IPHAS Early Data Release E. A. Gonzalez-Solares IPHAS Consortium AstroGrid National Astronomy Meeting, 2007
IPHAS: Summary INT/WFC Photometric H Survey of the Northern Galactic Plane Using WFC to image |b|<5˚, 30˚<l<215˚ in three filters: r’ (30 s), i’ (10 s) and H (120 s) to r’<20 Observations done in pairs, second pointing at an offset of 5’ W and 5’ S All objects imaged twice, coverage >99%
IPHAS: Summary Additional data: GPS (UKIDSS), UVEX (INT in U and g). VPHAS (VST) in the Southern Galactic plane.
Science Examples See talk at session P03 by Robert Greimel Drew et al. 2005
Science Examples Mampaso et al 2006
Early Data Release Observation started in August observing nights (~26% lost due to bad weather) ~200M objects (x2 observations) ~1800 square degrees
IPHAS EDR: Data Flow Raw data are processed at CASU through the standard pipeline: bias subtraction, linearity correction, flat fielding, gain correction, defringing, astrometry Band merged catalogues created with quality control information and object parameters
IPHAS EDR: Contents Images: photometrically and astrometrically calibrated images in the three survey bands Catalogues: band merged catalogues with image derived objects parameters and data quality control information
IPHAS EDR: Images Astrometry good to 0.1” (internal). Based on 2MASS. Photometry done using standard stars obtained during observations. No global photometric calibration yet.
IPHAS EDR: Catalogues Band merged catalogues with object parameters: Position, aperture corrected magnitudes Star/Galaxy Classification, Ellipticity Data Quality Control parameters: Seeing, magnitude limits, ZPs Sky brightness
“Loading the data is the weakest link in archive publishing. It is the most error- prone and time consuming yet least planned and budgeted part of archive operations.” Ani Thakar (JHU) Alex Szalay (JHU) Jim Gray (Microsoft Research) Maria Nieto (JHU)
Catalogues... Objects Position Aperture Magnitudes Star/Galaxy class Ellipticity, Pos angle Chip & Field provenance Flags
Catalogues DQC Mag ZP, mag limits Extinction, airmass Exposure time, date WCS Sky level, noise, seeing Number of objects
IPHAS EDR: Data Access Astrogrid provides... Images: Simple Image Access (SIA) Catalogues: Data Set Access (DSA)
IPHAS EDR: Data Access Simple web interface Graphical User Interface (AG Workbench) Programming Language
Access Method 1 Simple Web Interface
Access Method 2 Graphical User Interface -- See demo in Harrington Building Foyer --
Movie 1 Simple Cone Search
Movie 2 Advanced Query
Programming Language Access Method 3