Still playing catch up – but, we had our first colloquium presentation of the spring, and one more coming up!
“Learning about the Universe with Data Science”
Dr. Viviana Acquavivia (CUNY CityTech)
A galaxy’s Spectral Energy Distribution (SED) is a chart of the brightness of a galaxy as a function of wavelength. It contains information about, for example, the galaxy’s stellar population age, stellar mass, distance from Earth, and star formation history. In the last decade, large galaxy surveys have provided us with an unprecedented volume of data for many galaxies billions of light years away, and it has become increasingly crucial to improve the tools we use to extract information from these data. I will present two examples of how supervised machine learning algorithms can be used to learn about the Universe’s history. In the first one, we show how we can discriminate between nearby and faraway galaxies in order to improve our knowledge of dark energy, the mysterious source of the present accelerated expansion of the Universe. In the second, we attempt to recover the history of metal enrichment (the production and dissemination of elements heavier than helium, which astronomers improperly call “metals”) through cosmic time.
(*Note: Dr. Acquaviva presented on Tuesday, January 26th!)
“Extreme NYC Weather: Connecting the Ground-Station Events to the Large Scale Storms’”
Dr. James Booth (CUNY City College)
New York City and the Northeastern United States are subjected to multiple types of weather hazards. These events range from windstorms to flooding to heat waves. From an atmospheric science prospective, an important question is: what are the synoptic-scale weather features responsible for these events and have they changed over the recent past? In this talk, I will address these questions for three specific types of extremes: (1) wintertime windstorms, (2) storm surge, and (3) inland precipitation. For this analysis the strongest events are identified in weather station records using Extreme Value Theory. Then, using the existing physical understanding of the storms, we associate the extreme events with extratropical and/or tropical cyclones. The life cycles and track locations of these storms are analyzed, and these will be discussed in the context of the recent snowstorm, Jonas. Additionally, the work creates probabilistic estimates of the most common pathways for the storms that cause the different hazards.
Date: Tuesday, February 16th, 2016
Where: Hudson St. Gallery (325 Hudson St., NY, NY)
General Note: We’re proud to have this year’s events sponsored by the ESC STEM Club. Please join us after each talk for an informal Q&A with food. (Did I mention that there will be free food?)