Author
Gwenifer Raymond
Bio: Gwenifer Raymond is an academic researcher from Cardiff University. The author has contributed to research in topics: Galaxy & Redshift. The author has an hindex of 27, co-authored 40 publications receiving 3870 citations.
Papers
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University of Sussex1, California Institute of Technology2, Jet Propulsion Laboratory3, European Space Agency4, Ames Research Center5, University of Edinburgh6, Paris Diderot University7, Imperial College London8, University of Paris-Sud9, Aix-Marseille University10, Cornell University11, Spanish National Research Council12, University of La Laguna13, Complutense University of Madrid14, UK Astronomy Technology Centre15, University of Colorado Boulder16, University of California, Irvine17, Goddard Space Flight Center18, University of Nottingham19, Cardiff University20, University of Padua21, Institut d'Astrophysique de Paris22, University of Cambridge23, University of British Columbia24, European Space Research and Technology Centre25, University of Manchester26, University College London27, Rutherford Appleton Laboratory28, University of Lethbridge29, University of Oxford30, Commonwealth Scientific and Industrial Research Organisation31, University of Hertfordshire32, Harvard University33
TL;DR: The Herschel Multi-tiered Extragalactic Survey (HerMES) is a legacy program designed to map a set of nested fields totalling ∼380deg^2 as mentioned in this paper.
Abstract: The Herschel Multi-tiered Extragalactic Survey (HerMES) is a legacy programme designed to map a set of nested fields totalling ∼380 deg^2. Fields range in size from 0.01 to ∼20 deg^2, using the Herschel-Spectral and Photometric Imaging Receiver (SPIRE) (at 250, 350 and 500 μm) and the Herschel-Photodetector Array Camera and Spectrometer (PACS) (at 100 and 160 μm), with an additional wider component of 270 deg^2 with SPIRE alone. These bands cover the peak of the redshifted thermal spectral energy distribution from interstellar dust and thus capture the reprocessed optical and ultraviolet radiation from star formation that has been absorbed by dust, and are critical for forming a complete multiwavelength understanding of galaxy formation and evolution.
The survey will detect of the order of 100 000 galaxies at 5σ in some of the best-studied fields in the sky. Additionally, HerMES is closely coordinated with the PACS Evolutionary Probe survey. Making maximum use of the full spectrum of ancillary data, from radio to X-ray wavelengths, it is designed to facilitate redshift determination, rapidly identify unusual objects and understand the relationships between thermal emission from dust and other processes. Scientific questions HerMES will be used to answer include the total infrared emission of galaxies, the evolution of the luminosity function, the clustering properties of dusty galaxies and the properties of populations of galaxies which lie below the confusion limit through lensing and statistical techniques.
This paper defines the survey observations and data products, outlines the primary scientific goals of the HerMES team, and reviews some of the early results.
852 citations
University of Sussex1, California Institute of Technology2, Jet Propulsion Laboratory3, European Space Agency4, Ames Research Center5, University of Edinburgh6, Paris Diderot University7, Imperial College London8, Aix-Marseille University9, Cornell University10, University of La Laguna11, Spanish National Research Council12, Complutense University of Madrid13, UK Astronomy Technology Centre14, University of Colorado Boulder15, University of California, Irvine16, Goddard Space Flight Center17, University of Nottingham18, Cardiff University19, University of Padua20, Institut d'Astrophysique de Paris21, University of Cambridge22, University of British Columbia23, European Space Research and Technology Centre24, University of Manchester25, University College London26, University of Lethbridge27, Rutherford Appleton Laboratory28, University of Oxford29, Commonwealth Scientific and Industrial Research Organisation30, University of Hertfordshire31, Harvard University32
TL;DR: The Herschel Multi-tiered Extragalactic Survey (HerMES) is a legacy program designed to map a set of nested fields totalling ~380 deg^2 as mentioned in this paper.
Abstract: The Herschel Multi-tiered Extragalactic Survey, HerMES, is a legacy program designed to map a set of nested fields totalling ~380 deg^2. Fields range in size from 0.01 to ~20 deg^2, using Herschel-SPIRE (at 250, 350 and 500 \mu m), and Herschel-PACS (at 100 and 160 \mu m), with an additional wider component of 270 deg^2 with SPIRE alone. These bands cover the peak of the redshifted thermal spectral energy distribution from interstellar dust and thus capture the re-processed optical and ultra-violet radiation from star formation that has been absorbed by dust, and are critical for forming a complete multi-wavelength understanding of galaxy formation and evolution.
The survey will detect of order 100,000 galaxies at 5\sigma in some of the best studied fields in the sky. Additionally, HerMES is closely coordinated with the PACS Evolutionary Probe survey. Making maximum use of the full spectrum of ancillary data, from radio to X-ray wavelengths, it is designed to: facilitate redshift determination; rapidly identify unusual objects; and understand the relationships between thermal emission from dust and other processes. Scientific questions HerMES will be used to answer include: the total infrared emission of galaxies; the evolution of the luminosity function; the clustering properties of dusty galaxies; and the properties of populations of galaxies which lie below the confusion limit through lensing and statistical techniques.
This paper defines the survey observations and data products, outlines the primary scientific goals of the HerMES team, and reviews some of the early results.
707 citations
TL;DR: In this paper, the authors used the SPIRE instrument on the Herschel Multi-tiered Extra-Galactic Survey (HerMES) to directly resolve 15% of the infrared extra-galactic background at the wavelength near where it peaks.
Abstract: Emission at far-infrared wavelengths makes up a significant fraction of the total light detected from galaxies over the age of Universe. Herschel provides an opportunity for studying galaxies at the peak wavelength of their emission. Our aim is to provide a benchmark for models of galaxy population evolution and to test pre-existing models of galaxies. With the Herschel Multi-tiered Extra-galactic survey, HerMES, we have observed a number of fields of different areas and sensitivity using the SPIRE instrument on Herschel. We have determined the number counts of galaxies down to ~20 mJy. Our constraints from directly counting galaxies are consistent with, though more precise than, estimates from the BLAST fluctuation analysis. We have found a steep rise in the Euclidean normalised counts at <100 mJy. We have directly resolved 15% of the infrared extra-galactic background at the wavelength near where it peaks.
239 citations
University of Sussex1, European Space Agency2, University of California, Irvine3, University of Edinburgh4, Cardiff University5, Paris Diderot University6, Imperial College London7, California Institute of Technology8, Jet Propulsion Laboratory9, Aix-Marseille University10, Spanish National Research Council11, University of La Laguna12, University of Colorado Boulder13, Goddard Space Flight Center14, University of Padua15, University of British Columbia16, UK Astronomy Technology Centre17, University of Paris-Sud18, University of Manchester19, Institut d'Astrophysique de Paris20, University College London21, University of Lethbridge22, Rutherford Appleton Laboratory23, University of Oxford24, University of Warwick25, University of Hertfordshire26
TL;DR: In this paper, the authors used the SPIRE instrument on the Herschel Multi-tiered Extra-Galactic Survey (HerMES) to directly resolve ~15% of the infrared extra-galactic background at the wavelength near where it peaks.
Abstract: Emission at far-infrared wavelengths makes up a significant fraction of the total light detected from galaxies over the age of Universe. Herschel provides an opportunity for studying galaxies at the peak wavelength of their emission. Our aim is to provide a benchmark for models of galaxy population evolution and to test pre-existing models of galaxies. With the Herschel Multi-tiered Extra-galactic survey, HerMES, we have observed a number of fields of different areas and sensitivity using the SPIRE instrument on Herschel. We have determined the number counts of galaxies down to ~20 mJy. Our constraints from directly counting galaxies are consistent with, though more precise than, estimates from the BLAST fluctuation analysis. We have found a steep rise in the Euclidean normalised counts <100 mJy. We have directly resolved ~15% of the infrared extra-galactic background at the wavelength near where it peaks.
236 citations
University of Edinburgh1, UK Astronomy Technology Centre2, Max Planck Society3, INAF4, Paris Diderot University5, European Space Agency6, University of California, Irvine7, Cardiff University8, Imperial College London9, California Institute of Technology10, Jet Propulsion Laboratory11, Spanish National Research Council12, Aix-Marseille University13, University of Bologna14, University of Colorado Boulder15, Goddard Space Flight Center16, University of Sussex17, University of Padua18, University of British Columbia19, University of Paris-Sud20, University of Manchester21, University of Hawaii22, Institut d'Astrophysique de Paris23, National Radio Astronomy Observatory24, University College London25, Rutherford Appleton Laboratory26, University of Lethbridge27, University of Oxford28, University of Hertfordshire29
TL;DR: In this article, the authors determined the ratio, q(IR), of rest-frame 8-1000um flux to monochromatic radio flux, S(1.4GHz), for galaxies selected at far-IR and radio wavelengths, to search for signs that the ratio evolves with redshift, luminosity or dust temperature.
Abstract: We set out to determine the ratio, q(IR), of rest-frame 8-1000um flux, S(IR), to monochromatic radio flux, S(1.4GHz), for galaxies selected at far-IR and radio wavelengths, to search for signs that the ratio evolves with redshift, luminosity or dust temperature, and to identify any far-IR-bright outliers - useful laboratories for exploring why the far-IR/radio correlation is generally so tight when the prevailing theory suggests variations are almost inevitable. We use flux-limited 250-um and 1.4-GHz samples, obtained in GOODS-N using Herschel (HerMES; PEP) and the VLA. We determine bolometric IR output using ten bands spanning 24-1250um, exploiting data from PACS and SPIRE, as well as Spitzer, SCUBA, AzTEC and MAMBO. We also explore the properties of an L(IR)-matched sample, designed to reveal evolution of q(IR) with z, spanning log L(IR) = 11-12 L(sun) and z=0-2, by stacking into the radio and far-IR images. For 1.4-GHz-selected galaxies, we see tentative evidence of a break in the flux ratio, q(IR), at L(1.4GHz) ~ 10^22.7 W/Hz, where AGN are starting to dominate the radio power density, and of weaker correlations with z and T(d). From our 250-um-selected sample we identify a small number of far-IR-bright outliers, and see trends of q(IR) with L(1.4GHz), L(IR), T(d) and z, noting that some of these are inter-related. For our L(IR)-matched sample, there is no evidence that q(IR) changes significantly as we move back into the epoch of galaxy formation: we find q(IR) goes as (1+z)^gamma, where gamma = -0.04 +/- 0.03 at z=0-2; however, discounting the least reliable data at z 1.
231 citations
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TL;DR: In this article, the authors review the range of complementary techniques and theoretical tools that allow astronomers to map the cosmic history of star formation, heavy element production, and reionization of the Universe from the cosmic "dark ages" to the present epoch.
Abstract: Over the past two decades, an avalanche of data from multiwavelength imaging and spectroscopic surveys has revolutionized our view of galaxy formation and evolution. Here we review the range of complementary techniques and theoretical tools that allow astronomers to map the cosmic history of star formation, heavy element production, and reionization of the Universe from the cosmic "dark ages" to the present epoch. A consistent picture is emerging, whereby the star-formation rate density peaked approximately 3.5 Gyr after the Big Bang, at z~1.9, and declined exponentially at later times, with an e-folding timescale of 3.9 Gyr. Half of the stellar mass observed today was formed before a redshift z = 1.3. About 25% formed before the peak of the cosmic star-formation rate density, and another 25% formed after z = 0.7. Less than ~1% of today's stars formed during the epoch of reionization. Under the assumption of a universal initial mass function, the global stellar mass density inferred at any epoch matches reasonably well the time integral of all the preceding star-formation activity. The comoving rates of star formation and central black hole accretion follow a similar rise and fall, offering evidence for co-evolution of black holes and their host galaxies. The rise of the mean metallicity of the Universe to about 0.001 solar by z = 6, one Gyr after the Big Bang, appears to have been accompanied by the production of fewer than ten hydrogen Lyman-continuum photons per baryon, a rather tight budget for cosmological reionization.
3,104 citations
TL;DR: In this paper, the authors review progress over the past decade in observations of large-scale star formation, with a focus on the interface between extragalactic and Galactic studies.
Abstract: We review progress over the past decade in observations of large-scale star formation, with a focus on the interface between extragalactic and Galactic studies. Methods of measuring gas contents and star-formation rates are discussed, and updated prescriptions for calculating star-formation rates are provided. We review relations between star formation and gas on scales ranging from entire galaxies to individual molecular clouds.
2,525 citations
TL;DR: In this paper, the authors review the range of complementary techniques and theoretical tools that allow astronomers to map the cosmic history of star formation, heavy element production, and reionization of the Universe from the cosmic "dark ages" to the present epoch.
Abstract: Over the past two decades, an avalanche of data from multiwavelength imaging and spectroscopic surveys has revolutionized our view of galaxy formation and evolution. Here we review the range of complementary techniques and theoretical tools that allow astronomers to map the cosmic history of star formation, heavy element production, and reionization of the Universe from the cosmic "dark ages" to the present epoch. A consistent picture is emerging, whereby the star-formation rate density peaked approximately 3.5 Gyr after the Big Bang, at z~1.9, and declined exponentially at later times, with an e-folding timescale of 3.9 Gyr. Half of the stellar mass observed today was formed before a redshift z = 1.3. About 25% formed before the peak of the cosmic star-formation rate density, and another 25% formed after z = 0.7. Less than ~1% of today's stars formed during the epoch of reionization. Under the assumption of a universal initial mass function, the global stellar mass density inferred at any epoch matches reasonably well the time integral of all the preceding star-formation activity. The comoving rates of star formation and central black hole accretion follow a similar rise and fall, offering evidence for co-evolution of black holes and their host galaxies. The rise of the mean metallicity of the Universe to about 0.001 solar by z = 6, one Gyr after the Big Bang, appears to have been accompanied by the production of fewer than ten hydrogen Lyman-continuum photons per baryon, a rather tight budget for cosmological reionization.
1,626 citations
TL;DR: In the last decade, observations of the cool interstellar medium (ISM) in distant galaxies via molecular and atomic fine structure line (FSL) emission have gone from a curious look into a few extreme, rare objects to a mainstream tool for studying galaxy formation out to the highest redshifts as mentioned in this paper.
Abstract: Over the past decade, observations of the cool interstellar medium (ISM) in distant galaxies via molecular and atomic fine structure line (FSL) emission have gone from a curious look into a few extreme, rare objects to a mainstream tool for studying galaxy formation out to the highest redshifts. Molecular gas has been observed in close to 200 galaxies at z > 1, including numerous AGN host-galaxies out to z ∼ 7, highly star-forming submillimeter galaxies, and increasing samples of main-sequence color-selected star-forming galaxies at z ∼ 1.5 to 2.5. Studies have moved well beyond simple detections to dynamical imaging at kiloparsec-scale resolution and multiline, multispecies studies that determine the physical conditions in the ISM in early galaxies. Observations of the cool gas are the required complement to studies of the stellar density and star-formation history of the Universe as they reveal the phase of the ISM that immediately precedes star formation in galaxies. Current observations suggest that t...
1,041 citations
University of Paris1, Centre national de la recherche scientifique2, Academia Sinica3, California Institute of Technology4, Institute for the Physics and Mathematics of the Universe5, University of Cambridge6, University of Geneva7, Valparaiso University8, Smithsonian Astrophysical Observatory9, University of Edinburgh10, Niels Bohr Institute11, University of Rochester12, Space Telescope Science Institute13, ETH Zurich14, University of Bologna15, Max Planck Society16, University of Zagreb17, Kindai University18, University of the Western Cape19
TL;DR: The COSMOS2015(24) catalog as mentioned in this paper contains precise photometric redshifts and stellar masses for more than half a million objects over the 2deg(2) COSmOS field, which is highly optimized for the study of galaxy evolution and environments in the early universe.
Abstract: We present the COSMOS2015(24) catalog, which contains precise photometric redshifts and stellar masses for more than half a million objects over the 2deg(2) COSMOS field. Including new YJHK(s) images from the UltraVISTA-DR2 survey, Y-band images from Subaru/Hyper-Suprime-Cam, and infrared data from the Spitzer Large Area Survey with the Hyper-Suprime-Cam Spitzer legacy program, this near-infrared-selected catalog is highly optimized for the study of galaxy evolution and environments in the early universe. To maximize catalog completeness for bluer objects and at higher redshifts, objects have been detected on a chi(2) sum of the YJHK(s) and z(++) images. The catalog contains similar to 6 x 10(5) objects in the 1.5 deg(2) UltraVISTA-DR2 region and similar to 1.5 x 10(5) objects are detected in the “ultra-deep stripes” (0.62 deg(2)) at K-s \textless= 24.7 (3 sigma, 3 `', AB magnitude). Through a comparison with the zCOSMOS-bright spectroscopic redshifts, we measure a photometric redshift precision of sigma(Delta z(1) (+ zs)) = 0.007 and a catastrophic failure fraction of eta = 0.5%. At 3 \textless z \textless 6, using the unique database of spectroscopic redshifts in COSMOS, we find sigma(Delta z(1) (+ zs)) = 0.021 and eta = 13.2%. The deepest regions reach a 90% completeness limit of 10(10)M(circle dot) to z = 4. Detailed comparisons of the color distributions, number counts, and clustering show excellent agreement with the literature in the same mass ranges. COSMOS2015 represents a unique, publicly available, valuable resource with which to investigate the evolution of galaxies within their environment back to the earliest stages of the history of the universe. The COSMOS2015 catalog is distributed via anonymous ftp and through the usual astronomical archive systems (CDS, ESO Phase 3, IRSA).
1,002 citations