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

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Updated: 9 hours 5 min ago

Nuclear Particle Astrophysics (NPA) Seminar (note special day and time), Francesco D'Eramo, UC Berkeley, "Hunting for WIMPs" - Fri, May 15, 2015

Fri, 05/15/2015 - 11:28am
When: Friday, May 15, 2015 2:00 PM - 3:00 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: Francesco D'Eramo, UC Berkeley

Description: A Weakly Interacting Massive Particle (WIMP) is a well-motivated dark matter (DM) candidate that can be searched for by different experimental strategies. In this talk, I will review the complementary WIMP searches, emphasizing how they are sensitive to physics at vastly different energy scale. Crucially, such a separation of scales may have striking consequences when a connection between different experiments is attempted. This motivates the construction of an Effective Field Theory (EFT) framework to properly connect the different energy scales involved in constraining WIMP models. I will build such a formalism and I will apply it to derive model independent bounds on WIMP interactions. I will conclude with possible future directions, both on extending the EFT machinery and applications to specific models.

Open To: Yale Community Only
Contact Information:
   John Harris
   
   john.harris@yale.edu
   

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

Thu, 05/07/2015 - 4:28am
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
   

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

Wed, 05/06/2015 - 4:24am
When: Wednesday, May 6, 2015 1:00 PM - 2:00 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