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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, fourth, and fifth plots show the PS1, SDSS, and SNLS surveys separately. There are 20 bins of equal redshift size.
- The fourth plot shows only the PS1 surveysixth, seventh, and eighth plots show the PS1, SDSS, and SNLS surveys separately. 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
- In each plot, the upper panel shows the unbinned data and the lower panel shows the binned data
- binning scheme is 20 bins of equal redshift space, determined for each survey individually
- so in a field with multiple surveys, the bins for each survey are different and likely do not cover the whole displayed z-range; only the range covered by the survey in question
- binning scheme is 20 bins of equal redshift space, determined for each survey individually
- Qualitatively, I notice the following:
- In some of the fields (particularly 0, 1, 5, 8, and 9 most obviously), the PS1 data does appear to have a visible dip in residual around z~0.3
- In other fields (particular 2, 3 and maybe 4) there seems to be a slight 'hole' in the observed SN around this value
- In the remaining fields (6 and 7) I'd say one could try to convince oneself that the dip is there, but only after one knows to look for it (informed by the other fields).
- When the data is broken up like this, it's hard to say if there is evidence for other dips (like those marginally seen in the aggregated PS1MD SN above)
- Unfortunately, the other surveys with numerous SN that overlap on the sky with the PS1MD fields don't sample this z value very efficiently
- SNLS generally has higher z SN. In the 3 frames with both PS1MD and SNLS observations (0, 3, and 6), by eye
- frame 0 may show evidence that the SNLS data also have a dip around z ~ 0.3
- frame 3 seems to have a hole around z~0.3 (and maybe a smaller one around z ~ 0.8)
- frame 6 don't seem to have much of a drop in the SNLS residuals around z ~ 0.3
- Note that all of those behaviors (a dip in 0, a hole in 3 and relative flatness in 6) are similar to the behaviors of the PS1MD residuals in their respective frames (stressing again, that all of these observations are qualitative, 'by eye', notes)
- In the frames with both PS1MD and SDSS SN (8 and 9), the SDSS SN either don't go to high enough redshift (field 8) or are too few in number (field 9) to allow an effective sampling of the z value of interest
- By constraining ourselves to only the PS1MD fields, we are ignoring a lot of the SDSS SN. Perhaps we could now do something similar for the SDSS fields...
- SNLS generally has higher z SN. In the 3 frames with both PS1MD and SNLS observations (0, 3, and 6), by eye
- I attempted to fit some single mode gaussians to the data. The results of these fits are shown on the fit page.
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