N. P. Gentile Fusillo, Romano L. M. Corradi, N. A. Walton, P.R. Carter, Steven Phillipps, Nicholas J. Wright, Stuart E. Sale, Pablo Rodríguez-Gil, S. Pyrzas, Juan Fabregat, Antonio Hales, J. J. Drake, Robert Greimel, J. van Roestel, Simon Hodgkin, Jonathan Irwin, H. J. Farnhill, M. Mohr-Smith, Geert Barentsen, Christian Knigge, Eduardo Gonzalez-Solares, Jochen Eislöffel, Robert R. King, Danny Steeghs, Kerttu Viironen, C. Ruhland, M. J. Barlow, D. J. Lennon, R. Tata, Albert A. Zijlstra, L. Huckvale, Tim Naylor, Eric Lagadec, Rhys Morris, Thomas Kupfer, Quentin A. Parker, Sandra Greiss, Jorick S. Vink, Brent Miszalski, Janet E. Drew, Boris T. Gänsicke, Y. C. Unruh, Simone Scaringi, Mike Irwin, A. Aungwerojwit, Jack Lewis, J. Suso, Paul J. Groot, A.A. Henden, Gijs H. A. Roelofs, Antonio Mampaso, Laurence Sabin, and Roberto Raddi
The INT/WFC Photometric H-Alpha Survey of the Northern Galactic Plane (IPHAS) is a 1800 square degrees imaging survey covering Galactic latitudes |b| < 5 deg and longitudes l = 30 to 215 deg in the r, i and H-alpha filters using the Wide Field Camera (WFC) on the 2.5-metre Isaac Newton Telescope (INT) in La Palma. We present the first quality-controlled and globally-calibrated source catalogue derived from the survey, providing single-epoch photometry for 219 million unique sources across 92% of the footprint. The observations were carried out between 2003 and 2012 at a median seeing of 1.1 arcsec (sampled at 0.33 arcsec/pixel) and to a mean 5\sigma-depth of 21.2 (r), 20.0 (i) and 20.3 (H-alpha) in the Vega magnitude system. We explain the data reduction and quality control procedures, describe and test the global re-calibration, and detail the construction of the new catalogue. We show that the new calibration is accurate to 0.03 mag (rms) and recommend a series of quality criteria to select the most reliable data from the catalogue. Finally, we demonstrate the ability of the catalogue's unique (r-Halpha, r-i) diagram to (1) characterise stellar populations and extinction regimes towards different Galactic sightlines and (2) select H-alpha emission-line objects. IPHAS is the first survey to offer comprehensive CCD photometry of point sources across the Galactic Plane at visible wavelengths, providing the much-needed counterpart to recent infrared surveys., Comment: Accepted for publication in MNRAS. The catalogue is available in full from the survey website at http://www.iphas.org and has been submitted to Vizier