Astrophysics and Astronomy Commons^™

Temporal And Spectral Analysis Of 1es 2344+514 In Two Flaring States Observed By Veritas, Connor Poggemann

Physics

VERITAS observed the bright blazar 1ES 2344+514 during two flaring periods, one from Dec. 17 to Dec. 18, 2015 (MJD 57373-57374) with a peak flux of ~60% of the Crab and another from Nov. 28 to Dec. 3, 2021 (MJD 59546-59551) with a peak flux of ~20% of the Crab. This blazar, located at a redshift of z = 0.044, is classified as an extreme high-frequency-peaked BL Lacertae object (HBL). It is known to be variable, including several previous day-scale flares: Whipple on Dec. 20, 1995, VERITAS on Dec. 7, 2007, and MAGIC on Aug. 11, 2016. The VERITAS near-nightly …

Exploring The Mass To Light Ratio Of Massive Galaxies With The Rubin Dp0 Preview Dataset, Denvir Joy Higgins

Physics

The Vera C. Rubin Observatory will perform the 10-year long Legacy Survey of Space and Time expected to begin in 2024. LSST will cover the Southern Hemisphere, collecting over two million images with an 8.4-meter telescope and 3200-pixel camera. In collaboration with the scientific community and based on the Outer Rim Simulation \citep{heit19}, the Rubin Observatory released a simulated dataset (DP0) of the data that is expected to be in hand at the 5-year mark. Using this simulated dataset, I have explored the number and luminosity of the most massive local galaxies. Using a sample of the brightest, closest galaxies …

Calculating MBh Scaling Relations For Agns Using 2d Galaxy Decomposition Software To Analyse Hst Images, Jewel A. Capili

Physics

This study uses the 2D galaxy decomposition software GALFIT developed by Dr. Chien Peng to analyse Hubble Space Telescope images of 14 Active Galactic Nuclei (AGNs) and obtain their M_BH-spheroid luminosity scaling relations for comparison with previous studies.

Recreating Nasa Images Using Hubble Data: Two Populations Of Stars In Messier 5, Adam N. Looper

Physics

This project seeks to recreate a color photo from NASA using Hubble data that shows the two distinct populations of stars in the cluster. Although the colored image displays the two types of stars, scientists often recolor astronomical pictures for two reasons: in order to clearly define objects, or to convert an image taken outside the visible spectrum into color. Thus, overlapping Hubble images colored according to filter should verify that there are two populations of stars in Messier 5, and the colored NASA photograph is valid in highlighting the unusual distribution of stars.

A Comparison Of Exotic And Pyraf In Analyzing Exoplanet Transits, Kailei A. Gallup

Physics

In this paper we discuss the data analysis processes using PyRaf, a Python-based version of IRAF, which is one of the most commonly used coding softwares in the astronomy community, as well as the analysis process using EXOTIC. Additionally, we will compare the outcomes from each process to determine if either has significant benefits over the other.

Modeling Cherenkov Light Detection Timing For The Very Energetic Radiation Imaging Telescope Array System, Keilan Finn Ramirez

Physics

The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is an array of four 12-meter telescopes which use the Imaging Atmospheric Cherenkov Technique to conduct high-energy gamma-ray astronomy. VERITAS detects magnitude and location information associated with Cherenkov light, and uses this information to indirectly observe gamma-rays through a software reconstruction process. VERITAS also records timing information corresponding to Cherenkov light detection, and this additional information could theoretically be incorporated into the reconstruction process to improve the accuracy of gamma-ray observations. The first step to including timing information is to understand when Cherenkov light detection would be expected from a known …

Variability Of Active Galactic Nuclei From Differential Photometry, Nicholas Steven Yee

Physics

The Seoul AGN Monitoring Project, or SAMP for short, is an international project (PI Jonghak Woo from Korea) with the goal of measuring the masses of black holes residing in the center of massive active galactic nuclei (AGNs). AGNs are some of the brightest objects in the universe. Their light is attributed to the accretion of material onto the black hole. However, these objects are too distant to spatially resolve the gravitational sphere of influence of the black hole directly. Instead, we use a technique called reverberation mapping which observes the variability of the AGN power-law continuum emission and the …

Formation Pathways In Brightest Cluster Galaxies: Measuring The Distribution Of Ages, Metallicities, And Hydrodynamics Of Stellar Populations, Priscilla E. Holguin West

Physics

Brightest Cluster Galaxies (BCGs) are the most massive galaxies in the local universe and have had the full age of the universe to build. This makes their formation and evolution history particularly interesting as they offer a glimpse at potential evolutionary pathways for younger systems. We present the radial profile of ages, metallicities, and preliminary classification of companions to 23 BCGs observed using the SparsePak instrument on WIYN by running the STARLIGHT stellar population synthesis models. This analysis of the BCGs’ stellar populations is done by separating each BCG into different regions, and preliminary results of the stellar populations for …

Host-Galaxy Morphology Of 14 Local Active Galaxies As Imaged By The Hubble Space Telescope, Tomas Henry Snyder

Physics

Active galactic nuclei (AGNs) are galaxies with super-massive black holes, that are undergoing accretion, at their centers. The study of these objects provides us with a deeper understanding of how the black holes evolved along with their host galaxies since black hole mass is highly correlated with bulge mass. A sample of 66 AGNs were imaged using the Hubble Space Telescope (HST) and 14 of those are analyzed in this paper to determine their structure, bulge luminosity, and bulge type. The program GALFIT is implemented to determine these parameters, that will be used in further research in the future. These …

Brightest Cluster Galaxy Evolution Exploration: Comparing The Separation Of Cluster X-Ray Light And Visible Wavelength Galaxy Light With Spectral Data, Matthew Aaron Salinas

Physics

Brightest Cluster Galaxies (BCGs), the brightest galaxy in a cluster of hundreds to thousands of galaxies, are some of the biggest, brightest, and most massive galaxies in the universe. Characterizing a BCG can help discover more about galaxy evolution - the aging, changing, and possible merging (collisions) of galaxies. This project involves determining the separation of the peak of x-ray emission of the galaxy cluster, and the peak of visible emission of the BCG to characterize the system as being disturbed or undisturbed that can then lead to discoveries about its formation and evolution. We have found that 17.4% of …

Differential Photometry Of Active Galactic Nuclei Using Time Resolved Observations With The 1m Nickel Telescope Of Lick Observatory, Chance L. Spencer

Physics

Active galactic nuclei (AGNs) are exotic objects in the center of some galaxies with luminosities that can greatly outshine the stars of the host galaxy across the entire electromagnetic spectrum. The origin of the UV/optical light is thought to be due to accretion of material onto the supermassive black hole in their centers. Since these objects are too far away to resolve the gravitational sphere of influence of the black hole directly, we make use of a method called reverberation mapping. We measure the lag between the AGN power-law continuum emitted by the accretion disk and the Doppler-broadened emission lines …

Microcontroller Differential Gps To Subtract Signal Delay Due To Ambient Free Electrons In The Ionosphere, Diana Jane Swanson

Physics

The goal of this project is to create a Global Positioning System (GPS) receiver that is more precise than one GPS receiver on its own. The technique is to take the difference between a GPS receiver’s measured position and its actual position, then use radio frequency (RF) communication to send that differential value to another microcontroller GPS receiver. This differential value will be added to the measured second location to get a more accurate position for the second GPS receiver, thus creating a differential GPS.

Studying The Potential Of The [Oii] Emission Line As A Surrogate For Stellar Velocity Dispersion In Active Galactic Nuclei, Edward F. Donohue

Physics

We study the emission profiles of 80 active galaxies to find a surrogate for stellar velocity dispersion. We focus on the width of the emission line of once ionized oxygen, [OII], and compare our results to previous work that used [OIII]. In previous research, [OIII] was found to be a good candidate for a surrogate for stellar velocity dispersion, but analysis of the line was complicated by the presence of wings caused by gas infall and outflow in the region. Emission lines with lower ionization levels, like [OII], are known to have less artificial line-broadening from wings. The study of …

Probing The Black-Hole-Mass-Galaxy Connection Of Active Galaxies Using 2d Galaxy Fitting Techniques On Near-Infrared Images, Isak Dan Stomberg

Physics

Active Galactic Nuclei (AGNs) provide a unique opportunity to measure the mass of supermassive black holes located in the centers of their host galaxies. This enables studying the scaling relations between the mass of the black hole and the properties of the host galaxy.

In this thesis, we present an investigation of the relationship between black hole masses and the host galaxy bulge and total luminosity for a pilot sample of 15 objects imaged in the near-infrared with the 8m telescope of Gemini North observatory. We perform a 2D decomposition of the host galaxies using the software Galfit and obtain …

Elasticity Of Cylindrical Black Holes, Conrad Pearson

Physics

Black holes are regions of strong gravity, and are often regarded as behaving like drops of fluid. When this line of thought is applied to cylindrical black holes (black cylinders), a mapping can be made between known instabilities for black cylinders and ordinary fluid cylinders. However, this known correlation is increasingly less accurate for lower spatial dimensions, and I seek to correct this discrepancy in this thesis. By considering soft solids instead of pure fluids, elastic energy can be included, which brings us closer to a direct comparison. In improving this mapping, it becomes possible to better understand the behavior …

Black Holes Modeled As Fluid Droplets On Membranes, Anthony Bardessono

Physics

No abstract provided.

Teaching Numerical Methods In The Context Of Galaxy Mergers, Maria Kourjanskaia

Physics

Methods of teaching numerical methods to solve ordinary differential equations in the context of galaxy mergers were explored. The research published in a paper by Toomre and Toomre in 1972 describing the formation of galactic tails and bridges from close tidal interactions was adapted into a project targeting undergraduate physics students. Typically undergraduate physics students only take one Computational Physics class in which various techniques and algorithms are taught. Although it is important to study computational physics techniques, it is just as important to apply this knowledge to a problem that is representative of what computational physics researchers are investigating …

Probing The Fitting Accuracy Of Active Galaxy Spectra, Aaron T. Line

Physics

Prior to this study, Dr. Vardha N. Bennert and collaborators selected a sample of ~100 local active galaxies to study the relationships between black hole mass and host galaxy properties. The broad Hβ width is necessary to determine black hole mass. This value is determined using a spectral decomposition code was scripted in IDL by Dr. Daeseong Park. The script fit spectral features and collected data for properties such as width of emission lines and continuum contribution percentages. The results were logged for further analysis.

To probe the accuracy of the fitting process, artificial spectra were created and fitted to …

Low Intensity Gamma-Ray Spectroscopy Of The Lake Labyrinth Meteorite, Tristan C. Paul

Physics

A 23.7g fragment of the Lake Labyrinth Meteorite (fell in 1924, collected in 1934 at Lake Labyrinth in South Australia, Australia) was re-investigated for evidence of the presence of 98Tc using a two dimensional low-intensity gamma-ray spectrometer. A new calibration technique using 26Al sources found the gamma-rays previously thought to be due to 98Tc are more likely from 166Ho. The presence of 166Ho is most likely due to activation of the stable 165Ho in the meteorite from terrestrial background sources where it was stored.

Determining The Relationship Between The [Oiii] 5007 Å Emission Line Profile And The Stellar Velocity Dispersion In Active Galaxies, Nathaniel Milgram

Physics

The empirical relation between the stellar velocity dispersion (SVD) of the bulge and the mass of the central supermassive black hole (BH) suggests a link between host galaxy and BH evolution. For active galactic nuclei (AGNs), the BH mass (MBH) can be estimated in a straightforward way from the Doppler broadening of the broad emission lines using the so-called virial method. However, the powerful AGN continuum emission often outshines the underlying stellar absorption lines, making it difficult to measure SVD of the host galaxy. Thus, the MBH - SVD relation is difficult to establish for galaxies containing AGNs. As a …

Frequency Of Seyfert Type Transitions In A Sample Of 102 Local Active Galactic Nuclei, Jordan Runco

Physics

A sample of ∼100 type-1 local (0.02 ≤ z ≤ 0.1) active galaxies (AGNs) was selected from the Sloan Digital Sky Survey with black hole masses M_BH > 10⁷ M_ʘ and re-observed using the Keck 10-m telescope to study the local scaling relations between M_BH and the host galaxy properties. As a side product, the data provides insight into any changes of the broad-line region within the 3-9 year time-frame covered by the two sets of spectra. The variability of the broad Hβ emission line is of particular interest to us, not only because it is used …

Evidence Of Attenuation Of Vhe Blazar Spectra By Extragalactic Background Light, Cameron Allen

Physics

The spectrum of two blazar objects, 1ES 1959+650 and 1ES 2344+514, are analyzed for evidence of interactions with the Extragalactic Background Light (EBL), using combined data from the Very Energetic Radiation Imaging Telescope Array System and the Fermi Gamma-ray Space Telescope, By analyzing the distinct curvature across the combined spectrum, we infer that the very-high energy (VHE) gamma-rays must be attenuated by interactions with the EBL. We also find that the measured 1ES 1959+650 spectrum is sensitive to the intrinsic blazar model, with a preference for a power-law with an exponential cutoff (EPWL). The measured curvature is a combination of …

Static Interaction Of Black Holes In 1+1 Dimensions, Philip Greenwood

Physics

We consider a version of general relativity in two spacetime dimensions, and

study a solution describing two static black holes in the presence of a cosmological

constant. We first analytically find an embedding diagram to visualize the geometry

outside the black holes. We then examine how the two black holes must be

interacting to remain static. Our main result is to show how the black holes behave

effectively like two electric charges. This charge model exhibits both attraction and

repulsion, which evidently balance and moreover are localized in different regions

of space. We also begin an investigation of the black …

Time Variation Of The Broad Hβ And Hα Emission Lines In Active Galactic Nuclei, Bryan R. Scott

Physics

High-quality Keck/LRIS long-slit spectra for a sample of 97 active galaxies selected from the Sloan Digital Sky Survey (redshift between 0.02 & 0.1; Black Hole Mass approximately 10⁷ Solar Masses) were obtained between January 2009 and March 2010 in order to study the black hole (BH) mass scaling relation in the local universe. Typically, the width of the broad Hβ emission line is used to measure the mass of the black hole (MBH). However, signs of variability in the emission line profile are seen for eight objects: While broad Hβ emission lines had previously been observed in spectra from …

Counting Photons To Calibrate A Photometer For Stellar Intensity Interferometry, Jason Chew

Physics

We use a telescope and photometer to observe stellar photons and measure the rate of observed photons. Based on intensity spectra from the Spectrophotometric Catalogue of Stars, we also predict expected values for the photon rates, which we compare to our measurements. From this comparison, we measure the local optical depth to be τ = 0.60±0.25, a reasonable value. We find that our predictions are directly proportional to our measurements by a factor of 0.98 (+0.02, -0.27) . The similarity between our measurements and expectations shows that we are able to both predict and measure photon rates with accuracy.

Determining The Location Of The Coronal Line Region Within Local Active Galactic Nuclei Using [Fe Vii] Emission Line Properties, Charles Grant Showley

Physics

Given a sample of 99 local AGNs, we study the characteristics of the forbidden [Fe VII] coronal line for the purpose of determining the location of the coronal line region (CLR) within the AGN. We calculate the velocity of the clouds emitting [Fe VII] using the width of the [Fe VII] emission lines compared to [O II] emission lines to establish whether the clouds are inflowing or outflowing. We plot the [Fe VII] and [O II] flux ratios against the AGNs' known black hole masses and stellar velocity dispersions in order to see if there are any correlations between them. …

Selecting Island Pixels With A Likelihood Ratio, Jordan Tweddale

Physics

A new method, called the Log Likelihood Ratio (LLR), was employed in place of a Signal-to-Noise Ratio (SNR) to pick out signal pixels on the VERITAS (Very Energetic Radiation Imaging Telescope Array System ) telescopes. The LLR test was performed on both photoelectrons and timing for VERITAS to select island pixels in Stage 2 cleaning, which is where the camera image is processed to determine which pixels on the camera are signal, and which are background. The two LLRs were combined to form a final LLR, which has a numerical cut, LLR = 11.5, between signal and background pixels. The …

Modeling The Spectral Energy Distribution Of Mrk 421, Randall L. Oglesby

Physics

Blazars are astronomical objects thought to be powered by the release of gravitational energy by accretion of material into a supermassive black hole located in the central region of the host galaxy. Some AGN present strong relativistic outflows in the form of jets, with blazars being the particular subset whose jets are aligned with our line of sight. Even though blazars account for only a small fraction of all AGN, they are the dominant class source in the high-energy sky. In this thesis we study the spectral energy distribution of Mrk 421, a prototypical blazar. Using publicly available numerical code …

Determining Stellar Velocity Dispersion In Active Galaxies: Is The [Oiii] Width A Valid Surrogate?, Kelsi Flatland

Physics

The tight empirical relation between the stellar velocity dispersion (sigma) of the bulge and the mass of the supermassive black hole (BH) at its center indicates a close connection between galactic evolution and BH growth. The evolution of this relation with cosmic time provides valuable clues to its origin. While the mass of the BH can be easily estimated using the Doppler broadening of the Hbeta emission line in type I active galactic nuclei (AGNs), measuring sigma simultaneously is challenging, since the nuclear emission outshines the host galaxy. Thus, it is highly desirable to find an alternative way to estimate …

Variability Studies Of Multi-Wavelength Data From Gamma-Ray Blazars Mrk 421 And Mrk 501, Brandon Becker

Physics

In this thesis we take astronomical multi-wavelength data from nearby blazars Markarian 421 and Markarian 501 and perform computational analysis and correlative studies to determine any possible time lag across different bands of our targets as well as to measure the statistical significance of this calculated result. The data was taken over the interval of December 2010 to May 2012 from multiple instruments spanning a broad range of wavelengths. We used the Discrete Correlation Function (DCF) to determine the time lag factor across data set pairs, focusing on X-ray and Very-High-Energy (VHE; >100 GeV) data. To establish the significance of …