Papers reporting observations of this object include:
"The ROSAT all-sky survey bright source catalogue", Voges et al. (1999):
"SUMSS: a wide-field radio imaging survey of the southern sky - II. The source catalogue", Mauch et al. (2003):Voges et al. wrote:We present the ROSAT All-Sky Survey Bright Source Catalogue (RASS-BSC, revision 1RXS) derived from the all-sky survey performed during the first half year (1990/91) of the ROSAT mission. 18,811 sources are catalogued (i) down to a limiting ROSAT PSPC count-rate of 0.05 cts/s in the 0.1-2.4 keV energy band, (ii) with a detection likelihood of at least 15 and (iii) at least 15 source counts. The 18,811 sources underwent both an automatic validation and an interactive visual verification process in which for 94% of the sources the results of the standard processing were confirmed. The remaining 6% have been analyzed using interactive methods and these sources have been flagged. Flags are given for (i) nearby sources; (ii) sources with positional errors; (iii) extended sources; (iv) sources showing complex emission structures; and (v) sources which are missed by the standard analysis software. Broad band (0.1-2.4 keV) images are available for sources flagged by (ii), (iii) and (iv). For each source the ROSAT name, position in equatorial coordinates, positional error, source count-rate and error, background count-rate, exposure time, two hardness-ratios and errors, extent and likelihood of extent, likelihood of detection, and the source extraction radius are provided. At a brightness limit of 0.1 cts/s (8,547 sources) the catalogue represents a sky coverage of 92%. The RASS-BSC, the table of possible identification candidates, and the broad band images are available in electronic form (Voges et al. 1996a) via this http URL.
There are images of it obtained by Hubble's ACS, under proposal 11015 (also WFC2), and WFC3, under proposal 12326, and by FUSE, under proposal P214. There is also publicly available data on observations by IRAS, CGRO, ASCA, Einstein, 2MASS, ...Mauch et al. wrote:This paper is the second in a series describing the Sydney University Molonglo Sky Survey (SUMSS) being carried out at 843MHz with the Molonglo Observatory Synthesis Telescope (MOST). The survey will consist of ~590 4.3deg. x 4.3deg. mosaic images with 45"x45"cosec|dec.| resolution, and a source catalogue. In this paper we describe the initial release (version 1.0) of the source catalogue consisting of 107,765 radio sources made by fitting elliptical gaussians in 271 SUMSS mosaics to a limiting peak brightness of 6mJy/beam at dec.<=-50deg. and 10mJy/beam at dec.>-50deg.. The catalogue covers approximately 3500deg^2 of the southern sky with dec.<=-30deg., about 43 per cent of the total survey area. Positions in the catalogue are accurate to within 1"-2" for sources with peak brightness A>=20mJy/beam and are always better than 10". The internal flux density scale is accurate to within 3 per cent. Image artefacts have been classified using a decision tree, which correctly identifies and rejects spurious sources in over 96 per cent of cases. Analysis of the catalogue shows that it is highly uniform and is complete to 8mJy at dec.<=-50^deg. and 18mJy at dec.>-50deg.. In this release of the catalogue about 7000 sources are found in the overlap region with the NRAO VLA Sky Survey (NVSS) at 1.4GHz. We calculate a median spectral index of alpha=-0.83 between 1.4GHz and 843MHz. This version of the catalogue will be released via the World Wide Web with future updates as new mosaics are released.
I wonder how many of these sets of quantitative observations were analysed by Electric Universe proponents ... quantitatively?