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Tales of Cataloguing XIII -- the first Hazard
On the way to building the Million Quasar catalogue, I had the good
fortune of email exchanges with Cyril Hazard, a giant of the early quasar discovery days in the 60's-70's. Building on that, in the 1980's Hazard discovered a large set of quasars on objective prism plates from the UK Schmidt telescope. He didn't publish them but lent them to other researchers in the 1980's -- in that time it was common to withhold the precise location of the quasars so that they could be re-used in a proprietary fashion. Accordingly, many of Hazard's quasars were never published, but he allowed publication of 92 of them in my Half Million Quasars catalogue published as 2015 PASA 32 10. But Cyril didn't give out all his quasars to me. One he did not, or would not, share was "Q 0440-168", used by multiple papers in the 1980's. The contemporary quasar catalogues (Hewitt & Burbidge and Veron-Cetty & Veron) had no better position than its name -- that it was located in the rectangle of sky denoted by "0440-168", i.e. bounded by the points (B1950) 04h40m00s-16d48m00s (inclusive) and 04h41m00-16d54m00s (exclusive) -- the last digit of the name representing tenths of a degree. In our discussions, Cyril commented about this quasar: "I have the original finding chart in front of me now. In this, my first survey, it is numbered in my system as 0440-1 so clearly one of the more interesting objects on the plate." So I knew from Cyril's comment that this is a big bright quasar. But I could never find it in my own data. The best I could do was to publish it as an R=18.2 B=18.7 optical-only object at (J2000) 04 43 03.4 -16 43 55. I thought it should be brighter, and the location is slightly outside the B1950 rectangle.. My friends, the mystery is now solved -- I have found this object. NVSS pointed the way. I had no useful radio/X-ray association in this place, but when I looked up the NVSS finding chart I found one bold NVSS source there -- just one, but one is all I needed. My automated software didn't link it to any object, but when I looked there using the PAN-STARRS finding chart, there it was, a big bold blue boy with PS magnitudes r=16.87 g=17.24 -- offset 9 arcsec from the nominal NVSS centroid which is why my software missed it. That's the problem with automated processes, they're stupid, they only do what you tell them to do. This big boy is at (J2000) 04 42 40.30 -16 46 27.5 which in B1950 terms is 04 40 25.6 -16 52 05, so right in the designated box of sky. The reason I missed it before was because my optical data calls it "fuzzy in red" while I'd been looking only for stellar in both red & blue bands -- also I didn't have the NVSS guidance. But PAN-STARRS shows it is just stellar. These things happen with big data. Good to have finally found this. It is included in the latest edition of my Milliquas catalogue, just released today on https://heasarc.gsfc.nasa.gov/W3Brow...milliquas.html . I'll tell some more discovery stories shortly. Next one is about finding charts -- is it a quasar or is it a red dwarf? Coming. Eric Flesch 8-Jan-2019 |
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