Panchromatic spectral energy distributions of Herschel sources
Max Planck Society1, INAF2, Cornell University3, University of California, Irvine4, University of Padua5, Smithsonian Astrophysical Observatory6, Paris Diderot University7, Tel Aviv University8, University of Sussex9, University College London10, University of Bologna11, Ames Research Center12, University of Edinburgh13, University of British Columbia14, California Institute of Technology15
TL;DR: In this article, the authors combine far-infrared Herschel photometry from the PACS Evolutionary Probe (PEP) and Herschel Multi-tiered Extragalactic Survey (HerMES) guaranteed time programs with ancillary datasets in the GOODS-N, COSMOS fields, and it is possible to sample the 8-500μm spectral energy distributions (SEDs) of galaxies with at least 7-10 bands.
Abstract: Combining far-infrared Herschel photometry from the PACS Evolutionary Probe (PEP) and Herschel Multi-tiered Extragalactic Survey (HerMES) guaranteed time programs with ancillary datasets in the GOODS-N, GOODS-S, and COSMOS fields, it is possible to sample the 8–500 μm spectral energy distributions (SEDs) of galaxies with at least 7–10 bands. Extending to the UV, optical, and near-infrared, the number of bands increases up to 43. We reproduce the distribution of galaxies in a carefully selected restframe ten colors space, based on this rich data-set, using a superposition of multivariate Gaussian modes. We use this model to classify galaxies and build median SEDs of each class, which are then fitted with a modified version of the magphys code that combines stellar light, emission from dust heated by stars and a possible warm dust contribution heated by an active galactic nucleus (AGN). The color distribution of galaxies in each of the considered fields can be well described with the combination of 6–9 classes, spanning a large range of far- to near-infrared luminosity ratios, as well as different strength of the AGN contribution to bolometric luminosities. The defined Gaussian grouping is used to identify rare or odd sources. The zoology of outliers includes Herschel-detected ellipticals, very blue z ~ 1 Ly-break galaxies, quiescent spirals, and torus-dominated AGN with star formation. Out of these groups and outliers, a new template library is assembled, consisting of 32 SEDs describing the intrinsic scatter in the restframe UV-to-submm colors of infrared galaxies. This library is tested against L(IR) estimates with and without Herschel data included, and compared to eightother popular methods often adopted in the literature. When implementing Herschel photometry, these approaches produce L(IR) values consistent with each other within a median absolute deviation of 10–20%, the scatter being dominated more by fine tuning of the codes, rather than by the choice of SED templates. Finally, the library is used to classify 24 μm detected sources in PEP GOODS fields on the basis of AGN content, L(60)/L(100) color and L(160)/L(1.6) luminosity ratio. AGN appear to be distributed in the stellar mass (M_∗) vs. star formation rate (SFR) space along with all other galaxies, regardless of the amount of infrared luminosity they are powering, with the tendency to lie on the high SFR side of the “main sequence”. The incidence of warmer star-forming sources grows for objects with higher specific star formation rates (sSFR), and they tend to populate the “off-sequence” region of the M_∗ − SFR − z space.
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Max Planck Society1, University College London2, Collège de France3, ASTRON4, University of Maryland, College Park5, University of Toulouse6, ETH Zurich7, University of Bath8, University of California, Irvine9, Scuola Normale Superiore di Pisa10, The Racah Institute of Physics11, Tel Aviv University12, University of Arizona13
TL;DR: In this paper, the scaling relation between galaxy-integrated molecular gas masses, stellar masses, and star formation rates (SFRs), in the framework of the star formation main sequence (MS), with the main goal of testing for possible systematic effects.
Abstract: This paper provides an update of our previous scaling relations between galaxy-integrated molecular gas masses, stellar masses, and star formation rates (SFRs), in the framework of the star formation main sequence (MS), with the main goal of testing for possible systematic effects. For this purpose our new study combines three independent methods of determining molecular gas masses from CO line fluxes, far-infrared dust spectral energy distributions, and ∼1 mm dust photometry, in a large sample of 1444 star-forming galaxies between z=0 and 4. The sample covers the stellar mass range log(M * /M e)=9.0-11.8, and SFRs relative to that on the MS, δMS=SFR/SFR (MS), from 10 −1.3 to 10 2.2. Our most important finding is that all data sets, despite the different techniques and analysis methods used, follow the same scaling trends, once method-to-method zero-point offsets are minimized and uncertainties are properly taken into account. The molecular gas depletion time t depl , defined as the ratio of molecular gas mass to SFR, scales as (1+z) −0.6 ×(δMS) −0.44 and is only weakly dependent on stellar mass. The ratio of molecular to stellar mass μ gas depends on (* d +´´-) () () z M 1 M S 2.5 0.52 0.36 , which tracks the evolution of the specific SFR. The redshift dependence of μ gas requires a curvature term, as may the mass dependences of t depl and μ gas. We find no or only weak correlations of t depl and μ gas with optical size R or surface density once one removes the above scalings, but we caution that optical sizes may not be appropriate for the high gas and dust columns at high z.
533 citations
01 May 2001
TL;DR: The SWIRE project as mentioned in this paper is the largest of the SIRTF Legacy programs, which surveys 65 sq. deg. in seven high latitude fields selected to be the best wide low-extinction windows into the extragalactic sky.
Abstract: The largest of the SIRTF Legacy programs, SWIRE will survey 65 sq. deg. in seven high latitude fields selected to be the best wide low-extinction windows into the extragalactic sky. SWIRE will detect millions of spheroids, disks and starburst galaxies to z>3 and will map L* and brighter systems on scales up to 150 Mpc at z∼0.5–1. It will also detect ∼104 low extinction AGN and large numbers of obscured AGN. An extensive program of complementary observations is underway. The data are non-proprietary and will be made available beginning in Spring 2004.
484 citations
Max Planck Society1, University of Bologna2, Paris Diderot University3, INAF4, University of La Laguna5, Spanish National Research Council6, Foundation for Research & Technology – Hellas7, University of Crete8, California Institute of Technology9, Cornell University10, Smithsonian Astrophysical Observatory11, UK Astronomy Technology Centre12, University of Oxford13, University of Cambridge14, Carnegie Institution for Science15, Tel Aviv University16, University of British Columbia17
TL;DR: In this article, the authors present results from the deep Herschel-Photodetector Array Camera and Spectrometer (PACS) far-infrared blank field extragalactic survey, obtained by combining observations of the Great Observatories Origins Deep Survey (GOODS) fields from the PACS Evolutionary Probe (PEP) and GOODS-Herschel key programmes.
Abstract: We present results from the deepest Herschel-Photodetector Array Camera and Spectrometer (PACS) far-infrared blank field extragalactic survey, obtained by combining observations of the Great Observatories Origins Deep Survey (GOODS) fields from the PACS Evolutionary Probe (PEP) and GOODS-Herschel key programmes. We describe data reduction and theconstruction of images and catalogues. In the deepest parts of the GOODS-S field, the catalogues reach 3σ depths of 0.9, 0.6 and 1.3 mJy at 70, 100 and 160 μm, respectively, and resolve ~75% of the cosmic infrared background at 100 μm and 160 μm into individually detected sources. We use these data to estimate the PACS confusion noise, to derive the PACS number counts down to unprecedented depths, and to determine the infrared luminosity function of galaxies down to L_(IR) = 10^(11) L⊙ at z ~ 1 and L_(IR) = 10^(12) L⊙ at z ~ 2, respectively. For the infrared luminosity function of galaxies, our deep Herschel far-infrared observations are fundamental because they provide more accurate infrared luminosity estimates than those previously obtained from mid-infrared observations. Maps and source catalogues (>3σ) are now publicly released. Combined with the large wealth of multi-wavelength data available for the GOODS fields, these data provide a powerful new tool for studying galaxy evolution over a broad range of redshifts.
483 citations
Cites background from "Panchromatic spectral energy distri..."
...…luminosity functions of galaxies (e.g., Gruppioni et al. 2010, 2013; Casey et al. 2012) and the examination of their spectral energy distributions (e.g., Hwang et al. 2010; Elbaz et al. 2010, 2011; Nordon et al. 2010, 2012; Magnelli et al. 2010, 2012; Symeonidis et al. 2013; Berta et al. 2013)....
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INAF1, University of Bologna2, University of Padua3, Max Planck Society4, University of Provence5, Open University6, University of Trieste7, University of Sussex8, University of Edinburgh9, University of the Western Cape10, Spanish National Research Council11, Federal University of Rio de Janeiro12, University of Cambridge13, Ames Research Center14, California Institute of Technology15, Jet Propulsion Laboratory16, University of La Laguna17, Complutense University of Madrid18, Imperial College London19, University of Colorado Boulder20, University of California, Irvine21, Goddard Space Flight Center22, Cardiff University23, UK Astronomy Technology Centre24, European Space Research and Technology Centre25, University of Paris-Sud26, University of Manchester27, University College London28, Rutherford Appleton Laboratory29, University of Lethbridge30, University of Oxford31, University of British Columbia32, Commonwealth Scientific and Industrial Research Organisation33, University of Hertfordshire34, Harvard University35, Institut d'Astrophysique de Paris36, École Polytechnique Fédérale de Lausanne37, University of Toulouse38
TL;DR: In this article, the authors exploit the deep and extended far-IR data sets (at 70, 100 and 160 μm) of the GPS PACS Evolutionary Probe (PEP) Survey, in combination with the Herschel Multi-tiered Extragalactic Survey data at 250, 350 and 500 μm, to derive the evolution of the rest-frame 35-, 60-, 90- and total infrared luminosity functions (LFs) up to z ∼ 4.
Abstract: We exploit the deep and extended far-IR data sets (at 70, 100 and 160 μm) of the Herschel Guaranteed Time Observation (GTO) PACS Evolutionary Probe (PEP) Survey, in combination with the Herschel Multi-tiered Extragalactic Survey data at 250, 350 and 500 μm, to derive the evolution of the rest-frame 35-, 60-, 90- and total infrared (IR) luminosity functions (LFs) up to z ∼ 4. We detect very strong luminosity evolution for the total IR LF (LIR ∝ (1 + z)3.55 ± 0.10 up to z ∼ 2, and ∝ (1 + z)1.62 ± 0.51 at 2 < z ≲ 4) combined with a density evolution (∝(1 + z)−0.57 ± 0.22 up to z ∼ 1 and ∝ (1 + z)−3.92 ± 0.34 at 1 < z ≲ 4). In agreement with previous findings, the IR luminosity density (ρIR) increases steeply to z ∼ 1, then flattens between z ∼ 1 and z ∼ 3 to decrease at z ≳ 3. Galaxies with different spectral energy distributions, masses and specific star formation rates (SFRs) evolve in very different ways and this large and deep statistical sample is the first one allowing us to separately study the different evolutionary behaviours of the individual IR populations contributing to ρIR. Galaxies occupying the well-established SFR–stellar mass main sequence (MS) are found to dominate both the total IR LF and ρIR at all redshifts, with the contribution from off-MS sources (≥0.6 dex above MS) being nearly constant (∼20 per cent of the total ρIR) and showing no significant signs of increase with increasing z over the whole 0.8 < z < 2.2 range. Sources with mass in the range 10 ≤ log(M/M⊙) ≤ 11 are found to dominate the total IR LF, with more massive galaxies prevailing at the bright end of the high-z (≳2) LF. A two-fold evolutionary scheme for IR galaxies is envisaged: on the one hand, a starburst-dominated phase in which the Super Massive Black Holes (SMBH) grows and is obscured by dust (possibly triggered by a major merging event), is followed by an AGN-dominated phase, then evolving towards a local elliptical. On the other hand, moderately star-forming galaxies containing a low-luminosity AGN have various properties suggesting they are good candidates for systems in a transition phase preceding the formation of steady spiral galaxies.
461 citations
Cites methods from "Panchromatic spectral energy distri..."
...For this reason, we obtained measurements of the stellar masses of our objects containing an AGN by means of the specific decomposition technique developed by Berta et al. (2013), to separate stellar and nuclear emission components....
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...Masses of AGN estimated with the original MAGPHYS and with the Berta et al. (2013) code have been compared, showing very good agreement and small dispersion around the 1–1 relation....
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...Since the MAGPHYS code assumes that starlight is the only significant source of dust heating, thus ignoring the presence of a possible AGN component, Berta et al. (2013) have developed a modified version of the MAGPHYS code by adding a torus component to the modelled SED emission, combining the Da…...
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TL;DR: In this paper, the authors present an overview of AGN multi-wavelength properties with the aim of painting their "big picture" through observations in each electromagnetic band from radio to gamma-gamma -rays as well as AGN variability.
Abstract: Active galactic nuclei (AGN) are energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, and present unique observational signatures that cover the full electromagnetic spectrum over more than twenty orders of magnitude in frequency. The rich phenomenology of AGN has resulted in a large number of different “flavours” in the literature that now comprise a complex and confusing AGN “zoo”. It is increasingly clear that these classifications are only partially related to intrinsic differences between AGN and primarily reflect variations in a relatively small number of astrophysical parameters as well the method by which each class of AGN is selected. Taken together, observations in different electromagnetic bands as well as variations over time provide complementary windows on the physics of different sub-structures in the AGN. In this review, we present an overview of AGN multi-wavelength properties with the aim of painting their “big picture” through observations in each electromagnetic band from radio to $$\gamma $$
-rays as well as AGN variability. We address what we can learn from each observational method, the impact of selection effects, the physics behind the emission at each wavelength, and the potential for future studies. To conclude, we use these observations to piece together the basic architecture of AGN, discuss our current understanding of unification models, and highlight some open questions that present opportunities for future observational and theoretical progress.
384 citations
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TL;DR: The Sloan Digital Sky Survey (SDSS) as mentioned in this paper provides the data to support detailed investigations of the distribution of luminous and non-luminous matter in the Universe: a photometrically and astrometrically calibrated digital imaging survey of pi steradians above about Galactic latitude 30 degrees in five broad optical bands.
Abstract: The Sloan Digital Sky Survey (SDSS) will provide the data to support detailed investigations of the distribution of luminous and non- luminous matter in the Universe: a photometrically and astrometrically calibrated digital imaging survey of pi steradians above about Galactic latitude 30 degrees in five broad optical bands to a depth of g' about 23 magnitudes, and a spectroscopic survey of the approximately one million brightest galaxies and 10^5 brightest quasars found in the photometric object catalog produced by the imaging survey. This paper summarizes the observational parameters and data products of the SDSS, and serves as an introduction to extensive technical on-line documentation.
10,039 citations
Donald G. York1, Jennifer Adelman2, John E. Anderson2, Scott F. Anderson3 +148 more•Institutions (29)
TL;DR: The Sloan Digital Sky Survey (SDSS) as discussed by the authors provides the data to support detailed investigations of the distribution of luminous and non-luminous matter in the universe: a photometrically and astrometrically calibrated digital imaging survey of π sr above about Galactic latitude 30° in five broad optical bands to a depth of g' ~ 23 mag.
Abstract: The Sloan Digital Sky Survey (SDSS) will provide the data to support detailed investigations of the distribution of luminous and nonluminous matter in the universe: a photometrically and astrometrically calibrated digital imaging survey of π sr above about Galactic latitude 30° in five broad optical bands to a depth of g' ~ 23 mag, and a spectroscopic survey of the approximately 106 brightest galaxies and 105 brightest quasars found in the photometric object catalog produced by the imaging survey. This paper summarizes the observational parameters and data products of the SDSS and serves as an introduction to extensive technical on-line documentation.
9,835 citations
"Panchromatic spectral energy distri..." refers background in this paper
...Optical and near-infrared (NIR) surveys such as the Sloan Digital Sky Survey (SDSS, York et al. 2000), the Two Degree Field survey (Colless 1999), the Two Micron All Sky Survey (2MASS, Kleinmann et al. 1994), the Cosmic Evolution Survey (COSMOS, Scoville et al. 2007), the Great Observatories…...
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TL;DR: In this article, the authors focus on the broad patterns in the star formation properties of galaxies along the Hubble sequence and their implications for understanding galaxy evolution and the physical processes that drive the evolution.
Abstract: Observations of star formation rates (SFRs) in galaxies provide vital clues to the physical nature of the Hubble sequence and are key probes of the evolutionary histories of galaxies. The focus of this review is on the broad patterns in the star formation properties of galaxies along the Hubble sequence and their implications for understanding galaxy evolution and the physical processes that drive the evolution. Star formation in the disks and nuclear regions of galaxies are reviewed separately, then discussed within a common interpretive framework. The diagnostic methods used to measure SFRs are also reviewed, and a self-consistent set of SFR calibrations is presented as an aid to workers in the field. One of the most recognizable features of galaxies along the Hubble sequence is the wide range in young stellar content and star formation activity. This variation in stellar content is part of the basis of the Hubble classification itself (Hubble 1926), and understanding its physical nature and origins is fundamental to understanding galaxy evolution in its broader context. This review deals with the global star formation properties of galaxies, the systematics of those properties along the Hubble sequence, and their implications for galactic evolution. I interpret “Hubble sequence” in this context very loosely, to encompass not only morphological type but other properties such as gas content, mass, bar structure, and dynamical environment, which can strongly influence the largescale star formation rate (SFR).
6,640 citations
TL;DR: Herschel was launched on 14 May 2009, and is now an operational ESA space observatory o ering unprecedented observational capabilities in the far-infrared and sub-millimetre spectral range 55 671 m.
Abstract: Herschel was launched on 14 May 2009, and is now an operational ESA space observatory o ering unprecedented observational capabilities in the far-infrared and submillimetre spectral range 55 671 m. Herschel carries a 3.5 metre diameter passively cooled Cassegrain telescope, which is the largest of its kind and utilises a novel silicon carbide technology. The science payload comprises three instruments: two direct detection cameras/medium resolution spectrometers, PACS and SPIRE, and a very high-resolution heterodyne spectrometer, HIFI, whose focal plane units are housed inside a superfluid helium cryostat. Herschel is an observatory facility operated in partnership among ESA, the instrument consortia, and NASA. The mission lifetime is determined by the cryostat hold time. Nominally approximately 20,000 hours will be available for astronomy, 32% is guaranteed time and the remainder is open to the worldwide general astronomical community through a standard competitive proposal procedure.
3,359 citations
"Panchromatic spectral energy distri..." refers background in this paper
...After three years of operation, theHerschel Space Observatory (Pilbratt et al. 2010) has proven to be the ultimate machine to build detailed FIR SEDs of galaxies up to z > 3, without being limited to very luminous sources....
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...…PACS Evolutionary Probe survey (PEP1, Lutz et al. 2011) observed the most popular and widely studied extragalactic blank fields (The Lockman Hole, EGS, ECDFS, COSMOS, GOODS-N, and GOODS-S) with the PACS (Poglitsch et al. 2010) instrument aboardHerschel (Pilbratt et al. 2010) at 70, 100 and 160µm....
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...At long wavelengths, extragalactic surveys with the Infrared Astronomical Satellite (IRAS, Neugebauer et al. 1984), Infrared Space Observatory (ISO, e.g. ELAIS, Rowan-Robinson et al. 2004), Spitzer (e.g. Frayer et al. 2009; Le Floc’h et al. 2009; Magnelli et al. 2009; Lonsdale et al. 2003, 2004, Dickinson et al. 2001) and AKARI (e.g. Matsuura et al. 2009; Matsuhara et al. 2006) revealed the mid- and far-infrared (MIR, FIR) counterparts of local galaxies first, and of several thousands of distant sources up toz ∼ 3 in the latest incarnation of 80-cm class IR space telescopes....
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