span three frequency channel combinations (100-857 GHz, 100-545 and 100-353 GHz) 7 them constructed spectrally deprojecting Cosmic Infrared Background (CIB). This approach allows us, for first time in context finding, carefully assess...
Abstract We introduce cosmocnc , a new framework for computing the number count likelihood of galaxy cluster catalogues in fast, flexible and accurate way. offers three types likelihoods: an unbinned, binned, extreme value likelihood. It also supports addition stacked data, which is modelled consistently with catalogue. The unbinned likelihood, main focus framework, can take arbitrary mass observables as input deal several complexities such variations properties observable across survey...
Matched filters are routinely used in cosmology order to detect galaxy clusters from mm observations through their thermal Sunyaev-Zeldovich (tSZ) signature. In addition, they naturally provide an observable, the detection signal-to-noise or significance, which can be as a mass proxy number counts analyses of tSZ-selected cluster samples. this work, we show that observable is, general, non-Gaussian, and it suffers positive bias, refer optimisation bias. Both aspects arise fact is constructed...
ABSTRACT Cosmic microwave background (CMB) lensing is a promising, novel way to measure galaxy cluster masses that can be used, e.g. for mass calibration in counts analyses. Understanding the statistics of observable obtained with such measurements essential if their use subsequent analyses not lead biased results. We study CMB Planck-like experiment mock observations from an N-body simulation. quantify bias and intrinsic scatter associated this following two different approaches, one which...
We introduce cosmocnc, a Python package for computing the number count likelihood of galaxy cluster catalogues in fast, flexible and accurate way. cosmocnc offers three types likelihoods: an unbinned, binned, extreme value likelihood. It also supports addition stacked data, which is modelled consistently with catalogue. The unbinned likelihood, main focus code, can take arbitrary mass observables as input deal several complexities such variations properties observable across survey...
Multi-agent systems (MAS) utilizing multiple Large Language Model agents with Retrieval Augmented Generation and that can execute code locally may become beneficial in cosmological data analysis. Here, we illustrate a first small step towards AI-assisted analyses glimpse of the potential MAS to automate optimize scientific workflows Cosmology. The system architecture our example package, builds upon autogen/ag2 framework, be applied any area quantitative research. particular task apply...
Multi-frequency matched filters (MMFs) are routinely used to detect galaxy clusters from CMB data through the thermal Sunyaev-Zeldovich (tSZ) effect, leading cluster catalogues that can be for cosmological inference. In order applied, MMFs require knowledge of cross-frequency power spectra noise in maps. This is typically estimated and taken equal data, assuming contribution tSZ signal detections negligible. Using both analytical arguments \textit{Planck}-like mock observations, we show...
As demonstrated by Planck, SPT, and ACT, the abundance of Sunyaev-Zeldovich-detected galaxy clusters across mass redshift is a powerful cosmological probe. Upcoming experiments such as Simons Observatory (SO) will detect over an order magnitude more objects than what previous have found, thereby providing unprecedented constraining potential. However, in for this potential to be realised, cluster detection analysis pipelines built understood much higher level accuracy has been date. Here we...
class_sz is a versatile and robust code in C Python that can compute theoretical predictions for wide range of observables relevant to cross-survey science the Stage IV era. The public at https://github.com/CLASS-SZ/class_sz along with series tutorial notebooks (https://github.com/CLASS-SZ/notebooks). It will be presented full detail paper II. Here we give brief overview key features usage.
Galaxy clusters detected through the thermal Sunyaev-Zeldovich (tSZ) effect are a powerful cosmological probe from which constraints on parameters such as $Ω_{\mathrm{m}}$ and $σ_8$ can be derived. The measured cluster tSZ signal be, however, contaminated by Cosmic Infrared Background (CIB) emission, CIB is spatially correlated with field. We quantify extent of this contamination applying iterative multi-frequency matched filter (iMMF) cluster-finding method to mock Planck-like data Websky...