VPHAS+ - VST Photometric H-a Survey of the Southern Galactic Plane

The primary goal of the VST Photometric Halpha Survey of the Southern Galactic Plane and Bulge (VPHAS+) was to collect single-epoch ugri broad-band and Ha narrow-band photometry across the southern Galactic Plane within the latitude range -5 < b < +5 deg, down to point source magnitudes of ~21 or better. For reasons of resource limitations, the survey terminated in August 2018, omitting some parts of the 4th Galactic quadrant. The VPHAS+ footprint expands to include the inner Galactic Bulge, defined as a 20 x 20 deg2 box around the Galactic Centre. For all massive OBA stars this survey is deep enough to explore all but the most heavily obscured locations of the southern Plane, reaching up to 10 kpc from the Sun. The narrowband data yield a uniform view of southern emission line stars, giving more robust statistics on important scarce object types. The wide-area broadband photometry obtained can facilitate stellar population studies, tracing structure over much of the southern Plane. VPHAS+ data are also suited to trawling the star-formation history of the Galaxy as seen in stellar remnants of all types. More information on the four VPHAS+ data releases can be obtained from https://www.vphasplus.org/data.shtml. Releases 1, 2 and 4 at the ESO archive contain CASU-processed files, while release 3 includes tiles generated by WFAU, Edinburgh.

南天银道面与核球VST测光Hα巡天（VST Photometric Halpha Survey of the Southern Galactic Plane and Bulge，VPHAS+）的核心目标，是在银道面纬度范围-5°< b <+5°的南天银道面区域内，获取单历元ugri宽带测光与Hα窄带测光数据，极限点源星等可达约21等甚至更优。受观测资源限制，该巡天项目于2018年8月终止运行，未能覆盖银道面第四象限的部分区域。VPHAS+的观测天区还扩展至以银心为中心的20°×20°方形区域所定义的银核内部区域。对于所有大质量OBA型恒星而言，该巡天的探测深度足以覆盖南天银道面除重度消光区域外的全部区域，可探测到距离太阳至多10千秒差距的天体。其窄带测光数据能够均匀呈现南天发射线星的分布特征，为重要的稀有天体类型提供更为可靠的统计样本。获取的大视场宽带测光数据则可用于恒星族群研究，以追溯南天银道面大部分区域的结构分布。VPHAS+数据同样适用于通过各类恒星遗迹探究银河系恒星形成历史的相关研究。有关VPHAS+四次数据发布版本的更多信息可通过https://www.vphasplus.org/data.shtml获取。其中第1、2、4次发布的数据在欧洲南方天文台（ESO）档案库中收录了CASU处理的文件，而第3次发布的数据则包含由爱丁堡WFAU生成的天区瓦片文件。