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trunk/doc/release.2015/systematics.20140411/diffusion.tex
r40311 r40321 14 14 % \RequirePackage{code} 15 15 % \RequirePackage{pbox} 16 \input{magnier.tex} 16 % \input{magnier.tex} 17 \input{astro.sty} 17 18 18 19 %\newcommand\oldtext[1]{\color{red}#1} … … 32 33 %\def\plotmode{bw} 33 34 34 %\def\plotext{pdf}35 \def\plotext{eps}35 \def\plotext{pdf} 36 %\def\plotext{eps} 36 37 37 38 %\def\picdir{/home/eugene/chipresid.20140404} 38 39 %\def\picdir{/data/kukui.2/eugene/chipresid.20140404} 39 %\def\picdir{pics} %%% need to set this for local processing40 \def\picdir{.} %%% need to set this for the zip archive40 \def\picdir{pics} %%% need to set this for local processing 41 %\def\picdir{.} %%% need to set this for the zip archive 41 42 42 43 % Pick a terse version of the title here; … … 467 468 the median deviation for measurements at the given chip pixel 468 469 location compared with the average photometry for the given 469 object. Fringing dominates the \yps-band signal, saturating the 470 color scale to black or white in areas.} \label{fig:psfmags.by.filter}} 470 object. Fringing dominates the \yps-band signal.} \label{fig:psfmags.by.filter}} 471 471 \end{center} 472 472 \end{figure*} … … 575 575 \oldtext{The per-pixel standard deviations of these plots are listed 576 576 in Table~1.} The signal-to-noise of these structures is again 577 somewhat weak, but the pattern is clearly visible in \oldtext{these figures} \newtext{Figure~\ref{fig:all.effects.rband} (middle-left)}. 577 somewhat weak, but the pattern is clearly visible in \oldtext{these 578 figures} \newtext{Figure~\ref{fig:all.effects.rband} (middle-left)}. 578 579 579 580 \subsection{Flat-field Structures} 581 \label{sec:flat-fields} 580 582 581 583 % All Effects in r-band … … 613 615 614 616 % 2012ApJ...750...99T = Tonry et al PS1 phot system 615 \oldtext{Figure~4} \newtext{Figure~\ref{fig:all.effects.rband} (middle-right)} 616 shows the high-spatial-frequency 617 structures in the \newtext{\rps-band} flat-field\oldtext{ images}. For this measurement, we have 618 used a set of monochromatic flat-field images obtained with a tunable 619 laser. The laser is used to illuminate our flat-field screen which is 620 then observed by the PS1 telescope. These flat-field images were 621 obtained 2011 Feb 09 as part of a campaign to study the PS1 system 622 response \citep{2012ApJ...750...99T}. Flats were obtain in a set of 623 4nm steps sampling the spectral response curve of each filter. To 624 enhance the signal-to-noise, we have median-combined a set of 6 flats 625 at the wavelength center of the corresponding filter. 617 \oldtext{Figure~4} \newtext{Figure~\ref{fig:all.effects.rband} 618 (middle-right)} shows the high-spatial-frequency structures in the 619 \newtext{\rps-band} flat-field\oldtext{ images}. For this 620 measurement, we have used a set of monochromatic flat-field images 621 obtained with a tunable laser. The laser is used to illuminate our 622 flat-field screen which is then observed by the PS1 telescope. These 623 flat-field images were obtained 2011 Feb 09 as part of a campaign to 624 study the PS1 system response \citep{2012ApJ...750...99T}. Flats were 625 obtain in a set of 4nm steps sampling the spectral response curve of 626 each filter. To enhance the signal-to-noise, we have median-combined 627 a set of 6 flats at the wavelength center of the corresponding filter. 628 \newtext{Note that the flat-field images used for the science analysis 629 are made from broad-band dome flat, not these monochromatic flats. 630 The monochromatic flats were used here to avoid smearing out any 631 effects which changed as a function of wavelength.} 626 632 627 633 In order to mask pixels which do not flatten well, we generate a copy … … 632 638 pixels associated with each superpixel. 633 639 634 \oldtext{Figure~\ref{fig:flats.by.filter} shows the superpixel images for the 635 flat-fields in the five filters. These flat-field images are} \newtext{The flat-field image is} 636 displayed as fractional deviations relative to the median of the flat-field 637 image and can thus be compared to the magnitude residuals. When 638 flattening an image, \oldtext{these flat-fields} \newtext{the flat-field image} would be divided into the flux 639 of the raw image. The residuals are thus defined in the sense that a 640 positive feature in \oldtext{these flats} \newtext{the flat} which does {\em not} represent a real 641 quantum efficiency deviation would induce a {\em reduction} in the 642 measured flux in those pixels, and thus a {\em negative} deviation in 643 $\delta m_{psf}$ as defined above. The dynamic range of the color 644 scale in \oldtext{these plots} \newtext{this plot} is -0.01 to +0.01. The tree-ring pattern is 645 strong in the (\gps,\rps,\ips) images, but nearly swamped by fringing 646 in \zps, and completely lost to fringing in \yps. A diagonal banding 647 pattern is also seen in \gps\ and \rps: this feature is thought to be due to 648 the lithography process used to generate the CCD. A blob can also 640 \oldtext{Figure~\ref{fig:flats.by.filter} shows the superpixel images 641 for the flat-fields in the five filters. These flat-field images 642 are} \newtext{The flat-field image is} displayed as fractional 643 deviations relative to the median of the flat-field image and can thus 644 be compared to the magnitude residuals. When flattening an image, 645 \oldtext{these flat-fields} \newtext{the flat-field image} would be 646 divided into the flux of the raw image. The residuals are thus 647 defined in the sense that a positive feature in \oldtext{these flats} 648 \newtext{the flat} which does {\em not} represent a real quantum 649 efficiency deviation would induce a {\em reduction} in the measured 650 flux in those pixels, and thus a {\em negative} deviation in $\delta 651 m_{psf}$ as defined above. The dynamic range of the color scale in 652 \oldtext{these plots} \newtext{this plot} is -0.01 to +0.01. The 653 tree-ring pattern is strong in the (\gps,\rps,\ips) images, but nearly 654 swamped by fringing in \zps, and completely lost to fringing in \yps. 655 \newtext{For the broad-band dome flats used for the science analysis, 656 the tree-ring patterns are apparent for all filters: the fringe 657 patterns seen in the \zps\ and \yps\ monochromatic flats are 658 apparently washed out by the range of wavelengths in the broad-band 659 flats.} 660 661 A diagonal banding pattern is also apparent in \gps\ and \rps, though 662 it is largely removed in Figure~\ref{fig:all.effects.rband} by the 663 high-pass filtering mentioned above. This feature is thought to be due 664 to the lithography process used to generate the CCD. A blob can also 649 665 been seen covering 4 cells near the center of this chip; this is 650 666 apparently a deposit of some kind on the detector. Both of the latter … … 738 754 PSF ellipticity from the $e_1$ term. 739 755 740 \oldtext{Figure~5} \newtext{Figure~\ref{fig:all.effects.rband} (lower-left)} 741 shows the spatial trend of the smear, 742 $e_0$. The dynamic range of \oldtext{these images} \newtext{this image} is -0.3 to +0.3 pixel$^2$. A 743 tree-ring pattern is visible for all 5 filters, though \yps\ is 744 dominated by the fringing pattern. Structures with relatively low 745 spatial frequencies can also be seen. 756 \oldtext{Figure~5} \newtext{Figure~\ref{fig:all.effects.rband} 757 (lower-left)} shows the spatial trend of the smear, $e_0$. The 758 dynamic range of \oldtext{these images} \newtext{this image} is -0.3 759 to +0.3 pixel$^2$. A tree-ring pattern is visible for all 5 filters, 760 though \yps\ is dominated by the fringing pattern. Structures with 761 relatively low spatial frequencies can also be seen. 762 763 % All Effects in r-band 764 \begin{figure*}[htbp] 765 \begin{center} 766 \parbox[b]{\figwidth}{\includegraphics[width=5.0in]{\picdir/filter_trends.\plotext}} 767 \caption{Amplitude of the 4 effects which follow the tree-rings as a 768 function of filter, relative to the amplitude in the \gps-band.} 769 \label{fig:filter.trend} 770 \end{center} 771 \end{figure*} 746 772 747 773 \oldtext{Figure~6} \newtext{Figure~\ref{fig:all.effects.rband} (lower-right)} … … 756 782 variations are low-frequency and unrelated to the radial trend from 757 783 the upper-left corner. 758 759 % All Effects in r-band760 \begin{figure*}[htbp]761 \begin{center}762 \parbox[b]{\figwidth}{\includegraphics[width=5.0in]{\picdir/filter_trends.\plotext}}763 \caption{Amplitude of the 4 effects which follow the tree-rings as a764 function of filter, relative to the amplitude in the \gps-band.}765 \label{fig:filter.trend}766 \end{center}767 \end{figure*}768 784 769 785 \subsection{Correlations Between Tree-Ring Patterns} … … 831 847 For all four types of measurements, the \oldtext{slope of the fitted 832 848 lines} \newtext{amplitudes relative to \gps} are \oldtext{listed in 833 Table~2} \newtext{plotted in Figure~\ref{fig:filter.trend}}. There is a consistency in 834 the trend from \gps, with the strongest systematic tree-ring effects 835 to \yps, with the weakest effects. Note that the second moment smear 836 and astrometry terms have different relative strength in 837 \yps\ compared with \gps. 849 Table~2} \newtext{plotted in Figure~\ref{fig:filter.trend}}. There 850 is a consistency in the trend from \gps, with the strongest systematic 851 tree-ring effects, to \yps, with the weakest effects. Note that the 852 relative strength of the second moment smear in the reddest bands 853 compared to \gps\ is quite different from the relative strength of the 854 astrometry and flat-field terms in the reddest bands. 838 855 839 856 % smear trends by filter … … 1193 1210 % http://adsabs.harvard.edu/abs/2006NIMPA.568...41K 1194 1211 1212 The origin of the fringing patterns observed in the \yps\ PSF and 1213 aperture photometry is uncertain. The photometry fringe patterns are 1214 similar to the fringe patterns seen in the monochromatic flat-fields. 1215 However, since the broad-band flat-field images actually used for the 1216 science do not exhibit the fringes, the photometry fringes are not 1217 simply the result of having an inappropriate fringe term in the 1218 flat-field images. One possible cause could be the interaction 1219 between spectral features in the (largely M and K) stars used for the 1220 photometry analysis interacting with the fringe effect -- in other 1221 words, a flat-field image generated with a uniform spectral density 1222 source may not be exactly right for sources with strong spectral 1223 features. However, this explanation is clearly incomplete since it 1224 does not explain the difference in the amplitude of the fringes seen 1225 in the PSF vs the aperture photometry. In any case, the presence of 1226 the fringe pattern does not affect our conclusions regarding the 1227 charge diffusion effect. 1228 1195 1229 \section{Conclusion} 1196 1230 … … 1288 1322 1289 1323 \bibliographystyle{apj} 1290 %\bibliography{lib}{}1324 \bibliography{lib}{} 1291 1325 %\input{diffusion.bbl} 1292 \input{magnier_bib.tex}1326 %\input{magnier_bib.tex} 1293 1327 1294 1328 \end{document}
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