Source Measurement (PyBDSM) • Designed by EoR group (Niruj Mohan Ramanujam), for an accurate detection of extended emission • Get rid of all foreground signal • Python Source Extractor (PySE) • Designed by Transient group (Hanno Spreeuw) to be sensitive to point- like sources • Detect radio transient
the image 2. Fit the RMS noise across the image 3. Identify islands of contiguous pixels which appear above some multiple of the RMS 4. “Deblend” multi-component islands into the constituent parts 5. Perform initial estimation of source parameters 6. Fit each component with an elliptical Gaussian and return the result
100 square degree including no bright, complicated sources and distant from A-team sources. • Coordinates of the center: RA = 15 h; dec = +69 deg Heald et al., in prep. Dario Carbone
image. • Run PyBDSM and PySE separately on each band and then combine the results. • For each sourcefinder, the detected sources are associated across the bands using the nearest neighbor criterion. • Catalogues from PyBDSM and PySE are then cross- matched. • Positions and fluxes are taken from PyBDSM outputs (if available). Dario Carbone
• deblending turned on • deblending threshold = 90 • detection threshold = 10 σ • analysis threshold = 5 σ • Force-beam option turned on Parameter settings based on real maps and simulations and the requirement to be conservative for this first catalogue. Dario Carbone
of interest. • We compared HBA MSSS catalogue to the 7C survey @ 151 MHz. • We compared LBA MSSS catalogue to the VLSS @ 74 MHz and the 8C catalogue @ 38 MHz. Heald et al., in prep. Dario Carbone
as Jhhmmss+ddmmss using the IAU convention. • RA & eRA; Source J2000 Right Ascension, in decimal degrees & error on Right Ascension, in seconds of time. • DEC & eDEC; Source J2000 Declination, in decimal degrees & error Declination, in arcseconds. • SFFLAG000; Flag indicating how many sourcefinders detected the source (0 means it was detected in both; 1 only in PyBDSM; 2 only in PYSE.) • Sint000 & eSint000; Source integrated flux at 000 MHz, in Jy & error on integrated flux, in Jy. • Spk000 & eSpk000; Source peak flux at 000 MHz, in Jy & error on peak flux, in Jy. • SLBA & eSLBA; LBA flux density (from combined map). Effective frequency is 000 MHz & error on LBA flux density. • SHBA & eSHBA; HBA flux density (from combined map). Effective frequency is 000 MHz & error on HBA flux density. • SPIX & eSPIX; Spectral index & error on spectral index. • SCURV & eSCURV; Spectral curvature & error on spectral curvature. • MAJAX000 & eMAJAX000; Major axis of fitted ellipse at 000 MHz & error on major axis. • MINAX000 & eMINAX000; Minor axis of fitted ellipse at 000 MHz & error on minor axis. • PA000 & ePA000; Position angle of fitted ellipse at 000 MHz, in degrees & error on position angle. Dario Carbone
as Jhhmmss+ddmmss using the IAU convention. • RA & eRA; Source J2000 Right Ascension, in decimal degrees & error on Right Ascension, in seconds of time. • DEC & eDEC; Source J2000 Declination, in decimal degrees & error Declination, in arcseconds. • SFFLAG000; Flag indicating how many sourcefinders detected the source (0 means it was detected in both; 1 only in PyBDSM; 2 only in PYSE.) • Sint000 & eSint000; Source integrated flux at 000 MHz, in Jy & error on integrated flux, in Jy. • Spk000 & eSpk000; Source peak flux at 000 MHz, in Jy & error on peak flux, in Jy. • SLBA & eSLBA; LBA flux density (from combined map). Effective frequency is 000 MHz & error on LBA flux density. • SHBA & eSHBA; HBA flux density (from combined map). Effective frequency is 000 MHz & error on HBA flux density. • SPIX & eSPIX; Spectral index & error on spectral index. • SCURV & eSCURV; Spectral curvature & error on spectral curvature. • MAJAX000 & eMAJAX000; Major axis of fitted ellipse at 000 MHz & error on major axis. • MINAX000 & eMINAX000; Minor axis of fitted ellipse at 000 MHz & error on minor axis. • PA000 & ePA000; Position angle of fitted ellipse at 000 MHz, in degrees & error on position angle. This catalogue has 93 columns for the point sources, and 93 + 96 = 189 columns for extended sources!
MSSS is ready to be released. • This will contain a lot of data on several hundreds of sources. • Compared to other existing surveys at similar frequencies MSSS is behaving as expected. • Sourcefinding was done following a slightly more conservative approach than usual. • PySE is behaving very well on the Data Challenge maps as completeness, reliability, and flux recovery. • The force-beam option should be turned on as we are looking for point sources only.