Sources too bright in DC-0 run Radio Galaxies component

[zonca]

My processing mask is already built using the raw point source map so residuals like this are unexpected. I looked at the input maps and that source is very hot, 5.9 K_CMB. The brightest radio source in the Planck 30GHz map is 0.018 K_CMB. Some of this is simply due to the difference in beam size but not 300X. Based on the FWMH, I would expect the source amplitude to scale by 20X.

Sources unexpectedly bright:

• RA=32.9deg, Dec=-50.6deg
• RA=58.8deg, Dec=-33.2deg
• RA=49.5deg, Dec=-51.9deg

[zonca]

my tests comparing PySM rg1 to Planck was instead fine: https://www.zonca.dev/posts/2022-12-01-radio-galaxies-websky-planck

Investigating

[zonca]

@keskitalo it seems to me that the brightest point source in planck is 0.2 K_CMB, while in DC_0 it is 5 K_CMB, that is a factor of 25 which is not unreasonable given the different beam width.

[zonca]

Notebook I used: https://gist.github.com/zonca/3e337715d9fc6d479ea12a4151860822

[zonca]

sorry, I was comparing a Planck galactic source with a Websky extragalactic source.

If I check the brightest source in Websky at 30 Ghz, it has a flux of 455 Jy, instead if I check in the Planck map, Cygnus A has a flux of 64 Jy.

It is about a factor of 7, it seems reasonable to me, but I would like a confirmation from @giuspugl or @xzackli!

In particular if I compare the catalog at 24.5 GHz (the closest to LFL1), I find that the brightest source is more than 600 Jy, then if I compare with the DC-0 input map, I approximately get the same flux, so I think the processing of the maps is correct, please double-check my notebook here:

https://gist.github.com/zonca/3d65698d73c175754895ee517892cad1

[zonca]

@keskitalo forgot to tag you above

[giuspugl]

i think what we're observing is kinda expected from the Websky models. There is no constrains in the Websky catalogs for the brightest sources to be consistent with what has been observed by Planck.
this is mainly due to the fact that we constructed the websky radio galaxies to be totally _unconstrained _ realizations and to match statistically the properties of radio galaxies (e.g. the number counts and the spectral index of the sources).
As expected there are few sources in the high flux bin and that might result in producing too bright sources, brighter than what we have anthropically observed (credits to @xzackli for this explanation) .
We can work out a hybrid model of rg employing constrained realizations, e.g. the brightest sources observed by Planck and at lower fluxes combine those from Websky.

[keskitalo]

Thank you all. I would guess that a source that is 7 times brighter than any seen by Planck is a 10-sigma outlier. As long as you think there isn't anything obviously wrong with the radio source component, I'll just push ahead with the simulations.

[jdborrill]

I'm a bit confused ... 7 times brighter than anything seen by Planck is obviously wrong, no? Julian

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On Tue, Apr 25, 2023 at 10:27 AM Reijo Keskitalo ***@***.***> wrote: Thank you all. I would guess that a source that is 7 times brighter than any seen by Planck is a 10-sigma outlier. As long as you think there isn't anything obviously wrong with the radio source component, I'll just push ahead with the simulations. — Reply to this email directly, view it on GitHub <#23 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAC4LSRFU5A37FISFHNB7PTXDACR3ANCNFSM6AAAAAAXG75K4U> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[keskitalo]

I mostly meant to check if the extreme sources were expected and it sounds like Giuseppe and Zack are not surprised to see them. I should not try to comment on the physics of blazing radio sources like this, beyond pointing out that they must be extreme statistical outliers since we haven't seen anything like them in the Planck maps.

[zonca]

Once @keskitalo masks the bright sources in the mapmaker and the output maps have no artifacts, the downstream pipelines need to mask them and will not be affected much, right?
If this is correct, I would continue using the current model.

The Websky radio galaxy catalog/maps are already published, so we would need to implement into PySM a model which is different from the websky catalog following @giuspugl's idea. We currently have rg1 which is Websky, we need to implement rg2 which is websky with a constrained realization or a high flux cut.

[giuspugl]

we need to implement rg2 which is websky with a constrained realization or a high flux cut.

Sounds good ! The only cons that i see is the lack of correlation between the bright blazars from real data and the sources obtained with websky matter distribution (employed in CIB, SZ, etc.. ). In any case, we have to compromise something...

[jdborrill]

If I understand correctly, the masking is only in applying the filters, and the resulting maps will still have the sources in them. Julian

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On Tue, Apr 25, 2023 at 2:03 PM Giuseppe Puglisi ***@***.***> wrote: Sounds good ! The only cons of this is that than there 'll be lack of correlation between the bright blazars and the websky matter distribution (employed in CIB, SZ, etc.. ). In any case, we have to compromise something... — Reply to this email directly, view it on GitHub <#23 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAC4LSQLXJS3O63PCWZD2ADXDA3YNANCNFSM6AAAAAAXG75K4U> . You are receiving this because you commented.Message ID: ***@***.***>

[zonca]

yes, @jdborrill, but I think the downstream pipelines also apply masks

[zonca]

@keskitalo what do you think? do you prefer we work on a rg2 model more well-behaved at high flux?

@giuspugl do you have an estimate of how long it will take to implement rg2?