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Articles 1 - 13 of 13
Full-Text Articles in External Galaxies
Measuring Cosmic Expansion From Early To Late Times Using Quasars, Galaxies, & Local Supernovae, Rajeev Vaisakh
Measuring Cosmic Expansion From Early To Late Times Using Quasars, Galaxies, & Local Supernovae, Rajeev Vaisakh
Physics Theses and Dissertations
This dissertation investigates the evolution of cosmic expansion across a wide redshift ($z$) range by combining measurements from quasars \& galaxies in the distant universe $(z > 0.8)$ with those obtained from stripped-core collapse supernovae observations from the nearby universe $(z < 0.1)$. Using the DESI spectroscopic survey, we analyze large-scale clustering from quasars over $0.8 < z < 2.1$ and emission line galaxies over $0.8 < z < 1.6$, contributing to DESI DR2 BAO and full-shape measurements of cosmic expansion and structure growth. Combined with BBN in flat $\Lambda$CDM, DESI DR2 BAO gives $H_0 = 68.51 \pm 0.58$ km s$^{-1}$ Mpc$^{-1}$, while combinations of DESI BAO with CMB and supernova data show a preference for evolving dark energy, with representative constraints such as $w_0 = -0.752 \pm 0.057$ and $w_a = -0.86^{+0.23}_{-0.20}$ for DESI+CMB+DESY5. Using the ROTSE-III Supernova Survey and the expanding photosphere method (EPM), we measure distances to a sample of six supernovae for which the thermal phase can be clearly identified. This analysis focuses on testing whether reliable EPM distances can be obtained for this population. The resulting distances will eventually be compared with independent estimates from the literature. Establishing consistency with these external measurements represents an important step toward applying this methodology to larger samples, with the eventual goal of using ROTSE supernova distances to provide an independent measurement of the local Hubble constant.
Distance Calculations Of Faint Dwarf Galaxies Through Surface Brightness Fluctuations, Blake A. Richesin, Guinevere Herron, Burçin Mutlu-Pakdil
Distance Calculations Of Faint Dwarf Galaxies Through Surface Brightness Fluctuations, Blake A. Richesin, Guinevere Herron, Burçin Mutlu-Pakdil
Wetterhahn Science Symposium Posters
This study aims to test the effectiveness of the surface brightness fluctuations (SBF) technique in determining the distance to three distinct galaxy targets. The targets were dwarf galaxies Tucana B, Kamino, and Hedgehog. The technique used image masking, Sérsic profiles, and convolving with point spread functions (PSF). The study showed that redder, quenched galaxies are prime candidates for the SBF technique, while bluer, star-forming galaxies are more difficult to constrain the distance of.
Searching For Temporal Variations In The Fine-Structure Constant Using Espresso Spectrograph Data, David Hoffman Iv
Searching For Temporal Variations In The Fine-Structure Constant Using Espresso Spectrograph Data, David Hoffman Iv
Senior Theses
The fine-structure constant α is a dimensionless constant, defined as e²/(4πε₀ℏc) ≈ 1/137. On the order of human timescales, its value is very much unchanging, however, in recent years there has been extensive debate over whether or not the value of α has remained constant over cosmological timescales. With the natural corollary to a changing α being that either one or multiple of its constituent physical constants have also changed in value, observing a variation in the fine-structure constant would have vast ramifications for our understanding of the nature of the early universe and how it has evolved. While past …
Temporal And Spectral Analysis Of 1es 2344+514 In Two Flaring States Observed By Veritas, Connor Poggemann
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 …
Host-Galaxy Morphology Of 14 Local Active Galaxies As Imaged By The Hubble Space Telescope, Tomas Henry Snyder
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 …
Preparing A Database Of Extremely High Velocity Outflows In Quasars, Griffin Kowash, Carla P. Quintero, Sean S. Haas, Paola Rodriguez Hidalgo
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.
Exploring The Diffuse Neutral Hydrogen In And Around Nearby Galaxies, Amy Sardone
Exploring The Diffuse Neutral Hydrogen In And Around Nearby Galaxies, Amy Sardone
Graduate Theses, Dissertations, and Problem Reports (ETD)
We explore the environment of 36 nearby galaxies in neutral hydrogen (H I) as part of the MeerKAT H I Observations of Nearby Galactic Objects; Observing Southern Emitters (MHONGOOSE) survey with the Robert C. Byrd Green Bank Telescope (GBT), and the Imaging Galaxies Intergalactic and Nearby En- vironment (IMAGINE) survey with the Parkes Radio Telescope. We obtained deep observations of each of these galaxies, reaching column density detection sensitivities as low as NHI ∼ 1e17 cm^−2, which allowed us to quantify the amount of diffuse H I in both samples of galaxies. This allows us to search for evidence of …
Searching For A Connection Between Radio Emission And Uv/Optical Absorption In Quasars, Sean S. Haas, Carla P. Quintero, Paola Rodriguez Hidalgo
Searching For A Connection Between Radio Emission And Uv/Optical Absorption In Quasars, Sean S. Haas, Carla P. Quintero, Paola Rodriguez Hidalgo
IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt
No abstract provided.
Cosmological Distance Measurements With Rotse Supernovae Iip And Observational Systematics On Desi Emission Line Galaxy Clustering, Govinda Dhungana
Cosmological Distance Measurements With Rotse Supernovae Iip And Observational Systematics On Desi Emission Line Galaxy Clustering, Govinda Dhungana
Physics Theses and Dissertations
Both Supernovae (SNe) and Baryon Acoustic Oscillations (BAO) surveys emerged as complementary probes of the expansion history of the universe in the last few decades. SNe Ia cosmology has reached the systematic limits in the optical surveys. The most frequently occuring SNe Type IIP are emerging as equally rich distance probes for the next generation larger surveys. In this thesis, I highlight the astrophysical observables of these events in the context of ROTSE III SN survey and using the ROTSE SNe IIP sample, I present calibration in the framework of expanding photosphere method (EPM) to use them as cosmological distance …
The Encyclopedia Of Neutrosophic Researchers - Vol. 1, Florentin Smarandache
The Encyclopedia Of Neutrosophic Researchers - Vol. 1, Florentin Smarandache
Branch Mathematics and Statistics Faculty and Staff Publications
This is the first volume of the Encyclopedia of Neutrosophic Researchers, edited from materials offered by the authors who responded to the editor’s invitation. The authors are listed alphabetically. The introduction contains a short history of neutrosophics, together with links to the main papers and books. Neutrosophic set, neutrosophic logic, neutrosophic probability, neutrosophic statistics, neutrosophic measure, neutrosophic precalculus, neutrosophic calculus and so on are gaining significant attention in solving many real life problems that involve uncertainty, impreciseness, vagueness, incompleteness, inconsistent, and indeterminacy. In the past years the fields of neutrosophics have been extended and applied in various fields, such as: …
Unsolved Problems In Special And General Relativity, Florentin Smarandache, Fu Yuhua, Zhao Fengjuan
Unsolved Problems In Special And General Relativity, Florentin Smarandache, Fu Yuhua, Zhao Fengjuan
Branch Mathematics and Statistics Faculty and Staff Publications
This book includes 21 papers written by 23 authors and co-authors. All papers included herein are produced by scholars from People’s Republic of China, except two papers written by Prof. L. Sapogin, V. A. Dzhanibekov, Yu. A. Ryabov from Russia, and by Prof. Florentin Smarandache from USA. The editors hope that all these papers will contribute to the advance of scholarly research on several aspects of Special and General Relativity. This book is suitable for students and scholars interested in studies on physics. The first paper is written by Hua Di. He writes that Einstein’s general theory of relativity cannot …
Analysis Of The 2008 Flare Of Markarian 421 Flare With Veritas, Casey Allard
Analysis Of The 2008 Flare Of Markarian 421 Flare With Veritas, Casey Allard
Physics
A theoretical light curve model is fit to an observed short term flare of Markarian (Mrk) 421 in the very high energy spectrum. The flare is characterized by its measured light curve from the Very Energetic Radiation Imaging telescope Array System (VERITAS). The flare we analyzed occurred in May 2008. We successfully fit a theoretical model to the Mrk 421 data light curve. The data appears to agree with the Wagner [1] and Salvati [2] models. These models appear to fit both broad and sharp flaring regions found in the measured light curve. Furthermore the Wagner model is used to …
Basic Astronomy Labs, Terry L. Smith, Michael D. Reynolds, Jay S. Huebner
Basic Astronomy Labs, Terry L. Smith, Michael D. Reynolds, Jay S. Huebner
Physics Faculty Research and Scholarship
Providing the tools and know-how to apply the principles of astronomy first-hand, these 43 laboratory exercises each contain an introduction that clearly shows budding astronomers why the particular topic of that lab is of interest and relevant to astronomy. About one-third of the exercises are devoted solely to observation, and no mathematics is required beyond simple high school algebra and trigonometry.Organizes exercises into six major topics—sky, optics and spectroscopy, celestial mechanics, solar system, stellar properties, and exploration and other topics—providing clear outlines of what is involved in the exercise, its purpose, and what procedures and apparatus are to be used. …