Institute for Nuclear and Particle Astrophysics (INPA) at LBNL

The INPA Seminar weekly talks are on Fridays, starting at 12:00 pm, unless informed otherwise. The seminar talk starts with a brief presentation of the weekly scientific news. Typically, the talks conclude by 1:00 pm. The seminars are held in the Sessler Conference Room,  located in Bldg. 50A- 5132.

The committee members are:

The seminar schedule for the Institute for Nuclear and Particle Astrophysics (INPA) is tentative and becomes final a few days before the Friday talk.

Please send all suggestions for future INPA talks and speakers to the INPA Committee.

To be added to the INPA News Mailing List, please contact Erica Hall.

Samuel Flender (ANL) – Cosmology and the Sunyaev-Zel’dovich sky: Observations and simulations

The Sunyaev-Zel’dovich (SZ) effect is an important observational signature of galaxy clusters, the largest objects in the Universe today. In particular, the pairwise kinematic SZ signal probes the matter-velocity correlation function, scaled by the average optical depth of galaxy clusters, and is thus an interesting probe both from a cosmological and astrophysical point of view. […]

Ken Chen (NAOJ) – Lighting up the Universe with Extreme Supernovae

Recent all-sky transient searches have discovered new and unexpected explosion types that fall outside traditional SN classification schemes. These exotic outliers in many cases are due to the deaths of massive stars and therefore may have been prevalent in the primordial universe because the Pop III IMF is thought to be top-heavy. Depending on the […]

Javier Caravaca Rodriguez (UCB) – Cherenkov and Scintillation light separation with the CHESS experiment

The first step toward construction of a hybrid optical detector like THEIA is the demonstration of separation of scintillation and Cherenkov light in liquid scintillators (LS). This would allow reconstruction of particle directionality in a low energy threshold detector, and provide improved particle identification. The CHESS experiment successfully images Cherenkov rings on LS such as […]

Daniel Dwyer (LBNL) – Evidence against sterile neutrinos from the Daya Bay Experiment

50A-5132- Sessler 50A-5132 Sessler Conference Room, CA

Prevailing models of antineutrino emission by nuclear reactors do not agree with observations. This discrepancy has been considered possible evidence for neutrino oscillation to non-interacting, or sterile, neutrino states. Although the existence of sterile neutrinos would have profound implications, a variety of measurements by the Daya Bay Experiment disfavor sterile models. I will summarize these […]

Jessica Lu (UCB) – New Developments in Adaptive Optics: Wide Fields and Precise PSFs

Adaptive optics correct for the blurring effects of the Earth’s atmosphere. However, most AO systems today suffer from limited fields of view and point spread functions that vary over time and position. I will present results from several experiments to overcome these limitations. We have deployed a ground-layer adaptive optics experiment on the UH 2.2 […]

Jon Ouellet (MIT) – ABRACADABRA: A New Approach to the Search for Axion Dark Matter

The evidence for the existence of Dark Matter is well supported by many cosmological observations. But we have not yet been able to determine how this new type of matter fits into our understanding of the Universe on the smallest scales. Separately, long standing problems within the Standard Model point to new weakly interacting particles […]

Titouan Lazeyras (MPA) – Dark matter halo bias from separate universe sim-ulations

The large-scale local bias parameters of dark matter halos are essential to describe the statistics of halos and galaxies on large scales, as well as for the halo model of the matter distribution. Using so-called separate universe simulations, we recently obtained precise measurements of the three leading bias parameters. For b2 and b3, these are […]

Jose Ezquiaga (UAM) – Testing dark energy and gravity with the speed of gravitational waves

LIGO’s gravitational waves (GWs) detection has inaugurated an era to test the foundations of gravity. This includes also probing the nature of Dark Energy. Theories explaining the present acceleration of the Universe beyond the cosmological constant typically require adding extra gravitational degrees of freedom. This can lead to distinct signatures in the propagation of GWs. […]

Giovanni Benato (LBNL) – Discovery probability of next-generation neutrinoless double-β decay experiments

50A-5132- Sessler 50A-5132 Sessler Conference Room, CA

Neutrinoless double beta (0νββ) decay is the only process which can feasibly investigate the Majorana nature of neutrinos and total lepton number conservation. A broad international experimental program requiring considerable resources is being mounted to search for 0νββ decay in the region of parameter space allowed for Inverted Ordering. The Bayesian discovery probability of future […]

Samuel Hinton – Bayesian Hierarchical Methods for Supernova Cosmology

In the era of precision cosmology, systematic uncertainty is quickly becoming the limiting factor in modern cosmological analyses. In my work, I discuss a method for performing supernova analyses by combining a hierarchical Bayesian framework with Monte-Carlo simulation realisations. This gains both the flexibility and speed of an analytic analysis along with the nuance and […]

Eddie Schlafly (LBNL) – Mapping the Galaxy’s Dust in 3D

50A-5132- Sessler 50A-5132 Sessler Conference Room, CA

The Milky Way's dust is of basic importance in astronomy. It is both crucial to the formation of stars and is a pervasive observational nuisance. Despite the dust's importance, existing dust maps are largely limited to two dimensions, with the distance to the dust unknown. The advent of large surveys like Pan-STARRS1 has allowed us […]

Yi-Kuan Chiang (Johns Hopkins) – Which Galactic dust map should I use? Insights from extragalactic tomography

INPA Common Room 50-5026

Over the past few years, clustering-based redshift estimation has emerged as a new way to estimate redshifts and perform extragalactic tomography of arbitrary datasets. On a similar timescale, observations by Planck, WISE, Pan-STARRS and 21cm radio surveys have been used to create a multitude of SFD-type Galactic dust maps. I will explain how clustering-based redshift […]

Oliver Just (RIKEN)​ – Modeling remnants of neutron-star mergers and core-collapse supernovae

50A-5132- Sessler 50A-5132 Sessler Conference Room, CA

Neutron-star mergers and core-collapse supernovae are promising events to herald a new era of multi-messenger astronomy, as they release substantial amounts of energy in gravitational waves, neutrinos, and electromagnetic emission. Moreover, these events are connected to long-standing physics questions related to, e.g., heavy-element nucleosynthesis, gamma-ray bursts, and the nuclear equation of state. However, while offering […]

Stephen Portillo (Harvard) – Improved Source Detection in Crowded Fields using Probabilistic Cataloging

50A-5132- Sessler 50A-5132 Sessler Conference Room, CA

Cataloging is challenging in crowded fields because sources are extremely covariant with their neighbors and blending makes even the number of sources ambiguous. We present the first optical probabilistic stellar catalog, cataloging a crowded (~0.1 sources per pixel) Sloan Digital Sky Survey r band image from M2. Probabilistic cataloging returns an ensemble of catalogs inferred […]

Marie Lau (UC Santa Cruz) – Quasars Probing Quasars: the Circumgalactic Medium Surrounding z ~ 2 Quasars

50A-5132- Sessler 50A-5132 Sessler Conference Room, CA

Understanding the circumgalactic medium--the gaseous halo surrounding a galaxy, is an integral part to understanding galaxy evolution. The z ~ 2-3 universe is interesting as this is when the star formation rate and AGN activity peak. My work concludes the decade-long Quasars Probing Quasars survey designed for studying massive galaxy formation and quasar feedback. I […]

Michael Walther (UCSB) – New Constraints on Thermal Evolution in the IGM from the Small Scale Lyα Forest Power Spectrum

50A-5132- Sessler 50A-5132 Sessler Conference Room, CA

The line-of-sight power spectrum (P_F(k)) of the Ly-α forest has proven to be a valuable tool for doing cosmological observations. It also not only allows to constrain cosmological parameters, but enables us to measure the thermal state of the IGM at redshifts z>1.8. While at large scales (k<0.02 s/km) P_F(k) has been accurately measured using […]

Prabhat (NERSC at LBL) – Deep Learning for Science

50A-5132- Sessler 50A-5132 Sessler Conference Room, CA

Deep Learning has revolutionized the fields of computer vision, speech recognition and control systems. Can Deep Learning (DL) work for scientific problems? This talk will explore a variety of DOE/LBL applications that are currently benefiting from Deep Learning. We will review classification and regression problems in astronomy, cosmology, neuroscience, genomics and high-energy physics. We will […]

Xavier Prochaska (UCSD) – Deep Learning of Quasar Spectra

50A-5132- Sessler 50A-5132 Sessler Conference Room, CA

I will describe our development of a convolutional neural network (CNN) to learn to search for and characterize absorption lines in quasar spectra. Specifically, the algorithm discovers and measures the redshift and Hydrogen column density of damped Lya systems (DLAs). These systems dominate the neutral hydrogen gas of the universe, trace the interstellar medium of […]

INPA guests from campus can now come to the lab early on Fridays. The INPA Common Room (50-5026) is reserved for our guests from 10:00 a.m. to 12:00 noon and from 1 p.m. to 5 p.m. Note that the seminars are now held in 50A-5132 to accommodate a more significant number of attendees.

CPTea Series (also known as INPA Tea Series)

The Physics Division CPTea Series invites you to an In-Person Tea Series 1st Friday of every month at 3:30 pm INPA Conference Room 50-5026.

Everyone is welcome to attend the open forum. Tea and light refreshments will be served.

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INPA Common Room (50-5026)
Fridays
3:30 pm

Access to the Lab

For a shuttle pass, please email Erica Hall. The pass is only valid for the day of the seminar.

Erica Hall