Simulated observations of sub-millimetre galaxies: the impact of single-dish resolution and field variance

Abstract

Recent observational evidence suggests that the coarse angular resolution ($\sim 20"$ FWHM) of single-dish telescopes at sub-mm wavelengths has biased the observed galaxy number counts by blending together the sub-mm emission from multiple sub-mm galaxies (SMGs). We use lightcones computed from an updated implementation of the \galform semi-analytic model to generate $50$ mock sub-mm surveys of $0.5$ deg${}^2$ at $850$ $\mu$m, taking into account the effects of the finite single-dish beam in a more accurate way than has been done previously. We find that blending of SMGs does lead to an enhancement of source extracted number counts at bright fluxes ($S_{850\mu \mathrm{m}}\gtrsim 1$ mJy). Typically, $\sim 3-6$ galaxies contribute $90\%$ of the flux of an $S_{850\mu \mathrm{m}}=5$ mJy source and these blended galaxies are physically unassociated. We find that field-to-field variations are comparable to Poisson fluctuations for our $S_{850\mu \mathrm{m}}>5$ mJy SMG population, which has a median redshift $z_{50}=2.0$, but are greater than Poisson for the $S_{850\mu \mathrm{m}}>1$ mJy population ($z_{50}=2.8$). In a detailed comparison to a recent interferometric survey targeted at single-dish detected sources, we reproduce the difference between single-dish and interferometer number counts and find a median redshift ($z_{50}=2.5$) in excellent agreement with the observed value ($z_{50}=2.5\pm 0.2$). We also present predictions for single-dish survey number counts at $450$ and $1100$ $\mu$m, which show good agreement with observational data.

arXiv comment15 pages, 18 figures, Accepted to MNRAS

References in corpus (53)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Simulating the joint evolution of quasars, galaxies and their large-scale distribution
• Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy
• The broken hierarchy of galaxy formation
• The Herschel-SPIRE instrument and its in-flight performance
• The Formation of Galactic Disks
• Hierarchical Galaxy Formation
• Unveiling Dust-enshrouded Star Formation in the Early Universe: a Sub-mm Survey of the Hubble Deep Field
• A Deep Sub-millimeter Survey of Lensing Clusters: A New Window on Galaxy Formation and Evolution
• A Redshift Survey of the Submillimeter Galaxy Population
• Submillimeter Galaxies
• Dusty Star-Forming Galaxies at High Redshift
• The Spectrum of the Extragalactic Far Infrared Background from the COBE Firas Observations
• The Role of Pressure in GMC Formation II: The H_2 - Pressure Relation
• A primer on hierarchical galaxy formation: the semi-analytical approach
• The SCUBA HAlf Degree Extragalactic Survey (SHADES) -- II. Submillimetre maps, catalogue and number counts
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• Extragalactic millimeter-wave sources in South Pole Telescope survey data: source counts, catalog, and statistics for an 87 square-degree field
• An ALMA Survey of Submillimeter Galaxies in the Extended Chandra Deep Field South: The Redshift Distribution and Evolution of Submillimeter Galaxies
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• An ALMA survey of submillimeter galaxies in the Extended Chandra Deep Field South: Source catalog and multiplicity
• Generating Dark Matter Halo Merger Trees
• The infrared side of galaxy formation. I. The local universe in the semi-analytical framework
• An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: High resolution 870um source counts
• HerMES: deep number counts at 250, 350, and 500 microns in the COSMOS and GOODS-N fields and the build-up of the cosmic infrared background
• What Does a Submillimeter Galaxy Selection Actually Select? The Dependence of Submillimeter Flux Density on Star Formation Rate and Dust Mass
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• Lightcone mock catalogues from semi-analytic models of galaxy formation - I. Construction and application to the BzK colour selection
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• Dust-obscured star formation and AGN fuelling in hierarchical models of galaxy evolution
• Millimeter imaging of submillimeter galaxies in the COSMOS field: Redshift distribution
• Probing the submillimetre number counts at f(850um) < 2mJy
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• How to distinguish starbursts and quiescently star-forming galaxies: The `bimodal' submillimetre galaxy population as a case study
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• The Properties of Sub-mm Galaxies in Hierarchical Models
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• The SCUBA-2 Cosmology Legacy Survey: blank-field number counts of 450um-selected galaxies and their contribution to the cosmic infrared background
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• SMAObservations of GOODS 850-11 and GOODS 850-13 - First Examples of Multiple Submillimeter Sources Resolved by an Interferometer
• The LABOCA survey of the Extended Chandra Deep Field South - radio and mid-infrared counterparts to submillimetre galaxies
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• AzTEC half square degree survey of the SHADES fields - II. Identifications, redshifts, and evidence for large-scale structure

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