Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 8 of 8

Full-Text Articles in Astrophysics and Astronomy

Preparing A Database Of Extremely High Velocity Outflows In Quasars, Griffin Kowash, Carla P. Quintero, Sean S. Haas, Paola Rodriguez Hidalgo Sep 2019

Preparing A Database Of Extremely High Velocity Outflows In Quasars, Griffin Kowash, Carla P. Quintero, Sean S. Haas, Paola Rodriguez Hidalgo

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.


A Bayesian Approach To Deriving Ages Of Individual Field White Dwarfs, Erin M. O'Malley, Ted Von Hippel, David A. Van Dyk Aug 2019

A Bayesian Approach To Deriving Ages Of Individual Field White Dwarfs, Erin M. O'Malley, Ted Von Hippel, David A. Van Dyk

Ted von Hippel

We apply a self-consistent and robust Bayesian statistical approach to determine the ages, distances, and zero-age main sequence (ZAMS) masses of 28 field DA white dwarfs (WDs) with ages of approximately 4-8 Gyr. Our technique requires only quality optical and near-infrared photometry to derive ages with <15% uncertainties, generally with little sensitivity to our choice of modern initial-final mass relation. We find that age, distance, and ZAMS mass are correlated in a manner that is too complex to be captured by traditional error propagation techniques. We further find that the posterior distributions of age are often asymmetric, indicating that the standard approach to deriving WD ages can yield misleading results.


The Disk Structure Of Late Type Galaxies: Determining The Black Hole Mass Function Of Low Surface Brightness Galaxies Through Logarithmic Spiral Arm Pitch Angle Measurement, Michael S. Fusco Aug 2019

The Disk Structure Of Late Type Galaxies: Determining The Black Hole Mass Function Of Low Surface Brightness Galaxies Through Logarithmic Spiral Arm Pitch Angle Measurement, Michael S. Fusco

Graduate Theses and Dissertations

This dissertation pertains to the geometric structure of late type (spiral) galaxies, specifically on the relation between the logarithmic spiral pitch angle of the galactic spiral arms with other properties of the galaxy, such as central Supermassive Black Hole (SMBH) mass. Our work continues a study of the Black Hole Mass Function (BHMF) in local galaxies by recording the pitch angles of spiral galaxies with lower surface brightness than were previously included. We also conduct a case study on the structure of an interestingly shaped galaxy, UGC 4599. Previous studies on the topic of spiral arm pitch angles have measured …


Thornado-Hydro: Generalizing Discontinuous Galerkin Methods For A Nuclear Equation Of State For Supernova Hydrodynamics, Brandon Lynn Barker, Eirik Endeve, Anthony Mezzacappa May 2019

Thornado-Hydro: Generalizing Discontinuous Galerkin Methods For A Nuclear Equation Of State For Supernova Hydrodynamics, Brandon Lynn Barker, Eirik Endeve, Anthony Mezzacappa

Chancellor’s Honors Program Projects

No abstract provided.


Measuring Deterministic And Stochastic Gravitational Waves With Pulsar Timing Array Experiments, Kristina Islo May 2019

Measuring Deterministic And Stochastic Gravitational Waves With Pulsar Timing Array Experiments, Kristina Islo

Theses and Dissertations

Pulsar timing arrays (PTAs) are uniquely poised to detect the nanohertz-frequency gravitational waves from supermassive black hole binaries (SMBHBs) formed during galaxy merger. Efforts are underway to observe three species of gravitational signal from these systems: the stochastic ensemble, individual, adiabatic binary inspirals, and bursts with memory. This dissertation discusses all three.

A typical Bayesian search for evidence of a stochastic gravitational wave background from the superposition of many unresolvable SMBHB inspirals requires weeks to months to deliver results. This is due in part to the inclusion of inter-pulsar spatial and temporal correlations induced in PTA data by such a …


Waveband Luminosity Correlations In Flux-Limited Multiwavelength Data, Jack Singal, V. Petrosian, Sami Malik, Jibran Haider Jan 2019

Waveband Luminosity Correlations In Flux-Limited Multiwavelength Data, Jack Singal, V. Petrosian, Sami Malik, Jibran Haider

Physics Faculty Publications

We explore the general question of correlations among different waveband luminosities in a flux-limited multiband observational data set. Such correlations, often observed for astronomical sources, may be either intrinsic or induced by the redshift evolution of the luminosities and the data truncation due to the flux limits. We first address this question analytically. We then use simulated flux-limited data with three different known intrinsic luminosity correlations and prescribed luminosity functions and evolution similar to the ones expected for quasars. We explore how the intrinsic nature of luminosity correlations can be deduced, including exploring the efficacy of partial correlation analysis with …


Gwtc-1: A Gravitational-Wave Transient Catalog Of Compact Binary Mergers Observed By Ligo And Virgo During The First And Second Observing Runs, B. P. Abbott Jan 2019

Gwtc-1: A Gravitational-Wave Transient Catalog Of Compact Binary Mergers Observed By Ligo And Virgo During The First And Second Observing Runs, B. P. Abbott

Faculty & Staff Scholarship

We present the results from three gravitational-wave searches for coalescing compact binaries with component masses above 1 M⊙ during the first and second observing runs of the advanced gravitationalwave detector network. During the first observing run (O1), from September 12, 2015 to January 19, 2016, gravitational waves from three binary black hole mergers were detected. The second observing run (O2), which ran from November 30, 2016 to August 25, 2017, saw the first detection of gravitational waves from a binary neutron star inspiral, in addition to the observation of gravitational waves from a total of seven binary black hole mergers, …


The Invisible Sun: Building A Radio Interferometer Telescope, Isobel Curtin Jan 2019

The Invisible Sun: Building A Radio Interferometer Telescope, Isobel Curtin

Senior Projects Spring 2019

When we think of astronomy, we often associate the word implicitly with observing astronomical bodies with our own eyes, or from a signal collected in the visible light range. However, there is more information we can collect from these bodies when observing them using other kinds of light, unseen to the naked eye. Radio astronomy is an important tool in an astronomer’s toolkit, and can help us image hidden parts of the universe. Recently, radio astronomy was used to directly image a black hole in the center of a nearby galaxy for the first time!

This projects aims to further …