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- Here is a plot of the residual vs redshift (no sky directional information considered).
- For all 4 plots:
- The top panel shows the residuals of all individual Sn from the surveys considered
- The bottom panel shows the average residual in twenty bins of either even size or that contain the same number of SN (up to +/- 1)
- The first plot shows all surveys. There are 20 bins of equal redshift size.
- The second plot shows all surveys. There are 20 bins that contain an equal number of SN.
- The third plot shows only the PS1 survey. There are 20 bins of equal redshift size.
- The fourth plot shows only the PS1 survey. There are 20 bins that contain an equal number of SN.
- For all 4 plots:
- Now, in order to avoid conflating signals in z with those in extinction, let's look at the above plots divided into the 10 PS1 fields
- In addition to PS1, the other two relatively large surveys we have data on are: SDSS and SNLS
- There are 2 fields that have overlap between PS1 and SDSS and 3 fields that have overlap between PS1 and SNLS (no overlap between SDSS and SNLS)
- Each plot represents one field (generally ~2x2 degrees or so), so extinction is (hopefully) relatively consistent across
- Here are two plot for the mu residuals vs extinction (E(B-V) as measured with Finkbeiner et al: https://arxiv.org/pdf/1507.01005.pdf). The distinct plots are similar to the residual v redshift plots above
- For all 4 plots:
- The top panel shows the residuals of all individual Sn from the surveys considered
- The bottom panel shows the average residual in twenty bins of either even size or that contain the same number of SN (up to +/- 1)
- The first plot shows all surveys. There are 20 bins of equal extinction size.
- The second plot shows all surveys. There are 20 bins that contain an equal number of SN.
- The third plot shows only the PS1 survey. There are 20 bins of equal extinction size.
- The fourth plot shows only the PS1 survey. There are 20 bins that contain an equal number of SN.
- For all 4 plots:
- Here is a plot for the mu residuals and the extinction (as measured with Finkbeiner et al: https://arxiv.org/pdf/1507.01005.pdf) on the sky.
- Each of the 10 PanStars1 fields are displayed twice:
- the top frame is the extinction (E(B-V))
- the bottom is the PS1 SN,
- Each point represents a single SN
- The points themselves are color-coded by normalized mu residual (ie, [mu residual] / [mu uncertainty])
- The right colorbar is for the extinction contour plots
- All extinction contour plots are on the same logarithmic scale
- The left colorbar is for the SN scatter plots
- All SN are on the same linear scale
- I am not completely happy with this plot, but I am not sure what the best way to improve it is
- Each of the 10 PanStars1 fields are displayed twice:
Here is a first-pass at a plot showing the residual as a value of extinction and redshift together (presently for the PS1 data only).
- The color describes the value of the residuals, divided by the errors
- Linear interpolating is used to determine the value between points (a cubic interpolation produced some anomalously 'hot' and 'cold' regions)
- The uneven sampling in the space makes the contour plot a bit of a mess
- Another possibility might be to apply some sort of 'smoothing' to determine the value between points
Some notes:
- Almost all of the 1d projected plots suggest that the residuals are systematically negative. Some quick calculations confirm this:
- For ALL the SN mu residuals:
- The raw mean is ~ - 0.059 (0.005)
- The weighted mean is ~ - 0.067 (0.004)
- For just the PS1 mu residuals:
- The raw mean is ~ -0.065 (0.009)
- The weighted mean is ~ -0.068 (0.009)
- For ALL the SN mu residuals:
- Fitting seems like a good next step. Probably start with polynomials.
- Could also be interesting to see if patterns identified in one survey are consistent across surveys (PS1 and SDSS probably best places to look)
- Almost all of the 1d projected plots suggest that the residuals are systematically negative. Some quick calculations confirm this:
CWS notes June 26 2017-
- Perhaps make a fit of residuals vs. extinction for PanSTARRS data? By eye it looks like there is a statistically significant non-zero coherent residual at low extinction values.
- A different binning scheme might be equal number of SNe per bin?
- Another interesting plot would be contour surface of residual vs extinction and redshift, both.
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