Simons Observatory White Paper : An Interview With Director Dr. Brian Keating

Simons Observatory White Paper : An Interview With Director Dr. Brian Keating

The Simons Observatory is located in the high Atacama Desert in Northern Chile inside the Chajnator Science Preserve, at an altitude of 5,200 meters (17,000 ft). The Atacama Cosmology Telescope (ACT) and the Simons Array[1] are located nearby and these experiments are currently making observations of the Cosmic Microwave Background (CMB). Their goals are to study how the universe began, what it is made of, and how it evolved to its current state. The Simons Observatory shares many of the same goals but aims to take advantage of advances in technology to make far more precise and diverse measurements. In addition, it is envisaged that many aspects of the Simons Observatory (optical designs, detector technologies and so on) will be pathfinders for the future CMB-S4 array.[2][3][4]

The Simons Observatory has been made possible by a combined $40.1 million grant from the Simons Foundation and a number of participating universities.[5][6][7] The Collaboration is large and multinational with over 250 scientists at over 35 institutions across the world.

One of the primary goals of the Simons Observatory are polarization maps of the sky with an order of magnitude better sensitivity than the Planck satellite. These will enable better measurement of cosmological parameters and will also enable a wide range of other science. Examples include gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel’dovich effects. With delensing the large-angle polarization signal it will be possible to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources. Details have been published in a forecasts paper.[8]

Telescopes

To achieve a high enough angular resolution for some of the science goals, a telescope with an aperture larger than about 5 meters is needed. To reduce systematic effects which become the dominate source of errors in very low noise maps, the Simons Observatory will build a 6 meter telescope and under illuminate the primary mirror to 5.5 meters. At the same time other science goals require very low noise on large angular scales—something a 6 meter telescope will struggle to achieve. For this reason the Simons observatory will also build three 0.5 meter telescopes and combine the data sets in analysis.

Simons Observatory White Paper : An Interview With Director Dr. Brian Keating