YCAA Logo
YCAA Logo
The Crab Nebula in Blue and White Credit & Copyright: Jay Gallagher (U. Wisc.),
The Crab Nebula in Blue and White Credit & Copyright: Jay Gallagher (U. Wisc.),
Interstellar Dust-Bunnies of NGC 891 Credit: C. Howk & B. Savage (Wisconsin);
Interstellar Dust-Bunnies of NGC 891 Credit: C. Howk & B. Savage (Wisconsin);
Hubble. Credit: R. Williams (STScI), the Hubble Deep Field-South Team, and NASA
Hubble. Credit: R. Williams (STScI), the Hubble Deep Field-South Team, and NASA
Dumbell. Credit & (c): Michael Pierce (Indiana U.) et al., WIYN, AURA, NOAO, NSF
Dumbell. Credit & (c): Michael Pierce (Indiana U.) et al., WIYN, AURA, NOAO, NSF
Abell 39.    (c): George Jacoby (WIYN Obs.) et al., WIYN, AURA, NOAO, NSF
Abell 39. (c): George Jacoby (WIYN Obs.) et al., WIYN, AURA, NOAO, NSF
Bubbling. Credit: Jeffrey Kenney (Yale) et al., WFPC2, HST NASA
Bubbling. Credit: Jeffrey Kenney (Yale) et al., WFPC2, HST NASA

Mailing Address

Yale Center for Astronomy and Astrophysics
Physics Department
P.O. Box 208120
New Haven, CT 06520-8120

Campus Address

260 Whitney Avenue
454 J.W. Gibbs Laboratory

Telephone: (203) 432-3392

Fax: 203) 432-3824

E-mail: ycaa@yale.edu

Upcoming YCAA Seminars

Syndicate content
Updated: 3 hours 25 min ago

Nuclear Particle Astrophysics (NPA) Seminar: Jenni Kotila, Yale University, "Double Beta Decay and Neutrino Mass" - Thu, May 7, 2015

3 hours 25 min ago
When: Thursday, May 7, 2015 3:30 PM - 4:30 PM
Where:
   Wright Lab, EAL 108 Conference Room (EAL108)
   268 Whitney Avenue, New Haven 06520
   (Location is wheelchair accessible)
Tags: astrophysics, nuclear_physics, particle_theory, science, seminar, talk

Speaker/Performer: Jenni Kotila, Yale University

Description: The question of whether neutrinos are Majorana or Dirac particles and what are their average masses remains one of the most fundamental problems in physics today. Observation of neutrinoless double-β decay (0νββ) would verify the Majorana nature of the neutrino and constrain the absolute scale of the neutrino mass spectrum. The inverse half-life for 0νββ-decay is given by the product of a phase space factor and a nuclear matrix element, which both rely on theoretical description, and a function f containing the physics beyond the standard model.

In this talk, recent calculations of phase space factors and nuclear matrix elements for 0νββ -decay proceeding through mass mechanism will be presented together with comparison to other available calculations. The question of renormalization of gA is also addressed. These calculations serve the purpose of extracting the average neutrino mass if 0νββ is observed, and of guiding searches if 0νββ is not observed. The current situation is then analyzed by combining the theoretical results with experimental limits on the half-life of neutrinoless double beta decay. The extracted limits on the average neutrino mass will be discussed.

A second, somewhat exotic mechanism for 0νββ- decay involves the emission of one or two additional bosons called Majorons. This decay has different electron spectrum and, therefore, also a different phase space factors depending on the spectral index n. Calculations with different n will be discussed as well as the half-life predictions for the ordinary Majoron decay (spectral index n=1). Furthermore, comparing theoretical predictions with the obtained experimental lower bounds for this decay mode we are able to set some limits on the effective Majoron-neutrino coupling constant

Open To: Yale Community Only
Contact Information:
   Kyungeun Lim
   
   kyungeun.lim@yale.edu
   

Nuclear Particle Astrophysics (NPA) Seminar (note special time): Zoltan Fodor, Institute of Theoretical Physics, Eotvos Lorand University,"Ab initio calculation of the neutron-proton mass difference" - Wed, May 6, 2015

3 hours 25 min ago
When: Wednesday, May 6, 2015 1:30 PM - 2:30 PM
Where:
   Wright Lab, EAL 108 Conference Room (EAL108)
   268 Whitney Avenue, New Haven 06520
   (Location is wheelchair accessible)
   Enter building through Wright Lab-West (268 Whitney). All other external doors are locked.
Tags: astrophysics, nuclear_physics, particle_theory, science, seminar, talk

Speaker/Performer: Zoltan Fodor, Institute of Theoretical Physics, Eotvos Lorand University

Description: The existence and stability of atoms rely on the fact that neutrons are more massive than protons. The mass difference is only 0.14% of the average. This tiny mass splitting has significant astrophysical and cosmological implications. A slightly smaller or larger value would have led to a dramatically different universe. Here we show, how this difference results from the competition between electromagnetic and mass isospin breaking effects. First we discuss how the masses of hadrons are generated. Then we compute the neutron-proton mass splitting and show that it is greater than zero by five standard deviations. In addition, this neutron-proton mass splitting is determined as a function of quark-mass difference and electromagnetic coupling. As a tool we perform lattice Quantum-Chromodynamics plus Quantum-Electrodynamics computations.

Open To: Yale Community Only
Contact Information:
   Megan Connors
   
   megan.connors@yale.edu
   

YCAA Seminar, Catarina Alves de Oliveira, European Space AgencyTitle:'Star Formation in Nearby Young Clusters' - Tue, April 28, 2015

Tue, 04/28/2015 - 4:37am
When: Tuesday, April 28, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 BASS
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at 2:00pm at the hallway outside the 3rd flr. BASS auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Catarina Alves de Oliveira, European Space Agency

Description: Abstract: Infrared surveys of nearby star-forming regions in our Galaxy have uncovered a large population of brown dwarfs, objects not massive enough to sustain hydrogen fusion. However, understanding the dominant brown dwarf formation process and assessing whether it shares a common channel with the formation of solar-type stars or giant planets still represents a major challenge. This question is more pertinent for the lowest mass objects, since it also determines the mass limit for star formation to occur. The observational properties derived for brown dwarfs in young clusters seem to show a global scaling down trend from those of stars, arguing in favour of a common formation scenario. However, most studies in young star forming regions suffer from incompleteness both in mass and spatial content. It is therefore unknown if, as one moves to lower masses, other formation mechanisms dominate. To address this question, we have carried out a large photometric and spectroscopic survey of nearby young clusters. I will present the results for the Rho Ophiuchi and IC348 clusters, where we derived a complete census of the substellar population down to the planetary mass regime (few Jupiter masses), and studied the properties of this new population such as spatial distribution, disks, and mass function, that must be reproduced and explained by any successful star formation theory.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

YCAA Seminar, Catarina Alves de Oliveira, Title:'Star Formation in Nearby Young Clusters' - Tue, April 28, 2015

Wed, 04/22/2015 - 4:36am
When: Tuesday, April 28, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 BASS
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at 2:00pm at the hallway outside the 3rd flr. BASS auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Scientist Catarina Alves de Oliveira

Description: Abstract: Infrared surveys of nearby star-forming regions in our Galaxy have uncovered a large population of brown dwarfs, objects not massive enough to sustain hydrogen fusion. However, understanding the dominant brown dwarf formation process and assessing whether it shares a common channel with the formation of solar-type stars or giant planets still represents a major challenge. This question is more pertinent for the lowest mass objects, since it also determines the mass limit for star formation to occur. The observational properties derived for brown dwarfs in young clusters seem to show a global scaling down trend from those of stars, arguing in favour of a common formation scenario. However, most studies in young star forming regions suffer from incompleteness both in mass and spatial content. It is therefore unknown if, as one moves to lower masses, other formation mechanisms dominate. To address this question, we have carried out a large photometric and spectroscopic survey of nearby young clusters. I will present the results for the Rho Ophiuchi and IC348 clusters, where we derived a complete census of the substellar population down to the planetary mass regime (few Jupiter masses), and studied the properties of this new population such as spatial distribution, disks, and mass function, that must be reproduced and explained by any successful star formation theory.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

YCAA Seminar Grant Tremblay, Yale U.Title: "A Two Billion Solar Mass Fountain of Cold Molecular Gas Pumped by a Black Hole" - Tue, April 21, 2015

Tue, 04/21/2015 - 4:46am
When: Tuesday, April 21, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 BASS
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at 2:00pm at the hallway outside the 3rd flr. BASS auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Einstein Fellow Grant Tremblay

Description: Abstract:A new ALMA observation of cool core galaxy cluster Abell 2597 reveals that a supermassive black hole can act much like a mechanical pump in a water fountain, driving a convective flow of molecular gas that drains into the black hole accretion reservoir, is pushed outward again in a jet-driven outflow, and falls once more back toward the galaxy center from which it came. The high spatial resolution CO(2-1) maps reveal shadows cast by giant molecular clouds falling on ballistic trajectories towards the black hole in the innermost 500 parsecs of the galaxy, manifesting as deep redshifted continuum absorption features. The black hole accretion reservoir, fueled by these infalling cold clouds, powers an AGN that drives a jet-driven molecular outflow in the form of a 10 kpc-scale, billion solar mass expanding molecular bubble. The molecular shell is permeated with young stars, perhaps triggered in situ by the jet. Buoyant X-ray cavities excavated
by the propagating radio source may further uplift the molecular filaments, which are observed to fall inward toward the center of the galaxy from which they came, presumably keeping the fountain long-lived. The results are inconsistent with the ``hot mode'' Bondi-like accretion scenario envisaged by many theorists, and show that both the mass and kinetic luminosity budgets of black hole accretion and feedback can be dominated by the cold molecular phase, suggesting that an AGN can indeed couple to the most important catalyst for galaxy evolution. However, the results also demonstrate that kinetic AGN feedback is not a "switch" that shuts off star formation, as the fountain consists not only of molecular gas, but young stars as well.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

Nuclear Particle Astrophysics (NPA) Seminar: Reina Maruyama, Yale University, "Results from the search for neutrinoless double beta decay of 130Te with CUORE-0" - Thu, April 16, 2015

Thu, 04/16/2015 - 4:28am
When: Thursday, April 16, 2015 3:30 PM - 4:30 PM
Where:
   EAL 108 Conference Room, Wright Lab (EAL108), Wright Laboratory
   270 Whitney Avenue, New Haven 06520
   Enter building through Wright Lab-West (268 Whitney). All other external doors are locked.
Tags: astrophysics, nuclear_physics, particle_theory, science, seminar, talk

Speaker/Performer: Reina Maruyama, Yale University

Description: The Cryogenic Underground Observatory for Rare Events (CUORE) will search for neutrinoless double beta decay of 130Te with an array of 988 TeO2 bolometers and a combined mass of 206 kg of 130Te. The discovery of this decay would demonstrate lepton number violation, establish the Majorana nature of neutrinos, and constrain the effective Majorana neutrino mass. CUORE-0, the first element of the CUORE detector array, was commissioned at the Laboratori Nazionali del Gran Sasso as a standalone experiment and has been taking data since March 2013. This talk will report the first results of a search for neutrinoless double beta decay in 9.8 kg-years of 130Te exposure collected between March 2013 and February 2015, and discuss the implications for the upcoming CUORE experiment.

Open To: Yale Community Only
Contact Information:
   Karsten Heeger
   
   karsten.heeger@yale.edu
   

YCAA Seminar,Jaymie Matthews,U. of British Columbia,A decade of exoplanets with Canada's MOST space telescope:From dark giants to superEarths - Tue, April 14, 2015

Tue, 04/14/2015 - 4:50am
When: Tuesday, April 14, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 BASS
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at 2:00pm at the hallway outside the BASS 3rd floor auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Professor & Mission Scientist MOST Space Telescope Project Jaymie Matthews

Description: Abstract:MOST (Microvariability & Oscillations of STars) is a microsat who original role (a one-year mission to study 10 stars) grew to become a spacebased stellar photometer operating for more than a decade studying thousands of stars, with applications and operating modes its designers never dreamed. Among MOST's expanded roles has been to be an exoplanetary 'explorer'. It set strict limits on the low albedo of a hot Jupiter, a world as reflective as charcoal. MOST showed how the magnetic field lines of a star can become tangled with the magnetosphere of a close-in planet, opening a window on exoplanetary magnetism.
It witnessed a planet excite pulsations in its parent star.
And MOST played a key role in characterising two of three known volatile-rich superEarths. One goal of NASA's TESS (Transiting Exoplanet Survey Satellite) mission is to follow in MOST's footsteps and find more.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

Nuclear Particle Astrophysics (NPA) Seminar: Thomas Hemmick, Stony Brook University, "RHIC to eRHIC: Revolution within Evolution" - Thu, April 9, 2015

Thu, 04/09/2015 - 4:44am
When: Thursday, April 9, 2015 3:30 PM - 4:30 PM
Where:
   EAL 108 Conference Room, Wright Lab (EAL108), Wright Laboratory
   270 Whitney Avenue, New Haven 06520
   (Location is wheelchair accessible)
   Enter building through Wright Lab-West (268 Whitney). All other external doors are locked.
Tags: astrophysics, nuclear_physics, particle_theory, science, seminar, talk

Speaker/Performer: Thomas Hemmick, Stony Brook University

Description: The physics program based at BNL's Relativistic Heavy Ion Collider (RHIC) has been wildly successful in discovering and characterizing the Quark-Gluon Plasma. Although the RHIC Heavy Ion program will unquestionably remain vibrant for many years, another longer-term possibility is emerging in the form of the so-called Electron-Ion Collider (EIC). This machine might be realized at Brookhaven as a successor to RHIC (eRHIC) or at Jefferson Lab as injected by CEBAF (MEIC). Increasingly intensive R&D on both the accelerator design(s) and detector technologies is ongoing. It can and will be argued that the EIC represents an historic anomaly of opportunity to unite the most diverse group of nuclear scientists ever assembled at the most flexible collider ever conceived. Although this talk will center mainly on interesting aspects of the ongoing detector R&D program, the author will not be shy in offering candid opinions on the program as a whole.

Open To: Yale Community Only
Contact Information:
   Megan Connors
   
   megan.connors@yale.edu
   

YCAA seminar: Alyson Brooks, Rutgers University Title: "Re-Examining Astrophysical Constraints on the Dark Matter Model" - Tue, April 7, 2015

Tue, 04/07/2015 - 4:32am
When: Tuesday, April 7, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 BASS
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at 2:00pm at the 3rd flr. BASS outside the auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Professor Alyson Brooks

Description: Abstract:The cosmological model based on cold dark matter (CDM) and dark energy has been hugely successful in describing the observed evolution and large scale structure of our Universe. However, at small scales (in the smallest galaxies and at the centers of larger galaxies), a number of observations seem to conflict with the predictions CDM cosmology, leading to recent interest in Warm DarkMatter (WDM) and Self-Interacting Dark Matter (SIDM) models. These small scales, though, are also regions dominated by the influence of baryons. I will present results from high resolution cosmological galaxy simulations that include both baryons and darkmatter to show that baryonic physics can significantly alter the dark matter structure and substructure of galaxies, revolutionizing our expectations for galaxy structure and influencing our interpretation of the Dark Matter model.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

Nuclear Particle Astrophysics (NPA) Seminar: Paul Sorensen, Brookhaven National Laboratory, "Finding Simplicity: Experimental Progress on Emergent Properties of QCD" - Thu, April 2, 2015

Thu, 04/02/2015 - 4:35am
When: Thursday, April 2, 2015 3:30 PM - 4:30 PM
Where:
   Wright Laboratory (WL), EAL 108 Conference Room
   272 Whitney Avenue, New Haven, CT 06511
   (Location is wheelchair accessible)
   Enter building through Wright Lab-West (268 Whitney). All other external doors are locked.
Tags: astrophysics, nuclear_physics, particle_theory, science, seminar, talk

Speaker/Performer: Paul Sorensen, Brookhaven National Laboratory

Description: "At some point, when you make things complicated enough, they become simple again.” That’s not good advice for how to write a talk, it is a quote from Arthur Poskanzer explaining the idea that drove him to become one of the experimental founders of the field of Heavy Ion Collisions. I’ll present exciting new results on extracting information about the emergent properties of finite temperature QCD and the phases of nuclear matter.

Open To: Yale Community Only
Contact Information:
   Megan Connors
   
   megan.connors@yale.edu
   

YCAA Seminar Kim-Vy Tran, Texas A&M, Title: "ZFOURGE: The Four-Star Galaxy Evolution Survey" - Tue, March 31, 2015

Tue, 03/31/2015 - 4:25am
When: Tuesday, March 31, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 BASS Auditorium
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at 2:00pm at the 3rd flr. BASS hallway outside the auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Kim Vy-Tran

Description: Abstract:ZFOURGE is a galaxy survey composed of approximately 30,000 galaxies at redshifts of 1z~7 Lyman Break galaxies, and discovery of a galaxy cluster at z=2.1.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

NPA Seminar: Edward Fenner, York University, "Smashing Atoms for Science & Profit: A brief history of the Van de Graaff Generator & High Voltage Engineering Corporation" - Thu, March 26, 2015

Thu, 03/26/2015 - 4:44am
When: Thursday, March 26, 2015 2:30 PM - 3:30 PM
Where:
   EAL 108 Conference Room (EAL108)
   270 Whitney Avenue, New Haven 06520
   (Location is wheelchair accessible)
   Enter building through WNSL-West (268 Whitney). All other external doors are locked.
Tags: astrophysics, nuclear_physics, particle_theory, science, seminar, talk

Speaker/Performer: Edward Fenner, York University

Description: Pioneering American physicists Robert J. Van de Graaff and John G. Trump, in 1946, created High Voltage Engineering Corporation (HVEC) to meet the intense demand for “atom smashers” for the new field of experimental atomic physics. HVEC would, for a time, be the world's leading manufacturer of high-quality accelerators and, over the several decades design, make, and distribute over 500 accelerators around the globe – many of which are still in use. This seminar will discuss: What kinds of contributions did these scientists and their machines make? How did a couple of virtuous professors end up as reluctant entrepreneurs? How influential was this company and technology to entrepreneurial science? Why mass-produce accelerators, anyway?

Open To: Yale Community Only
Contact Information:
   Karsten Heeger
   
   karsten.heeger@yale.edu
   

YCAA Seminar, Ji Wang, Yale University, Title: "Planet Formation Under Different Environments" - Tue, March 24, 2015

Tue, 03/24/2015 - 4:27am
When: Tuesday, March 24, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 BASS Auditorium
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at 2:00 pm at the 3rd flr. hallway outside the auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Ji Wang, Yale Astronomy Dept.

Description: Abstract:Abstract: Understanding planet formation under different environments constrains theory of planet formation and provides a pathway for future missions in search for habitable terrestrial planets. Planet formation and evolution is a complicated physical process with many variables.
Each variable affects the outcome of planet formation, e.g., planet occurrence rate. My research focuses on quantifying the influence of these variables on planet occurrence rate with a suite of observational studies. In particular, I will show that metal abundance affects not only gas giant planet formation but also terrestrial planets.
Terrestrial planets occur more frequently around stars with higher metallicity. In addition, I will provide observational evidence that planet formation in binary stars is different from that in single stars.
A stellar companion in a binary star can significantly influence the formation of planets. The influence varies as a function of companion separation, companion mass, and planet radius.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

YCAA Seminar Michelle Collins, Yale University Title: The Faintest Galaxies as Probes of Dark Matter and Galactic Evolution" - Tue, March 17, 2015

Tue, 03/17/2015 - 4:29am
When: Tuesday, March 17, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 BASS Auditorium
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at the 3rd flr BASS hallway outside the auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Hubble Fellow Michelle Collins

Description: Abstract:The masses measured for the faintest galaxies in the Universe — the dwarf spheroidals — appear to be at odds with those expected from cosmological simulations. The tension is that the systems we observe around the Milky Way have lower masses than predicted by dark matter only models. This leads to what has been termed the ‘Too Big to Fail’ (TBTF) problem. In this talk, I will present spectroscopic observations of the dwarf spheroidal galaxies orbiting our nearest spiral neighbor, Andromeda, in order to test some of the proposed solutions to the TBTF problem. I will examine whether this tension can be resolved by assuming the Milky Way has a fairly low mass, and whether the tidal forces exerted on dwarf galaxies as they orbit their hosts are much stronger than assumed in dark matter only simulations. I will also show new results for several surprisingly low mass dwarf spheroidal galaxies in the Local Group, whose properties challenge our expectations, and discuss various processes that may have led them to their present state.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

NPA Seminar: Krishna Kumar, Stony Brook University, "Electrons are not Ambidextrous: New Insights from a Subatomic Matter of Fact" - Thu, March 5, 2015

Thu, 03/05/2015 - 5:38am
When: Thursday, March 5, 2015 3:30 PM - 4:30 PM
Where:
   EAL 108 Conference Room (EAL108)
   270 Whitney Avenue, New Haven 06520
   (Location is wheelchair accessible)
   Enter building through WNSL-West (268 Whitney). All other external doors are locked.
Tags: astrophysics, nuclear_physics, science, seminar, talk

Speaker/Performer: Krishna Kumar, Stony Brook University

Description: Fixed target experiments at accelerators have been used since the dawn of modern physics to study the structure of matter. The most precise and detailed information on fundamental forces and the size and shapes of atomic nuclei and their constituents have come from electron scattering experiments. Over the past forty years, significant new discoveries about subatomic matter have been made by employing longitudinally polarized electron beams. There is a tiny difference (of order parts per million) between the probabilities for scattering left- and right-handed electrons off subatomic matter (this constitutes a failure of parity symmetry), which can be used to gain unique new insights into neutron distributions in nuclei, the nature of constituent quarks and sea quarks in nucleons, and to search for new interactions that might have shaped the evolution of the early universe. I will describe the experimental technique to measure the tiny left-right parity-violating asymmetries in electron scattering, report on the nuclear and particle physics implications of recent measurements, and motivate the need for new and more precise experiments.

Open To: Yale Community Only
Contact Information:
   Megan Connors
   
   megan.connors@yale.edu
   

YCAA Seminar, Cora Dvorkin, CfA, Harvard Title: "Deciphering the Early Universe" - Tue, March 3, 2015

Tue, 03/03/2015 - 5:40am
When: Tuesday, March 3, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 Bass Auditorium
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at 2:00pm at the 3rd flr. hallway outside the auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Hubble Fellow Cora Dvorkin

Description: Abstract:Cosmological observations have provided us with answers to age-old questions, involving the age, geometry, and composition of the universe. However, there are profound questions that still remain unanswered.
The origin of the small anisotropies that later grew into the stars and galaxies that we see today is still unknown. However, the nature of the anisotropies in the Cosmic Microwave Background (CMB) provides strong evidence that they were generated long before the CMB radiation had its last interaction with ordinary matter.
In the first part of this talk, I will explain how we can use measurements of the CMB, which was last scattered when the universe was 380,000 years old, to reconstruct the detailed physics of much earlier epochs, when the universe was only a tiny fraction of a second old.
In the last part of this talk, I will present the results of a joint analysis from BICEP2/Keck Array and Planck measurements of CMB polarization at different frequencies, and I will discuss the potential of upcoming high-sensitivity experiments to further constrain the physics underlying inflation.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

YCAA Seminar:Daniel Huber, NASA/AMES Title: "The Space Photometry Revolution of Asteroseismology & Exoplanets" - Tue, February 24, 2015

Tue, 02/24/2015 - 6:09am
When: Tuesday, February 24, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 BASS
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at 2:00pm at the 3rd floor BASS hallway outside the auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Dr. Daniel Huber

Description: Abstract:Asteroseismology - the study of stellar oscillations - is a powerful tool to probe the structure and evolution of stars. In addition to the large number of newly discovered exoplanets, space-based telescopes such as Kepler have revolutionized asteroseismology by detecting oscillations in thousands of stars from the main sequence to the red-giant branch. In this talk I will highlight the most recent asteroseismic discoveries by Kepler, focusing in particular on exoplanet host stars. I will furthermore discuss current efforts to improve fundamental properties of the Kepler parent sample and their importance for deriving accurate planet occurrence rates. Finally I will present first asteroseismic results by Kepler's ecliptic plane follow-up mission, K2, and discuss its role for probing the chemo-dynamical history of stellar populations in our Galaxy (galactic archeology).

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

YCAA Seminar, Johanna Teske, Carnegie Institution, Title:"Constraining Exoplanet Compositions via Host Star Abundances" - Tue, February 17, 2015

Tue, 02/17/2015 - 6:28am
When: Tuesday, February 17, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 BASS
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at 2:00pm at the 3rd floor BASS hallway outside the auditorium 305
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Dr. Johanna Teske

Description: Abstract:It is an open and actively researched question how/to what extent the presence and chemical compositions of planets correlate with those of their host stars, beyond the well-known giant planet-metallicity correlation. Particularly interesting is the relative importance of elements like C, O, Mg, or Si in the formation and heavy element enrichment of giant planets. The C/O ratio can be indicative of planetary formation history and location, and these are currently the most promising elements for measurement in both star and exoplanet atmospheres. Giant planet formation may be (more strongly) regulated by the presence of more refractory elements, like Si and/or Mg, if cores are dominated by rocky rather than icy material. The formation of small planets does not seem to show the same overall dependence on host star metallicity, but studies of solar twins and analogs suggest the formation of small planets may still imprint a signature on their host star abundances. I will present results of ongoing high resolution, high S/N spectroscopic studies of host star abundances to investigate how/to what extent planet composition, atmospheric and interior, is dependent on host star composition. I will also highlight why binary host stars are a valuable opportunity for disentangling how an individual star’s atmosphere may be affected by the formation of planets and its broader position in/motion through the Galaxy.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

YCAA Seminar, Mar Mezcua, Harvard, CfA, Title: Growing Black Holes: From the First Seeds to Active Galactic Nuclei - Tue, February 10, 2015

Tue, 02/10/2015 - 5:27am
When: Tuesday, February 10, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 BASS auditorium
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at the 3rd floor BASS hallway outside the auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Mar Mezcua

Description: Abstract:Supermassive black holes of up to 10^9 solar masses already existed when the Universe was less than ~1 Gyr old. To reach this mass in such a short time, they should have started as seed intermediate-mass black holes (IMBHs) of 100-10^6 solar masses and grow very fast via accretion and mergers. Such IMBHs are the missing link between stellar and supermassive black holes and they should be present in the nucleus of low-mass galaxies and in the halos of large galaxies, e.g. in the form of ultraluminous X-ray sources (ULXs). Nevertheless, observational evidence of their existence is still scarce.
To probe the existence of the initial seed IMBHs from which supermassive black holes grow, we studied jet radio emission in ULXs. The observations reveal two potential IMBH candidates, one of them in the nucleus of a dwarf galaxy, as well as the detection of the largest non-nuclear extragalactic jet ever discovered. Its location in the arm of a spiral galaxy likely undergoing a minor merger indicates that the nuclei of minor mergers remain amongst the best candidates for IMBHs. We thus carried out a photometric study of double-nucleus disk galaxies candidates to minor mergers. We find that active galactic nuclei (AGN) activity can be triggered by mergers, as expected from simulations, and define one of the largest samples of binary AGN candidates with physical separations below 1 kpc.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu
   

YCAA Seminar, Karoline Gilbert, STScI, Title:Stellar Halo Formation in a Hierarchical Universe: Lesson from Andromeda - Tue, February 3, 2015

Tue, 02/03/2015 - 6:13am
When: Tuesday, February 3, 2015 2:30 PM - 3:30 PM
Where:
   Bass Center for Molecular and Structural Biology (BASS), 305 Bass Auditorium
   266 Whitney Ave., New Haven, CT 06511
   (Location is wheelchair accessible)
   Tea will be served at 2:00pm at the 3rd floor BASS hallway outside the auditorium
Tags: astrophysics, science, seminar, talk

Speaker/Performer: Karoline Gilbert

Description: Abstract:Diffuse, extended stellar populations encode information about the earliest stages of a galaxy’s formation. The growth of the outer stellar halos of large disk galaxies like the Milky Way and Andromeda are thought to be dominated by the hierarchical merging of smaller stellar systems, while the inner halos are thought to be built through a combination of mergers and in situ star formation. Stellar halos thus provide a window into the growth of structure as well as an archaeological record of the population of dwarf galaxies that did not survive until the present day.
Large scale surveys of Andromeda's resolved stellar populations have revolutionized our view of this galaxy over the past decade. The combination of large-scale, contiguous photometric surveys and pointed spectroscopic surveys has been particularly powerful for discovering and following up new substructures and disentangling the structural components of Andromeda. I will review what we have learned about Andromeda's stellar halo, dwarf galaxy population, and disk from these surveys, with a focus on recent results from the SPLASH survey, which has now amassed spectra of nearly ten thousand red giant branch stars in Andromeda.

Open To: General Public
Contact Information:
   Laurelyn Celone
   
   laurelyn.celone@yale.edu