What is sz effect

The initial search was based on existing optical and IR images of the sky, from which the authors identify overdensities of galaxies. The contours represent the strength of the S-Z effect.

The measurements were made of the sky in three different frequencies to pick out the unique CMB spectral signature induced by the S-Z effect. After being detected using this method, half of these cluster candidates were further confirmed using follow-up imaging.

This was done using relatively small optical telescopes for low redshift clusters, while high redshift clusters were identified using data from Spitzer and WISE. Even though the authors have successfully identified these clusters with the SZ effect and confirmed their observations with additional imaging, there still are a number of clusters in the survey that remain unconfirmed i.

The abundances of galaxy clusters are highly sensitive to initial conditions in large scale structure formation, so the depth and coverage of this sample of clusters will be useful for testing cosmological models. Email Address. Suggest a Paper Topic! About the Author. My main interests involve high redshift cosmology, dark matter, and structure formation.

Leave a Reply Cancel reply. Subscribe Enter your email to receive notifications of new posts. Follow us on Twitter Follow astrobites. The diagram above shows a cartoon version of this effect. It is possible to use a combination of the Sunyaev-Zeldovich effect and the X-ray emission from the hot gas to derive a distance to the cluster.

This effect is proportional to 1 the number density of electrons, 2 the thickness of the cluster along our line of sight, and 3 the electron temperature. The usual order of magnitude for y is about 0. I am not clear about the purpose of the arrows in the figure but I have put them in to make my version of the figure more like the Sunyaev and Zeldovich figure. The actual shape of the distorted spectrum is always a widened, lowered and shifted to the right version of the input spectrum.

As a result the cross-over frequency, which is slightly higher than the mean, is increased by a factor of about 1. Since I got tired of seeing the weird red spectrum in too many talks, I have generated the exact spectrum plot shown below.