Spitzer Deep Wide-Field Survey (SDWFS) 3.6 micron Epoch 1 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.

斯皮策深场宽视场巡天 (Spitzer Deep, Wide-Field Survey, SDWFS) 是一项依托斯皮策空间望远镜 (Spitzer Space Telescope) 搭载的红外阵列相机 (Infrared Array Camera, IRAC)，针对NOAO深场宽视场巡天 (NOAO Deep Wide-Field Survey) 牧夫座天区10平方度天区开展的四次观测历元红外巡天项目。作为斯皮策望远镜第4周期遗产项目 (Spitzer Cycle 4 Legacy project)，SDWFS在其他斯皮策巡天所定义的天区-深度巡天参数空间中占据独特地位。构成SDWFS的四次观测历元，首次实现了在宽视场范围内以年为时间尺度遴选红外变源与高自行天体。得益于其广阔的巡天体积，SDWFS可探测红移z~3的星系，且除极少数最致密的天体系统外，宇宙方差 (cosmic variance) 对其影响相对微弱。因此，SDWFS数据集尤其适用于刻画红移z>1.5之外的星系演化进程。本次数据发布包含四次观测历元各自的四波段匹配测光星表，以及SDWFS总叠加巡天数据对应的星表，总计20套星表。所有IRAC波段（3.6、4.5、5.8与8微米）的测光结果均采用韦克星等 (Vega magnitudes) 标定并发布。每个源天体均通过三种方式完成测光：4角秒直径孔径测光、6角秒直径孔径测光，以及基于Kron半径的孔径测光（对应SExtractor软件中的MAG_AUTO测光参数）。源天体的坐标匹配2微米全天巡天 (Two Micron All-Sky Survey, 2MASS) 星表位置，坐标偏差不超过0.2角秒。表格中给出的测光不确定度为SExtractor仅统计得到的不确定度的两倍，以此系统性计入测光过程中的系统误差。本数据集或服务由加州理工学院依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。