Browsing by Author "Oliver, S.J."

Now showing 1 - 7 of 7
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    The complex physics of dusty star-forming galaxies at high redshifts as revealed by Herschel and Spitzer
    (IOP Publishing, 2013) Lo Faro, Barbara; Franceschini, Alberto; Vaccari, M.; Silva, L.; Rodighiero, G.; Berta, S.; Bock, J.; Burgarella, D.; Buat, V.; Cava, A.; Clements, D.L.; Cooray, Asantha; Farrah, D.; Feltre, Anna; Gonzalez-Solares, Eduardo A.; Hurley, P.; Lutz, D.; Magdis, G.; Magnelli, B.; Marchetti, L.; Oliver, S.J.; Page, Matthew J.; Popesso, P.; Pozzi, F.; Rigopoulou, D.; Rowan-Robinson, M.; Roseboom, I.G.; Scott, Douglas; Smith, A.J.; Symeonidis, Myrto; Wang, L.; Wuyts, S.
    We combine far-infrared photometry from Herschel (PEP/HerMES) with deep mid-infrared spectroscopy from Spitzer to investigate the nature and the mass assembly history of a sample of 31 luminous and ultraluminous infrared galaxies ((U)LIRGs) at z ∼ 1 and 2 selected in GOODS-S with 24μm fluxes between 0.2 and 0.5 mJy.We model the data with a self-consistent physical model (GRASIL) which includes a state-of-the-art treatment of dust extinction and reprocessing. We find that all of our galaxies appear to require massive populations of old (>1 Gyr) stars and, at the same time, to host a moderate ongoing activity of star formation (SFR 100M yr−1). The bulk of the stars appear to have been formed a few Gyr before the observation in essentially all cases. Only five galaxies of the sample require a recent starburst superimposed on a quiescent star formation history.We also find discrepancies between our results and those based on optical-only spectral energy distribution (SED) fitting for the same objects; by fitting their observed SEDs with our physical model we find higher extinctions (by ΔAV ∼ 0.81 and 1.14) and higher stellar masses (by Δlog(M ) ∼ 0.16 and 0.36 dex) for z ∼ 1 and z ∼ 2 (U)LIRGs, respectively. The stellar mass difference is larger for the most dust-obscured objects. We also find lower SFRs than those computed from LIR using the Kennicutt relation due to the significant contribution to the dust heating by intermediate-age stellar populations through “cirrus” emission (∼73% and ∼66% of the total LIR for z ∼ 1 and z ∼ 2 (U)LIRGs, respectively).
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    HELP: The Herschel Extragalactic Legacy Project
    (Oxford University Press, 2021) Jarvis, M.J.; Shirley, R; Duncan, K; Campos Varillas, M.C.; Hurley, P.D.; Malek, K; Roehlly, Y; Oliver, S.J.
    We present the Herschel Extragalactic Legacy Project (HELP). This project collates, curates, homogenizes and creates derived data products for most of the premium multiwavelength extragalactic data sets. The sky boundaries for the first data release cover 1270 deg2 defined by the Herschel SPIRE extragalactic survey fields; notably the Herschel Multi-tiered Extragalactic Survey (HerMES) and the Herschel Atlas survey (H-ATLAS). Here, we describe the motivation and principal elements in the design of the project. Guiding principles are transparent or 'open' methodologies with care for reproducibility and identification of provenance. A key element of the design focuses on the homogenization of calibration, metadata, and the provision of information required to define the selection of the data for statistical analysis. We apply probabilistic methods that extract information directly from the images at long wavelengths, exploiting the prior information available at shorter wavelengths and providing full posterior distributions rather than maximum-likelihood estimates and associated uncertainties as in traditional catalogues. With this project definition paper, we provide full access to the first data release of HELP; Data Release 1 (DR1), including a monolithic map of the largest SPIRE extragalactic field at 385 deg2 and 18 million measurements of PACS and SPIRE fluxes. We also provide tools to access and analyse the full HELP database. This new data set includes far-infrared photometry, photometric redshifts, and derived physical properties estimated from modeling the spectral energy distributions over the full HELP sky. All the software and data presented are publicly available. © 2021 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.
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    HerMES: Candidate gravitationally lensed galaxies and lensing statistics at submillimeter wavelengths
    (American Astronomical Society, 2013) Wardlow, Julie L.; Cooray, Asantha; De Bernardis, Francesco; Amblard, A.; Arumugam, V.; Aussel, H.; Baker, A.J.; Bethermin, M.; Blundell, R.; Bock, J.; Boselli, A.; Bridge, C.; Buat, V.; Burgarella, D.; Bussmann, R.S.; Cabrera-Lavers, A.; Calanog, J.A.; Carpenter, J.M.; Casey, C.M.; Castro-Rodríguez, N.; Cava, A.; Chanial, P.; Chapin, E.; Chapman, S.C.; Clements, D.L.; Conley, A.; Cox, P.; Dowell, C.D.; Dye, S.; Eales, S.; Farrah, D.; Ferrero, P.; Franceschini, Alberto; Frayer, D.T.; Frazer, C.; Fu, Hai; Gavazzi, R.; Glenn, J.; González Solares, E.A.; Griffin, M.; Gurwell, M.A.; Harris, A.I.; Hatziminaoglou, Evanthia; Hopwood, R.; Hyde, A.; Ibar, Edo; Ivison, R.J.; Kim, S.; Lagache, G.; Levenson, L.; Marchetti, L.; Marsden, G.; Martinez-Navajas, P.; Negrello, M.; Neri, R.; Nguyen, H.T.; OHalloran, B.; Oliver, S.J.; Omont, A.; Page, Matthew J.; Panuzzo, P.; Papageorgiou, A.; Pearson, C.P.; Perez-Fournon, E.; Pohlen, M.; Riechers, D.; Rigopoulou, D.; Roseboom, I.G.; Rowan-Robinson, M.; Schulz, B.; Scott, Douglas; Scoville, N.; Seymour, N.; Shupe, D.L.; Smith, A.J.; Streblyanska, A.; Strom, A.; Symeonidis, Myrto; Trichas, M.; Vaccari, M.; Vieira, J.D.; Viero, M. P.; Wang, L.; Xu, C.K.; Zemcov, M.; Yan, L.
    Gravitational lensing increases the angular size and integrated flux of affected sources. It is exploited to investigate the mass distribution of the foreground lensing structures and the properties of the background lensed galaxies (see reviews by Bartelmann 2010; Treu 2010). The magnification provided by gravitational lensing makes it an effective tool for identifying and studying intrinsically faint and typically distant galaxies (e.g., Stark et al. 2007; Richard et al. 2008, 2011). The flux boost from lensing yields an improved detection, and the associated spatial enhancement increases the ability to investigate the internal structure of distant galaxies to levels otherwise unattainable with the current generation of instrumentation (e.g., Riechers et al. 2008; Swinbank et al. 2010, 2011; Gladders et al. 2012). Furthermore, gravitational lensing probes the total mass of the foreground deflectors, including the relative content of dark and luminous mass. In combination with dynamical studies, lensing mass reconstruction allows one to obtain the density profile of the dark matter in individual lensing galaxies down to ~10 kpc scales (e.g., Miralda-Escude 1995; Dalal & Kochanek 2002; Metcalf & Zhao 2002; Rusin & Kochanek 2005; Treu & Koopmans 2004).
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    Hermes: Cosmic infrared background anisotropies and the clustering of dusty star-forming galaxies
    (American Astronomical Society, 2013) Viero, M. P.; Wang, L.; Zemcov, M.; Addison, G.; Amblard, A.; Arumugam, V.; Aussel, H.; Bethermin, M.; Bock, J.; Boselli, A.; Buat, V.; Burgarella, D.; Casey, C.M.; Clements, D.L.; Conley, A.; Conversi, L.; Cooray, Asantha; de Zotti, G.; Dowell, C.D.; Farrah, D.; Franceschini, Alberto; Glenn, J.; Griffin, M.; Hatziminaoglou, Evanthia; Heinis, S.; Ibar, Edo; Ivison, R.J.; Lagache, G.; Levenson, L.; Marchetti, L.; Marsden, G.; Nguyen, H.T.; OHalloran, B.; Oliver, S.J.; Omont, A.; Page, Matthew J.; Papageorgiou, A.; Pearson, C.P.; Perez-Fournon, I.; Pohlen, M.; Rigopoulou, D.; Roseboom, I.G.; Rowan-Robinson, M.; Schulz, B.; Scott, Douglas; Seymour, N.; Shupe, D.L.; Smith, A.J.; Symeonidis, Myrto; Vaccari, M.; Valtchanov, I.; Vieira, J.D.; Wardlow, Julie L.; Xu, C.K.
    Star formation is well traced by dust, which absorbs the UV/optical light produced by young stars in actively starforming regions and re-emits the energy in the far-infrared/ submillimeter (FIR/submm; e.g., Savage & Mathis 1979). Roughly half of all starlight ever produced has been reprocessed by dusty star-forming galaxies (DSFGs; e.g., Hauser & Dwek 2001; Dole et al. 2006), and this emission is responsible for the ubiquitous cosmic infrared background (CIB; Puget et al. 1996; Fixsen et al. 1998). The mechanisms responsible for the presence or absence of star formation are partially dependent on the local environment (e.g., major mergers: Narayanan et al. 2010; condensation or cold accretion: Dekel et al. 2009, photoionization heating, supernovae, active galactic nuclei, and virial shocks: Birnboim & Dekel 2003; Granato et al. 2004; Bower et al. 2006). Thus, the specifics of the galaxy distribution—which can be determined statistically to high precision by measuring their clustering properties—inform the relationship of star formation and dark matter density, and are valuable inputs for models of galaxy formation. However, measuring the clustering of DSFGs has historically proven difficult to do.
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    HerMES: The contribution to the cosmic infrared background from galaxies selected by mass and redshift
    (American Astronomical Society, 2013) Viero, M. P.; Monclesi, L.; Quadri, L.F.; Arumugam, V.; Assef, R.J.; Bethermin, M.; Bock, J.; Bridge, C.; Casey, C.M.; Conley, A.; Cooray, Asantha; Farrah, D.; Glenn, J.; Heinis, S.; Ibar, Edo; Ikarashi, S.; Ivison, R.J.; Kohno, K.; Marsden, G.; Oliver, S.J.; Roseboom, I.G.; Schulz, B.; Scott, Douglas; Serra, P.; Vaccari, M.; Vieira, J.D.; Wang, L.; Wardlow, Julie L.; Wilson, G.W.; Yun, M.S.; Zemcov, M.
    The cosmic infrared background (CIB), discovered in Far Infrared Absolute Spectrophotometer (FIRAS) data from the Cosmic Background Explorer (COBE; Puget et al. 1996; Fixsen et al. 1998), originates from thermal re-radiation of imagine cutting out hundreds of thumbnails from a map centered on the positions where galaxies are known to be, and averaging those thumbnails together until an image of the average galaxy emerges from the noise. These positional priors can come in many forms, e.g., they could be catalogs of UV, optical, IR, or radio sources. Note that the output is the average of that population in the stacked maps, i.e., there will likely be sources whose actual fluxes are higher or lower. Thus, the more homogeneous the sources comprising the input list, the more meaningful the stacked flux will be.
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    HerMES: The far-infrared emission from dust-obscured galaxies
    (American Astronomical Society, 2013) Calanog, J.A.; Wardlow, Julie L.; Fu, Hai; Cooray, Asantha; Assef, R.J.; Bock, J.; Casey, C.M.; Conley, A.; Farrah, D.; Ibar, Edo; Kartaltepe, J.; Magdis, G.; Marchetti, L.; Oliver, S.J.; Perez-Fournon, I.; Riechers, D.; Rigopoulou, D.; Roseboom, I.G.; Schulz, B.; Scott, Douglas; Symeonidis, Myrto; Vaccari, M.; Viero, M. P.; Zemcov, M.
    The far-infrared (far-IR) luminosities of luminous infrared galaxies (LIRGs) and ultra-LIRGs (ULIRGs) are dominated by reprocessed thermal dust emission, due to a combination of star formation and active galactic nucleus (AGN) activity, with star formation typically being the more dominant component (e.g., Watabe et al. 2009; Elbaz et al. 2010). Locally, these sources are rare, although out to z - 1 they become more numerous and increasingly dominate the IR luminosity function of galaxies with increasing redshift (e.g., Le Floc’h et al. 2005; P´erez-Gonz´alez et al. 2005; Caputi et al. 2007; Magnelli et al. 2009; Rodighiero et al. 2010; Eales et al. 2010). (U)LIRGs are thought to trace a phase of intense star formation activity, which is likely followed by, or partially concurrent with, an episode of vigorous black hole accretion. It is postulated that upon the cessation of these phases, each produces an early-type galaxy (Genzel et al. 2001; Farrah et al. 2003; Lonsdale et al. 2006; Veilleux et al. 2009).
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    Herschel PEP/HerMES: the redshift evolution of dust attenuation and of the total (UV+IR) star formation rate density
    (EDP Sciences, 2013) Burgarella, D.; Buat, V.; Gruppioni, C.; Cucciati, O.; Heinis, S.; Berta, S.; Bethermin, M.; Bock, J.; Cooray, Asantha; Dunlop, J.S.; Farrah, D.; Franceschini, Alberto; Le Floch, E.; Lutz, D.; Magnelli, B.; Nordon, R.; Oliver, S.J.; Page, Matthew J.; Popesso, P.; Pozzi, F.; Riguccini, L.; Vaccari, M.; Viero, M. P.
    Using new homogeneous luminosity functions (LFs) in the far-ultraviolet (FUV) from VVDS and in the far-infrared (FIR) from Herschel/PEP and Herschel/HerMES, we studied the evolution of the dust attenuation with redshift. With this information, we were able to estimate the redshift evolution of the total (FUV + FIR) star formation rate density (SFRDTOT). By integrating SFRDTOT, we followed the mass building and analyzed the redshift evolution of the stellar mass density (SMD). This article aims at providing a complete view of star formation from the local Universe to z ~ 4 and, using assumptions on earlier star formation history, compares this evolution with previously published data in an attempt to draw a homogeneous picture of the global evolution of star formation in galaxies. Our main conclusions are that: 1) the dust attenuation AFUV is found to increase from z = 0 to z ~ 1.2 and then starts to decrease until our last data point at z = 3.6; 2) the estimated SFRD confirms published results to z ~ 2. At z > 2, we observe either a plateau or a small increase up to z ~ 3 and then a likely decrease up to z = 3.6; 3) the peak of AFUV is delayed with respect to the plateau of SFRDTOT and a probable origin might be found in the evolution of the bright ends of the FUV and FIR LFs; 4) using assumptions (exponential rise and linear rise with time) for the evolution of the star formation density from z = 3.6 to zform = 10, we integrated SFRDTOT and obtained a good agreement with the published SMDs.