Associate Professor
Professor Vieira is an observational cosmologist who works across the electromagnetic spectrum. His scientific interests include: the cosmic microwave background, experimental tests of inflation; dark matter; dark energy; gravitational lensing; high redshift galaxies; instrumentation.
He builds experiments, conducts cosmological surveys, and performs observations of the distant Universe. He works with data from the South Pole Telescope (SPT), Dark Energy Survey (DES), Herschel, Hubble, Spitzer, Chandra, and ALMA.
He is currently helping to build future mm and sub-millimeter facilities, pondering the cosmic evolution of dust and ionized carbon, and working to detect signatures of inflation through polarized measurements of the cosmic microwave background (CMB).
Prof. Vieira is currently looking for graduate students to work on the following projects:
1) Analysis of South Pole Telescope (SPT) survey data.
2) Observations of strong gravitationally lensed galaxies at high-redshift.
3) Development of cryogenic optics for next-generation CMB experiments.
4) The Terahertz Intensity Mapper (TIM), a NASA-funded balloon project to build and fly a 2-m FIR telescope around Antartica and make a 3D map of the Universe with the redshifted 158 micron ionized carbon line.
Students are welcome and encouraged to drop by with questions about science, instrumentation, or available research projects.
I am always looking for undergraduates to work on analysis and instrumentation projects. I prefer taking on promising students in their first or second year. It's best to just come chat with me during office hours. Come prepared with a CV, some background reading, and questions. Students from traditionally underrepresented groups in science are encouraged to inquire about research opportunities in my group.
For more information, visit: obscos.astro.illinois.edu
U of I Professor Joaquin Vieira and his team built all of the cryogenic optics for the SPT-3G camera, which were a critical component of the project. This entailed developing a new type of anti-reflection coating for the optics that could survive down to 0.3 degrees above absolute zero, a feat that required about four years of research and development.
A team of scientists using the Dark Energy Camera (DECam), the primary observing tool of the Dark Energy Survey (DES), was among the first to observe the fiery aftermath of a recently detected burst of gravitational waves, recording images of the first confirmed explosion from two colliding neutron stars ever seen by astronomers.
Scientists on the DES joined forces with a team of astronomers based at the Harvard-Smithsonian Center for Astrophysics (CfA) for this effort, working with observatories around the world to bolster the original data from DECam. Images taken with DECam captured the flaring-up and fading over time of a kilonova – an explosion similar to a supernova, but on a smaller scale – that occurs when collapsed stars (called neutron stars) crash into each other, creating heavy radioactive elements.
Two scientists at the University of Illinois at Urbana-Champaign are members of the DES collaboration, Professors Joaquin Vieira of the Departments of Astronomy and of Physics and Felipe Menanteau of the Department
Imagine planting a single seed and, with great precision, being able to predict the exact height of the tree that grows from it. Now imagine traveling to the future and snapping photographic proof that you were right.
If you think of the seed as the early universe, and the tree as the universe the way it looks now, you have an idea of what the Dark Energy Survey (DES) collaboration has just done. In a presentation today at the American Physical Society Division of Particles and Fields meeting at the U.S. Department of Energy’s (DOE) Fermi National Accelerator Laboratory, DES scientists will unveil the most accurate measurement ever made of the present large-scale structure of the universe.
These measurements of the amount and “clumpiness” (or distribution) of dark matter in the present-day cosmos were made with a precision that, for the first time, rivals that of inferences from the early universe by the European Space Agency’s orbiting Planck observatory. The new DES result (the tree, in the above metaphor) is close to “forecasts” made from the Planck measurements of the distant past (the seed), allowing scientists to understand more about the ways the universe has evolved over 14 billion years.
“This result is beyond exciting,” said Scott Dodelson of Fermilab, one of the lead scientists on this result. “For the first time, we’re able to see the current structure of the universe with the same clarity that we can see its infancy, and we can follow the threads from one to the other, confirming many predictions along the way.”
"For decades, astronomers have known that supermassive black holes and the stars in their host galaxies grow together," said co-author Joaquin Vieira of the University of Illinois at Urbana-Champaign. "Exactly why they do this is still a mystery. SPT0346-52 is interesting because we have observed an incredible burst of stars forming, and yet found no evidence for a growing supermassive black hole. We would really like to study this galaxy in greater detail and understand what triggered the star formation and how that affects the growth of the black hole."