Color Correction to 353 GHz Templates

[brandonshensley]

Based on the slides emailed on Oct. 19, @delabrou recommends we, "[m]ultiply dust template maps by 0.92 to get a template at 353 GHz rather than integrated in the Planck 353 GHz band." Note that a similar color correction factor appears in Planck 2018 XI, Table 2 as 1/1.098 = 0.911. I suggest we use this value so that we can cite the Planck table. @giuspugl

[delabrou]

Yes, let's use the published value. Jacques

On 1 Dec 2021, at 15:02, brandonshensley @.***> wrote:

Based on the slides emailed on Oct. 19, @delabrou https://github.com/delabrou recommends we, "[m]ultiply dust template maps by 0.92 to get a template at 353 GHz rather than integrated in the Planck 353 GHz band." Note that a similar color correction factor appears in Planck 2018 XI https://www.aanda.org/articles/aa/pdf/2020/09/aa32618-18.pdf, Table 2 as 1/1.098 = 0.911. I suggest we use this value so that we can cite the Planck table. @giuspugl https://github.com/giuspugl — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/galsci/pysm/issues/99, or unsubscribe https://github.com/notifications/unsubscribe-auth/ACXLM5LGDLJLFLEKRS3F72LUO2SPXANCNFSM5JFV2OYQ. Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[zonca]

Added to the notebook that generates the templates.

[zonca]

I just added this to the docs.

@giuspugl @brandonshensley @delabrou there is no equivalent color correction for synchrotron, right?

[brandonshensley]

I'm not aware of anything that discusses this. In principle there should be the same issue, but it may be that the corrections are small for a standard synchrotron spectrum. For dust, it's really only 353 GHz that has a significant color correction factor. Maybe @delabrou or @NicolettaK has more info?

[delabrou]

A color correction factor should be applied also for synchrotron if the reference is obtained from a non-monochromatic band. However, at this point the synchrotron model is less constrained that that of the dust: in intensity there is considerable uncertainty because the WMAP and LFI observations are a mix of synchrotron, free-free and spinning dust. In polarization the observations are noisy, in particular in high-latitude regions. I have noticed inconsistencies in the synchrotron cross-calibration between various observations and in data products, which trace uncertainties in the spectral index, the band shapes of the instrumnets, or both. I am working on a new synchrotron template that will try to fix the issue (as much as possible). I can discuss it in a future PanEx foregrounds telecon.

On 21 Jun 2022, at 11:23, brandonshensley @.***> wrote:

I'm not aware of anything that discusses this. In principle there should be the same issue, but it may be that the corrections are small for a standard synchrotron spectrum. For dust, it's really only 353 GHz that has a significant color correction factor. Maybe @delabrou https://github.com/delabrou or @NicolettaK https://github.com/NicolettaK has more info?

— Reply to this email directly, view it on GitHub https://github.com/galsci/pysm/issues/99#issuecomment-1162153607, or unsubscribe https://github.com/notifications/unsubscribe-auth/ACXLM5MG2YE7NX3ZEQI5QEDVQICCRANCNFSM5JFV2OYQ. You are receiving this because you were mentioned.

[zonca]

@delabrou @NicolettaK @brandonshensley I think we need to clarify the issue of calibration of the Synchrotron templates in the next couple of weeks, before proceeding to running large simulations for Simons Observatory. Anyone has suggestions?