Poster Abstracts

Stay tuned for this page to be updated with your abstracts!

Galaxies in Transition: Morphologies of Post-Starburst Galaxies in the SQuIGGLE Survey

Presenter: Emma Krofcheck

Topic: Post-starburst Galaxies

Abstract: At present, the mechanisms that lead to the cessation of star formation in a galaxy (known as “quenching”) are poorly understood. The SQuIGGLE survey is a multi-wavelength study of post-starburst galaxies, designed specifically to study quenching in galaxies. In this study, post-starburst galaxies identified in the SQuIGGLE survey were matched with resolved images from the HSC survey. Sersic surface brightness profiles were fit to these images using GALFIT. The fits were visually analyzed and flagged based on the quality of the fit. Of the 93 galaxies that were fit, 63 were categorized as good fits. The remaining 30 were analyzed to see if a better fit was possible (e.g., by adding a second Sersic profile) or if tidal features made the galaxy difficult to model with a Sersic profile. These tidal features are indicative of galaxy mergers and may suggest a link between merging and quenching.

Searching for Planets Around Millisecond Pulsars

Presenter: Erica Behrens

Topic: Pulsars

Abstract: We search for extrasolar planets around millisecond pulsars (MSPs) using pulsar timing data and seek to determine the minimum detectable planetary masses as a function of orbital period. Using the 11-year data release from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), we look for variations from our models of pulse arrival times due to the presence of exoplanets. No planets are detected around the MSPs in the NANOGrav 11-year data set, but taking into consideration the noise levels specific to each pulsar as well as the sampling rate of our observations, we develop limits that show we are sensitive to planetary masses as low as those of the moon and even large asteroids.

A Method to Detect Neutron Star Mergers in Radio with ASKAP

Presenter: Emma Mirizio

Topic: Radio Astronomy

Abstract: The gravitational wave event GW170817 was historic in that it was the first neutron star merger to be detected not only by the Laser Interferometer Gravitational-Wave Observatory (LIGO), but in multiple electromagnetic wavelengths including radio. Recently, LIGO moved into its third observing run and has seen an influx of detections. Thus, it is important to develop a reliable method to search for radio signals following these transients. In this project, we utilized the capabilities of the Australian Square Kilometre Array Pathfinder (ASKAP) to search for the possible neutron star merger S190510g using images from ASKAP surrounding the detection of the candidate event. ASKAP has the sensitivity necessary to detect events such as GW170817, and the image collected following the event covered a large portion of LIGO’s sky localization for S190510g. By cross matching candidate optical galaxies with sources found in the radio images, we narrowed the analysis in the ASKAP field to 75 galaxies on the basis that radio sources without an optical counterpart are at too high a redshift to be detectable by LIGO. This method will be employed for future gravitational wave events that are poorly localized by LIGO to discover radio counterparts to neutron star mergers.

Constraining Type Ia Progenitor Environments with Late-Time Observations

Presenter: Jasmin Washington

Topic: Type Ia SNe

Abstract: A Type Ia supernova occurs when a white dwarf (WD) is disrupted, but how this occurs is unknown. One idea is the single degenerate scenario, where a white dwarf accretes mass from its nondegenerate companion until it reaches the Chandrasekhar limit (1.4 M) and explodes. In the double degenerate scenario, a Type Ia occurs when the white dwarf explodes due to interaction or a merger with another white dwarf. One thing astronomers look for to determine the progenitor scenario is a common envelope (CE) since it is more likely to be produced by a double degenerate scenario. Data were collected using the Very Large Array (VLA) in Socorro, NM. Radio observations were used since they are only sensitive to the synchrotron emission produced by the shock sweeping over material surrounding the explosion. Unlike previous studies, the focus of this project was older SNe, >1 yr after explosion, to take advantage of the VLA’s higher sensitivity to lower densities at later times and larger radii. All observations were nondetections so only upper limits could be calculated. The upper limits for the density of the material surrounding the explosion site were compared to radial density profiles of NGC 6818 and two epochs (A4 and A1) of a simulated planetary nebula from Garcia-Segura et al. 2018. Using a binomial distribution, it can be said with 3σ confidence that <13% of Type Ia’s are surrounded by NGC 6818-like common envelopes and <11% of Type Ia’s are surrounded by an A4-like common envelope. Since there are no constraints on A1, 100% of SNe Ia are consistent with being surrounded by an A1-like common envelope.

Dusty Tails of Disintegrating Exoplanets: A Multi-Wavelength Study

Presenter: Mary Elisabeth Brewer

Topic: Diffuser-Assisted, Multi-Wavelength Exoplanet Transit Photometry

Abstract: We are executing a ground-based, photometric, multi-wavelength observing campaign of K2-22 over ~15 months to study the light curve of the disintegrating, terrestrial exoplanet K2-22b. This campaign is investigating the temporal variation in transit depth, shape, and color-dependence of K2-22b's light curve. By determining the color dependence of transit shape, we will constrain the dust grain size in the comet-like tail. Time-dependent variations of the transit depth will allow us to ascertain the current status of the planet's disintegration.

Exoplanet Detection

Presenter: Helena Richie

Topic: Survey of Transiting Extrasolar Planets at the University of Pittsburgh

Abstract: STEPUP is an undergraduate research group lead by Helena Richie with the goal of discovering new exoplanets using transit photometry. By conducting observations using the 16” Keeler telescope based out of the Allegheny Observatory in Pittsburgh, PA, STEPUP is able to collect and analyze photometric data on planet candidate targets to draw conclusions about the existence of the planet. To process our data, we use STEPUP Image Analysis (SIA), an image analysis routine developed by Helena Richie that is responsible for calibrating, plate-solving, and performing absolute differential photometry on the datasets.

In the past, we have done work to contribute to data platforms such as the Exoplanet Transit Database, the American Association of Variable Star Observers, and publish unknown planetary parameters by collaborating observation. Currently, STEPUP is focusing its efforts on contributing data to the Transiting Extrasolar Survey Satellite (TESS) collaboration as members of the TESS Follow-up Observing Program Sub-Group 1 (TFOP SG1), which consists of seeing-limited photometric observers that do follow-up observations on TESS planet candidates (PCs) to weed out false positives.

A survey of low-speed meteor showers

Presenter: Kris Laferriere

Topic: Meteor showers

Abstract: The NASA Meteoroid Environment Office monitors and predicts meteor shower activity for active spacecraft and satellites. Currently, meteors detected by the NASA All Sky Fireball Network are identified as members of meteor showers using the times at which they occur and their geocentric velocity vectors. This creates an observational bias in which fast meteor showers appear more prominent; meteor showers with low geocentric velocities will have larger apparent scatter in the night sky. However, meteor showers of any geocentric velocity may produce significant particle fluxes which can be damaging to spacecraft. To reduce our detection bias against slow meteor showers, we instead survey the data for meteors clustered in time, heliocentric velocity, and heliocentric radiant. We present our findings, comparing our heliocentric shower survey results with those obtained using geocentric parameters.

Enlightening Students about Dark Matter

Presenter: Kathleen Hamilton-Campos

Topic: Dark Matter

Abstract: Dark matter pervades the universe. While it is invisible to us, we can detect its influence on matter we can see. To illuminate this concept, we have created an interactive javascript program illustrating predictions made by six different models for dark matter distributions in galaxies. Students are able to match the predicted data with actual experimental results, drawn from several astronomy papers discussing dark matter’s impact on galactic rotation curves. Programming each new model requires integration of density equations with parameters determined by nonlinear curve-fitting using MATLAB scripts we developed. Using our javascript simulation, students can determine the most plausible dark matter models as well as the average percentage of dark matter lurking in galaxies, areas where the scientific community is still continuing to research. In that light, we strive to use the most up-to-date and accepted concepts: two of our dark matter models are the pseudo-isothermal halo and Navarro-Frenk-White, and we integrate out to each galaxy’s virial radius. Currently, our simulation includes NGC3198, NGC2403, and our own Milky Way.

Time-Dependent Particle Acceleration in Crab Flares

Presenter: Claire Hinrichs

Topic: Supernova Remnants

Abstract: The Crab nebula and its pulsar (known together as the Crab) is one of the best studied astrophysical objects in our observable universe. In recent years, scientists have observed the Crab system flaring in high-energy gamma-rays, lasting time-scales of weeks. Observations of these flares exceed energies thought physically possible in pulsar wind nebulae, making the Crab one of the biggest astrophysics mysteries to date. I present our current observations of the Crab flares with the NASA Fermi Gamma Ray Space Telescope and our current understanding of the system. In my investigation, I constructed power density spectrums to determine frequency dependence in the flares. In addition, I performed a Bayesian block based analysis to define substructure in the flare light curves, and what physical parameters these might elude to. Lastly, I discuss how shock driven magnetic reconnection can be the key to understanding these unexpected observations.

Looking for Variability in Cygnus X-1

Presenter: Bailey Conrad

Topic: Black Holes

Abstract: We present observations of HDE 226868, the companion to Cygnus X-1. Low resolution (R=4.3 Å per pixel) spectra of the visible region, 6500 Å to 3000 Å, made with Maryland Space Grant Consortium’s 0.5-meter telescope at John Hopkins University over the summer. In the autumn, we made observations with Towson University’s 0.4-meter telescope. This region includes emissions from hydrogen and helium which are shown to be time variable by Gies et al. (2003), Yan et al. (2008). We examined these spectra for variability.

Probing Resonant Modes in Exotic Compact Objects via Gravitational Waves

Presenter: Yasmeen Asali

Topic: Gravitational Waves

Abstract: Gravitational waves are caused by accelerating massive objects and have been detected by LIGO. Quasi-normal modes are perturbations in the field that decay over time, and they can be excited during the inspiral of exotic compact objects due to internal resonances. Resonantly excited quasi-normal modes will result in a speeding up of the phasing of the gravitational waveform as energy is absorbed by the resonance. This feature has been shown in binary neutron star mergers, and this work explores similar resonant modes in exotic compact objects in the black hole mass range. We show that resonances with resultant phase shifts of order unity or larger can produce detectable events using a background-foreground approach for Bayesian model selection.

Modeling Galaxy Redshift in the LSST survey Context

Presenter: Zhiyao Li

Topic: Astrophysics, Machine Learning

Abstract:

Better Lyman Alpha Analysis for DESI Cosmology

Presenter: Wanting Niu (Victoria)

Topic: Lyman Alpha Analysis, Cosmological Measurement

Abstract: The Lyman Alpha Forest in the spectra of high-redshift quasars provides a useful tool for cosmological measurements because it contains information about the matter density distribution along the line of sight. However, about 12% of quasars have Broad Absorption Line (BAL) troughs that can make it difficult to measure the quasar redshift and the matter distribution. For large surveys like the Dark Energy Spectroscopic Instrument (DESI), which will measure the Lyman Alpha Forest with nearly a million high-redshift (z>2) quasars, it is particularly significant to have tools to simulate and automatically identify BAL quasars. We have developed an automatic “balfinder” that identifies BAL troughs in quasars and demonstrate the performance of this tool on simulated DESI observations of BAL quasars. The automated tool measures the location of the BAL troughs, which may be masked to improve redshift performance and increase the pathlength of the forest for Lyman alpha forest analysis. We are using this tool to revisit previous cosmological studies of the forest and present the current status of our analysis.

Acquiring Radio Sky Data to Train Machine Learning-Based Detection Algorithms for Research in Cosmology

Presenter: Ellie White

Topic: HI Cosmology, Radio Astronomy Instrumentation

Abstract: Strong galactic foreground emissions make it challenging for astronomers to detect the faint signature of neutral hydrogen (HI) from the Dark Ages of the Universe. The ground-based Cosmic Twilight Polarimeter (CTP) and the Dark Ages Polarimeter Pathfinder (DAPPER, a NASA mission concept for an instrument which will be launched into lunar orbit) are projects which will make use of the newly-developed dynamic polarimetry method to subtract foreground emissions out of cosmological HI measurements. In order to implement dynamic polarimetry in the CTP and DAPPER’s data pipelines, machine learning techniques will be used to create sky models of the galactic foreground. The goal of this summer’s project was to commission a radio telescope system to obtain observations of the galactic foreground for use in machine learning training sets. To achieve this, a disused antenna element from a decommissioned project was refurbished, a backend data analysis system was developed, and post-processing programs were written to enable the collection of sky data from the antenna’s deployment site at the Green Bank Observatory. The CTP and DAPPER project teams will utilize the data collected by this antenna to create machine-learning sky models to extract the cosmologically-significant HI signal using dynamic polarimetry.

A Multiwavelength Study of Messier 100

Presenter: Gracy Frost

Topic: Messier 100

Abstract: We present an HI, CO (J=1-0), and optical analysis of Messier 100 using unpublished archival data taken with the VLA, ALMA, and CFHT. Messier 100 is a grand design intermediate spiral galaxy of similar structure to the Milky Way and is one of the largest and brightest galaxies in the Virgo cluster. Our moment 0 maps show the HI has ring morphology, with a central H2 region implying central star-forming activity. We also produce rotation curves from the HI and H2 moment 1 maps.

Adding Water Worlds to a Model of the Kepler Exoplanets

Presenter: Jessica Liston

Topic: Exoplanets

Abstract: The Kepler survey has characterized the radius-period distribution of exoplanets, and ground-based telescopes have characterized the mass-radius relation. We expand upon the work of Neil & Rogers 2019, which creates a model to combine these into a joint mass-radius-period distribution of the Kepler exoplanets using Bayesian statistics and Markov-Chain Monte Carlo methods. We expand their models to include water worlds. We find that so far, a model which includes intrinsically icy, rocky evaporated core, and gaseous planets best fits the Kepler data. A model including only populations of rocky and icy planets does not fit the data well, but models of increasing complexity are needed.

Validation Tests for DESC Image Simulations

Presenter: Neha Joshi

Topic: galaxy catalog simulation validation

Abstract: In the LSST DESC DC2 catalogs, testing is needed to verify the latest catalog is valid. Plotting observational properties, splitting this data into quartiles and plotting each quartile for each Galaxy property, then comparing the plots of the observational and corresponding Galaxy properties shows how the observation of these galaxies affects the object catalogs. Ideally there should be no correspondence, and each quartile of the observational properties will look the same on the galaxy property plots.

Presenter: Gabriela Himmele

Topic: Gravity Waves, Notilucent Clouds

Abstract: Noctilucent clouds, also called polar mesospheric clouds (PMCs), one of the most unique visible events that occur in the upper atmosphere, require very specific conditions under which these clouds can form. Because of this, PMCs are extremely sensitive to the local environmental conditions especially atmospheric gravity waves. The tenuous nature of PMCs allows for any gravity waves propagating through the layer to be easily identified, offering the opportunity to observe and characterize the gravity waves visible in Cloud Imaging and Particle Size (CIPS) data. With gravity waves being the main driver of circulation in the mesosphere, the classification and analyses of the wave motion is especially important if a complete understanding of the meridional circulation in the mesosphere is to be desired. The goal of the ongoing research presented in this paper is to empirically classify the wave variance present in images provided by NASA’s Aeronomy of Ice in the Mesosphere (AIM) satellite using CIPS images. It has been found, when using two days of data as the statistical set, i.e., Julian days 194 and 211 in 2007 (30 orbits total), both of which contain concentric wave events, that the along-orbit extension of a 20-60 km wave packet will most likely reside in the layer between 900-1000 km. Additionally we found a higher fraction of wave structures possess lower albedo power corresponding to a smaller wave amplitude.