We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the solar system, exploring the transient optical sky, and mapping the Milky Way. LSST will be a large, wide-field ground-based system designed to obtain repeated images covering the sky visible from Cerro Pachón in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg 2 field of view, a 3.2-gigapixel camera, and six filters (ugrizy) covering the wavelength range 320-1050 nm. The project is in the construction phase and will begin regular survey operations by 2022. About 90% of the observing time will be devoted to a deep-wide-fast survey mode that will uniformly observe a 18,000 deg 2 region about 800 times (summed over all six bands) during the anticipated 10 yr of operations and will yield a co-added map to r∼27.5. These data will result in databases including about 32 trillion observations of 20 billion galaxies and a similar number of stars, and they will serve the majority of the primary science programs. The remaining 10% of the observing time will be allocated to special projects such as Very Deep and Very Fast time domain surveys, whose details are currently under discussion. We illustrate how the LSST science drivers led to these choices of system parameters, and we describe the expected data products and their characteristics.
The Sloan Digital Sky Survey (SDSS) is an imaging and spectroscopic survey that will eventually cover approximately one-quarter of the celestial sphere and collect spectra of %10 6 galaxies, 100,000 quasars, 30,000 stars, and 30,000 serendipity targets. In 2001 June, the SDSS released to the general astronomical community its early data release, roughly 462 deg 2 of imaging data including almost 14 million detected objects and 54,008 follow-up spectra. The imaging data were collected in drift-scan mode in five bandpasses (u, g, r, i, and z); our 95% completeness limits for stars are 22.0, 22.2, 22.2, 21.3, and 20.5, respectively. The photometric calibration is reproducible to 5%, 3%, 3%, 3%, and 5%, respectively. The spectra are flux-and wavelength-calibrated, with 4096 pixels from 3800 to 9200 Å at R % 1800. We present the means by which these data are distributed to the astronomical community, descriptions of the hardware used to obtain the data, the software used for processing the data, the measured quantities for each observed object, and an overview of the properties of this data set.
We have created a variety of composite quasar spectra using a homogeneous data set of over 2200 spectra from the Sloan Digital Sky Survey (SDSS). The quasar sample spans a redshift range of 0.044 ¹ z ¹ 4.789 and an absolute r@ magnitude range of [18.0 to [26.5. The input spectra cover an observed wavelength range of 3800È9200 at a resolution of 1800. The median composite covers a rest-A wavelength range from 800 to 8555 and reaches a peak signal-to-noise ratio of over 300 per 1 A A resolution element in the rest frame. We have identiÐed over 80 emission-line features in the spectrum. Emission-line shifts relative to nominal laboratory wavelengths are seen for many of the ionic species. Peak shifts of the broad permitted and semiforbidden lines are strongly correlated with ionization energy, as previously suggested, but we Ðnd that the narrow forbidden lines are also shifted by amounts that are strongly correlated with ionization energy. The magnitude of the forbidden line shifts is [100 km s~1, compared with shifts of up to 550 km s~1 for some of the permitted and semiforbidden lines. At wavelengths longer than the Lya emission, the continuum of the geometric mean composite is well Ðtted by two power laws, with a break at B5000 The frequency power-law index, is [0.44 from B1300 A. a l , to 5000 and [2.45 redward of B5000 The abrupt change in slope can be accounted for partly by A A. host-galaxy contamination at low redshift. Stellar absorption lines, including higher order Balmer lines, seen in the composites suggest that young or intermediate-age stars make a signiÐcant contribution to the light of the host galaxies. Most of the spectrum is populated by blended emission lines, especially in the range 1500È3500 which can make the estimation of quasar continua highly uncertain unless large A , ranges in wavelength are observed. An electronic table of the median quasar template is available.
Citation for published item:viskeD tF nd fldryD sFuF nd hriverD FF nd u'sD FtF nd elpslnD wF nd endreD iF nd froughD F nd gluverD wFiF nd qrootesD wFF nd qunwrdhnD wFvFF nd uelvinD vFF nd vovedyD tF nd oothmD eFFqF nd ylorD iFxF nd fmfordD FF nd flndErwthornD tF nd frownD wFtFsF nd hrinkwterD wFtF nd ropkinsD eFwF nd weyerD wFtF nd xorergD F nd eokD tFeF nd egiusD xFuF nd endrewsD FuF nd fuerD eFiF nd ghingD tFrFF nd gollessD wF nd gonselieD gFtF nd groomD FwF nd hviesD vFtFwF nd he roprisD F nd hunneD vF nd irdleyD iFwF nd illisD F nd posterD gF nd prenkD gFF nd r¤ ußlerD fF nd rolwerdD fFF nd rowlettD gF nd srrD rF nd trvisD wFtF nd tonesD hFrF nd u)eD FF nd veyD gFqF nd vngeD F nd vrEv¡ opezD wFeF nd v¡ opezE¡ nhezD ¡ eFF nd wddoxD F nd wdoreD fFpF nd wxughtEoertsD F nd wo'ettD eFtF nd xiholD FgF nd ywersD wFF nd lmrD hF nd ennyD FtF nd hillippsD F nd imletD uFeF nd opesuD gFgF nd resottD wF nd rotorD F nd dlerD iFwF nd nsomD eFiF nd eiertD wF nd hrpD F nd utherlndD F nd ¡ zquezEwtD tFeF nd vn umpenD iF nd ilkinsD FwF nd illimsD F nd rightD eFrF @PHISA 9qlxy end wss essemly @qeweA X end of survey report nd dt relese PF9D wonthly noties of the oyl estronomil oietyFD RSP @PAF ppF PHVUEPIPTF Further information on publisher's website: Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. ABSTRACTThe Galaxy And Mass Assembly (GAMA) survey is one of the largest contemporary spectroscopic surveys of low redshift galaxies. Covering an area of ∼286 deg 2 (split among five survey regions) down to a limiting magnitude of r < 19.8 mag, we have collected spectra and reliable redshifts for 238 000 objects using the AAOmega spectrograph on the Anglo-Australian Telescope. In addition, we have assembled imaging data from a number of independent surveys in order to generate photometry spanning the wavelength range 1 nm-1 m. Here, we report on the recently completed spectroscopic survey and present a series of diagnostics to assess its final state and the quality of the redshift data. We also describe a number of survey aspects and procedures, or updates thereof, including changes to the input catalogue, redshifting and re-redshifting, and the derivation of ultraviolet, optical and near-infrared photometry. Finally, we present the second public release of GAMA data. In this release, we provide input catalogue and targeting information, spectra, redshifts, ultraviolet, optical and near-infrared photometry, single-component Sérsic fits, stellar masses, Hα-derived star formation rates, environment information, and group p...
Citation for published item:fryntD tFtF nd ywersD wFF nd oothmD eFFqF nd groomD FwF nd hriverD FF nd hrinkwterD wFtF nd vorenteD xFFpF nd gorteseD vF nd ottD xF nd gollessD wF nd heferD eF nd ylorD iFxF nd uonstntopoulosD sFF nd ellenD tFF nd fldryD sF nd frnesD vF nd fuerD eFiF nd flndErwthornD tF nd floomD tFF nd frooksD eFwF nd froughD F nd geilD qF nd gouhD F nd grotonD hF nd hviesD F nd illisD F nd pogrtyD vFwFF nd posterD gF nd qlzerookD uF nd qoodwinD wF nd qreenD eF nd qunwrdhnD wFvF nd rmptonD iF nd roD sFEF nd ropkinsD eFwF nd uewleyD vF nd vwreneD tFF nd veonEvlD FqF nd veslieD F nd wilroyD F nd vewisD qF nd viskeD tF nd v¡ opezE¡ nhezD ¡ eFF nd whjnD F nd wedlingD eFwF nd wetlfeD xF nd weyerD wF nd wouldD tF nd yreshkowD hF nd y9ooleD F nd ryD wF nd ihrdsD FxF nd hnksD F nd hrpD F nd weetD FwF nd homsD eFhF nd oniniD gF nd lherD gFtF @PHISA 9he ews qlxy urvey X instrument spei(tion nd trget seletionF9D wonthly noties of the oyl estronomil oietyFD RRU @QAF ppF PVSUEPVUWF Further information on publisher's website: Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. ABSTRACTThe SAMI Galaxy Survey will observe 3400 galaxies with the Sydney-AAO Multi-object Integral-field spectrograph (SAMI) on the Anglo-Australian Telescope in a 3-yr survey which began in 2013. We present the throughput of the SAMI system, the science basis and specifications for the target selection, the survey observation plan and the combined properties of the selected galaxies. The survey includes four volume-limited galaxy samples based on cuts in a proxy for stellar mass, along with low-stellar-mass dwarf galaxies all selected from the Galaxy And Mass Assembly (GAMA) survey. The GAMA regions were selected because of the vast array of ancillary data available, including ultraviolet through to radio bands. These fields are on the celestial equator at 9, 12 and 14.5 h, and cover a total of 144 deg 2 (in GAMA-I). Higher density environments are also included with the addition of eight clusters. The clusters have spectroscopy from 2-degree Field Galaxy Redshift Survey (2dFGRS) and Sloan Digital Sky Survey (SDSS) and photometry in regions covered by the SDSS and/or VLT Survey Telescope/ATLAS. The aim is to cover a broad range in stellar mass and environment, and therefore the primary survey targets cover redshifts 0.004 < z < 0.095, magnitudes r pet < 19.4, stellar masses 10 7 -10 12 M , and environments from isolated field galaxies through groups to clusters of ∼10 15 M .
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