Dear All,<br><div class="gmail_quote"><div><br></div><div>we performed a more detailed study of completeness/contamination of our KIDS catalogs by comparing</div><div>KIDS vs. CFHT photometry in the field of KIDS_135_-1.5.</div>
<div><br></div><div>Here it's the steps we followed:</div><div><br></div><div>1) We downloaded the last version of the images, that shouldn't be affected</div><div>by the satellite track issue we found in the previous version of the coadd's.</div>
<div> </div><div>1) We ran KIDSCAT on the r-band images, with 6 different setups, changing DETECTION_MINAREA</div><div>and DETECTION_THRESHOLD in the S-Ex .configuration file. We considered:</div><div>MINAREA: 3, 5</div>
<div>THRESHOLD: 1.5, 2.0, 2.5</div><div>Besides that, we also ran KIDSCAT on the g and i band images with MINAREA=3, and THRESHOLD=2.0, 2.5</div><div><br></div><div><br></div><div>2) The catalogs were matched to the CFHT ones (pls ask Mario for details)</div>
<div><br></div><div>3) The first attached plot, CFHT_KIDS_....._THRESHOLD.jpg, summarizes the completeness/contamination with different setups for the r-band coadd.</div>
<div>Top and bottom panels correspond to MINAREA=3 and 5, respectively.</div><div>For each panel, the solid curves plot the fraction of spurious sources (i.e. objects with no matching to CFHT)</div><div>as a function of magnitude. We considered magnitudes in the same aperture of 5'' in both catalogs (KIDS and CFHT).</div>
<div>Curves with different colors correspond to different DETECTION_THRESHOLDs as labeled.</div><div>The completeness mags, for each THRESHOLD value (i.e. color), are marked with a vertical dashed line.</div><div>(Here completeness is defined as the mag value where CFHT counts keep increasing, while KIDS counts remain constant/decrease).</div>
<div><br></div><div>4) The second attached plot shows the spatial distribution of spurious sources in the area "previously" affected by the satellite track. </div><div><br></div><div>5) We would conclude as follows:</div>
<div> A) for THRESHOLD=1.5 contamination increases significantly, up to ~20-22% around the completeness mag</div><div> B) completeness improves by ~0.15-0.2mag when moving from THRESHOLD 2.5 to 2.0, and by the same amount from 2.0 to 1.5.</div>
<div> C) changing MINAREA to 5 we get slightly lower completeness (by~0.1-0.15mag), and slightly lower contamination (by a few percent)</div><div> D) the satellite track issue is still there</div><div><br></div><div>Depending on what is the maximum level of contamination we can allow in the catalogs, we think we might adopt either THRESHOLD=2.5 (current value)</div>
<div>or THRESHOLD=2.0, as in the latter value we get slightly better completeness, at the price of a bit worst contamination. </div><div>Notice that the contamination fractions are indeed upper limits (see our previous email on the subject), as there are many sources</div>
<div>not present in the CFHT catalogs because of (e.g.) deblending issues. </div><div><br></div><div>Finally, the last attached plot, CFHT_KIDS_COMPLETENESS_CONTAMINATION_THRESHOLD_g_i_bands.jpg, shows completeness and contamination</div>
<div>for g band (upper panel) and i band (lower panel), both for MINAREA=3. Resuts are similar to those for r band. </div><div><br></div><div>Eagerly waiting for your feedback, so that we can finalize the S-Ex configuration file.</div>
<div><br></div><div>Cheers,</div><div>Francesco, Nicola, Mario</div><div><br>
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