A5062553102- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Labor Movements and Unions
- Particle Detector Development and Performance
- Astronomical Observations and Instrumentation
- Rheology and Fluid Dynamics Studies
- Spectroscopy and Laser Applications
- Photopolymerization techniques and applications
- Historical and Cultural Archaeology Studies
- Polysaccharides Composition and Applications
- Phase Equilibria and Thermodynamics
- Superconducting and THz Device Technology
- Italian Fascism and Post-war Society
- Archaeology and ancient environmental studies
- Plant Water Relations and Carbon Dynamics
- Historical Astronomy and Related Studies
- Astro and Planetary Science
- Historical and Architectural Studies
- Geophysics and Gravity Measurements
Leiden University
2021-2024
University of Waterloo
2024
Weatherford College
2023
McMaster University
2014-2022
University of Warwick
2014-2015
Durham University
1995-2014
East Sussex County Council
2013
University of Leicester
2007-2012
London School of Hygiene & Tropical Medicine
2005-2007
University of London
2007
In this paper we present a large sample of jellyfish galaxies in low redshift clusters (z<0.05), identified through 120-168 MHz radio continuum from the LOFAR Two-metre Sky Survey (LoTSS). From parent 29 X-ray-detected SDSS galaxy and their spectroscopic members, visually identify 95 star-forming, LoTSS with 144 tails. Star formation rates (SFRs) stellar masses are obtained for all SED fits. For each determine tail orientation respect to cluster centre quantify prominence tails shape...
A critical appraisal of the Casson model for measuring chocolate versus a new proposed method is performed. The validated with both research grade rheometers and factory viscometers. This includes elements measurement uncertainty. In this way, reference viscosity related cocoa products using It involves recording: (1) value stress at shear rate 5 s ‐1 to represent yield chocolate, (2) 40 high viscosity, (3) difference between measured during ramp up down in thixotropy. Results relate solid...
The Coma cluster is the nearest massive ($M \gtrsim 10^{15}\,\mathrm{M_\odot}$) galaxy cluster, making it an excellent laboratory to probe influence of environment on star formation. Here, we present a sample 41 galaxies with disturbed morphologies consistent ram pressure stripping. These are identified visually using high-quality, multi-band imaging from Canada-France-Hawaii telescope covering ~9 $\mathrm{deg^2}$ cluster. "stripping candidates" clear outliers in common quantitative...
Numerous examples of ram pressure stripping in galaxy clusters are present literature; however, substantially less work has been focused on lower mass groups. In this we use the LOFAR Two-metre Sky Survey (LoTSS) to search for jellyfish galaxies ~500 SDSS groups (z<0.05), making most comprehensive date. We identify 60 with extended, asymmetric radio continuum tails, which found across entire range group from $10^{12.5} < M_\mathrm{group} 10^{14}\,h^{-1}\,\mathrm{M_\odot}$. compare identified...
Abstract We compile a sample of Sloan Digital Sky Survey (SDSS) galaxy clusters with high-quality Chandra X-ray data to directly study the influence dense intracluster medium (ICM) on quenching satellite galaxies. quenched fractions galaxies as function ICM density for low- (10 9 ≲ M ⋆ 10 ⊙ ), intermediate- 10.5 and high-mass ( ≳ ) >3000 across 24 low-redshift z < 0.1) clusters. For low-mass we find evidence broken power-law trend between fraction local density. The increases modestly...
We present the Virgo Environment Traced in CO (VERTICO) survey, a new effort to map $^{12}$CO($2-1$), $^{13}$CO($2-1$), and C$^{18}$O($2-1$) 51 Cluster galaxies with Atacama Compact Array, part of Large Millimeter/submillimeter Array (ALMA). The primary motivation VERTICO is understand physical mechanisms that perturb molecular gas disks, therefore star formation galaxy evolution, dense environments. This first paper contains an overview VERTICO's design sample selection, $^{12}$CO($2-1$)...
In this VERTICO early science paper we explore in detail how environmental mechanisms, identified HI, affect the resolved properties of molecular gas reservoirs cluster galaxies. The is probed using ALMA ACA (+TP) observations 12CO(2-1) 51 spiral galaxies Virgo (of which 49 are detected), all included VIVA HI survey. sample spans a stellar mass range 9 < log M*/Msol 11. We study radial profiles, isodensity radii, and surface densities as function galaxy deficiency morphology. There weak...
Abstract Ram pressure stripping is a crucial evolutionary driver for cluster galaxies. It thought to be able accelerate the evolution of their star formation, trigger activity central active galactic nucleus (AGN) and interplay between environmental gas, eventually dissipate gas reservoirs. We explored outcomes ram by studying nonthermal radio emission jellyfish galaxy JW100 in A2626 ( z = 0.055), combining LOw Frequency Array, MeerKAT, Very Large Array observations from 0.144 5.5 GHz....
This article suggests that much recent work relates age to working life is mis-cast in looking at specific groups isolation. Rather than addressing the problem of younger or older workers, this we need develop a framework which can more centrally accommodate inter-generational structures social reproduction collective worker. Focusing upon current Government concerns an active old age, argues such strategy likely be misconceived unless it address changing nature within ‘new capitalism’. It...
We study the dependence of satellite star formation rate and morphology on group dynamics for a sample SDSS groups. classify dynamical state properties populations galaxies at small large group-centric radii. For radii we find no differences in star-forming or disc fraction those Gaussian groups compared to non-Gaussian By comparing fractions infalling field evidence pre-processing both morphology. The strength increases with halo mass is highest low-mass onto high-mass haloes. show that...
With MaNGA integral field spectroscopy, we present a resolved analysis of star formation for 29 jellyfish galaxies in nearby clusters, identified from radio continuum imaging taken by the Low Frequency Array. Simulations predict enhanced on "leading half" undergoing ram pressure stripping, and this work report observational evidence elevated formation. The dividing line (through galaxy center) that maximizes enhancement is systematically tied to observed direction stripped tail, suggesting...
Wide-field radio continuum observations of galaxy clusters are revealing an increasing number spiral galaxies hosting tens kpc-long tails produced by the nonthermal interstellar medium being displaced ram pressure. We present a semi-empirical model for multi-frequency emission from pressure stripped based on pure synchrotron cooling plasma moving along stripping direction with uniform velocity. combine LOFAR and uGMRT at 144 400 MHz to study flux density spectral index profiles 7 in Abell...
It has previously been found that the galaxy cluster environment can affect fueling and evolution of Active Galactic Nuclei (AGN). This work examines effect merging on properties radio-AGN by comparing radio morphology members in a sample four eight relaxed clusters at low redshift (z<0.2). Using 144-MHz data from LOFAR Two-metre Sky Survey (LoTSS) Zooniverse, we classify radio-detected using following classes: compact, compact extended, jetted, disturbed. We find statistically significant,...
Ram pressure stripping is a well-known environmental quenching mechanism that removes gas from galaxies infalling into groups and clusters. In some extreme examples of ram stripping, with extended tails show evidence enhanced star formation prior to quenching. this work we use sample 5277 local satellite in which stripped tail has not necessarily been observed, quantify the strength pressure-enhanced compare these results control 8360 field galaxies. We u-band imaging Ultraviolet-Near...
Abstract Ram pressure stripping is a well-known environmental quenching mechanism that removes gas from galaxies infalling into groups and clusters. In some extreme examples of ram stripping, with extended tails show evidence enhanced star formation prior to quenching. this work we use sample 5277 local satellite in which stripped tail has not necessarily been observed, quantify the strength ram-pressure-enhanced compare these results control 8360 field galaxies. We u -band imaging...
Abstract It has previously been found that the galaxy cluster environment can affect fueling and evolution of active galactic nuclei (AGN). This work examines effect merging on properties radio AGN by comparing morphology members in a sample four eight relaxed clusters at low redshift ( z < 0.2). Using 144 MHz data from LOFAR Two-meter Sky Survey Zooniverse, we classify radio-detected using following classes: compact, compact extended, jetted, disturbed. We find statistically significant,...
In this paper we report the first identification of jellyfish galaxies in Perseus cluster (Abell 426). We identified four (LEDA 2191078, MCG +07-07-070, UGC 2654, 2665) within central $2^\circ \times 2^\circ$ ($2.6\,\mathrm{Mpc} 2.6\,\mathrm{Mpc}$) based on presence one-sided radio continuum tails that were detected at $144\,\mathrm{MHz}$ by LOw Frequency ARray (LOFAR). The observed tails, as well orientation morphological features rest-frame optical, are consistent with these being impacted...
ABSTRACT We investigate how large-scale cosmic filaments impact the quenching of galaxies within one virial radius 324 simulated clusters from The Three Hundred project. track with versatile, observation-friendly program DisPerSE and identify haloes hosting VELOCIRaptor. find that cluster close to tend be more star forming, bluer, contain cold gas than their counterparts further away filaments. This effect is recovered at all stellar masses. in stark contrast residing outside clusters, where...
Abstract The quenching of cluster satellite galaxies is inextricably linked to the suppression their cold interstellar medium (ISM) by environmental mechanisms. While removal neutral atomic hydrogen (H i ) at large radii well studied, how environment impacts remaining gas in centres galaxies, which are dominated molecular gas, less clear. Using new observations from Virgo Environment traced CO survey (VERTICO) and archival H data, we study within optical discs on 1.2-kpc scales with...
Context. Environmental effects such as ram pressure stripping (RPS) shape the evolution of galaxies in dense regions. Aims. We used nearby Virgo cluster a laboratory to study environmental on nonthermal components star-forming galaxies. Methods. constructed sample 17 RPS and statistical control 119 from Herschel Reference Survey. All objects these samples were detected LOFAR 144 MHz observations come with H α and/or far-UV star formation rate (SFR) estimates. Results. derived radio–SFR...
This paper is based on the research of middle managers in three countries (The Netherlands, Sweden, and UK) public private sector organisations. The findings indicate that increasing pressures to perform within a surge management initiatives policy moves make organisations more profitable (in sector) “efficient” accountable invariably lead contradictions their performance perceived roles. In context oxymoron “they are do with less”, this will increased stresses strains those performing...
Abstract Jellyfish galaxies, characterized by long filaments of stripped interstellar medium extending from their disks, are the prime laboratories to study outcomes ram pressure stripping. At radio wavelengths, they often show unilateral emission beyond stellar disk, and an excess luminosity with respect that expected current star formation rate. We present new 144 MHz images provided LOFAR Two-metre Sky Survey for a sample six galaxies GASP survey. These high global at (6−27 × 10 22 W Hz...
We measure the molecular-to-atomic gas ratio, $R_{\rm mol}$, and star formation rate (SFR) per unit molecular mass, SFE$_{\rm in 38 nearby galaxies selected from Virgo Environment Traced CO (VERTICO) survey. determine their scale-lengths for stellar components find a roughly 3:5 ratio between them compared to $\sim$1:1 field galaxies, indicating that emission is more centrally concentrated than stars. compute mol}$ as function of different physical quantities. While spatially-resolved on...