V. Arumugam
A5071172705- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Calibration and Measurement Techniques
- Dark Matter and Cosmic Phenomena
- Scientific Research and Discoveries
- Superconducting and THz Device Technology
- Particle Accelerators and Free-Electron Lasers
- Plant Water Relations and Carbon Dynamics
- Remote Sensing in Agriculture
- Atmospheric Ozone and Climate
- Adaptive optics and wavefront sensing
- Pulsars and Gravitational Waves Research
Institut de Radioastronomie Millimétrique
2019-2024
Ausonius Institut de Recherche sur l'Antiquité et le Moyen age
2024
European Southern Observatory
2014-2020
Royal Observatory
2010-2019
University of Edinburgh
2010-2019
Scottish Universities Physics Alliance
2016
UK Astronomy Technology Centre
2011-2014
The Herschel Multi-tiered Extragalactic Survey (HerMES) is a legacy programme designed to map set of nested fields totalling ∼380 deg2. Fields range in size from 0.01 ∼20 deg2, using the Herschel-Spectral and Photometric Imaging Receiver (SPIRE) (at 250, 350 500 μm) Herschel-Photodetector Array Camera Spectrometer (PACS) 100 160 μm), with an additional wider component 270 deg2 SPIRE alone. These bands cover peak redshifted thermal spectral energy distribution interstellar dust thus capture...
We exploit the deep and extended far infrared data sets (at 70, 100 160 um) of Herschel GTO PACS Evolutionary Probe (PEP) Survey, in combination with HERschel Multi tiered Extragalactic Survey (HerMES) at 250, 350 500 um, to derive evolution restframe 35 60 90 total (IR) luminosity functions (LFs) up z~4. detect very strong for IR LF combined a density evolution. In agreement previous findings, increases steeply z~1, then flattens between z~1 z~3 decrease z greater than 3. Galaxies different...
We present a catalogue of nearly 3,000 submillimetre sources detected at 850um over ~5 square degrees surveyed as part the James Clerk Maxwell Telescope (JCMT) SCUBA-2 Cosmology Legacy Survey (S2CLS). This is largest survey its kind 850um, probing meaningful cosmic volume peak star formation activity and increasing sample size galaxies selected by an order magnitude. describe wide component S2CLS, which covers key extragalactic fields: UKIDSS-UDS, COSMOS, Akari-NEP, Extended Groth Strip,...
ABSTRACT We analyse the physical properties of a large, homogeneously selected sample ALMA-located sub-millimetre galaxies (SMGs). This survey, AS2UDS, identified 707 SMGs across ∼1 deg2 field, including ∼17 per cent, which are undetected at K ≳ 25.7 mag. interpret their ultraviolet-to-radio data using magphys and determine median redshift z = 2.61 ± 0.08 (1σ range 1.8–3.4) with just ∼6 cent > 4. Our survey provides massive dusty 1, dust stellar masses Md (6.8 0.3) × 108 M⊙ (thus, gas...
We report on the sensitivity of SPIRE photometers <i>Herschel<i/> Space Observatory. Specifically, we measure confusion noise from observations taken during science demonstration phase Multi-tiered Extragalactic Survey. Confusion is defined to be spatial variation sky intensity in limit infinite integration time, and found consistent among different fields our survey at level 5.8, 6.3 6.8 mJy/beam 250, 350 500 <i>μ<i/>m, respectively. These results, together with measured instrument noise,...
We set out to determine the ratio, q(IR), of rest-frame 8-1000um flux, S(IR), monochromatic radio S(1.4GHz), for galaxies selected at far-IR and wavelengths, search signs that ratio evolves with redshift, luminosity or dust temperature, identify any far-IR-bright outliers - useful laboratories exploring why far-IR/radio correlation is generally so tight when prevailing theory suggests variations are almost inevitable. use flux-limited 250-um 1.4-GHz samples, obtained in GOODS-N using...
ABRIGED Herschel/SPIRE has provided confusion limited maps of deep fields at 250, 350, and 500um, as part the HerMES survey. Due to confusion, only a small fraction Cosmic Infrared Background can be resolved into individually-detected sources. Our goal is produce galaxy number counts redshift distributions below limit, which we then use place strong constraints on origins cosmic infrared background models evolution. We individually extracted bright SPIRE with method using positions, flux...
Emission at far-infrared wavelengths makes up a significant fraction of the total light detected from galaxies over age Universe. Herschel provides an opportunity for studying peak wavelength their emission. Our aim is to provide benchmark models galaxy population evolution and test pre-existing galaxies. With Multi-tiered Extra-galactic survey, HerMES, we have observed number fields different areas sensitivity using SPIRE instrument on Herschel. We determined counts down ~20 mJy....
The <i>Herschel<i/> Space Observatory enables us to accurately measure the bolometric output of starburst galaxies and active galactic nuclei (AGN) by directly sampling peak their far-infrared (IR) emission. Here we examine whether spectral energy distribution (SED) dust temperature have strongly evolved over last 80% age Universe. We discuss possible consequences for determination star-formation rates (SFR) any evidence a major change in properties. use deep extragalactic surveys from 100...
Using Herschel data from the deepest SPIRE and PACS surveys (HerMES PEP) in COSMOS GOODS (N+S), we examine dust properties of IR-luminous (L_IR>10^10 L_sun) galaxies at 0.1<z<2 determine how these evolve with cosmic time. The unique angle this work is rigorous analysis survey selection effects, making first study star-formation-dominated, population within a framework almost entirely free biases. We find that have SEDs broad far-IR peaks characterised by cool/extended emission average...
We present the cross-identification and source photometry techniques used to process Herschel SPIRE imaging taken as part of Multi-Tiered Extragalactic Survey (HerMES). Cross-identifications are performed in map-space so minimise blending effects. make use a combination linear inversion model selection produce reliable catalogues based on Spitzer MIPS 24 micron positions. Testing simulations real observations show that this approach gives robust results for even faintest sources S250~10 mJy....
Nuclear and starburst activity are known to often occur concomitantly. Herschel-SPIRE provides sampling of the FIR SEDs type 1 2 AGN, allowing for separation between hot dust (torus) cold (starburst) emission. We study large samples spectroscopically confirmed AGN lying within Herschel Multi-tiered Extragalactic Survey (HerMES) fields observed during science demonstration phase, aiming understand their colour distributions constrain contributions. find that one third in HerMES have 5-sigma...
We present the first results from KMOS (K-band Multi-Object Spectrograph) AGN (active galactic nuclei) Survey at High redshift (KASHz), a VLT/KMOS integral-field spectroscopic (IFS) survey of z ≳ 0.6 AGN. galaxy-integrated spectra 89 X-ray (L2–10 keV = 1042–1045 erg s−1), for which we observed [O iii] (z ≈ 1.1–1.7) or Hα emission 0.6–1.1). The targets have luminosities representative parent population and explore emission-line as function luminosity. For targets, ≈50 per cent ionized gas...
We study the dust properties of galaxies in redshift range 0.1<z<2.8 observed by Herschel Space Observatory field Great Observatories Origins Deep Survey-North as part PEP and HerMES key programmes. Infrared (IR) luminosity (L_IR) temperature (T_dust) are derived from spectral energy distribution (SED) fit far-infrared (FIR) flux densities obtained with PACS SPIRE instruments onboard Herschel. As a reference sample, we also obtain IR luminosities temperatures local at z<0.1 using AKARI IRAS...
We present a list of 13 candidate gravitationally lensed submillimeter galaxies (SMGs) from 95 deg2 the Herschel Multi-tiered Extragalactic Survey, surface density 0.14 ± 0.04 deg−2. The selected sources have 500 μm flux densities (S500) greater than 100 mJy. Gravitational lensing is confirmed by follow-up observations in 9 systems (70%), and status four remaining undetermined. also supplementary sample 29 (0.31 0.06 deg−2) SMG candidates with S500 = 80–100 mJy, which are expected to contain...
We quantify the fraction of cosmic infrared background (CIB) that originates from galaxies identified in UV/optical/near-infrared by stacking 81,250 (∼35.7 arcmin−2) K-selected sources (KAB < 24.0) split according to their rest-frame U − V versus J colors into 72,216 star-forming and 9034 quiescent galaxies, on maps Spitzer/MIPS (24 μm), Herschel/PACS (100, 160 Herschel/SPIRE (250, 350, 500 AzTEC (1100 μm). The CIB resolved our catalog is (69% ± 15%) at 24 μm, (78% 17%) 70 (58% 13%) 100 18%)...
We present measurements of the auto- and cross-frequency power spectra cosmic infrared background (CIB) at 250, 350, 500 μm (1200, 860, 600 GHz) from observations totaling ∼70 deg2 made with SPIRE instrument aboard Herschel Space Observatory. measure a fractional anisotropy δI/I = 14% ± 4%, detecting signatures arising clustering dusty star-forming galaxies in both linear (2-halo) nonlinear (1-halo) regimes; that transition 2- to 1-halo terms, below which originates predominantly multiple...
The first deep blank-field 450um map (1-sigma~1.3mJy) from the SCUBA-2 Cosmology Legacy Survey (S2CLS), conducted with James Clerk Maxwell Telescope (JCMT) is presented. Our covers 140 arcmin^2 of COSMOS field, in footprint HST CANDELS area. Using 60 submillimetre galaxies (SMGs) detected at >3.75-sigma, we evaluate number counts 450um-selected flux densities S_450>5mJy. 8-arcsec JCMT beam and high sensitivity now make it possible to directly resolve a larger fraction cosmic infrared...
We present a method for selecting $z>4$ dusty, star forming galaxies (DSFGs) using Herschel/SPIRE 250/350/500 $\mu m$ flux densities to search red sources. apply this 21 deg$^2$ of data from the HerMES survey produce catalog 38 high-$z$ candidates. Follow-up first 5 these sources confirms that is efficient at DSFGs, with 4/5 $z=4.3$ $6.3$ (and remaining source $z=3.4$), and they are some most luminous dusty known. Comparison previous DSFG samples, mostly selected longer wavelengths (e.g.,...
We present the catalogue and basic properties of sources in AS2UDS, an 870-|$\mu$|m continuum survey with Atacama Large Millimetre/sub-millimetre Array (ALMA) 716 single-dish sub-millimetre detected UKIDSS/UDS field by SCUBA-2 Cosmology Legacy Survey. In our sensitive ALMA follow-up observations, we detect 708 galaxies (SMGs) at >4.3σ significance across ∼1°-diameter field. combine precise positions extensive multiwavelength coverage UDS which yields spectral energy distributions for SMGs a...
We present physical properties [redshifts (z), star-formation rates (SFRs) and stellar masses (Mstar)] of bright (S850>4mJy) submm galaxies in the ~2deg2 COSMOS UDS fields selected with SCUBA-2/JCMT. complete galaxy identification process for all (~2000) S/N>3.5 850-um sources, but focus our scientific analysis on a high-quality sub-sample 651 S/N>4 sources multi-wavelength coverage including 1.1-mm imaging. check reliability identifications, robustness SCUBA-2 fluxes by revisiting recent...
Abstract We present a multiwavelength analysis using the Submillimeter Array (SMA), James Clerk Maxwell Telescope, NOEMA, JWST, Hubble Space Telescope (HST), and Spitzer of two dusty strongly star-forming galaxies, 850.1 850.2, seen through massive cluster lens A 1489. These SMA-located sources both lie at z = 4.26 have bright dust continuum emission, but 850.2 is UV-detected Lyman-break galaxy, while undetected ≲ 2 μ m, even with deep JWST/NIRCam observations. investigate their stellar,...
The study of distant galaxy groups and clusters at the peak epoch star formation is limited by lack a statistically homogeneously selected spectroscopically confirmed sample. Recent discoveries concentrated starburst activities in cluster cores have opened new window to hunt for these structures based on their integrated IR luminosities. Here, we carry out large NOEMA (NOrthern Extended Millimeter Array) program targeting statistical sample infrared-luminous sources associated with...