When Will We Know If Planck Discovered B Mode Polarisation?

In summary: So, while it is definitely possible that Planck may find some evidence for the B mode polarization, it's by no means a sure thing, and there is a lot of work that still needs to be done before we can say anything for sure.
  • #1
skydivephil
474
9
In case you didn't know already the first all sky Cmb map will be released at a press conference at ESA HQ March 21st
http://smsc.cnes.fr/PLANCK/Fr/GP_actualites.htm
This will be followed by a conference to discuss the cosmological data in Holland April 2nd-April 5th.
http://congrexprojects.com/13a11
 
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  • #2
Ohhh, nice. Can't wait to see the results!
 
  • #3
And only a couple months late ... were they trying to smooth out any 'axis of evil' effects? [a conspiracy theory thing].
 
  • #4
Im excited by this prospect, we could get something really new. But on the other hand it could just be WMAp to a few extra decimal places, that would be so dissapointing.
Hopefully if so there be a bit more interest to build a deidcated b polarisation mission.
 
  • #5
Chronos said:
And only a couple months late ... were they trying to smooth out any 'axis of evil' effects? [a conspiracy theory thing].
Haha, well, I think it's been set for March for quite some time, though I don't recall precisely.

Anyway, I think the main thing that makes it take so long is nailing down the systematic effects, such as the precise beam shapes and noise properties. These can all have subtle and difficult-to-nail-down impacts on the scientific products.
 
  • #6
skydivephil said:
Im excited by this prospect, we could get something really new. But on the other hand it could just be WMAp to a few extra decimal places, that would be so dissapointing.
Hopefully if so there be a bit more interest to build a deidcated b polarisation mission.

I was in a seminar listening to Martin Bucher from Planck Mission today, he said that we have to wait *another year* for polarization data... :uhh:
 
  • #7
yenchin said:
I was in a seminar listening to Martin Bucher from Planck Mission today, he said that we have to wait *another year* for polarization data... :uhh:
That sounds about right to me. The polarization signal is much, much lower, which means it's much, much harder to nail the systematic effects down well enough to make for a good signal. It doesn't help that Planck wasn't really built to be a polarimeter: it was built for temperature anisotropies. Polarization was tacked-on later, and it's actually not all that good at it. It should still be better than WMAP for polarization, of course, but dedicated polarization experiments, such as EBEX, are much, much better when it comes to controlling systematic effects related to polarization.
 
  • #8
I have been under the impression that whilst discovering the B mode polarisation is unlikely, there is some small chance that Planck could do this.
However from what I read above, it appears that even if it does make this discovery ( i know its not desinged for that) we won't know about it this MArch/ April, but it's another year away?
 
  • #9
skydivephil said:
I have been under the impression that whilst discovering the B mode polarisation is unlikely, there is some small chance that Planck could do this.
However from what I read above, it appears that even if it does make this discovery ( i know its not desinged for that) we won't know about it this MArch/ April, but it's another year away?

That's my understanding from the seminar; we will know soon later this month if they do release any polarization data.
 
  • #10
skydivephil said:
I have been under the impression that whilst discovering the B mode polarisation is unlikely, there is some small chance that Planck could do this.
However from what I read above, it appears that even if it does make this discovery ( i know its not desinged for that) we won't know about it this MArch/ April, but it's another year away?
Right. Polarization data is really really finicky, and subject to all sorts of potential problems. One major issue is that systematic effects which cancel when performing a temperature measurement may add and become even larger when taking a polarization measurement.

This is becomes the temperature signal comes from averaging the value of the polarization signals together, while the polarization signal comes from subtracting them. So if one systematic effect pushes one signal up while the other signal goes down, the temperature signal is unaffected, but the polarization signal sees a huge result. And because the actual polarization signal is only a small fraction of the temperature signal, any systematic effects that remain in the data are bad news.
 

1. When will the next Planck data release be?

The next Planck data release is scheduled for 2021. However, the exact date has not been announced yet.

2. How often are Planck data releases?

Planck data releases occur approximately every two years, with the last one being in 2018. However, this timeline is subject to change based on the data analysis process.

3. What type of data is included in Planck data releases?

Planck data releases include a wide range of data related to the cosmic microwave background, including temperature and polarisation maps, as well as other astrophysical data such as galaxy clusters and dust emission.

4. Can anyone access Planck data releases?

Yes, all Planck data releases are publicly available through the Planck Legacy Archive and can be accessed by anyone.

5. How is the data in Planck data releases collected?

The data in Planck data releases is collected by the Planck satellite, which was launched by the European Space Agency (ESA) in 2009. The satellite measured the cosmic microwave background radiation across the entire sky for over four years.

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