Princeton University Gravity Group Lunch Seminar

Carlos Sierra, Stanford University

"SPECTER: a new instrument concept for measuring the CMB spectral distortions"

The standard cosmological model predicts deviations from a perfect blackbody spectrum in the cosmic microwave background (CMB). A precise measurement of the CMB energy spectrum, last performed by the COBE-FIRAS instrument over 30 years ago, could unlock a unique window into the earliest moments of our universe and new beyond-standard-model physics. In this talk I introduce SPECTER, a new instrument concept for measuring the mu-type spectral distortions. This ambitious mission proposal utilizes proven photometric technology and a robust calibration system to obtain an absolute temperature measurement of the sky to unprecedented precision. With the unique advantage of independently tunable spectral channels, we show that SPECTER can achieve a >5 sigma detection of the mu-type distortions.

Michael Randall, UC San Diego

"The Simons Observatory: Deployment and Initial Commissioning of the First Small-Aperture Telescope"

The Simons Observatory is a ground-based Cosmic Microwave Background (CMB) survey experiment located at an elevation of 5,200m in the Atacama Desert in Chile. The survey consists of three 0.5m small-aperture telescopes and one 6m large-aperture telescope. Each of the Small-Aperture Telescopes (SATs) will observe with over 12,000 superconducting Transition-Edge Sensor (TES) detectors with the aim to observe the primordial gravitational wave signals predicted in the CMB by a class of inflationary cosmological models. In order to make sensitive enough observations of the CMB to detect these signals, we must accurately calibrate the instruments at the Chile site so that its behavior is well understood for future analysis and map-making. Here I discuss the deployment of and some of the calibration efforts undergone by the first SAT deployed for the Simons Observatory as well as efforts undertaken to maximize the performance of the instrument.

Jeffrey McMahon, University of Chicago

"Development of Integral Field Units for Intensity Mapping"

Millimeter-wave intensity mapping provides an avenue to extend measurements of large-scale structure to significantly higher redshift than has yet been well mapped. A sensitive spectroscopic survey covering 100–300 GHz would detect the redshifted emission from carbon monoxide (z=2~>4) and ionized carbon (up to z=10). The three-dimensional distribution of these signals would provide valuable insights into large-scale structure and astrophysical emissions, yielding new cosmological and astrophysical constraints. Realizing such measurements requires the deployment of thousands of spectroscopic pixels, representing a substantial advancement over the current state of the art. In this talk I describe efforts to develop dense arrays of millimeter-wave spectrometers, known as integral field units (IFUs). Our goal is to produce IFUs that would be nearly drop-in compatible with CMB detector arrays to enable such surveys.
 

: a new instrument concept for measuring the CMB spectral distortions"

The standard cosmological model predicts deviations from a perfect blackbody spectrum in the cosmic microwave background (CMB). A precise measurement of the CMB energy spectrum, last performed by the COBE-FIRAS instrument over 30 years ago, could unlock a unique window into the earliest moments of our universe and new beyond-standard-model physics. In this talk I introduce SPECTER, a new instrument concept for measuring the mu-type spectral distortions. This ambitious mission proposal utilizes proven photometric technology and a robust calibration system to obtain an absolute temperature measurement of the sky to unprecedented precision. With the unique advantage of independently tunable spectral channels, we show that SPECTER can achieve a >5 sigma detection of the mu-type distortions.

Michael Randall, UC San Diego

"The Simons Observatory: Deployment and Initial Commissioning of the First Small-Aperture Telescope"

The Simons Observatory is a ground-based Cosmic Microwave Background (CMB) survey experiment located at an elevation of 5,200m in the Atacama Desert in Chile. The survey consists of three 0.5m small-aperture telescopes and one 6m large-aperture telescope. Each of the Small-Aperture Telescopes (SATs) will observe with over 12,000 superconducting Transition-Edge Sensor (TES) detectors with the aim to observe the primordial gravitational wave signals predicted in the CMB by a class of inflationary cosmological models. In order to make sensitive enough observations of the CMB to detect these signals, we must accurately calibrate the instruments at the Chile site so that its behavior is well understood for future analysis and map-making. Here I discuss the deployment of and some of the calibration efforts undergone by the first SAT deployed for the Simons Observatory as well as efforts undertaken to maximize the performance of the instrument.

Jeffrey McMahon, University of Chicago

"Development of Integral Field Units for Intensity Mapping"

Millimeter-wave intensity mapping provides an avenue to extend measurements of large-scale structure to significantly higher redshift than has yet been well mapped. A sensitive spectroscopic survey covering 100–300 GHz would detect the redshifted emission from carbon monoxide (z=2~>4) and ionized carbon (up to z=10). The three-dimensional distribution of these signals would provide valuable insights into large-scale structure and astrophysical emissions, yielding new cosmological and astrophysical constraints. Realizing such measurements requires the deployment of thousands of spectroscopic pixels, representing a substantial advancement over the current state of the art. In this talk I describe efforts to develop dense arrays of millimeter-wave spectrometers, known as integral field units (IFUs). Our goal is to produce IFUs that would be nearly drop-in compatible with CMB detector arrays to enable such surveys.