Loading Events

« All Events

Physics & Astronomy Colloquium

October 25 @ 3:30 pm - 5:00 pm

Speaker: Nicholas Suntzeff , Texas A&M University

Title: Supernova Cosmology: Thirty Two Years of Watching Stars Blow Up

Abstract: Starting in 1986, Mark Phillips, Mario Hamuy, and I began the study of the properties of nearby supernovae, and were the first to produce a light curve based on CCD data. With Jose Maza, in 1989, we began the concentrated study of nearby supernovae called the Calán/Tololo Survey, which led to discoveries including the establishment of Type Ia supernovae as standardizable candles, the deeper understanding of reddening and temperature effects in light curves and spectra, and with the HST calibration of distances to nearby host galaxies of these SNe, the modern value of the Hubble constant based on the quiet Hubble flow defined by supernovae. In 1994, Brian Schmidt and I founded the High-Z Supernova Team utilizing the Calán/Tololo results and MLCS techniques developed by Adam Riess. The image subtraction software was developed by Schmidt and later Tonry. These techniques underlie the discovery by both the HZT and the Supernova Cosmology Project of Saul Perlmutter et al (who developed independent software) of the apparent accelerated expansion of the Universe. All these discoveries rest on the rickety photometric system astronomers have organically developed over the last 60 years. With the improvement in the fundamental calibration system led by HST astronomers, and a reanalysis of astronomical photometric techniques by Stubbs and Tonry, we now see the results of supernova cosmology are limited by the systematic errors in how we do photometry. We founded the Carnegie Supernova Project to create a new and precisely calibrated set of nearby supernovae to dig into these systematic effects and to anchor the acceleration results. In this talk, I will present the background of supernova cosmology and reveal the strengths and pitfalls of this field.

 

Speaker Biography:

Nicholas B Suntzeff
University Distinguished Professor
Mitchell/Heep/Munnerlyn Professor of Observational Astronomy
Mitchell Institute for Fundamental Physics and Astronomy
Texas A&M University

Prof. Nicholas Suntzeff is an observational astronomer, working the fields of cosmology, supernovae, galaxy evolution and large-scale structure, stellar populations, astronomical site surveys, and instrumentation. Suntzeff studied mathematics at Stanford University (B.S. with distinction 1974) and astronomy and astrophysics at Lick Observatory, UC Santa Cruz (Ph.D. 1980). He has worked as an astronomer at the University of Washington, the Carnegie Observatories in Pasadena, and the US National Optical Astronomy Observatory/Cerro Tololo Inter-American Observatory in La Serena, Chile where he was the Associate Director for Science for NOAO. In 1994 with Dr. Brian Schmidt, he co-founded the High-Z Supernova Team which in 1998 discovered acceleration and the presence of Dark Energy in the Universe. He was also a co-founder of the Calan/Tololo Supernova Survey which established Type Ia supernovae as the most precise markers for measuring cosmological distances.

Prof. Nicholas Suntzeff is the winner of the following awards:

Details

Date:
October 25
Time:
3:30 pm - 5:00 pm
Event Categories:
,
Website:
https://physics.ua.edu/recent-events/colloquia/

Organizer

Karen Lynn

Venue

227 Gallalee Hall
514 University Blvd.
Tuscaloosa, AL 35401 United States
+ Google Map
Website:
physics.ua.edu