Events Archive

Tracing the origins of the relations between super-massive black holes and their host galaxies

Tue, Dec 15, 2015 at 1:00 pm

131A Campbell Hall

Benny Trakhtenbrot (Zurich)

In the local Universe, super-massive black holes (SMBHs) are observed to be closely linked to their host galaxies. In this talk I will address the co-evolution of SMBHs and their hosts, from the local Universe, out to z~4. Several observational studies suggest that SMBH growth generally precedes that of the stellar population in the host. Among these, I will present new results from a Keck …

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Examining the Role of Environment in AGN Jet Production

Mon, Dec 14, 2015 at 12:00 pm

131A Campbell Hall

Ashley King (Stanford)

Precise determination of fuelling and triggering mechanisms of AGN and their outflows is vital to understanding the feedback processes from supermassive black holes. By examining the frequency of AGN and their outflows in and outside of clusters, one can determine the effects of merging, gas stripping, and other dynamical effects. X-ray studies of this nature have shown that AGN are affected …

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Brown Dwarfs and Planets with Kepler and K2

Wed, Dec 9, 2015 at 3:00 pm

131A Campbell Hall

Ben Montet (Caltech)

While we know of thousands of brown dwarfs, only a handful have measured masses and radii. These  are typically younger or hotter than the field brown dwarf population, complicating efforts to understand the physical properties of field brown dwarfs for which atmospheric characterization is relatively simple. I will present an analysis …

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The Upgraded GMRT : Current Status and Future Prospects

Tue, Dec 8, 2015 at 12:00 pm

121 Campbell Hall

Yashwant Gupta (National Centre for Radio Astrophysics, Pune, India)

The Giant Metrewave Radio Telescope (GMRT) is today a major international Radio Astronomy facility working in five discrete bands in the frequency range of 150 MHz to 1500 MHz, with a maximum instantaneous bandwidth of 32 MHz. Consisting of 30 fully steerable antennas of 45 metre diameter each, it can be used as an aperture-synthesis array for imaging, as well as a phased …

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Molecular Gas, Chemical Enrichment, and Feedback on the Molecular ISM of Dusty Galaxies in the Early Universe

Mon, Dec 7, 2015 at 3:00 pm

131A Campbell Hall

Justin Spilker (Arizona)

Out to at least z~4, the abundance of galaxies with stellar masses above log(M*/Msun)~11 suffers an exponential drop. These galaxies host little ongoing star formation, and appear to have been quickly and efficiently "quenched," but the process(es) by which quenching occurs are poorly understood. Recent observations and circumstantial evidence suggest that the bulk of star formation …

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Dynamo Activity in Strongly Magnetized Accretion Disks

Mon, Dec 7, 2015 at 12:00 pm

131A Campbell Hall

Greg Salvesen (JILA)

Strongly magnetized accretion disks around black holes have attractive features that may explain enigmatic aspects of X-ray binary behavior.  The structure and evolution of these disks are governed by a dynamo-like mechanism, which channels part of the accretion power liberated by the magnetorotational instability (MRI) into an ordered toroidal magnetic field.  To study dynamo …

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Department Lunch Talk 12-3

Thu, Dec 3, 2015 at 12:30 pm

131A Campbell Hall

Ann-Marie Madigan (UCB)
Casey Law (UCB)
Tanmoy Laskar (UCB)

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.

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CIPS Seminar 12/2

Wed, Dec 2, 2015 at 3:00 pm

131A Campbell Hall

Paul Duffell (UC Berkeley)
David Romps (UC Berkeley)

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

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Constrain Galaxy Formation Physics from Large-Scale Structure Measurements and Weak Lensing

Tue, Dec 1, 2015 at 1:00 pm

131A Campbell Hall

Ying Zu, CMU

Galaxy formation is one of the most intractable phenomena in astrophysics due to the enormous complexity and diversity in the assembly histories of individual galaxies. Modern galaxy surveys provide a unique avenue to understanding galaxy formation physics in a statistical context, through various large-scale structure measurements and the weak gravitational lensing of large numbers of …

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A Cluster of Receding Halo Stars Towards Norma

Mon, Nov 30, 2015 at 3:00 pm

131A Campbell Hall

Sukanya Chakrabarti (Rochester Institute of Technology)

We present results from follow-up spectroscopic observations of clustered Cepheid candidates identified from K-band light curves towards the Norma constellation (Chakrabarti et al. 2015), as well as others that we have found more recently. The average radial velocity of these stars is ~ 200 km/s, which is large and distinct from that of the Galaxy’s stellar disk. These objects at l ~ …

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Turbulent Heating from Central AGN in Galaxy Clusters Brightest in X-rays

Mon, Nov 30, 2015 at 12:00 pm

131A Campbell Hall

Irina Zhuravleva (Stanford)

Cores of relaxed galaxy clusters are often disturbed by AGN activity as revealed by deep Chandra observations. Such perturbations reflect density and temperature fluctuations in the hot X-ray gas induced by shocks, subsonic gas motions, bubbles of relativistic plasma, etc. In my talk I will address the questions on the nature and energetics of the AGN-driven perturbations in the brightest …

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Characterizing Infrared Excess Sources in the Galactic Center with Adaptive Optics

Mon, Nov 23, 2015 at 12:00 pm

131A Campbell Hall

Breann Sitarski (UCLA)

The nature of G2, the cold emission-line object at the Galactic Center that survived its 2014 closest approach to the supermassive black hole at the center of our Galaxy, has been heatedly debated for the last several years. Its survival means that it most likely has a stellar core. Its large inferred size and cold temperature implies that it may be a black-hole driven binary merger. Using …

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The Multiwavelength Perspective on Gas, Dust and Star Formation in Nearby Galaxies

Thu, Nov 19, 2015 at 4:00 pm

131A Campbell Hall

Karin Sandstrom (UCSD)

The efficiency at which interstellar gas is converted into stars is one of the major factors governing the evolution and observable properties of galaxies at all redshifts.  In the Milky Way we can study the star formation process in great detail, but only over a limited range of environmental conditions.   We must move to nearby galaxies to expand this range.  Over the …

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Department Lunch Talk 11-19

Thu, Nov 19, 2015 at 12:30 pm

131A Campbell Hall

Kazumi Kashiyama, UCB
Mike Belyaev, UCB
Karin Sandstrom, UCSD [colloq. spkr.]

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.

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Towards an age for every star: calibrating the age-rotation relations

Wed, Nov 18, 2015 at 3:00 pm

131A Campbell Hall

Ruth Angus (Oxford)

In order to explore the evolution of planetary systems, we first need to improve the existing methods for inferring stellar ages. The age-rotation, or 'gyrochronology' relations have the potential to be an extremely powerful stellar dating method since only measurements of rotation period and mass (or mass proxy) are required to infer a star's age. However, data from the Kepler …

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