METHOD
A large sample of SDSS quasars were extracted from the 2010 catalogue compiled by Veron. The astrometric data was then used as an input file for the WISE database. As can be seen the colour-colour diagram for the quasars is very different from that for a random selection of entries in the WISE database.
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The average distance between the positional data for the quasars extracted from Veron and that for the matching 2MASS entry (this is included in the WISE results) was 0.46 arcsec (SD 0.37). However the average distance between the positional data extracted from Veron and that for the matching WISE entry was 0.81 arcsec (SD 0.39).
Only one quasar - corresponding to WISE J104423.03+805439.5 at right ascension 161.0959778 degrees and declination +80.9109726 degrees - showed significant variation in brightness in any of the four infra red bands covered by WISE. This is a well known object, a Blazar, with over 100 references in Simbad!
Over the last few years I have carried out many astronomical data mining or data analysis projects. Most remain unpublished and this series of papers aims to put them all into the public domain. I welcome constructive feedback from readers and encourage colleagues to take the work forward, perhaps as far as peer reviewed publication. I can be contacted by email. and this address is monitored daily.
Martin Piers Nicholson - Shropshire, United Kingdom.
This page was last updated on July 26th 2011.