Behzad Ansarinejad
A5062026336- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Scientific Research and Discoveries
- Computational Physics and Python Applications
- Solar and Space Plasma Dynamics
- Adaptive optics and wavefront sensing
- Geophysics and Gravity Measurements
- Statistical and numerical algorithms
- Particle physics theoretical and experimental studies
- Superconducting and THz Device Technology
- Earth Systems and Cosmic Evolution
- Natural Language Processing Techniques
- Quantum Mechanics and Applications
- Advanced Thermodynamics and Statistical Mechanics
- Scientific Computing and Data Management
- Gaussian Processes and Bayesian Inference
- Economic Growth and Productivity
The University of Melbourne
2021-2025
Durham University
2018-2023
The University of Western Australia
2020
International Centre for Radio Astronomy Research
2020
University of St Andrews
2016
Linde (United States)
2016
The Open University
2016
University of Manchester
2016
Abstract The DESI Legacy Imaging Surveys ( http://legacysurvey.org/ ) are a combination of three public projects (the Dark Energy Camera Survey, the Beijing–Arizona Sky and Mayall z -band Survey) that will jointly image ≈14,000 deg 2 extragalactic sky visible from northern hemisphere in optical bands g , r using telescopes at Kitt Peak National Observatory Cerro Tololo Inter-American Observatory. combined survey footprint is split into two contiguous areas by Galactic plane. imaging...
We present cosmological constraints from the analysis of two-point correlation functions between galaxy positions and lensing measured in Dark Energy Survey (DES) Year 3 data measurements cosmic microwave background (CMB) South Pole Telescope (SPT) Planck. When jointly analyzing DES-only DES cross-correlations with SPT+Planck CMB lensing, we find Ωm=0.344±0.030 S8≡σ8(Ωm/0.3)0.5=0.773±0.016, assuming ΛCDM. additionally combining autospectrum, Ωm=0.306+0.018−0.021 S8=0.792±0.012. The high...
We present a catalog of 689 galaxy cluster candidates detected at significance $\xi>4$ via their thermal Sunyaev-Zel'dovich (SZ) effect signature in 95 and 150 GHz data from the 500-square-degree SPTpol survey. use optical infrared Dark Energy Camera Wide-field Infrared Survey Explorer (WISE) Spitzer satellites, to confirm 544 these as clusters with $\sim94\%$ purity. The sample has an approximately redshift-independent mass threshold redshift $z>0.25$ spans $1.5 \times 10^{14} < M_{500c} 9...
Abstract We present component-separated maps of the primary cosmic microwave background/kinematic Sunyaev–Zel’dovich (SZ) amplitude and thermal SZ Compton- y parameter, created using data from South Pole Telescope (SPT) Planck satellite. These maps, which cover ∼2500 deg 2 southern sky imaged by SPT-SZ survey, represent a significant improvement over previous such products available in this region virtue their higher angular resolution ( <?CDATA $1\buildrel{\,\prime}\over{.} 25$?> <mml:math...
We present a measurement of gravitational lensing over 1500 deg2 the Southern sky using SPT-3G temperature data at 95 GHz and 150 taken in 2018. The amplitude relative to fiducial Planck 2018 Lambda cold dark matter (ΛCDM) cosmology is found be 1.020±0.060, excluding instrumental astrophysical systematic uncertainties. conduct extensive null tests check robustness measurements, report minimum-variance combined power spectrum angular multipoles 50<L<2000, which we use constrain cosmological...
Our current understanding of the Universe is established through pristine measurements structure in cosmic microwave background (CMB) and distribution shapes galaxies tracing large scale (LSS) Universe. One key ingredient that underlies cosmological observables field sources observed assumed to be initially Gaussian with high precision. Nevertheless, a minimal deviation from Gaussianityis perhaps most robust theoretical prediction models explain Universe; itis necessarily present even...
Inflation may provide unique insight into the physics at highest available energy scales that cannot be replicated in any realistic terrestrial experiment. Features primordial power spectrum are generically predicted a wide class of models inflation and its alternatives, observationally one most overlooked channels for finding evidence non-minimal inflationary models. Constraints from observations cosmic microwave background cover widest range feature frequencies, but sensitive constraints...
Our current understanding of the Universe is established through pristine measurements structure in cosmic microwave background (CMB) and distribution shapes galaxies tracing large scale (LSS) Universe. One key ingredient that underlies cosmological observables field sources observed assumed to be initially Gaussian with high precision. Nevertheless, a minimal deviation from Gaussianityis perhaps most robust theoretical prediction models explain Universe; itis necessarily present even...
ABSTRACT We present an extension to a Sunyaev–Zel’dovich Effect (SZE) selected cluster catalogue based on observations from the South Pole Telescope (SPT); this extends lower signal noise than previous SPT–SZ and therefore includes mass clusters. Optically derived redshifts, centres, richnesses, morphological parameters together with contamination completeness statistics are extracted using multicomponent matched filter (MCMF) algorithm applied S/N &gt; 4 candidate list Dark Energy...
The hot dense environment of the early universe is known to have produced large numbers baryons, photons, and neutrinos. These extreme conditions may also other long-lived species, including new light particles (such as axions or sterile neutrinos) gravitational waves. effects any such relics can be observed through their unique imprint in cosmic microwave background (CMB), large-scale structure, primordial element abundances, are important determining initial universe. We argue that future...
Abstract We present a catalog of 4195 optically confirmed Sunyaev–Zel’dovich (SZ) selected galaxy clusters detected with signal-to-noise ratio >4 in 13,211 deg 2 sky surveyed by the Atacama Cosmology Telescope (ACT). Cluster candidates were applying multifrequency matched filter to 98 and 150 GHz maps constructed from ACT observations obtained 2008 2018 using deep, wide-area optical surveys. The span redshift range 0.04 < z 1.91 (median = 0.52). contains 222 > 1 clusters, total 868...
We present cosmological constraints from the abundance of galaxy clusters selected via thermal Sunyaev-Zel'dovich (SZ) effect in South Pole Telescope (SPT) data with a simultaneous mass calibration using weak gravitational lensing Dark Energy Survey (DES) and Hubble Space (HST). The cluster sample is constructed combined SPT-SZ, SPTpol ECS, 500d surveys, comprises 1,005 confirmed redshift range $0.25-1.78$ over total sky area 5,200 deg$^2$. use DES Year 3 weak-lensing for 688 redshifts...
Cosmic shear, galaxy clustering, and the abundance of massive halos each probe large-scale structure Universe in complementary ways. We present cosmological constraints from joint analysis three probes, building on latest analyses lensing-informed clusters identified by South Pole Telescope (SPT) auto- cross-correlation position weak lensing measurements (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mn>3</a:mn><a:mo>×</a:mo><a:mn>2</a:mn><a:mi>pt</a:mi></a:math>)...
ABSTRACT We perform a cross validation of the cluster catalogue selected by red-sequence Matched-filter Probabilistic Percolation algorithm (redMaPPer) in Dark Energy Survey year 1 (DES-Y1) data matching it with Sunyaev–Zel’dovich effect (SZE) from South Pole Telescope SPT-SZ survey. Of 1005 redMaPPer clusters measured richness $\hat{\lambda }\gt 40$ joint footprint, 207 are confirmed SPT-SZ. Using mass information SZE signal, we calibrate richness–mass relation using Bayesian population...
Abstract We provide the first combined cosmological analysis of South Pole Telescope (SPT) and Planck cluster catalogs. The aim is to an independent calibration for scaling relations, exploiting constraining power SPT-SZ catalog its dedicated weak lensing (WL) X-ray follow-up observations. build a new version likelihood. In ν Λ CDM scenario, focusing on mass slope bias we find <?CDATA ${\alpha }_{\mathrm{SZ}}={1.49}_{-0.10}^{+0.07}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Abstract We show the improvement to cosmological constraints from galaxy cluster surveys with addition of cosmic microwave background (CMB)-cluster lensing data. explore implications adding mass information 3.1 σ detection gravitational CMB by clusters Sunyaev–Zel’dovich (SZ) selected sample 2500 deg 2 SPT-SZ survey and targeted optical X-ray follow-up In ΛCDM model, combination Planck power spectrum measurements prefers <?CDATA ${\sigma }_{8}{\left({{\rm{\Omega...
We present a Hubble Space Telescope (HST) weak gravitational lensing study of nine distant and massive galaxy clusters with redshifts $1.0 \lesssim z 1.7$ ($z_\mathrm{median} = 1.4$) Sunyaev Zel'dovich (SZ) detection significance $\xi > 6.0$ from the South Pole (SPT-SZ) survey. measured shapes in HST/ACS F606W F814W images used additional observations HST/WFC3 F110W VLT/FORS2 $U_\mathrm{HIGH}$ to preferentially select background galaxies at $z\gtrsim 1.8$, achieving high purity. combined...
Abstract The environments where galaxies reside crucially shape their star formation histories. We investigate a large sample of 1626 cluster located within 105 galaxy clusters spanning range in redshift (0.26 < z 1.13). are massive ( M 500 ≳ 2 × 10 14 ⊙ ) and uniformly selected from the SPT ACT Sunyaev–Zel’dovich surveys. With spectra hand for thousands members, we use galaxies’ position projected phase space as proxy infall times, which provides more robust measurement environment than...
Abstract We measure the stacked lensing signal in direction of galaxy clusters Dark Energy Survey Year 3 (DES Y3) redMaPPer sample, using cosmic microwave background (CMB) temperature data from SPT-3G, third-generation CMB camera on South Pole Telescope (SPT). Here, we estimate maps constructed initial 2 years SPT-3G 'Main' survey, covering 1500 deg Southern sky. then use this as a proxy for mean cluster mass DES sample. The thermal Sunyaev-Zel'dovich (tSZ) signal, which can contaminate if...
Abstract We forecast constraints on cosmological parameters enabled by three surveys conducted with SPT-3G, the third-generation camera South Pole Telescope. The cover separate regions of 1500, 2650, and 6000 deg 2 to different depths, in total observing 25% sky. These will be measured white noise levels roughly 2.5, 9, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>12</mml:mn> <mml:mspace width="0.33em"/> <mml:mi>μ</mml:mi> <mml:mi...
This is a solicited whitepaper for the Snowmass 2021 community planning exercise. The paper focuses on measurements and science with Cosmic Microwave Background (CMB). CMB foundational to our understanding of modern physics continues be powerful tool driving cosmology particle physics. In this paper, we outline broad unique impact High Energy Frontier in upcoming decade. We also describe progression ground-based experiments, which shows that prepared develop key capabilities facilities...
Parametric modeling of galaxy cluster density profiles from weak lensing observations leads to a mass bias, whose detailed understanding is critical in deriving accurate mass-observable relations for constraining cosmological models. Drawing existing methods, we develop robust framework calculating this bias one-parameter fits simulations dark matter halos. We show that our approach has the advantage being independent absolute noise level, so only number halos given simulation and...
This Snowmass 2021 White Paper describes the Cosmic Microwave Background Stage 4 project CMB-S4, which is designed to cross critical thresholds in our understanding of origin and evolution Universe, from highest energies at dawn time through growth structure present day. We provide an overview science case, technical design, plan.