60 episodes

Joint Colloquia are held at 4:00 pm (MST) on Thursdays during the academic year in Steward Observatory Room N210.  Refreshments are served in the Steward Observatory Lobby at 3:30pm.  All are welcome to attend, although the talks are intended for professional astronomers and astronomy students.

We are pleased to acknowledge support by the National Science Foundation, ADVANCE and the American Physical Society.

Steward/NOAO Joint Colloquium Series University of Arizona

    • Science

Joint Colloquia are held at 4:00 pm (MST) on Thursdays during the academic year in Steward Observatory Room N210.  Refreshments are served in the Steward Observatory Lobby at 3:30pm.  All are welcome to attend, although the talks are intended for professional astronomers and astronomy students.

We are pleased to acknowledge support by the National Science Foundation, ADVANCE and the American Physical Society.

    • video
    New Worlds, New Horizons in Astronomy and Astrophysics: How Astronomers Pick the Next Big Thing! - Astronomy 2010 Decadal Surve

    New Worlds, New Horizons in Astronomy and Astrophysics: How Astronomers Pick the Next Big Thing! - Astronomy 2010 Decadal Surve

    Marcia J. Rieke is Professor of Astronomy. Her research areas are: Extragalactic Astronomy and Cosmology, Infrared Astronomy, and Galactic Astronomy. Presented October 11, 2010.

    • 1 hr 3 min
    • video
    Evolution of Dust Obscuration and Implications for Galaxy Growth

    Evolution of Dust Obscuration and Implications for Galaxy Growth

    Abstract: I will review recent work to constrain the star formation history of the Universe based on UV measurements, and will discuss what we have learned about the dust properties of typical star-forming galaxies at high redshift. In particular, I will briefly summarize our results on the UV luminosity function at redshifts z~2-3; the
    steep faint-end slope at these redshifts has interesting implications for the shape of the galaxy stellar mass function and budget of total stellar mass at high redshift. I will focus on how dust obscuration evolves with bolometric and UV luminosity, redshift, stellar population age, and metallicity. I show that evolution in the luminosity function and dust obscuration significantly impacts our understanding of the cosmic star formation history and its reconciliation with the buildup of stellar mass at early epochs. Fall 2010.

    • 1 hr 5 min
    • video
    Primordial Ices in the Solar System

    Primordial Ices in the Solar System

    Abstract: One of the most important keys to understanding how our solar system formed is identifying where and how primordial materials may be retained in present day solar system bodies. Thermally volatile ices are a tracer of this primitive material. The outer solar system, and in particular the thousands of known Kuiper Belt Objects (KBOs), provides the richest unexplored area of the solar system. Only the large (appoximately 500 km diameter) KBOs have been surveyed for the presence of ices, and these can be roughly divided into water ice rich, methane ice rich, and neutral types. We have undertaken a new survey of the much more numerous small KBOs using custom passband near-infrared filters on the Gemini North and Magellan telescopes. The goal of the survey is to classify the smaller KBOs into water ice, methane ice, and neutral types to identify correlations between physical (surface) characteristics and dynamical (orbital) characteristics. I will present our initial
    survey results and review other recently identified trends of the KBOs involving optical colors, binary fraction, inclination distribution and the presence of a collisional family. With few exceptions, all of these physical observations seem consistent with dynamical simulations suggesting a surprisingly chaotic past to our solar system. September 30, 2010.

    • 57 min
    • video
    Extragalactic Astronomy with Herschel and Spitzer:

    Extragalactic Astronomy with Herschel and Spitzer:

    Abstract: With the almost seamless transition from the Spitzer Space Telescope cryogenic mission (2003-2009) to the operation of the Herschel Space Observatory (2009-), it is no exaggeration to say that we have been enjoying a golden age of space infrared (IR)/submillimeter (Submm) astronomy in recent years. In this talk, I will report the results from the following three large extragalactic programs our group is currently conducting here at the Steward Observatory: (1) Herschel-Spitzer observations of galaxy clusters: gravitationally lensed galaxies and IR/Submm-bright cluster members (2) HST-Spitzer observations of 5.7<z<7.0 galaxies in the Subaru Deep Field (SDF) (3) Herschel-Spitzer observations of IR-luminous brightest cluster galaxies (BCGs) in cooling-flow clusters I will also describe our ground-based observing programs that are being carried out in coordination with these space programs. Through these wide-ranging science topics, I will highlight the key results, and will identify major unsolved questions. October 21, 2010.

    • 1 hr 4 min
    • video
    The Dynamics of Transiting Planets

    The Dynamics of Transiting Planets

    Dan Fabrycky is a Michelson Postdoctoral Fellow at the Harvard-Smithsonian Center for Astrophysics. He works on orbital dynamics of planets, including tides, migration, and resonances. He has a special affection for time-domain surveys and transiting planets.

    • 1 hr 3 min
    • video
    Probing Cosmic Origins: from Exoplanet Atmospheres to the Intergalactic Medium with the HST/COS

    Probing Cosmic Origins: from Exoplanet Atmospheres to the Intergalactic Medium with the HST/COS

    Abstract: The Cosmic Origins Spectrograph (COS), an ultra-sensitive ultraviolet spectrograph, was successfully installed on the Hubble Space Telescope during Servicing Mission 4 in 2009. COS covers the 1150 -- 3200 A range with moderate spectral resolution (R~20,000) at sensitivities that are 2 to 30 times better than the previous capabilities on HST. Due to its low FUV background, COS has up to 100 times more observing efficiency for faint targets. The unprecedented sensitivity of COS has opened up new parameter space for surveys in a number of science fields united by the theme of probing cosmic origins, from the atmospheres of solar system bodies out to the large scale structure of the modern universe. In this talk, I will present results from the first year of COS science operations, with an emphasis on observations obtained as part of the Guaranteed Time Observations allocated to the COS science team. These include observations of the extended atmospheres of transiting hot Jupiters; probes of the link between accretion and outflow from black hole X-ray binaries to AGN; and highlights of surveys of the local intergalactic medium, from the spatial studies of IGM filaments, through observations of the He II epoch of reionization, to the first probes of the diffuse IGM at overdensities comparable to those regularly studied at higher redshifts.

    • 56 min

Top Podcasts In Science

Listeners Also Subscribed To

More by University of Arizona