Cosmology & Astrophysics

Cosmology and Astrophysics study fundamental questions about the universe, such as its origins, the processes that govern it, and the nature of its components.

CCD imager
The CCD imager of the Dark Energy Camera (DECam) used by the Dark Energy Survey.

The Duke Cosmology Group, composed of professors Dan Scolnic, Michael Troxel, and Chris Walter, studies the nature of dark energy and dark matter. The group uses some of the largest astronomical sky-surveys to make the most precise measurements of the expansion of the universe and its composition.

Cosmology-related projects in the Duke Cosmology Group are:

  • The Vera C. Rubin Observatory (Rubin): A wide-field optical “survey” telescope that will observe the entire available southern sky every few nights to study the nature of dark energy and dark matter. The Rubin Observatory is currently under construction and is being commissioned, with operations expected to start in 2024. 
  • The Dark Energy Survey (DES): An optical survey of 5000 square degrees (1/8th) of the southern sky that has found thousands of supernovae and observed hundreds of millions of galaxies to make the most precise measurements of the nature of dark energy and dark matter. 
  • Nancy Grace Roman Space Telescope (Roman): The top-ranked large space mission of the 2010 National Academies’ Astro2010 Decadal Survey. Roman will observe thousands of square degrees of the sky in the near-infrared from a position in space 1 million miles from Earth. The planned launch date is in 2026. 

The Cosmology group now has over 20 postdocs/grad students/undergrads working on a variety of projects.  

Duke Cosmology Group meeting
Duke cosmology group members during a group meeting in 2021.
Some members of Duke Cosmology Group at LSST Meeting in 2020
Some members of the Duke Cosmology Group at an LSST Meeting in 2020.

 

The last 5 papers by grad students this year are:

Measuring Cosmological Parameters with Type Ia Supernovae in redMaGiC galaxies - Rebecca Chen, ApJ.

Weak Gravitational Lensing Shear Estimation with Metacalibration for the Roman High-Latitude Imaging Survey - Masaya Yamamoto, MNRAS, 2022.

The Pantheon+ Analysis: Evaluating Peculiar Velocity Corrections in Cosmological Analyses with Nearby Type Ia Supernovae - Erik Peterson, ApJ.

A Unified Catalog-level Reanalysis of Stage-III Cosmic Shear Surveys - Emily P. Longley, MNRAS.

The Pantheon+ Analysis: Forward-Modeling the Dust and Intrinsic Colour Distributions of Type Ia Supernovae, and Quantifying their Impact on Cosmological Inferences, ApJ, Brodie Popovic.

 

Recent awards made to group members include:

Grad Student Rebecca Chen - DOE SGSR award - 2022

Postdoc Maria Vincenzi - URA Graduate Thesis award - 2022

Postdoc Maria Vincenzi - Michael Penston Thesis Prize by the Royal Astronomical Society - 2021

Dan Scolnic - Sloan Fellowship - 2021

Michael Troxel - 10 Most Brilliant Young Scientists and Engineers by Popular Science - 2021

Dan Scolnic - DOE Early Career Award - 2021

Michael Troxel -  DOE Early Career Award - 2020

Dan Scolnic - Packard Fellowship - 2019

Brodie Popovic - DOE SGSR award - 2020

Emily Phillips Longley- DOE SGSR award - 2019

 

One related astrophysics group is the Duke HEP neutrino group, whose research focuses on neutrinos from core collapse supernovae and other astrophysical sources. See their website for more information on Duke’s astrophysics-related projects.

Teaching and outreach activities take place at the Duke teaching observatory.