40th Annual Central Pennsylvania
Consortium
Astronomers' Meeting
Saturday, April 20, 2024
8:15 a.m. - 4:00 p.m.
Franklin & Marshall College
LSP Room 142
Schedule of Events
We'd like there to be ample time for discussion after each
presentation. The times listed after the talks indicate the talk time
+ discussion time (in units of minutes). Speakers should make sure
that their talks are no longer than the talk time.
All oral presentations will be in LSP Room 142.
Morning Oral Session
8:15 - 9:00 a.m.: Registration and Breakfast in LSP Lobby
9:00 - 9:15 a.m.: Welcome to Franklin and Marshall College
9:15 - 9:35 a.m.: Steven Clark (Hood College), "Ascertaining
the Primordial Matter Power Spectrum Through Gravitational Waves and
Primordial Black Holes" (15+5)
The primordial matter power spectrum is a description of how matter
was distributed in the early universe. Due to its location in
cosmological history, it is difficult to measure, but future
gravitational wave experiments offer a possible path through the
stochastic background. Primordial black holes on the other hand are
produced in the early universe due to large curvature perturbations
and can provide another possible avenue through measurements of their
electromagnetic signature. By correlating both signals, very precise
measurements of the matter power spectrum can be achieved.
9:35 - 9:55 a.m.: Stephanie Douglas (Lafayette College),
"Constraining Stellar Rotation at the Zero-Age Main Sequence" (15+5)
As stars approach the main sequence, they contract and spin more
rapidly; once they reach the main sequence, they stop contracting and
their spin speed decreases. This spin-down is widely considered to be
caused by angular momentum lost via stellar winds. At and beyond the
zero-age main sequence (ZAMS), internal angular momentum transport
between the core and outer envelope is thought to be crucial for
understanding surface spin rates. We present the first robust
observational constraints on rotation for FGK stars at this critical
age. We analyze TESS light curves for 1410 members of five young open
clusters with ages between 25 and 55 Myr. In total, we measure 868
rotation periods, including 96 new, high-quality periods for stars
around 1 M_sun. This is an increase of ten times the existing
literature sample at the ZAMS. We then compare our data to models for
stellar angular momentum evolution. Although the ages derived from
these rotation models do not match isochronal ages, we show that these
observations can clearly discriminate between different models for
stellar wind torques. In addition, our results indicate that magnetic
braking and/or internal angular momentum transport significantly
impact rotational evolution even on the pre-main sequence.
9:55 - 10:15 a.m.: Braden Wolf (Gettysburg College), "The CPALS
Algorithm: Accounting for Light Speed in Simulations" (15 +5)
Projecting data from cosmological simulations to match observations
of galaxy clusters has traditionally been a computationally expensive
method, due to the requirements for running the common light cone
algorithms and the storage of additional simulation snapshots. This
paper presents a numerical algorithm for creating projections of
galaxy clusters from cosmological simulation data using the "onion
method" of light cone generation. Our method differs from the typical
method in that it can be run on simulation data posteriori, from
archived simulation snapshots, rather than at the time of simulation.
My talk will describe the underlying method we implement in our
algorithm, as well as presenting a comparison of some newly projected
data to the original. The resulting projected output data may then be
used to compute astrophysical statistics of interest (such as radial
velocity dispersion). To illustrate one possible application for the
method, we will compare some of those statistics between both the
projected and unprojected simulation clusters. I will also provide
some performance analyses of our method, which we are calling the
Cluster Projection Accounting for Light Speed (CPALS) algorithm.
10:15 - 10:35 a.m.: W. N. Brandt (Penn State), "New Results from
the XMM-SERVS X-ray Survey of the LSST Deep-Drilling Fields" (15+5)
Cosmic X-ray surveys over the past two decades have played a
critical role in transforming our understanding of growing
supermassive black holes (SMBHs) in the distant universe. I will
describe new results from one key survey advancing this effort: the
13.1 deg^2 XMM-SERVS survey. XMM-SERVS has successfully mapped three
LSST Deep-Drilling Fields (DDFs) at 50 ks XMM-Newton depth, focusing
on the SERVS areas of W-CDF-S, XMM-LSS, and ELAIS-S1. These fields
have first-rate multiwavelength coverage already and are LSST/DES
DDFs, MOONS/PFS/4MOST massive spectroscopy fields, prime TolTEC/ALMA
fields, and SDSS-V/4MOST multi-object reverberation-mapping
fields. About 12,000 X-ray sources have been detected and
characterized, the majority of which (86%) are active galactic nuclei
(AGNs), and these are presently being studied. I will summarize
science investigations including multiwavelength fitting of
infrared-to-X-ray spectral energy distributions, identification of the
most highly X-ray obscured AGNs, dwarf AGN studies, combined
radio/X-ray AGN investigations, and mapping of cosmic SMBH growth as a
function of galaxy stellar mass.
10:35 - 10:55 a.m.: Emily Wilson (Lycoming College), "ChatGPT
in Advanced Stellar Evolution Course" (15+5)
Generative AI is a tool that our students will be expected to know
how to use in the workforce. Though it continues to advance, it will
always have limitations. In an upper-level stellar evolution course,
students were asked to prompt ChatGPT to write and solve an advanced
astrophysics problem related to class concepts, then analyze the
solution on their own. During this process, not only were robust
student perceptions of ChatGPT recorded, but the critical thinking
skills demonstrated by students far exceeded any other assignment
submitted throughout the semester. Several anecdotes indicate that
assigning this type of ChatGPT project may serve to develop a modern
skill and serve as an evaluable demonstration of widely applicable
problem solving skills for students.
10:55 - 11:25 a.m.: Coffee Break and Poster Session
11:25 a.m. - 12:25 p.m.: KEYNOTE ADDRESS, Arpita Roy (Schmidt
Futures), "The Ecosystem of Astrophysics: Your Science in Context of
the World"
Astronomical discovery is an incredibly engaging pursuit, from the
quest for life on nearby exoplanets to cosmic questions about the
birth and death of the Universe. However, as you step into the world
of professional science, it is just as valuable to understand the
ecosystem in which our science is enabled. In this talk, I will ask us
to look beyond our telescopes and Jupyter notebooks for a moment, to
consider the organization and trajectory of the field itself. The
ecosystem of astrophysics is created by the priorities and opinions of
people within it, and we will discuss how policy decisions and funding
mechanisms cascade through the academic hierarchy, ultimately
influencing the opportunities available to students and
researchers. We will discuss why some subfields thrive while others
wait decades for resources and data, and we will challenge ourselves
to consider the balance between leading and following the trends
within the field. Situating your scientific interest in a global
context also allows you to see the profound impact we often have, far
from the esoteric core of our work. We will touch on the ambitious
observatories and missions that are promised for your use in the
coming decades, and how you might navigate this interconnected
landscape to make a lasting impact on both the field and the future.
Lunch
Afternoon Oral Session
1:25 - 1:45 p.m.: Charles Reisner (Franklin and Marshall
College), "Modeling High-Redshift Emission Lines from the CECILIA
Survey" (15+5)
The recent CECILIA survey has demonstrated that JWST will
facilitate observations of high-wavelength emission lines from
star-forming galaxies at high redshifts (z >= 2). Although observed
emission lines provide information about several characteristics of
their sources, the values of the parameters that produce them are not
fully understood. Matching modeled emission lines of star-forming
regions to those observed can provide insight into approximately which
chosen parameters may be responsible for the observed data. Using
Cloudy photoionization code and spectral synthesis models, I attempt
to replicate the conditions that produced the emission lines measured
in the CECILIA survey. I vary emission line intensities as a function
of the ionization parameter, the nebular and stellar metallicities of
the star-forming region, and extinction. I then use Markov Chain
Monte Carlo (MCMC) methods to statistically compare the
model-generated emission lines to those of CECILIA.
1:45 - 2:05 p.m.: Adib Kabir (Gettysburg College), "Measurement
of Proton's Energy Loss Through Thin Gold Film" (15+5)
The National Institute of Standards and Technology (NIST) aims to
reduce the systematic uncertainties of the energy spectrum in the
neutron's lifetime experiment, but the presence of any "dead" layer
inside the detector affects the energy spectrum of low-energy ions. In
order to take this factor into account, we conducted this experiment
to determine energy loss spectra of proton beam within the Gold dead
layer and compare this spectra with the Stopping Power (SP) of Gold
from the NIST's database. To that end, we generated 50-200 keV energy
proton beam in Gettysburg College's 200 keV Van de Graff proton
accelerator and collected the proton counts received by the detector,
containing Gold layer, for different corresponding energy channels
using energy spectra measuring software. As a result, we had to
evaporate gold onto different batches of circular glass slides, and Si
detector within the Gold Evaporator chamber and determined the
thickness of gold layers by utilizing UV-Vis Spectroscopy technology,
and AFM Technology. Employing these data, we plotted SP of the Gold
dead layer versus the kinetic energy of the proton beam using the
thickness function of the Gold and differentiated this plot with the
graph of SP of Gold collected from the NIST database.
2:05 - 2:25 p.m.: Melissa Morris (Lycoming College), "What Can
Radio AGN with Bent Jets Tell Us About Galactic Environments?" (15+5)
A galaxy's environment has a huge impact on its evolution. This is
seen across a wide range of locations, from the densest of galaxy
clusters to vast voids of space. How environments affect galaxy
evolution largely depends on the amount of gas that permeates these
dense regions of space. Galaxy groups, which are typically smaller
than clusters, host most of the galaxies in our local universe, yet
direct observation of the gas that exists in these environments has
proven challenging for modern X-ray observatories. However, by
studying the effect this gas can have on galaxies that are embedded
within it, we can begin to measure how much gas actually resides in
these environments. Radio AGN are unique tools in studying galaxy
environments, as their morphologies are particularly sensitive to
their surroundings. Specifically, an AGN's jets can be bent back by
ram pressure from a surrounding medium. We can use observations of
these bent jets to measure the density of the medium through which
they are traveling. We've studied a sample of bent and unbent AGN jets
to characterize their environments and found that bent AGN tend to
exist in denser, larger, dynamically younger environments than other
radio AGN, supporting the fact that they are being bent back by a
surrounding gaseous medium. Furthermore, we have used a sample of bent
AGN in galaxy clusters to estimate the density of the intracluster
medium, allowing us to compare our measurements to X-ray
measurements. Preliminary results have shown that our method can
effectively carry out this measurement, as long as we can estimate the
relative velocity between the AGN and the surrounding medium. Current
and future work involves using AGN with bent jets to measure the
density of gas in a sample of 13 galaxy groups and expanding our
sample of AGN with bent jets using the Very Large Array Sky Survey.
2:25 - 2:45 p.m.: Fan Zou (Penn State), "How Do Supermassive
Black Holes Grow from z=4 to z=0?" (15+5)
Supermassive black holes (SMBHs) grow together with their host
galaxies throughout cosmic time, and two growth channels are present -
accretion and merger. I will talk about our recent efforts to build a
complete picture of the SMBH growth under these two channels. First,
regarding the accretion channel, it has been shown that the population
mean SMBH accretion rate primarily correlates with galaxy stellar mass
and redshift for the general galaxy population. I will present the
best measurements of this function with our compilation of an
unprecedentedly large sample from nine high-quality survey fields and
our development of an advanced semiparametric Bayesian method. I will
then combine our observationally constrained accretion channel with
modern cosmological simulations, which provide merger information, to
illustrate how SMBHs evolve from z=4 to z=0. Our analyses can address
multiple issues about the SMBH population, such as their mass
function, their scaling relation with their host stellar mass, and the
contributions of the two growth channels to the overall SMBH
population growth.
2:45 - 3:05 p.m.: Coffee Break and Poster Session
3:05 - 3:25 p.m.: George Carson (Dickinson College),
"Photometric Analysis of the Eclipsing Binary KH 15D" (15+5)
The edge-on binary T Tauri star V582 Mon (KH 15D) is surrounded by
a tilted disk of dusty material that has occulted one or both stars
periodically since first being noticed in 1995. The circumbinary disk
has been modeled to have a period of approximately 1000
years. Following the complete obscuration of both stars, which ended
in 2012, the trailing edge of the circumbinary disk began to uncover
the orbit of star B, and will soon begin to uncover the orbit of star
A. We present results from recent (2018-2024) observing campaigns as
collected by Dickinson's Britton Observatory as well as data from
Lowell Observatory, Cerro Tololo Inter-American Observatory (CTIO),
and multiple amateur astronomers. Following an extensive
reorganization of this and historical data for future standardization,
we have confirmed results on the orbital period of the binary to be
48.37 days through periodogram analysis. Despite star B being mostly
unobscured, we were unable to extract a rotation period through a
similar periodogram analysis. Currently, we are exploring the
inconsistent density of the circumbinary disk, notably the presence of
non-uniform clumps of material in the trailing edge compared to the
sharpness of the leading edge. Extinction and color changes of the
system's light curve allow insight into the size of the particles
within the trailing clumps assisting our understanding of the
properties of the disk. Using data collected in 2018-2019 and data
from 2022-2023, we report on how the morphology of the disk has
changed through extinction analysis. In the future, we hope to collect
enough data for the period of star B to be resolvable and hopefully
begin to view star A. We plan on continuing work on extinction and
color analysis for 2019-2022 and for new data collected in 2024 to get
a better picture of the changing structure in the outer disk. The
clumpiness and transparency of the outer occulting material provide a
unique opportunity to study the properties of dust grains in a
potential planet-forming zone. Continued observations of the system
carry significant importance since, in relatively short order, we will
no longer be able to utilize the geometry of the system to probe the
disk material.
3:25 - 3:45 p.m.: Phill Reed (Kutztown University),
"TESS Reveals Details of KU Cygni's Accretion Disk" (15+5)
KU Cygni is a long-period (~38.4 days) interacting Algol-type
eclipsing binary star known to exhibit strong double-peaked hydrogen
emission lines due to its relatively persistent accretion
disk. However, it has also been shown to undergo episodic dimming
events arising from a thickening of the disk, followed by brightening
as dust presumably migrates inward through the disk and
evaporates. This makes KU Cyg an excellent natural laboratory for
observing dynamic physical processes within its accretion disks and
for investigating the disk's physical properties such as viscosity. We
present high-cadence TESS photometry and identify rapid variability
(flickering) that is likely due to transits of high density/opacity
disk regions across the line of sight to the primary star, and we
support these observations with coinciding ground-based spectroscopy
and multi-band photometry. We show that the secondary star is not
significantly variable and we identify a correlation between the
observed photometric variations and the strengths of certain
absorption lines associated with the primary star, such as Fe II.
3:45 - 4:00 p.m.: Concluding Remarks
Poster Presentations
Matthew Motuz (Lycoming College), "Exomoons Can Survive Stellar
Engulfment"
Adib Kabir (Gettysburg College), "Measurement of Proton's Energy Loss
Through Thin Gold Film"
Yaman Acharya (Gettysburg College), "Simulating the Cosmic Web with
Zeldovich Pancake"
Charles Reisner (Franklin and Marshall College), "Rotation Slicing:
Using Astropy to Investigate Tilted Infall Regions"
Menelaos Raptis (Franklin and Marshall College), "CECILIA: A Direct-method Metallicity Calibration for Cosmic Noon through the Epoch of Reionization"
Melanie Ficarra (Franklin and Marshall College), "Monitoring Radio
Source NVSS J054710-02319: Image Pipeline Progress Report, Part 1"
Serena Almy (Franklin and Marshall College), "Monitoring Radio Source
NVSS J054710-02319: Image Pipeline Progress Report, Part 2 (Fixing
Astrometry.Net's Inaccurate Plate Solutions)"
E. Levy, R. Richi, M. Golden, M. Shaw (Franklin and Marshall
College), "The AGN of the Mariposa Nebula"
Ginny McSwain (Lehigh University), "Stellar Paternity Tests: Tracing
Stars Back to the Cluster of their Birth"
Hannah Peik (Lehigh University), "Machine Learning for Asteroid
Classification"
Lincoln Capwell (Lehigh University), "Characterization of TESS
Eclipsing Binary Orbital Periods with KELT"
Emma Babula (Lehigh University), "Photometric Study of Centaurs With
Sky Surveys"
Catrina Hamilton-Drager (Dickinson College), "Optical Observations of
the Eclipsing Binary VZ Psc"
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