https://pfspipe.ipmu.jp/jira This file is an XML representation of an issue en-us 8.3.4 803005 13-09-2019 https://pfspipe.ipmu.jp/jira/browse/PIPE2D-1336 DRP 2-D Pipeline <p>The flux calibration vectors for EDR2 are often jagged. I mistakenly thought that this was due to bad extraction before, but I confirmed that this is due to bad flux calibration vectors. An example spectrum is attached here. This is a flux-calibrated CALSPEC star. It is a very bright star and the S/N is supposed to be very high. The jagged spectrum is due to bad flux calibration. In each exposure, we have 40-100 FLUXSTD, each of which is slightly off from the fiber center (and the amount of offset is different from fiber to fiber). This results in flux cabration vectors with varying normalizations. When we combine them into the master flux calibration vector, the pipeline applies clipping at each wavelength, making the master vector look jagged. The solution is to normalize the flux calibration vectors to the best one (i.e., the one closest to the fiber center) before combining them into the master vector.</p> <p> </p> PIPE2D-1336

flux calibration vetor is jagged

Task Normal Done Done sogo.mineo Masayuki Tanaka EDR Thu, 30 Nov 2023 05:22:55 +0000 Fri, 1 Dec 2023 02:18:18 +0000 Fri, 1 Dec 2023 02:18:18 +0000 0 3 <p>Mineo-kun made a fix and I confirmed that improved the flux calibration vector. An example is here. The first figure is the problematic flux calibration vector and the 2nd one is after the fix. The improvement is obvious. The figure is missing the labels, but the horizontal axis is wavelength in nm, and the vertical axis is the e-/sec -&gt; nJy conversion factor.<br/> <span class="image-wrap" style=""><img src="https://pfspipe.ipmu.jp/jira/secure/attachment/16916/16916_image-2023-11-30-14-25-57-354.png" height="269" width="359" style="border: 0px solid black" /></span><span class="image-wrap" style=""><img src="https://pfspipe.ipmu.jp/jira/secure/attachment/16918/16918_image-2023-11-30-14-27-17-819.png" height="269" width="359" style="border: 0px solid black" /></span></p> <p>Could you review this PR?</p> <p>Why is the conversion factor negative for much of that plot? Are you plotting the logarithm?</p> <p>Yes, I took the logarithm on the vertical axis. I should have plotted the axis. Here are the revised ones:<br/> <span class="image-wrap" style=""><img src="https://pfspipe.ipmu.jp/jira/secure/attachment/16920/16920_image-2023-12-01-08-57-28-415.png" height="305" width="407" style="border: 0px solid black" /></span><span class="image-wrap" style=""><img src="https://pfspipe.ipmu.jp/jira/secure/attachment/16921/16921_image-2023-12-01-08-57-53-696.png" height="308" width="411" style="border: 0px solid black" /></span></p> <p>Merged to master. Thanks for the review.</p> Relates PIPE2D-1251 Development Epic Link PIPE2D-303 Rank 0|zzt0jz: Reviewers price