Events Archive

Planet Hunting with ALMA Observations of Molecular Emission

Mon, Oct 12, 2015 at 12:00 pm

131A Campbell Hall

Ilse Cleeves (CfA Harvard)

During the initial phases of planet-formation, young, self-luminous gas giants embedded in cold molecular disks can directly heat their local environment. The accretion luminosity from the planet can sublimate ices in the immediate vicinity that are otherwise fully frozen-out onto dust grains, creating a unique gas-phase signature. We have modeled the 3D chemical structure induced by the …

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Globular Clusters, Halo Stars and Galaxy Assembly

Thu, Oct 8, 2015 at 4:00 pm

1 LeConte

Jean Brodie (UCSC)

A variety of evidence suggests that metal rich globular clusters (GCs) trace the build-up of galaxy bulges, while metal poor GCs trace the build up of their halos. Wide field observations of galaxies are critically important for testing the currently favored two-phase paradigm for galaxy formation, because many signatures of galaxy assembly processes are only revealed at large radius.  …

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Department Lunch Talk 10-8

Thu, Oct 8, 2015 at 12:30 pm

131A Campbell Hall

Andrew Simieon (UCB)
David Jones (JHU)
Jean Brodie (UCSC)

The Department Lunch Talk series is a weekly event that features three 20 minute talks presented mainly by local scientists of any level to present their work to a broad spectrum of the department and usually includes one short talk by the astronomy colloquium speaker of the day. Subjects can include personal scientific research, reporting on other work appearing in journals, education and public outreach efforts, science policy, and professional development issues. Continue reading for this week's talk titles.

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CIPS Seminar 10-7

Wed, Oct 7, 2015 at 3:00 pm

131A Campbell Hall

Gérard Massacrier (CRAL, Lyon)
Shuai Zhang (UC Berkeley)

This weeks CIPS Seminar will feature two speakers (please continuing reading for complete abstracts and titles).

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Testing Gravity using Galaxy Redshift Surveys and CMB

Tue, Oct 6, 2015 at 1:00 pm

131A Campbell Hall

Shadab Alam, CMU

The Redshift Space Distortions (RSD) in galaxy redshift surveys can probe the local dynamics at a given epoch of galaxy. I will discuss how redshift can help us learn the local dynamics and hence measure the nature of gravity at the epoch of the galaxy. I will show results from our recent analysis of SDSS-III high redshift sample (CMASS). I will then talk about combining similar RSD …

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The Zen of Galaxies

Mon, Oct 5, 2015 at 12:00 pm

131A Campbell Hall

John Forbes (UCSC)

Over the past decade a quiet revolution has taken place in our picture of galaxy evolution. Rather than evolving through violent mergers, galaxies live quiet lives on narrow scaling relations. This is explained elegantly by the so-called "equilibrium model" of galaxy formation. I will present a simple extension to this model that can explain the finite scatter observed in …

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Reverberation Mapping as a Probe of Black hole Masses and AGN Structure: New Results from Intensive Monitoring Campaigns

Thu, Oct 1, 2015 at 4:00 pm

1 LeConte Hall

Aaron Barth (UC Irvine)

The method of reverberation mapping uses the time delay between continuum and emission-line variations in active galactic nuclei to probe the structure of the broad-line region and to derive estimates of black hole masses. Reverberation mapping results provide a fundamental low-redshift calibration for the methods used to trace the cosmological evolution of supermassive black holes. I will …

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Department Lunch Talk 10-1

Thu, Oct 1, 2015 at 12:30 pm

131A Campbell Hall

Francois Foucart (UCB)
Jeffrey Fung (UCB)
Aaron Barth (UCI)

Francois Foucart (UCB) - "Gravitational waves and electromagnetic signals from neutron star mergers" Jeffrey Fung (UCB) - "3D Disk-Planet Interaction using GPU Computing" Aaron Barth (UCI [colloq. spkr.],) - "ALMA observations of molecular gas disks in early-type galaxies".

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Giant Planet Formation and Snowlines in Protoplanetary Disks

Wed, Sep 30, 2015 at 3:00 pm

131A Campbell Hall

Ana-Maria Piso (Harvard)

The composition of planets is determined by and tightly linked to the composition of the protoplanetary disk in which they form. In the first part of my talk, I will discuss giant planet formation through core accretion. Specifically, I will show how the minimum core mass required to form a giant planet during the lifetime of the protoplanetary disk depends on the location in the disk, the …

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The Hydrodynamics of Common Envelope Episodes and the Formation of Close Neutron Star Binaries

Mon, Sep 28, 2015 at 12:00 pm

131A Campbell Hall

Morgan Macleod (UCSC)

A dynamic and crucial phase in the evolution of a binary star system comes when one star engulfs its companion in a shared gaseous envelope. The two stellar cores spiral tighter in response to drag forces. Eventually, they may deposit enough energy and momentum to expel the envelope, leaving behind a binary transformed by orbital tightening and mass accretion. This talk explores the …

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New Constraints on Cosmic Reionization from Planck and Hubble Space Telescope

Thu, Sep 24, 2015 at 4:00 pm

1 LeConte Hall

Brant Robertson (UCSC)

Understanding cosmic reionization requires the identification and characterization of early sources of hydrogen-ionizing photons. The 2012 Hubble Ultra Deep Field (UDF12) campaign acquired the deepest blank-field infrared images with the Wide Field Camera 3 aboard Hubble Space Telescope and, for the first time, systematically explored the galaxy population deep into the era when cosmic …

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Department Lunch Talk 9-24

Thu, Sep 24, 2015 at 12:30 pm

131A Campbell Hall

Dick McCray (UCB) - "Mapping the reverse shock in SN1987A" Vikram Ravi (Caltech) - "Pulsar timing limit on gravitational waves necessitates re-think of binary supermassive black hole evolution" Brant Robertson (UCSC [colloq. spkr.]) - “A New Model for Understanding Supersonic Turbulence”.

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The nature of resolved structures in protoplanetary disks

Wed, Sep 23, 2015 at 3:00 pm

131A Campbell Hall

Robin Dong (UC Berkeley)

In the past few years, direct imaging at near-infrared (NIR) wavelengths and interferometric observations at millimeter wavelengths have revealed a panoply of fine structures in gaseous protoplanetary disks, such as spiral arms, gaps, streamers, and azimuthal asymmetries. The origins of these features are unknown at the moment, although many of them are widely speculated to be created by …

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Large Opacity Variations in the z~5.5 Lyman-alpha Forest: Implications for Cosmic Reionization

Tue, Sep 22, 2015 at 1:00 pm

131A Campbell Hall

Anson D’Aloisio (Washington)

When the first galaxies emerged, ~100 - 500 million years after the Big Bang, their starlight reionized and heated the intergalactic hydrogen that had existed since cosmological recombination. Much is currently unknown about this process, including what spatial structure it had, when it started and completed, and even which sources drove it. Recent observations of high-redshift quasars show …

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Molecular Gas and the Evolutionary Connection Between Submillimeter Galaxies and AGN at z~2-3

Mon, Sep 21, 2015 at 3:00 pm

131A Campbell Hall

Chelsea Sharon (Cornell)

Theoretical work has suggested that active galactic nuclei (AGN) play an important role in quenching star formation in massive galaxies. Direct evidence for AGN affecting the molecular ISM (the gas phase that fuels star formation) has so far been limited to detections of molecular outflows in low-redshift systems and extreme excitation regions which represent a tiny fraction of the total gas. …

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