Spitzer Deep Wide-Field Survey (SDWFS) 4.5 micron Epoch 3 Catalog

The Spitzer Deep, Wide-Field Survey (SDWFS) is a four-epoch infrared survey of 10 square degrees in the Boötes field of the NOAO Deep Wide-Field Survey using the IRAC instrument on the Spitzer Space Telescope. SDWFS, a Spitzer Cycle 4 Legacy project, occupies a unique position in the area-depth survey space defined by other Spitzer surveys. The four epochs that make up SDWFS permit - for the first time - the selection of infrared-variable and high proper motion objects over a wide field on timescales of years. Because of its large survey volume, SDWFS is sensitive to galaxies out to z ~ 3 with relatively little impact from cosmic variance for all but the richest systems. The SDWFS data sets will thus be especially useful for characterizing galaxy evolution beyond z ~ 1.5.

The delivery consists of four band-matched catalogs for each of the four epochs and for the total SDWFS coadd data, a total of 20 catalogs. Vega magnitudes are reported for each IRAC band: 3.6, 4.5, 5.8, and 8 microns. Each source was measured three ways: 4 arcsec diameter aperture, 6 arcsec diameter aperture, and Kron radius aperture (MAG_AUTO in SExtractor). Source coordinates correspond to 2MASS catalog positions to within 0.2 arcsec. The tabulated uncertainties are twice the SExtractor (statistical only) uncertainties as an attempt to account for systematic uncertainties.

This dataset or service is made available by the Infrared Science Archive (IRSA) at IPAC, which is operated by the California Institute of Technology under contract with the National Aeronautics and Space Administration.

斯皮策深场广域巡天（Spitzer Deep, Wide-Field Survey, SDWFS）是依托斯皮策空间望远镜搭载的IRAC（Infrared Array Camera，红外阵列相机）仪器，对NOAO深场广域巡天牧夫座天区的10平方度天区开展的四历元红外巡天项目。作为斯皮策周期4遗产项目，SDWFS在其他斯皮策巡天所界定的天区-深度巡天参数空间中占据独特地位。本次巡天的四个观测历元，首次实现了在广域天区中以年为时间尺度筛选红外变源与高自行天体。凭借庞大的巡天体积，SDWFS可探测红移z~3的星系，且除最致密的天体系统外，宇宙方差对其影响相对微弱。因此，该数据集对于表征红移z~1.5以外的星系演化过程具有特殊应用价值。本次数据交付包含四个观测历元与总叠加SDWFS数据各自的四波段匹配星表，总计20个星表。每个IRAC波段（3.6、4.5、5.8及8微米）均给出织女星系统星等（Vega magnitudes）。每个源天体采用三种测光方式进行测量：4角秒直径孔径测光、6角秒直径孔径测光，以及Kron半径孔径测光（对应SExtractor软件中的MAG_AUTO测光参数）。源天体坐标与2MASS星表位置的偏差不超过0.2角秒。表格中所列的不确定度为SExtractor统计不确定度的两倍，以尝试覆盖系统不确定度。本数据集或服务由加州理工学院根据与美国国家航空航天局（National Aeronautics and Space Administration, NASA）签订的合同运营的IPAC下属红外科学档案馆（Infrared Science Archive, IRSA）提供。