Research Professor in the
Department of Astronomy & Astrophysics
Kavli Institute for Cosmological Physics.
University of Chicago.
For the past 15 years, I have worked on a single project: The
10-meter South Pole Telescope (SPT).
The SPT is a millimeter-wave telescope designed to make sensitive
measurements of diffuse, low-contrast emission, such as anisotropy
cosmic microwave background (CMB).
The first camera on the SPT was
equipped with a highly sensitive, kilo-pixel bolometer array
capable of mapping the arcminute-scale anisotropy of the
CMB to exquisite precision. The primary goal of this camera was to survey 2500 square degrees of the southern sky, using
the CMB as a backlight to discover distant, massive clusters of
galaxies through their interaction with the CMB, known as the
Sunyaev-Zel'dovich (SZ) effect.
The full survey was completed in late 2011.
In January, 2012, a new polarization-sensitive receiver was installed on the
telescope. Two years of data has been collected with this receiver, and
it is anticipated that the first year's data will lead to the first ever detection of
B-mode polarization in the CMB. UPDATE: And it has! The result is now published in Physical Review Letters (see
or the arxiv preprint). This result
was named one of the top 10 breakthroughs in all of physics for 2013 by
As the data from this receiver continue to be collected, and exciting
results continue to be published, we are simultaenously working on the
third-generation receiver for the SPT. This camera will have over 15,000
polarization-sensitive detectors and will represent a fundamental step
forward in our ability to characterize the CMB and the millimeter-wave sky.
In addition to the B-mode result, SPT data has led to numerous other groundbreaking publications.
In 2008, the SPT team
the first successful use of SZ observations to find previously unknown clusters.
Using only 10% of the survey data, the team also published
the first cosmological constraints from an SZ-selected sample of clusters,
the first detection of the SZ power spectrum,
the first millimeter-wave detection of fluctuations in the cosmic infrared background,
the discovery of a new family of high-redshift star-forming galaxies.
More recently, the team has made the highest signal-to-noise measurement of
the gravitational lensing of the CMB
and used that measurement to
constrain the clustering bias of galaxies,
and the team has used the full 2500 square-degree survey data to
make the most sensitive measurement yet of the
damping tail of the primary CMB power spectrum.
During my time on this project, I have
particpated in the design of the telescope, optics, and receiver;
I have designed and built a protoype SPT receiver (which was used
to qualify the secondary mirror and cold optics box); I have traveled to
the South Pole with four other team members to assemble the primary
reflector, and now I am
one of the leaders of the data analysis effort.
I also play an active role in planning for the next-generation "Stage-4"
ground-based CMB experiment,
CMB-S4, including co-authoring the
"Snowmass" documents (I was corresponding author on the inflation document), which are generally
considered the starting point of the case for CMB-S4, and as one of the core authors
of the CMB-S4 Science Book.