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Niv Drory - One of the best experts on this subject based on the ideXlab platform.
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sdss iv manga ifs galaxy Survey Survey Design execution and initial data quality
The Astronomical Journal, 2016Co-Authors: Kevin Bundy, Niv Drory, Matthew A Bershady, Brett H Andrews, Brian Cherinka, Aleksandar M Diamondstanic, Nicholas Macdonald, Jose R Sanchezgallego, Daniel Thomas, David B WakeAbstract:The MaNGA Survey (Mapping Nearby Galaxies at Apache Point Observatory) is one of three core programs in the Sloan Digital Sky Survey IV. It is obtaining integral field spectroscopy for 10,000 nearby galaxies at a spectral resolution of R ~ 2000 from 3622 to 10354 A. The Design of the Survey is driven by a set of science requirements on the precision of estimates of the following properties: star formation rate surface density, gas metallicity, stellar population age, metallicity, and abundance ratio, and their gradients; stellar and gas kinematics; and enclosed gravitational mass as a function of radius. We describe how these science requirements set the depth of the observations and dictate sample selection. The majority of targeted galaxies are selected to ensure uniform spatial coverage in units of effective radius (R e ) while maximizing spatial resolution. About two-thirds of the sample is covered out to 1.5R e (Primary sample), and one-third of the sample is covered to 2.5R e (Secondary sample). We describe the Survey execution with details that would be useful in the Design of similar future Surveys. We also present statistics on the achieved data quality, specifically the point-spread function, sampling uniformity, spectral resolution, sky subtraction, and flux calibration. For our Primary sample, the median r-band signal-to-noise ratio is ~70 per 1.4 A pixel for spectra stacked between 1R e and 1.5R e . Measurements of various galaxy properties from the first-year data show that we are meeting or exceeding the defined requirements for the majority of our science goals.
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sdss iv manga ifs galaxy Survey Survey Design execution and initial data quality
arXiv: Astrophysics of Galaxies, 2016Co-Authors: Renbin Yan, Niv Drory, Kevin Bundy, Matthew A Bershady, Brett H Andrews, Brian Cherinka, Aleksandar M Diamondstanic, Nicholas Macdonald, David R Law, Jose R SanchezgallegoAbstract:The MaNGA Survey (Mapping Nearby Galaxies at Apache Point Observatory) is one of three core programs in the Sloan Digital Sky Survey IV. It is obtaining integral field spectroscopy (IFS) for 10K nearby galaxies at a spectral resolution of R~2000 from 3,622-10,354A. The Design of the Survey is driven by a set of science requirements on the precision of estimates of the following properties: star formation rate surface density, gas metallicity, stellar population age, metallicity, and abundance ratio, and their gradients; stellar and gas kinematics; and enclosed gravitational mass as a function of radius. We describe how these science requirements set the depth of the observations and dictate sample selection. The majority of targeted galaxies are selected to ensure uniform spatial coverage in units of effective radius (Re) while maximizing spatial resolution. About 2/3 of the sample is covered out to 1.5Re (Primary sample), and 1/3 of the sample is covered to 2.5Re (Secondary sample). We describe the Survey execution with details that would be useful in the Design of similar future Surveys. We also present statistics on the achieved data quality, specifically, the point spread function, sampling uniformity, spectral resolution, sky subtraction, and flux calibration. For our Primary sample, the median r-band signal-to-noise ratio is ~73 per 1.4A pixel for spectra stacked between 1-1.5 Re. Measurements of various galaxy properties from the first year data show that we are meeting or exceeding the defined requirements for the majority of our science goals.
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the virus p exploration of nearby galaxies venga Survey Design data processing and spectral analysis methods
The Astronomical Journal, 2013Co-Authors: Guillermo A Blanc, Tim Weinzirl, Mimi Song, Amanda Heiderman, Karl Gebhardt, Shardha Jogee, Neal J Evans, Remco C E Van Den Bosch, Rongxin Luo, Niv DroryAbstract:We present the Survey Design, data reduction, and spectral fitting pipeline for the VIRUS-P Exploration of Nearby Galaxies (VENGA). VENGA is an integral field spectroscopic Survey, which maps the disks of 30 nearby spiral galaxies. Targets span a wide range in Hubble type, star formation activity, morphology, and inclination. The VENGA data cubes have 5 ''.6 FWHM spatial resolution, similar to 5 angstrom FWHM spectral resolution, sample the 3600 angstrom-6800 angstrom range, and cover large areas typically sampling galaxies out to similar to 0.7R(25). These data cubes can be used to produce two-dimensional maps of the star formation rate, dust extinction, electron density, stellar population parameters, the kinematics and chemical abundances of both stars and ionized gas, and other physical quantities derived from the fitting of the stellar spectrum and the measurement of nebular emission lines. To exemplify our methods and the quality of the data, we present the VENGA data cube on the face-on Sc galaxy NGC 628 (a.k.a. M 74). The VENGA observations of NGC 628 are described, as well as the construction of the data cube, our spectral fitting method, and the fitting of the stellar and ionized gas velocity fields. We also propose a new method to measure the inclination of nearly face-on systems based on the matching of the stellar and gas rotation curves using asymmetric drift corrections. VENGA will measure relevant physical parameters across different environments within these galaxies, allowing a series of studies on star formation, structure assembly, stellar populations, chemical evolution, galactic feedback, nuclear activity, and the properties of the interstellar medium in massive disk galaxies.
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the virus p exploration of nearby galaxies venga Survey Design data processing and spectral analysis methods
arXiv: Cosmology and Nongalactic Astrophysics, 2013Co-Authors: Guillermo A Blanc, Tim Weinzirl, Mimi Song, Amanda Heiderman, Karl Gebhardt, Shardha Jogee, Neal J Evans, Remco C E Van Den Bosch, Rongxin Luo, Niv DroryAbstract:We present the Survey Design, data reduction, and spectral fitting pipeline for the VIRUS-P Exploration of Nearby Galaxies (VENGA). VENGA is an integral field spectroscopic Survey, which maps the disks of 30 nearby spiral galaxies. Targets span a wide range in Hubble type, star formation activity, morphology, and inclination. The VENGA data-cubes have 5.6'' FWHM spatial resolution, ~5A FWHM spectral resolution, sample the 3600A-6800A range, and cover large areas typically sampling galaxies out to ~0.7 R_25. These data-cubes can be used to produce 2D maps of the star formation rate, dust extinction, electron density, stellar population parameters, the kinematics and chemical abundances of both stars and ionized gas, and other physical quantities derived from the fitting of the stellar spectrum and the measurement of nebular emission lines. To exemplify our methods and the quality of the data, we present the VENGA data-cube on the face-on Sc galaxy NGC 628 (a.k.a. M 74). The VENGA observations of NGC 628 are described, as well as the construction of the data-cube, our spectral fitting method, and the fitting of the stellar and ionized gas velocity fields. We also propose a new method to measure the inclination of nearly face-on systems based on the matching of the stellar and gas rotation curves using asymmetric drift corrections. VENGA will measure relevant physical parameters across different environments within these galaxies, allowing a series of studies on star formation, structure assembly, stellar populations, chemical evolution, galactic feedback, nuclear activity, and the properties of the interstellar medium in massive disk galaxies.
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the hetdex pilot Survey i Survey Design performance and catalog of emission line galaxies
Astrophysical Journal Supplement Series, 2011Co-Authors: Joshua J Adams, Guillermo A Blanc, Karl Gebhardt, Niv Drory, Gary J Hill, R Bender, Joyce Byun, Robin Ciardullo, Mark E CornellAbstract:We present a catalog of emission-line galaxies selected solely by their emission-line fluxes using a wide-field integral field spectrograph. This work is partially motivated as a pilot Survey for the upcoming Hobby-Eberly Telescope Dark Energy Experiment. We describe the observations, reductions, detections, redshift classifications, line fluxes, and counterpart information for 397 emission-line galaxies detected over 169 {open_square}' with a 3500-5800 A bandpass under 5 A full-width-half-maximum (FWHM) spectral resolution. The Survey's best sensitivity for unresolved objects under photometric conditions is between 4 and 20x 10{sup -17} erg s{sup -1} cm{sup -2} depending on the wavelength, and Ly{alpha} luminosities between 3 x 10{sup 42} and 6 x 10{sup 42} erg s{sup -1} are detectable. This Survey method complements narrowband and color-selection techniques in the search of high-redshift galaxies with its different selection properties and large volume probed. The four Survey fields within the COSMOS, GOODS-N, MUNICS, and XMM-LSS areas are rich with existing, complementary data. We find 105 galaxies via their high-redshift Ly{alpha} emission at 1.9 44 {open_square}' which appear to be extended Ly{alpha} nebulae. We also find three high-z objects with rest-frame Ly{alpha} EW above the level believed to be achievable with normal star formation, EW{sub 0}>240 A. Future papers will investigate the physical properties of this sample.« less
Michael Pracy - One of the best experts on this subject based on the ideXlab platform.
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the wigglez dark energy Survey Survey Design and first data release
Monthly Notices of the Royal Astronomical Society, 2010Co-Authors: M J Drinkwater, Russell J Jurek, Chris Blake, David Woods, Kevin A Pimbblet, Karl Glazebrook, R Sharp, Michael PracyAbstract:The WiggleZ Dark Energy Survey is a Survey of 240 000 emission-line galaxies in the distant Universe, measured with the AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope (AAT). The primary aim of the Survey is to precisely measure the scale of baryon acoustic oscillations (BAO) imprinted on the spatial distribution of these galaxies at look-back times of 4–8 Gyr. The target galaxies are selected using ultraviolet (UV) photometry from the Galaxy Evolution Explorer satellite, with a flux limit of NUV < 22.8 mag . We also require that the targets are detected at optical wavelengths, specifically in the range 20.0 < r < 22.5 mag . We use the Lyman break method applied to the UV colours, with additional optical colour limits, to select high-redshift galaxies. The galaxies generally have strong emission lines, permitting reliable redshift measurements in relatively short exposure times on the AAT. The median redshift of the galaxies is z_(med)= 0.6 . The redshift range containing 90 per cent of the galaxies is 0.2 < z < 1.0 . The Survey will sample a volume of ~1 Gpc^3 over a projected area on the sky of 1000 deg^2, with an average target density of 350 deg^(−2). Detailed forecasts indicate that the Survey will measure the BAO scale to better than 2 per cent and the tangential and radial acoustic wave scales to approximately 3 and 5 per cent, respectively. Combining the WiggleZ constraints with existing cosmic microwave background measurements and the latest supernova data, the marginalized uncertainties in the cosmological model are expected to be σ(Ω_m) = 0.02 and σ(w) = 0.07 (for a constant w model). The WiggleZ measurement of w will constitute a robust, precise and independent test of dark energy models. This paper provides a detailed description of the Survey and its Design, as well as the spectroscopic observations, data reduction and redshift measurement techniques employed. It also presents an analysis of the properties of the target galaxies, including emission-line diagnostics which show that they are mostly extreme starburst galaxies, and Hubble Space Telescope images, which show that they contain a high fraction of interacting or distorted systems. In conjunction with this paper, we make a public data release of data for the first 100 000 galaxies measured for the project.
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the wigglez dark energy Survey Survey Design and first data release
arXiv: Cosmology and Nongalactic Astrophysics, 2009Co-Authors: M J Drinkwater, Russell J Jurek, Chris Blake, David Woods, Kevin A Pimbblet, Karl Glazebrook, R Sharp, Michael PracyAbstract:The WiggleZ Dark Energy Survey is a Survey of 240,000 emission line galaxies in the distant universe, measured with the AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope (AAT). The target galaxies are selected using ultraviolet photometry from the GALEX satellite, with a flux limit of NUV<22.8 mag. The redshift range containing 90% of the galaxies is 0.2
Jiasheng Huang - One of the best experts on this subject based on the ideXlab platform.
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s candels the spitzer cosmic assembly near infrared deep extragalactic Survey Survey Design photometry and deep irac source counts
Astrophysical Journal Supplement Series, 2015Co-Authors: M L N Ashby, S P Willner, G G Fazio, J S Dunlop, E Egami, S M Faber, Henry C Ferguson, Norman A Grogin, J L Hora, Jiasheng HuangAbstract:The Spitzer-Cosmic Assembly Deep Near-infrared Extragalactic Legacy Survey (S-CANDELS; PI G.Fazio) is a Cycle 8 Exploration Program Designed to detect galaxies at very high redshifts (). To mitigate the effects of cosmic variance and also to take advantage of deep coextensive coverage in multiple bands by the Hubble Space Telescope (HST) Multi-cycle Treasury Program CANDELS, S-CANDELS was carried out within five widely separated extragalactic fields: the UKIDSS Ultra-deep Survey, the Extended Chandra Deep Field South, COSMOS, the HST Deep Field North, and the Extended Groth Strip. S-CANDELS builds upon the existing coverage of these fields from the Spitzer Extended Deep Survey (SEDS), a Cycle 6 Exploration Program, by increasing the integration time from SEDS? 12 hr to a total of 50 hr but within a smaller area, 0.16 deg2. The additional depth significantly increases the Survey completeness at faint magnitudes. This paper describes the S-CANDELS Survey Design, processing, and publicly available data products. We present Infrared Array Camera (IRAC) dual-band catalogs reaching to a depth of 26.5 AB mag. Deep IRAC counts for the roughly 135,000 galaxies detected by S-CANDELS are consistent with models based on known galaxy populations. The increase in depth beyond earlier Spitzer/IRAC Surveys does not reveal a significant additional contribution from discrete sources to the diffuse Cosmic Infrared Background (CIB). Thus it remains true that only roughly half of the estimated CIB flux from COBE/DIRBE is resolved.
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s candels the spitzer cosmic assembly near infrared deep extragalactic Survey Survey Design photometry and deep irac source counts
arXiv: Astrophysics of Galaxies, 2015Co-Authors: M L N Ashby, S P Willner, G G Fazio, J S Dunlop, E Egami, S M Faber, Henry C Ferguson, Norman A Grogin, J L Hora, Jiasheng HuangAbstract:The Spitzer-Cosmic Assembly Deep Near-Infrared Extragalactic Legacy Survey (S-CANDELS; PI G. Fazio) is a Cycle 8 Exploration Program Designed to detect galaxies at very high redshifts (z > 5). To mitigate the effects of cosmic variance and also to take advantage of deep coextensive coverage in multiple bands by the Hubble Space Telescope Multi-Cycle Treasury Program CANDELS, S-CANDELS was carried out within five widely separated extragalactic fields: the UKIDSS Ultra-Deep Survey, the Extended Chandra Deep Field South, COSMOS, the HST Deep Field North, and the Extended Groth Strip. S-CANDELS builds upon the existing coverage of these fields from the Spitzer Extended Deep Survey (SEDS) by increasing the integration time from 12 hours to a total of 50 hours but within a smaller area, 0.16 square degrees. The additional depth significantly increases the Survey completeness at faint magnitudes. This paper describes the S-CANDELS Survey Design, processing, and publicly-available data products. We present IRAC dual-band 3.6+4.5 micron catalogs reaching to a depth of 26.5 AB mag. Deep IRAC counts for the roughly 135,000 galaxies detected by S-CANDELS are consistent with models based on known galaxy populations. The increase in depth beyond earlier Spitzer/IRAC Surveys does not reveal a significant additional contribution from discrete sources to the diffuse Cosmic Infrared Background (CIB). Thus it remains true that only roughly half of the estimated CIB flux from COBE/DIRBE is resolved.
S M Faber - One of the best experts on this subject based on the ideXlab platform.
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s candels the spitzer cosmic assembly near infrared deep extragalactic Survey Survey Design photometry and deep irac source counts
Astrophysical Journal Supplement Series, 2015Co-Authors: M L N Ashby, S P Willner, G G Fazio, J S Dunlop, E Egami, S M Faber, Henry C Ferguson, Norman A Grogin, J L Hora, Jiasheng HuangAbstract:The Spitzer-Cosmic Assembly Deep Near-infrared Extragalactic Legacy Survey (S-CANDELS; PI G.Fazio) is a Cycle 8 Exploration Program Designed to detect galaxies at very high redshifts (). To mitigate the effects of cosmic variance and also to take advantage of deep coextensive coverage in multiple bands by the Hubble Space Telescope (HST) Multi-cycle Treasury Program CANDELS, S-CANDELS was carried out within five widely separated extragalactic fields: the UKIDSS Ultra-deep Survey, the Extended Chandra Deep Field South, COSMOS, the HST Deep Field North, and the Extended Groth Strip. S-CANDELS builds upon the existing coverage of these fields from the Spitzer Extended Deep Survey (SEDS), a Cycle 6 Exploration Program, by increasing the integration time from SEDS? 12 hr to a total of 50 hr but within a smaller area, 0.16 deg2. The additional depth significantly increases the Survey completeness at faint magnitudes. This paper describes the S-CANDELS Survey Design, processing, and publicly available data products. We present Infrared Array Camera (IRAC) dual-band catalogs reaching to a depth of 26.5 AB mag. Deep IRAC counts for the roughly 135,000 galaxies detected by S-CANDELS are consistent with models based on known galaxy populations. The increase in depth beyond earlier Spitzer/IRAC Surveys does not reveal a significant additional contribution from discrete sources to the diffuse Cosmic Infrared Background (CIB). Thus it remains true that only roughly half of the estimated CIB flux from COBE/DIRBE is resolved.
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s candels the spitzer cosmic assembly near infrared deep extragalactic Survey Survey Design photometry and deep irac source counts
arXiv: Astrophysics of Galaxies, 2015Co-Authors: M L N Ashby, S P Willner, G G Fazio, J S Dunlop, E Egami, S M Faber, Henry C Ferguson, Norman A Grogin, J L Hora, Jiasheng HuangAbstract:The Spitzer-Cosmic Assembly Deep Near-Infrared Extragalactic Legacy Survey (S-CANDELS; PI G. Fazio) is a Cycle 8 Exploration Program Designed to detect galaxies at very high redshifts (z > 5). To mitigate the effects of cosmic variance and also to take advantage of deep coextensive coverage in multiple bands by the Hubble Space Telescope Multi-Cycle Treasury Program CANDELS, S-CANDELS was carried out within five widely separated extragalactic fields: the UKIDSS Ultra-Deep Survey, the Extended Chandra Deep Field South, COSMOS, the HST Deep Field North, and the Extended Groth Strip. S-CANDELS builds upon the existing coverage of these fields from the Spitzer Extended Deep Survey (SEDS) by increasing the integration time from 12 hours to a total of 50 hours but within a smaller area, 0.16 square degrees. The additional depth significantly increases the Survey completeness at faint magnitudes. This paper describes the S-CANDELS Survey Design, processing, and publicly-available data products. We present IRAC dual-band 3.6+4.5 micron catalogs reaching to a depth of 26.5 AB mag. Deep IRAC counts for the roughly 135,000 galaxies detected by S-CANDELS are consistent with models based on known galaxy populations. The increase in depth beyond earlier Spitzer/IRAC Surveys does not reveal a significant additional contribution from discrete sources to the diffuse Cosmic Infrared Background (CIB). Thus it remains true that only roughly half of the estimated CIB flux from COBE/DIRBE is resolved.
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the deep2 galaxy redshift Survey Design observations data reduction and redshifts
Astrophysical Journal Supplement Series, 2013Co-Authors: Jeffrey A Newman, Charlie Conroy, S M Faber, Michael C Cooper, Marc Davis, Alison L Coil, Puragra Guhathakurta, Andrew C PhillipsAbstract:We describe the Design and data analysis of the DEEP2 Galaxy Redshift Survey, the densest and largest high-precision redshift Survey of galaxies at z ~ 1 completed to date. The Survey was Designed to conduct a comprehensive census of massive galaxies, their properties, environments, and large-scale structure down to absolute magnitude M_B = −20 at z ~ 1 via ~90 nights of observation on the Keck telescope. The Survey covers an area of 2.8 deg^2 divided into four separate fields observed to a limiting apparent magnitude of R_(AB) = 24.1. Objects with z ≾0.7 are readily identifiable using BRI photometry and rejected in three of the four DEEP2 fields, allowing galaxies with z > 0.7 to be targeted ~2.5 times more efficiently than in a purely magnitude-limited sample. Approximately 60% of eligible targets are chosen for spectroscopy, yielding nearly 53,000 spectra and more than 38,000 reliable redshift measurements. Most of the targets that fail to yield secure redshifts are blue objects that lie beyond z ~ 1.45, where the [O ii] 3727 A doublet lies in the infrared. The DEIMOS 1200 line mm^(−1) grating used for the Survey delivers high spectral resolution (R ~ 6000), accurate and secure redshifts, and unique internal kinematic information. Extensive ancillary data are available in the DEEP2 fields, particularly in the Extended Groth Strip, which has evolved into one of the richest multiwavelength regions on the sky. This paper is intended as a handbook for users of the DEEP2 Data Release 4, which includes all DEEP2 spectra and redshifts, as well as for the DEEP2 DEIMOS data reduction pipelines. Extensive details are provided on object selection, mask Design, biases in target selection and redshift measurements, the spec2d two-dimensional data-reduction pipeline, the spec1d automated redshift pipeline, and the zspec visual redshift verification process, along with examples of instrumental signatures or other artifacts that in some cases remain after data reduction. Redshift errors and catastrophic failure rates are assessed through more than 2000 objects with duplicate observations. Sky subtraction is essentially photon-limited even under bright OH sky lines; we describe the strategies that permitted this, based on high image stability, accurate wavelength solutions, and powerful B-spline modeling methods. We also investigate the impact of targets that appear to be single objects in ground-based targeting imaging but prove to be composite in Hubble Space Telescope data; they constitute several percent of targets at z ~ 1, approaching ~5%–10% at z > 1.5. Summary data are given that demonstrate the superiority of DEEP2 over other deep high-precision redshift Surveys at z ~ 1 in terms of redshift accuracy, sample number density, and amount of spectral information. We also provide an overview of the scientific highlights of the DEEP2 Survey thus far.
David Woods - One of the best experts on this subject based on the ideXlab platform.
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the wigglez dark energy Survey Survey Design and first data release
Monthly Notices of the Royal Astronomical Society, 2010Co-Authors: M J Drinkwater, Russell J Jurek, Chris Blake, David Woods, Kevin A Pimbblet, Karl Glazebrook, R Sharp, Michael PracyAbstract:The WiggleZ Dark Energy Survey is a Survey of 240 000 emission-line galaxies in the distant Universe, measured with the AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope (AAT). The primary aim of the Survey is to precisely measure the scale of baryon acoustic oscillations (BAO) imprinted on the spatial distribution of these galaxies at look-back times of 4–8 Gyr. The target galaxies are selected using ultraviolet (UV) photometry from the Galaxy Evolution Explorer satellite, with a flux limit of NUV < 22.8 mag . We also require that the targets are detected at optical wavelengths, specifically in the range 20.0 < r < 22.5 mag . We use the Lyman break method applied to the UV colours, with additional optical colour limits, to select high-redshift galaxies. The galaxies generally have strong emission lines, permitting reliable redshift measurements in relatively short exposure times on the AAT. The median redshift of the galaxies is z_(med)= 0.6 . The redshift range containing 90 per cent of the galaxies is 0.2 < z < 1.0 . The Survey will sample a volume of ~1 Gpc^3 over a projected area on the sky of 1000 deg^2, with an average target density of 350 deg^(−2). Detailed forecasts indicate that the Survey will measure the BAO scale to better than 2 per cent and the tangential and radial acoustic wave scales to approximately 3 and 5 per cent, respectively. Combining the WiggleZ constraints with existing cosmic microwave background measurements and the latest supernova data, the marginalized uncertainties in the cosmological model are expected to be σ(Ω_m) = 0.02 and σ(w) = 0.07 (for a constant w model). The WiggleZ measurement of w will constitute a robust, precise and independent test of dark energy models. This paper provides a detailed description of the Survey and its Design, as well as the spectroscopic observations, data reduction and redshift measurement techniques employed. It also presents an analysis of the properties of the target galaxies, including emission-line diagnostics which show that they are mostly extreme starburst galaxies, and Hubble Space Telescope images, which show that they contain a high fraction of interacting or distorted systems. In conjunction with this paper, we make a public data release of data for the first 100 000 galaxies measured for the project.
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the wigglez dark energy Survey Survey Design and first data release
arXiv: Cosmology and Nongalactic Astrophysics, 2009Co-Authors: M J Drinkwater, Russell J Jurek, Chris Blake, David Woods, Kevin A Pimbblet, Karl Glazebrook, R Sharp, Michael PracyAbstract:The WiggleZ Dark Energy Survey is a Survey of 240,000 emission line galaxies in the distant universe, measured with the AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope (AAT). The target galaxies are selected using ultraviolet photometry from the GALEX satellite, with a flux limit of NUV<22.8 mag. The redshift range containing 90% of the galaxies is 0.2