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-374 DRP 2-D Pipeline <p>Following <a href="https://pfspipe.ipmu.jp/jira/browse/PIPE2D-367" title="Derive P(Teff, log g, Z) from model templates" class="issue-link" data-issue-key="PIPE2D-367">PIPE2D-367</a>, write code to combine the P_HSC(Teff, log g, Z) and P_PFS(Teff, log g, Z) probabilities in order to construct the best fit spectrum. </p> PIPE2D-374

Combine P_HSC and P_PFS and construct the best-fit spectrum

Task Normal Done Done Takuji Yamashita hassan flux-calibration model-spectra-fitting Tue, 19 Feb 2019 21:01:40 +0000 Wed, 7 Jul 2021 05:06:00 +0000 Tue, 6 Jul 2021 04:49:39 +0000 0 4 <p>I combined two probability distribution functions from broad-band fitting (<a href="https://pfspipe.ipmu.jp/jira/browse/PIPE2D-539" title="Stellar typing with HSC broad-band data" class="issue-link" data-issue-key="PIPE2D-539"><del>PIPE2D-539</del></a>) and chi-square fitting of spectra (<a href="https://pfspipe.ipmu.jp/jira/browse/PIPE2D-835" title="Spectral fitting of ETC simulator spectra for flux calibration" class="issue-link" data-issue-key="PIPE2D-835"><del>PIPE2D-835</del></a>) to find the best fit model template of a flux standard. The combination of two PDFs is a one-to-one merge.<br/>  <br/> The following figures are the results of the simulated spectra with ETC and the HSC 5-bands photometry with S/N=100. The input stellar parameters of the ETC simulation are Teff = 7000 K, log(g/(cm/s^2)) = 4.5, Z = 0, and <span class="error">&#91;a/Fe&#93;</span> = 0.0.<br/>  <br/> A combined PDF of an r = 13 AB mag case, the PDF of the broad-band fitting, and the spectral fitting, from the top, respectively.</p> <p><span class="image-wrap" style=""><a id="13889_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13889/13889_BBP_p7000_g%2B4.5_m0.0_t01_z%2B0.00_a%2B0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Cont.png" title="BBP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Cont.png" file-preview-type="image" file-preview-id="13889" file-preview-title="BBP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Cont.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13892/_thumb_13892.png" style="border: 0px solid black" /></a></span><br/> <span class="image-wrap" style=""><a id="13889_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13889/13889_BBP_p7000_g%2B4.5_m0.0_t01_z%2B0.00_a%2B0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Cont.png" title="BBP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Cont.png" file-preview-type="image" file-preview-id="13889" file-preview-title="BBP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Cont.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13889/_thumb_13889.png" style="border: 0px solid black" /></a></span></p> <p><span class="image-wrap" style=""><a id="13890_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13890/13890_SFP_p7000_g%2B4.5_m0.0_t01_z%2B0.00_a%2B0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Cont.png" title="SFP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Cont.png" file-preview-type="image" file-preview-id="13890" file-preview-title="SFP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Cont.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13890/_thumb_13890.png" style="border: 0px solid black" /></a></span></p> <p> </p> <p>The input spectrum (ETC) and the best-fit spectrum. </p> <p><span class="image-wrap" style=""><a id="13893_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13893/13893_CombinedP_p7000_g%2B4.5_m0.0_t01_z%2B0.00_a%2B0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Spec.png" title="CombinedP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Spec.png" file-preview-type="image" file-preview-id="13893" file-preview-title="CombinedP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.Spec.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13893/_thumb_13893.png" style="border: 0px solid black" /></a></span></p> <p> <br/> A ratio of the best-fit spectrum to the input. There is a large deviation at a short wavelength of &lt; 430 nm. This could be from small differences of Teff and log(g).<br/> <span class="image-wrap" style=""><a id="13894_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13894/13894_CombinedP_p7000_g%2B4.5_m0.0_t01_z%2B0.00_a%2B0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.SpecRatio.png" title="CombinedP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.SpecRatio.png" file-preview-type="image" file-preview-id="13894" file-preview-title="CombinedP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r13.0.txt.expt450s.SpecRatio.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13894/_thumb_13894.png" style="border: 0px solid black" /></a></span></p> <p>These figures are the case of r = 19 mag. <br/> The simulated spectrum is noisier, and therefore the constraint from spectral fitting is weak. As a result, the combined PDF is dominated by the broad-band fitting. </p> <p>A combined PDF.<br/> <span class="image-wrap" style=""><a id="13895_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13895/13895_CombinedP_p7000_g%2B4.5_m0.0_t01_z%2B0.00_a%2B0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png" title="CombinedP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png" file-preview-type="image" file-preview-id="13895" file-preview-title="CombinedP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13895/_thumb_13895.png" style="border: 0px solid black" /></a></span></p> <p>Broad-band fitting PDF.<br/> <span class="image-wrap" style=""><a id="13895_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13895/13895_CombinedP_p7000_g%2B4.5_m0.0_t01_z%2B0.00_a%2B0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png" title="CombinedP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png" file-preview-type="image" file-preview-id="13895" file-preview-title="CombinedP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13896/_thumb_13896.png" style="border: 0px solid black" /></a></span> </p> <p>Spectral fitting PDF.<br/> <span class="image-wrap" style=""><a id="13896_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13896/13896_BBP_p7000_g%2B4.5_m0.0_t01_z%2B0.00_a%2B0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png" title="BBP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png" file-preview-type="image" file-preview-id="13896" file-preview-title="BBP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13897/_thumb_13897.png" style="border: 0px solid black" /></a></span> </p> <p>The best-fit spectrum and the input spectrum.<br/> <span class="image-wrap" style=""><a id="13897_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13897/13897_SFP_p7000_g%2B4.5_m0.0_t01_z%2B0.00_a%2B0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png" title="SFP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png" file-preview-type="image" file-preview-id="13897" file-preview-title="SFP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Cont.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13898/_thumb_13898.png" style="border: 0px solid black" /></a></span> </p> <p>The flux ratio of the best-fit to the input.<br/> <span class="image-wrap" style=""><a id="13898_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13898/13898_CombinedP_p7000_g%2B4.5_m0.0_t01_z%2B0.00_a%2B0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Spec.png" title="CombinedP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Spec.png" file-preview-type="image" file-preview-id="13898" file-preview-title="CombinedP_p7000_g+4.5_m0.0_t01_z+0.00_a+0.00.AMBRE_Extp.ABmag_r19.0.txt.expt450s.Spec.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13899/_thumb_13899.png" style="border: 0px solid black" /></a></span> </p> <p>This is the fitting accuracy as a function of the magnitude. The y-axis is the median absolute deviation of the flux ratio of the best-fit to the input. </p> <p> <span class="image-wrap" style=""><a id="13929_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13929/13929_mad_rmag_wlimit.png" title="mad_rmag_wlimit.png" file-preview-type="image" file-preview-id="13929" file-preview-title="mad_rmag_wlimit.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13900/_thumb_13900.png" style="border: 0px solid black" /></a></span> </p> <p>The measured dispersions in the flux ratio of the best-fit spectrum to the simulation spectrum are dominated by the noise in the simulation spectra. I add the dispersion only from the noise in a spectrum in the above figure (open red circles). The measured dispersions are close to the noise dispersions.<br/> <span class="image-wrap" style=""><a id="13900_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13900/13900_mad_rmag.png" title="mad_rmag.png" file-preview-type="image" file-preview-id="13900" file-preview-title="mad_rmag.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13929/_thumb_13929.png" style="border: 0px solid black" /></a></span></p> <p>In the three arms, the blue arm has an offset from the noise dispersions. This is due to a mismatch of the best-fit model to the simulation in the blue arm. We should improve this. <br/> <span class="image-wrap" style=""><a id="13929_thumb" href="https://pfspipe.ipmu.jp/jira/secure/attachment/13929/13929_mad_rmag_wlimit.png" title="mad_rmag_wlimit.png" file-preview-type="image" file-preview-id="13929" file-preview-title="mad_rmag_wlimit.png"><img src="https://pfspipe.ipmu.jp/jira/secure/thumbnail/13930/_thumb_13930.png" style="border: 0px solid black" /></a></span><br/>  <br/> The flux ratios of the best-fit and the simulation are small compared with the noise in the spectra in this test case. We should check other cases to see the fitting goodness.</p> <p>The above test shows that the fitting accuracy is about 10% for 19 magnitude stars. Although this is higher than the 1% accuracy we are aiming at, we think we can improve it by the following approaches. </p> <p>1. Because we will have several tens of standard stars in an FoV, we can statistically reduce the accuracy by combining all the standards. </p> <p>2. The dispersion of the flux ratio is dominated by the noise in the simulated spectrum. Because we expect that a flux calibration vector is smooth along the wavelength, we can fit it with a function and reduce the dispersions. </p> <p>These works to improve the fitting accuracy will be addressed during the implementation phase. </p> <p>You can't assume that the flux calibration vector is completely smooth in wavelength: it should include the atmospheric absorption bands.</p> <p>Yes. Please let me make a few corrections and add some words. The flux calibration vector includes both a smooth component and a non-smooth one.</p> <p>Although this idea needs further investigation and discussion, for example, we will fit the smooth component in the flux calibration vector with a function after masking the atmospheric absorption bands to separate the smooth component from the vector. We will use the averaged flux calibration vector with a high S/N over an FoV for this. The non-smooth component made up of the atmospheric absorption bands will be reproduced using a template or a model. By combining the fitted smooth component and the reproduced non-smooth one, we will get a more accurate flux calibration vector.</p> Blocks PIPE2D-837 PIPE2D-367 Development Rank 0|02qpth: Reviewers hassan Story Points 3.0