Monday, October 20
Location: UCB, Hearst Field Annex B1, 3:10 p.m.
Speaker: Tabitha Voytek (Carnegie Mellon University)
Title: Hydrogen and the First Stars: First Results from the SCI-HI 21-cm all-sky spectrum experiment
Abstract: I will be introducing the “Sonda Cosmologica de las Islas para la Deteccion de Hidrogeno Neutro” (SCI-HI) experiment. This experiment is an all-sky 21-cm brightness temperature spectrum experiment studying the cosmic dawn (z~15-35) through the temporal evolution of the IGM. The experiment is a collaboration between Carnegie Mellon University (CMU) and Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE) in Mexico. Initial deployment of the SCI-HI experiment occurred in June 2013 on Guadalupe; a small island about 250 km off of the Pacific coast of Baja California in Mexico. I will discuss the preliminary measurements from this deployment, placing first constraints on the 21-cm all-sky spectrum around 70 MHz (z~20), see Voytek et al (2014). I will also discuss the current work to improve the experiment; including both instrumental improvements and deployment locations.
Tuesday October 21
Berkeley Cosmology Seminars
Location: UCB – Hearst Field Annex B1, 1:10 p.m. (also videoconferenced to LBNL 50-5026)
Speaker: Josh Dillon, MIT
Title: “Chasing the Cosmic Dawn with 21 cm Tomography”
Abstract: Realizing the promise of 21 cm cosmology to provide an exquisite probe of astrophysics and cosmology during the cosmic dark ages and the epoch of reionization has proven extremely challenging. We’re looking for a small signal buried under foregrounds orders of magnitude stronger. We know that we’re going to need very sensitive, and thus very large, low frequency interferometers, which present their own set of difficulties. And, as I will explain, we’re going to need a rigorous statistical analysis of the maps we make to extract interesting cosmological information. I will discuss the steps we’ve taken to overcome these obstacles with prototype data from the Murchison Widefield Array by isolating foregrounds to a region of Fourier space outside a clean “epoch of reionization window.” Additionally, I will present some of most recent and exciting predictions for what 21 cm cosmology can tell us as we move to larger telescopes like the Hydrogen Epoch of Reionization Array and higher redshifts.
For future BCCP talks, see this page.
BCCP Workshop: 5th annual Essential Cosmology for the Next Generation Meeting
BCCP and the Instituto Avanzado de Cosmologia Mexico held the 5th annual Essential Cosmology for the Next Generation meeting January 13-17, 2014, popularly known as Cosmology on the Beach. The conference blends a winter school of lecture courses by world-leading scholars with plenary talks on hot research topics. This year, topics included CMB polarization, gravitational wave cosmology, particle physics, tests of gravity, and statistical and experimental methods.
For slides from the BCCP/IAC meeting Essential Cosmology for the Next Generation 2014 workshop, click here. They are also available on the Presentations Page.
There are no open job opportunities at BCCP at this time. Please check back for future job postings.
A $2.1 million grant from the Gordon and Betty Moore Foundation to the University of California at Berkeley, through the Berkeley Center for Cosmological Physics (BCCP), will fund the development of revolutionary technologies for BigBOSS, a project now in the proposal stage designed to study dark energy with unprecedented precision. BigBOSS is based at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).
“BigBOSS is the next big thing in cosmology,” says Uroš Seljak, Director of the BCCP, who is a professor of physics and astronomy at UC Berkeley and a member of Berkeley Lab’s Physics Division. “It would map millions and millions of galaxies, allowing us to measure dark energy to high precision – and would yield other important scientific results as well, including determining neutrino mass and the number of neutrino families.”
Dark energy is the unknown something that appears to account for almost three-quarters of the mass-energy of the universe and is the cause of its accelerating expansion. The discovery of the accelerating universe, announced in 1998 by two teams, resulted in the 2011 Nobel Prize in Physics, divided between Berkeley Lab and UC Berkeley astrophysicist Saul Perlmutter, leader of the Supernova Cosmology Project, and Brian Schmidt and Adam Riess of the competing High‑z Supernova Search team.
“After we won the Nobel Prize, the question we all heard most was, ‘Now that you’ve discovered dark energy, what comes next?’” says Perlmutter, who is the Executive Director of the BCCP as well as principal investigator for the Moore Foundation’s BigBOSS grant. “The answer is pretty clear: we have to find out what dark energy is. There’s no end of theories. To know which are possible, what we need most is the kind of accurate observational evidence that only BigBOSS and other advanced experiments can give us.”
New data from the South Pole Telescope indicates that the birth of the first massive galaxies that lit up the early universe was an explosive event, happening faster and ending sooner than suspected.
Extremely bright, active galaxies formed and fully illuminated the universe by the time it was 750 million years old, or about 13 billion years ago, according to Oliver Zahn, a postdoctoral fellow at the Berkeley Center for Cosmological Physics (BCCP) at the University of California, Berkeley, who led the data analysis.