Will the upcoming experiment PICO measure kSZ temperature anisotropy?

In summary, PICO will be able to measure polarization anisotropies with high fidelity, including making full-sky Compton-y maps. The satellite's angular resolution will allow for measurements of kSZ temperature anisotropy at l=3000, as seen in Fig 2.1. However, the primary focus is on low-multipole B modes, which require multiple frequency bands and good control of systematic errors. The B-mode signal is much smaller than the E-mode signal and is swamped by noise, particularly due to lensing of large scale structure. As a result, the useful information for B-mode polarization is limited to around l=100.
  • #1
SherLOCKed
13
1
I know for sure PICO will be measuring polarization anisotropies with high fidelity. In addition, the PICO science paper shows that it will make full-sky Compton-y maps but the plots are mostly limited to l=1000. Will PICO be able to measure kSZ temperature anisotropy at l=3000?
 
Space news on Phys.org
  • #2
Based upon the described angular resolution of the satellite, absolutely. For E-mode anisotropies. Indeed, if you look at Fig 2.1, you see they've plotted the E-mode anisotropies up to around 4000. But those aren't the primary focus, as the low-multipole B modes are the most critical for new cosmology. What's important for measuring those are:
1) Lots of frequency bands (this requires a satellite)
2) Good control of systematic errors for polarization

The high multipoles are swamped by noise for the B-mode polarization signal, as the B-mode polarization signal is much smaller than the E-mode signal. One of the limiting factors here is that for B-mode polarization, lensing of large scale structure mixes E and B modes, which creates a noise-like signal (this is the "lensing residual"). The instrument noise will still be below this threshold, but we just don't get useful information out of the B-mode spectrum above a hundred or so.
 
  • Informative
Likes SherLOCKed

1. What is the purpose of experiment PICO?

The purpose of experiment PICO is to measure the kSZ (kinetic Sunyaev-Zel'dovich) temperature anisotropy in the cosmic microwave background (CMB). This will help us better understand the early universe and the processes that shaped it.

2. How will experiment PICO measure kSZ temperature anisotropy?

Experiment PICO will use a specialized instrument called a polarimeter to measure the polarization of the CMB. This polarization is caused by the interaction between the CMB photons and the hot gas in galaxy clusters, which produces the kSZ effect. By analyzing the polarization patterns, PICO will be able to measure the kSZ temperature anisotropy.

3. What is kSZ temperature anisotropy?

KSZ temperature anisotropy refers to the small fluctuations in the temperature of the CMB caused by the kSZ effect. This effect occurs when CMB photons pass through hot gas in galaxy clusters, resulting in a change in the photon's energy and therefore its temperature. These fluctuations can provide valuable insights into the properties and distribution of galaxy clusters in the early universe.

4. What makes experiment PICO unique?

Experiment PICO is unique because it will have the ability to measure the kSZ temperature anisotropy with unprecedented precision. It will also cover a wide range of frequencies, allowing for a more comprehensive analysis of the CMB polarization. Additionally, PICO will have a large field of view, allowing it to observe a larger portion of the sky than previous experiments.

5. What are the potential implications of the PICO results?

The results from PICO could have significant implications for our understanding of the early universe and the formation of large-scale structures such as galaxy clusters. It could also provide insights into the properties of dark matter and dark energy. Additionally, the precise measurements from PICO could help constrain cosmological models and potentially lead to new discoveries in physics.

Similar threads

Replies
3
Views
1K
Replies
2
Views
1K
Replies
8
Views
2K
Replies
6
Views
3K
Replies
13
Views
2K
  • Beyond the Standard Models
Replies
5
Views
2K
Replies
1
Views
1K
Replies
6
Views
3K
Replies
8
Views
3K
Back
Top