Stellar astrophysics

We study mulitple aspects of stellar astrophysics, from star formation and stellar populations to the nucleosynthesis sites within stars.


Stellar Astrophysics

These projects focus on the internal structure and evolution of stars.

Stellar Chemistry (observational)

Chemical abundance determinations for stars in globular clusters, components of the Galaxy, and nearby dwarf galaxies from high resolution spectroscopy (UV, optical, near-IR).

The Pristine Survey is narrow-band photometric survey using the northern hemisphere with the wide-field imager MegaCam on the Canada-France-Hawaii Telescope (CFHT).

Contact: Kim VennPatrick Cote

Students:

  • Collin Kielty
  • Spencer Bialek
  • Teaghan O'Briain
  • Fletcher Waller

 

Stellar Evolution (theory)

Detailed computations of stellar interiors and evolution, including MESA and Vandenberg's stellar evolution codes.

Contact: Falk Herwig, Pavel Denisenkov

Students:

  • Ondrea Clarkson
  • David Stephens
  • Austin Davis

Stellar Populations (imaging)

Homogeneous photometry of stars (and variables) in globular clusters (GeMS) and nearby galaxies (The Solo Survey).

Contact: Peter StetsonAlan McConnachieKim Venn, Dave Andersen

Students:

  • Mojtaba Taheri
  • Tarun Kumar
  • Clare Higgs

Star Formation

These projects focus on the formation and evolution of stars.

KEYSTONE (K-band Focal Plane Array Examinations of Young STellar Object Natal Environments)

The KEYSTONE (K-band Focal Plane Array Examinations of Young STellar Object Natal Environments) survey required several hundred hours of observing using the 100m Green Bank Telescope (GBT) to observe ammonia in molecular clouds forming massive stars.  This project complements GAS by extending the environments surveyed to regions forming stars much more vigorously than our nearest molecular clouds. Initial results and further information can be found here

Contact: James Di Francesco and Helen Kirk

Image: The integrated intensity of the NH3 (1,1) line associated with some of Cygnus X North (DR21) and the circles show the location and intensity of H2O maser emission also detected with the survey.

Cgynus X North

JCMT Gould Belt Survey

The JCMT Gould Belt Survey is one of the original Legacy Surveys for the James Clerk Maxwell Telescope, which used several hundred hours of observing time to create large-scale (several square degrees) maps of the cold dust in nearby molecular clouds at 850 and 450 microns as well as somewhat smaller, targeted maps of the associated CO gas emission.  The JCMT GBS provides excellent sensitivity to cold and dense star-forming gas known as dense cores.  With the large-area coverage of multiple nearby clouds, we are studying the properties of dense cores in an unbiased manner across a range of star-forming environments.

Contact: Helen Kirk, James Di Francesco, Doug Johnstone & Brenda Matthews

 

Image: The Ophiuchus star forming region. RGB image (SCUBA-2 850 micron, Herschel 100 micron, Spitzer 8 micron). Credit: JCMT/Herschel Gould Belt Surveys/Spitzer c2d Survey/Pattle et al., 2015.  Image created by R. Friesen

Ophiuchus star forming region

Green Bank Ammonia Survey

The Green Bank Ammonia Survey required several hundred hours of observing using the 100m Green Bank Telescope to observe ammonia in nearby molecular clouds.  Ammonia is a good tracer of the cold and dense gas involved in forming stars, and allows us to measure both gas motions and temperature.  Many of the same molecular clouds were mapped with GAS and the JCMT GBS, and these observations allow us to better characterize and understand the conditions necessary for star formation across a range of environments.

Contact: Helen Kirk, James Di Francesco

Students:

  • Mike Chen

Image: Ammonia, a tracer of star-forming gas, in the Orion Nebula as seen with the GBT (orange). Background in blue is a WISE telescope infrared image showing the dust in the region. Image credit: GBO/AUI/NSF

Orion nebula


Nuclear Astrophysics

These projects focus on the nucleosynthesis of elements in the early Universe, within stars and in stellar explosions. 

Nucleosynthesis Grid (NuGrid)

Collaboration to study the major element production sites in stars and stellar explosions. The simulation datasets are input for models of chemical evolution in galaxies.

Contact: Chris RuizFalk Herwig

Isotope Separator and Accelerator (ISAC)

Experiments at TRIUMF to obtain nuclear physics data needed in computations of the origin of elements in stars. More information on nuclear astrophysics at TRIUMF .

Contact: Chris RuizIris Dillman

Joint Institute for Nuclear Astrophysics - Centre for the Evolution of the Elements (JINA-CEE)

Research program to understand the rise of the elements in the early universe.

Contact: Falk HerwigChris RuizIris Dillman