The VST photometric hα survey of the Southern Galactic Plane and Bulge (VPHAS+)
Küpcü Yoldas, A
Monthly Notices of the Royal Astronomical Society
Oxford University Press
This is the final version of the article. Available from Oxford University Press via the DOI in this record.
The VST Photometric Hα Survey of the Southern Galactic Plane and Bulge (VPHAS+) is surveying the southern Milky Way in u, g, r, i and Hα at ~1 arcsec angular resolution. Its footprint spans the Galactic latitude range -5o < b < +5° at all longitudes south of the celestial equator. Extensions around the Galactic Centre to Galactic latitudes ±10° bring in much of the Galactic bulge. This European Southern Observatory public survey, begun on 2011 December 28, reaches down to ~20th magnitude (10σ) and will provide single-epoch digital optical photometry for ~300 million stars. The observing strategy and data pipelining are described, and an appraisal of the segmented narrow-band Hα filter in use is presented. Using model atmospheres and library spectra, we compute main-sequence (u - g), (g - r), (r - i) and (r - Hα) stellar colours in the Vega system. We report on a preliminary validation of the photometry using test data obtained from two pointings overlapping the Sloan Digital Sky Survey. An example of the (u - g, g - r) and (r - Hα, r - i) diagrams for a full VPHAS+ survey field is given. Attention is drawn to the opportunities for studies of compact nebulae and nebular morphologies that arise from the image quality being achieved. The value of the u band as the means to identify planetary-nebula central stars is demonstrated by the discovery of the central star of NGC 2899 in survey data. Thanks to its excellent imaging performance, the VLT Survey Telescope (VST)/OmegaCam combination used by this survey is a perfect vehicle for automated searches for reddened early-type stars, and will allow the discovery and analysis of compact binaries, white dwarfs and transient sources. © The Authors 2014. Published by Oxford University Press on behalf of The Royal Astronomical Society.
JED and GB acknowledge the support of a grant from the Science & Technology Facilities Council of the UK (STFC, ref ST/J001335/1). The research leading to these results has also benefitted from funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007- 2013)/ERC Grant Agreement n. 320964 (WDTracer). BTG was also supported in part by the UK STFC (ST/I001719/1). RLMC and AMR acknowledge funding from the Spanish AYA2007-66804 and AYA2012-35330 grants. HJF and MM-S both acknowledge STFC postgraduate studentships. NJW is in receipt of a Royal Astronomical Society Fellowship. RW acknowledges funding from the Marie Curie Actions of the European Commission (FP7-COFUND).
Monthly Notices of the Royal Astronomical Society, 2014, Vol. 440, Issue 3, pp. 2036 - 2058