A Literary Analysis Of The Oort Cloud: Summarising Its History And Proposing A Mission To Image Oort Cloud Objects,
2023
Eastern Michigan University
A Literary Analysis Of The Oort Cloud: Summarising Its History And Proposing A Mission To Image Oort Cloud Objects, Avital Keeley
Senior Honors Theses and Projects
The Oort Cloud was hypothesised in 1950 but has lost popularity as a research topic. This literary research summarises the most notable articles and simulations on the Oort Cloud with an analysis on the outdated simulations and assumptions. Finally, this research conflates the hypothesised values of Oort Cloud parameters to calculate the required specifications of instrumentation needed to image an Oort Cloud Object, and a rough budget is proposed of $5 million to launch a 35 km interferometer.
The Radial Quenching Progression Of Nearby Galaxies,
2023
University of Kentucky
The Radial Quenching Progression Of Nearby Galaxies, Chenyu Zhao
Theses and Dissertations--Physics and Astronomy
In this dissertation, we explore the spatial distribution of quiescent regions within galaxies using data from the Sloan Digital Sky Survey IV Mapping Nearby Galaxies at Apache Point Observatory (SDSS-IV MaNGA). Our analysis focuses on a radial range spanning from 0.3 R e to 1.2 R e and involves the development of innovative data selection and processing methods. Through this investigation, we identify two prominent types of transition galaxies: central-star-forming galaxies (C-SF galaxies) and central-quiescent galaxies (C-Q galaxies). Notably, we observe a correlation between galaxy mass and the predominant type of transition, with more massive galaxies tending to be C-Q …
A Multidimensional View On The Emission-Line Diagnostics Of The Warm Ionized Gas In Nearby Galaxies,
2023
University of Kentucky
A Multidimensional View On The Emission-Line Diagnostics Of The Warm Ionized Gas In Nearby Galaxies, Xihan Ji
Theses and Dissertations--Physics and Astronomy
The baryonic cycle, being a fundamental process that shapes the cosmic ecosystem, describes the transformation and migration of baryonic matter in different phases. The warm ionized interstellar medium (ISM), defined as low-density gas that has temperature of the order of 10,000 K, represents an important link of the baryonic cycle and can be produced by a variety of energetic activities in galaxies, such as star formations, active galactic nuclei, and so forth. More importantly, the formation and evolution of the warm ionized gas not only traces the ongoing activities of the galaxies, but also reveals the past evolution of galaxies …
Spatially Resolved Imaging Of The Inner Fomalhaut Disk Using Jwst/Miri,
2023
The University of Arizona
Spatially Resolved Imaging Of The Inner Fomalhaut Disk Using Jwst/Miri, András Gáspár, Schuyler Grace Wolff, George H. Rieke, Jarron M. Leisenring, Jane Morrison, Kate Y.L. Su, Kimberly Ward-Duong, Jonathan Aguilar, Marie Ygouf, Charles Beichman, Jorge Llop-Sayson, Geoffrey Bryden
Astronomy: Faculty Publications
Planetary debris disks around other stars are analogous to the asteroid and Kuiper belts in the Solar System. Their structure reveals the configuration of small bodies and provides hints for the presence of planets. The nearby star Fomalhaut hosts one of the most prominent debris disks, resolved by the Hubble Space Telescope, Spitzer, Herschel and the Atacama Large Millimeter Array. Images of this system at mid-infrared wavelengths using JWST/MIRI not only show the narrow Kuiper belt-analogue outer ring, but also that (1) what was thought from indirect evidence to be an asteroid-analogue structure is instead broad, extending outward into the …
Delineating A Stream Network At Gale Crater, Mars, On Arcgis Pro: A Geographic Information Systems Approach,
2023
The Pennsylvania State University
Delineating A Stream Network At Gale Crater, Mars, On Arcgis Pro: A Geographic Information Systems Approach, Elpidio Guzman De La Cruz
West Chester University Master’s Theses
The northwestern region of the Gale crater experienced flooding in the past. Delineation of stream networks for the northwestern region of Gale Crater, Mars employing geographic information systems (GIS) techniques is applied. The stream network produced by the algorithm in the study traverses the clay unit in Gediz Vallis, and visual HiRISE imagery analysis correlates with a topologic cross section of an inverted river channel of 750 meters wide and 90 meters deep. HiRISE imagery analysis further confirms a sulfate and clay stratigraphic unit in a stream 125 meters wide and 25 meters deep. Lastly, data smoothing procedures in the …
A Milky Way-Like Barred Spiral Galaxy At A Redshift Of 3,
2023
University of Massachusetts Amherst
A Milky Way-Like Barred Spiral Galaxy At A Redshift Of 3, Yingjie Cheng, Mauro Giavalisco, Et. Al.
Astronomy Department Faculty Publication Series
The majority of massive disk galaxies in the local Universe show a stellar barred structure in their central regions, including our Milky Way. Bars are supposed to develop in dynamically cold stellar disks at low redshift, as the strong gas turbulence typical of disk galaxies at high redshift suppresses or delays bar formation. Moreover, simulations predict bars to be almost absent beyond z = 1.5 in the progenitors of Milky Way-like galaxies. Here we report observations of ceers-2112, a barred spiral galaxy at redshift zphot ≈ 3, which was already mature when the Universe was only 2 Gyr old. The …
Evolution Of Density And Velocity Perturbations In A Slowly Contracting Universe,
2023
University of Central Florida
Evolution Of Density And Velocity Perturbations In A Slowly Contracting Universe, Olivia R. Bitcon
Honors Undergraduate Theses
One focus of research in cosmology regards the growth of structure in the universe: how we end up with stars, galaxies, galaxy clusters, and large scale structure in a universe that appears homogeneous and isotropic on large scales. Using cosmological perturbation theory, we investigate the evolution of density and velocity perturbations corresponding to a universe that is slowly contracting (Ijjas and Steinhardt), testing with and comparing different values for the equation-of-state parameter. This allows for the comparison of the growth of large scale structure in scenarios including a matter-dominated expanding universe, a dark energy-dominated expanding universe, and now, an ekpyrotic …
Towards A Prototype Paleo-Detector For Supernova Neutrino And Dark Matter Detection,
2023
University of North Florida
Towards A Prototype Paleo-Detector For Supernova Neutrino And Dark Matter Detection, Emilie Marie Lavoie-Ingram
UNF Graduate Theses and Dissertations
Using ancient minerals as paleo-detectors is a proposed experimental technique expected to transform supernova neutrino and dark matter detection. In this technique, minerals are processed and closely analyzed for nanometer scale damage track remnants from nuclear recoils caused by supernova neutrinos and possibly dark matter. These damage tracks present the opportunity to directly detect and characterize the core-collapse supernova rate of the Milky Way Galaxy as well as the presence of dark matter. Current literature presents theoretical estimates for these potential tracks, however, there is little research investigating the experimental feasibility of this technique. At the University of North Florida, …
Infrared Spectra Of Small Radicals For Exoplanetary Spectroscopy: Oh, Nh, Cn, And Ch: The State Of Current Knowledge,
2023
Old Dominion University
Infrared Spectra Of Small Radicals For Exoplanetary Spectroscopy: Oh, Nh, Cn, And Ch: The State Of Current Knowledge, Svatopluk Civiš, Adam Pastorek, Martin Ferus, Sergei N. Yurchenko, Noor-Ines Boudjema
Chemistry & Biochemistry Faculty Publications
In this study, we present a current state-of-the-art review of middle-to-near IR emission spectra of four simple astrophysically relevant molecular radicals—OH, NH, CN and CH. The spectra of these radicals were measured by means of time-resolved Fourier transform infrared spectroscopy in the 700–7500 cm−1 spectral range and with 0.07–0.02 cm−1 spectral resolution. The radicals were generated in a glow discharge of gaseous mixtures in a specially designed discharge cell. The spectra of short-lived radicals published here are of great importance, especially for the detailed knowledge and study of the composition of exoplanetary atmospheres in selected new planets. Today, …
Dynamical Hotness, Star Formation Quenching, And Growth Of Supermassive Black Holes,
2023
University of Massachusetts Amherst
Dynamical Hotness, Star Formation Quenching, And Growth Of Supermassive Black Holes, Hui Hong, Huiyuan Wang, H. J. Mo, Ziwen Zhang, Guangwen Chen, Wentao Luo, Tinggui Wang, Pengfei Li, Yao Yao, Aoxiang Jiang
Astronomy Department Faculty Publication Series
A stellar system is dynamically hot when its kinetic energy is dominated by random motion represented by the velocity dispersion σhot. We use MaNGA data to obtain the inner and outer dispersion of a galaxy, σin and σout, to characterize its dynamical status and study its connection with star formation quenching and the growth of its supermassive black hole (SMBH). We divide galaxies into fully quenched (FQGs), partially quenched (PQGs), and fully star-forming (FSGs) populations, and identify quenched central cores (QCCs) in PQGs. The galaxy distribution in (σin/σhot)–(σout/σhot) diagram …
Introducing The Texas Euclid Survey For Lyα (Tesla) Survey: Initial Study Correlating Galaxy Properties To Lyα Emission,
2023
University of Massachusetts Amherst
Introducing The Texas Euclid Survey For Lyα (Tesla) Survey: Initial Study Correlating Galaxy Properties To Lyα Emission, John R. Weaver, Et. Al.
Astronomy Department Faculty Publication Series
We present the Texas Euclid Survey for Lyα (TESLA), a spectroscopic survey in the 10 deg2 of the Euclid North Ecliptic Pole (NEP) field. Using TESLA, we study how the physical properties of Lyα emitters (LAEs) correlate with Lyα emission to understand the escape of Lyα emission from galaxies at redshifts of 2–3.5. We present an analysis of 43 LAEs performed in the NEP field using early data from the TESLA survey. We use Subaru Hyper Suprime-Cam imaging in the grizy bands, Spitzer/IRAC channels 1 and 2 from the Hawaii 20 deg2 (H20) survey, and spectra …
The Jwst Pearls View Of The El Gordo Galaxy Cluster And Of The Structure It Magnifies,
2023
University of Massachusetts Amherst
The Jwst Pearls View Of The El Gordo Galaxy Cluster And Of The Structure It Magnifies, Carlos Diaz, Daniel Wang, Et. Al.
Astronomy Department Faculty Publication Series
The massive galaxy cluster El Gordo (z = 0.87) imprints multitudes of gravitationally lensed arcs onto James Webb Space Telescope Near-Infrared Camera (NIRCam) images. Eight bands of NIRCam imaging were obtained in the "Prime Extragalactic Areas for Reionization and Lensing Science" ("PEARLS") program. Point-spread function–matched photometry across Hubble Space Telescope and NIRCam filters supplies new photometric redshifts. A new light-traces-mass lens model based on 56 image multiplicities identifies the two mass peaks and yields a mass estimate within 500 kpc of (7.0 ± 0.30) × 1014M⊙. A search for substructure in the 140 cluster members with spectroscopic …
Near-Infrared Emission Line Diagnostics For Agn From The Local Universe To Z ∼ 3*,
2023
University of Massachusetts Amherst
Near-Infrared Emission Line Diagnostics For Agn From The Local Universe To Z ∼ 3*, Mauro Giavalisco, Et. Al.
Astronomy Department Faculty Publication Series
Optical rest-frame spectroscopic diagnostics are usually employed to distinguish between star formation and active galactic nucleus (AGN) powered emission. However, this method is biased against dusty sources, hampering a complete census of the AGN population across cosmic epochs. To mitigate this effect, it is crucial to observe at longer wavelengths in the rest-frame near-infrared (near-IR), which is less affected by dust attenuation and can thus provide a better description of the intrinsic properties of galaxies. AGN diagnostics in this regime have not been fully exploited so far, due to the scarcity of near-IR observations of both AGN and star-forming galaxies, …
Uncover: Illuminating The Early Universe—Jwst/Nirspec Confirmation Of Z > 12 Galaxies,
2023
University of Massachusetts Amherst
Uncover: Illuminating The Early Universe—Jwst/Nirspec Confirmation Of Z > 12 Galaxies, Sam E. Cutler, John R. Weaver, Katherine E. Whitaker, Et. Al.
Astronomy Department Faculty Publication Series
Observations of high-redshift galaxies provide a critical direct test to the theories of early galaxy formation, yet to date, only three have been spectroscopically confirmed at z > 12. Due to strong gravitational lensing over a wide area, the galaxy cluster field A2744 is ideal for searching for the earliest galaxies. Here we present JWST/NIRSpec observations of two galaxies: a robust detection at zspec 12.393 0.001 0.004 = - + , and a plausible candidate at zspec 13.079 0.001 0.013 = - + . The galaxies are discovered in JWST/NIRCam imaging and their distances are inferred with JWST/NIRSpec spectroscopy, all from …
Unveiling The Nature Of Infrared Bright, Optically Dark Galaxies With Early Jwst Data,
2023
University of Massachusetts Amherst
Unveiling The Nature Of Infrared Bright, Optically Dark Galaxies With Early Jwst Data, L Barrufet, P A. Oesch, A Weibel, G Brammer, R Bezanson, R Bouwens, Y Fudamoto, V Gonzalez, R Gottumkkala, G Illingworth, K E. Heintz, B Holden, I Labbe, D Magee, R P. Naidu, E Nelson, M Stefanon, R Smit, P Van Dokkum, J R. Weaver, C C. Williams
Astronomy Department Faculty Publication Series
Over the last few years, both Atacama Large Millimeter/submillimeter Array (ALMA) and Spitzer observations have revealed a population of likely massive galaxies at z > 3 that was too faint to be detected inHubble Space Telescope(HST) rest-frame ultraviolet imaging. However, due to the very limited photometry for individual galaxies, the true nature of these so-called HST-dark galaxies has remained elusive. Here, we present the first sample of such galaxies observed with very deep, high-resolution NIRCam imaging from the Early Release Science programme CEERS. 30 HST-dark sources are selected based on their red colours across 1.6–4.4 …
An Xmm-Newton View Of The Andromeda Galaxy As Explored In A Legacy Survey (New-Angels). I. The X-Ray Source Catalog,
2023
University of Massachusetts Amherst
An Xmm-Newton View Of The Andromeda Galaxy As Explored In A Legacy Survey (New-Angels). I. The X-Ray Source Catalog, Q. Daniel Wang, Et. Al.
Astronomy Department Faculty Publication Series
We introduce the New-ANGELS program, an XMM-Newton survey of a ∼7.2 deg2 area around M31, which aims to study the X-ray populations in the M31 disk and the X-ray-emitting hot gas in the inner halo of M31 up to 30 kpc. In this first paper, we report the catalog of 4506 detected X-ray sources and attempt to cross-identify or roughly classify them. We identify 352 single stars in the foreground, 35 globular clusters, and 27 supernova remnants associated with M31, as well as 62 active galactic nuclei, 59 galaxies, and one galaxy cluster in the background. We uniquely classify 236 …
Universal Upper End Of The Stellar Initial Mass Function In The Young And Compact Legus Clusters,
2023
University of Massachusetts Amherst
Universal Upper End Of The Stellar Initial Mass Function In The Young And Compact Legus Clusters, Dooseok Escher Jung, Daniela Calzetti, Matteo Messa, Mark Heyer, Mattia Sirressi, Sean T. Linden, Et. Al.
Astronomy Department Faculty Publication Series
We investigate the variation in the upper end of the stellar initial mass function (uIMF) in 375 young and compact star clusters in five nearby galaxies within ∼5 Mpc. All the young stellar clusters (YSCs) in the sample have ages ≲ 4 Myr and masses above 500 M⊙, according to standard stellar models. The YSC catalogs were produced from Hubble Space Telescope images obtained as part of the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. They are used here to test whether the uIMF is universal or changes as a function of the cluster's stellar mass. We perform …
Tracing The Most Powerful Galactic Cosmic-Ray Accelerators With The Hawc Observatory,
2023
Michigan Technological University
Tracing The Most Powerful Galactic Cosmic-Ray Accelerators With The Hawc Observatory, Dezhi Huang
Dissertations, Master's Theses and Master's Reports
Since Victor Hess's groundbreaking detection of cosmic rays in the Earth's atmosphere in 1912, the origins of these charged particles have remained an enduring mystery. Recent studies suggest that these cosmic rays are accelerated beyond Peta electronvolts by powerful astrophysical sources within our own galaxy. While the cosmic rays themselves are being deflected in all directions by magnetic fields, the gamma rays produced by them, being electrically neutral, travel to the observer in a straight line. They carry crucial information, allowing us to trace cosmic-ray accelerators within our galaxy. The High Altitude Water Chrenkov (HAWC) Observatory, located on the slopes …
Impact On Infinite Asteroids: Analysis Of Ejecta Outcomes In Small Body Binary Systems,
2023
University of Central Florida
Impact On Infinite Asteroids: Analysis Of Ejecta Outcomes In Small Body Binary Systems, Jennifer Larson
Electronic Theses and Dissertations, 2020-
Binary asteroid systems make up roughly 15% of objects occupying near-Earth space, the Main Belt, and trans-Neptunian space. The impact history of asteroids in binary systems represents an interesting aspect of the general problem pertaining to the nature and evolution of surfaces for such objects. Specifically, the post-impact dynamics of ejecta and its relation to surface modification is a challenging question owing, in part, to the unusual gravitational field in a binary system and the subsequent capture and emplacement of debris on either binary component. Observable differences or similarities between the two bodies in the color, reflectance, thermal properties, and …
Development Of Regolith Simulants Of Lunar Permanently Shadowed Regions And Jupiter Trojan Asteroids,
2023
University of Central Florida
Development Of Regolith Simulants Of Lunar Permanently Shadowed Regions And Jupiter Trojan Asteroids, Karlis Slumba
Electronic Theses and Dissertations, 2020-
Every scientific experiment or innovation goes through a phase of testing equipment. This is not only true for experiments in the laboratory, but also very relevant for experiments on other planetary bodies. In order to test tools and robotic equipment that are destined for another planet, moon, asteroid or comet, it is necessary to simulate the regolith environment on that surface. In this thesis we have provided an overview of two methods for regolith simulant development. In one approach we made simulants in different compositions to find the best spectral fit to Jupiter Trojan asteroids. At visible to near-infrared (VNIR) …
