Astrophysics and Astronomy Commons^™

Abiogenesis: The Carter Argument Reconsidered, Daniel P. Whitmire

Mathematical Sciences Faculty Publications and Presentations

The observation of life on Earth is commonly believed to be uninformative regarding the probability of abiogenesis on other Earth-like planets. This belief is based on the selection effect of our existence. We necessarily had to find ourselves on a planet where abiogenesis occurred, thus nothing can be inferred about the probability of abiogenesis from this observation alone. This argument was first formalized in a Bayesian framework by Brandon Carter. Though we definitely had to find ourselves on a planet where abiogenesis occurred, I argue here that (1) the Carter conclusion is based on what is known as the ‘Old …

Thermodynamic Modelling Of Perchlorate/Chloride And Perchlorate/Chlorate Deliquescence At Mars-Relevant Temperatures, Vincent F. Chevrier, Alec Fitting, Amira Elsenousy, Edgar G. Rivera-Valentin

Space and Planetary Science Faculty Publications and Presentations

Perchlorate (ClO₄^-) salts were discovered on Mars and are known to absorb water vapor from the atmosphere and deli-quesce into the aqueous phase. Other species such as chlorides (Cl^-) and chlorates (ClO₃^-) were also identified; these species can affect the deliquescence of perchlorates. Here we generate phase diagrams of perchlorate/chloride and perchlorate/chlo-rate binary mixtures for K, Na, Mg and Ca in the temperature range 223-273 K. Using a new approach based on thermo-dynamic modelling of evaporation, we determined the deliquescence relative humidity (the minimum relative humidity at which a salt converts into …

The California Legacy Survey. Iii. On The Shoulders Of (Some) Giants: The Relationship Between Inner Small Planets And Outer Massive Planets, Lee J. Rosenthal, Heather A. Knutson, Yayaati Chachan, Fei Dai, Andrew W. Howard, Benjamin J. Fulton, Ashley Chontos, Justin R. Crepp, Paul A. Dalba, Gregory W. Henry, Stephen R. Kane, Erik A. Petigura, Lauren M. Weiss, Jason T. Wright

Information Systems and Engineering Management Research Publications

We use a high-precision radial velocity survey of FGKM stars to study the conditional occurrence of two classes of planets: close-in small planets (0.023–1 au, 2–30 M⊕) and distant giant planets (0.23–10 au, 30–6000 M⊕). We find that 41 %13 15 - + of systems with a close-in, small planet also host an outer giant, compared to 17.6 %1.9 2.4 - + for stars irrespective of small planet presence. This implies that small planet hosts may be enhanced in outer giant occurrences compared to all stars with 1.7σ significance. Conversely, we estimate that 42 %13 17 - + of cold …

The Physical Properties Of Low-Redshift Felobal Quasars. Iii. The Location And Geometry Of The Outflows, Hyunseop Choi, Karen M. Leighly, Collin Dabbieri, Donald M. Terndrup, Sarah C. Gallagher, Gordon T. Richards

Physics and Astronomy Publications

We present continued analysis of a sample of low-redshift iron low-ionization broad-absorption-line quasars (FeLoBALQs). Choi et al. presented SimBAL spectral analysis of broad-absorption-line (BAL) outflows in 50 objects. Leighly et al. analyzed the optical emission lines of 30 of those 50 objects and found that they are characterized by either a high accretion rate (L Bol/L Edd > 0.3) or low accretion rate (0.03 < L Bol/L Edd < 0.3). We report that the outflow velocity is inversely correlated with the BAL location among the high-accretion-rate objects, with the highest velocities observed in parsec-scale outflows. In contrast, the low-Eddington-ratio objects showed the opposite trend. We confirmed the known relationship between the outflow velocity and L Bol/L Edd and found that the scatter plausibly originates in the force multiplier (launch radius) in the low(high)-accretion-rate objects. A log volume filling factor between −6 and −4 was found in most outflows but was as high as −1 for low-velocity compact outflows. We investigated the relationship between the observed [O iii] emission and that predicted from the BAL gas. We found that these could be reconciled if the emission-line covering fraction depends on the Seyfert type and BAL location. The difference between the predicted and observed [O iii] luminosity is correlated with the outflow velocity, suggesting that [O iii] emission in high-Eddington-ratio objects may be broad and hidden under Fe ii emission. We suggest that the physical differences in the outflow properties as a function of location in the quasar and accretion rate point to different formation, acceleration, and confinement mechanisms for the two FeLoBALQ types.

Nustar Observations Of Intrinsically X-Ray Weak Quasar Candidates: An Obscuration-Only Scenario, Chaojun Wang, B. Luo, W. N. Brandt, D. M. Alexander, F. E. Bauer, Sarah C. Gallagher, Jian Huang, Hezhen Liu, D. Stern

Physics and Astronomy Publications

We utilize recent NuSTAR observations (co-added depth ≈55-120 ks) of PG 1001+054, PG 1254+047, and PHL 1811 to constrain their hard X-ray (≳5 keV) weakness and spectral shapes and thus to investigate the nature of their extreme X-ray weakness. These quasars showed very weak soft X-ray emission, and they were proposed to be intrinsically X-ray weak, with the X-ray coronae producing weak continuum emission relative to their optical/UV emission. However, the new observations suggest an alternative explanation. The NuSTAR 3-24 keV spectral shapes for PG 1001+054 and PHL 1811 are likely flat (effective power-law photon indices Γeff=1.0-0.6+0.5 and Γeff=1.4-0.7+0.8, respectively), …

Passages: The Large Millimeter Telescope And Alma Observations Of Extremely Luminous High-Redshift Galaxies Identified By The Planck, Derek A. Berman, Min S. Yun, K. C. Harrington, P. Kamieneski, J. Lowenthal, B. L. Frye, Q. D. Wang, G. W. Wilson, I. Aretxaga, M. Chavez, R. Cybulski, V. De La Luz, N. Erickson, D. Ferrusca, D. H. Hughes, A. Montaña, G. Narayanan, D. Sánchez-Argüelles, F. P. Schloerb, K. Souccar, E. Terlevich, R. Terlevich, J. A. Zavala

Astronomy: Faculty Publications

The Planck All-Sky Survey to Analyze Gravitationally-lensed Extreme Starbursts project aims to identify a population of extremely luminous galaxies using the Planck all-sky survey and to explore the nature of their gas fuelling, induced starburst, and the resulting feedback that shape their evolution. Here, we report the identification of 22 high-redshift luminous dusty star-forming galaxies (DSFGs) at z = 1.1-3.3 drawn from a candidate list constructed using the Planck Catalogue of Compact Sources and Wide-field Infrared Survey Explorer all-sky survey. They are confirmed through follow-up dust continuum imaging and CO spectroscopy using AzTEC and the Redshift Search Receiver on the …

Gj 3090 B: One Of The Most Favourable Mini-Neptune For Atmospheric Characterisation, J. M. Almenara, X. Bonfils, J. F. Otegi, O. Attia, M. Turbet, N. Astudillo-Defru, K. A. Collins, A. S. Polanski, V. Bourrier, C. Hellier, C. Ziegler, F. Bouchy, C. Briceno, D. Charbonneau, M. Cointepas, K. I. Collins, I. Crossfield, X. Delfosse, R. F. Diaz, C. Dorn, J. P. Doty, T. Forveille, G. Gaisné, T. Gan, R. Helled, K. Hesse, J. M. Jenkins, Eric L.N. Jensen, D. W. Latham, N. Law, A. W. Mann, S. Mao, B. Mclean, F. Murgas, G. Myers, S. Seager, A. Shporer, T. G. Tan, J. D. Twicken, J. Winn

Physics & Astronomy Faculty Works

We report the detection of GJ 3090 b (TOI-177.01), a mini-Neptune on a 2.9-day orbit transiting a bright (K = 7.3 mag) M2 dwarf located at 22 pc. The planet was identified by the Transiting Exoplanet Survey Satellite and was confirmed with the High Accuracy Radial velocity Planet Searcher radial velocities. Seeing-limited photometry and speckle imaging rule out nearby eclipsing binaries. Additional transits were observed with the LCOGT, Spitzer, and ExTrA telescopes. We characterise the star to have a mass of 0.519 ± 0.013 M_⊙ and a radius of 0.516 ± 0.016 R_⊙. We modelled …

Using Neural Network To Search For Isolated Hα Clouds In The Virgo Cluster, Audra Carver

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Exploring The Interaction Between Black Hole Feedback And Cold Fronts In Galaxy Clusters, Isabelle Wingate

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

The Jwst Early Release Science Program For The Direct Imaging And Spectroscopy Of Exoplanetary Systems, Sasha Hinkley, Aarynn L. Carter, Shrishmoy Ray, Andrew Skemer, Beth Biller, Elodie Choquet, Maxwell A. Millar-Blanchaer, Stephanie Sallum, Brittany Miles, Niall Whiteford, Polychronis Patapis, Marshall Perrin, Laurent Pueyo, Glenn Schneider, Karl Stapelfeldt, Jason Wang, Kimberly Ward-Duong, Brendan P. Bowler, Anthony Boccaletti, Julien H. Girard, Dean Hines, Paul Kalas, Jens Kammerer, Pierre Kervella, Jarron Leisenring, Eric Pantin, Yifan Zhou, Michael Meyer, Michael C. Liu, Mickael Bonnefoy, Thayne Currie, Michael Mcelwain

Astronomy: Faculty Publications

The direct characterization of exoplanetary systems with high-contrast imaging is among the highest priorities for the broader exoplanet community. As large space missions will be necessary for detecting and characterizing exo-Earth twins, developing the techniques and technology for direct imaging of exoplanets is a driving focus for the community. For the first time, JWST will directly observe extrasolar planets at mid-infrared wavelengths beyond 5 μm, deliver detailed spectroscopy revealing much more precise chemical abundances and atmospheric conditions, and provide sensitivity to analogs of our solar system ice-giant planets at wide orbital separations, an entirely new class of exoplanet. However, in …

Mining The Data Cubes In Sub-Mm And Optical Astronomy, Nathanael Pichette

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Astrophysics, Cosmology And Particle Phenomenology At The Energy Frontier, Jorge Fernandez Soriano

Dissertations, Theses, and Capstone Projects

This dissertation consists of two parts, treating significantly separated fields. Each part consists on several chapters, each treating a somewhat isolated topic from the rest. In each chapter, I present some of the work developed during my passage through the graduate program, which has mostly been published elsewhere.

Part I – Cosmic Rays and Particle Physics

• Chapter 1: In this chapter we present an introduction to the topic of cosmic ray physics, with an special focus on the so-called ultra high energy cosmic rays: their potential origins, effects during their propagation between their sources and Earth, the different techniques used …

Stacking The Gamma-Ray Sky To Search For Faint Astrophysical Populations, Yuzhe Song

Dissertations, Theses, and Capstone Projects

Gamma-ray emission can be generated from a wide variety of high-energy astrophysical phenomena, from stellar flares to pulsating neutron stars, and from interstellar clouds to the center of the Milky Way Galaxy. Entering the 13th year of its orbit around Earth, the Fermi Space Gamma-ray Telescope has been continually surveying the γ-ray sky with its Large Area Telescope (LAT) on board. The latest Fermi source catalog contains over 6000 sources. Yet, a lot of sources that are expected to emit γ-rays are not detected, and only small percentages of some populations are detected. For example, solar flares are detected in …

Diagnostics Of Energy Release In Solar Flares With Radio Dynamic Imaging Spectroscopy, Yingjie Luo

Dissertations

Studies of the magnetic energy release and conversion process lie at the core of solar flare physics. Radio observations serve as a unique diagnostic method. In this dissertation, taking advantage of broadband radio dynamic imaging spectroscopy observations made by the Karl G. Jansky Very Large Array (VLA), studies are carried out on the flare energy release processes using different types of radio emissions.

The VLA is a general-purpose radio observatory located in New Mexico, which provides high-quality radio dynamic imaging spectroscopic observations with an ultra-fast time cadence. In the first study, stochastic decimetric radio spike bursts are observed by the …

Understanding The Role Of Magnetic Field Evolution In The Initiation And Development Of Solar Eruptions, Nian Liu

Dissertations

This dissertation aims to understand the initiation and evolution of solar eruptions. The essential science questions to answer include: What is the role of magnetohydro dynamic (MHD) instabilities and magnetic reconnection in triggering and driving eruptions? What are the role of Kink Instability (KI) and Torus Instability (TI) in determining the successful and failed eruptions? What is the thermal behavior of flare precursors in the initiation stage of solar eruptions? Finally, how does the corona magnetic field respond to the flare eruptions? The dissertation mainly includes the following studies.

First, this dissertation presents a multi-instrument study of the two precursor …

Galaxy And Mass Assembly (Gama): Bulge-Disc Decomposition Of Kids Data In The Nearby Universe, Sarah Casura, Jochen Liske, Aaron S G Robotham, Sarah Brough, Simon P. Driver, Alister W. Graham, Boris Häußler, Benne Holwerda, Andrew M. Hopkins, Lee S. Kelvin, Amanda J. Moffett, Dan S. Taranu, Edward N. Taylor

Faculty and Staff Scholarship

We derive single Sérsic fits and bulge-disc decompositions for 13 096 galaxies at redshifts z < 0.08 in the GAMA II equatorial survey regions in the Kilo-Degree Survey (KiDS) g, r, and i bands. The surface brightness fitting is performed using the Bayesian two-dimensional profile fitting code PROFIT. We fit three models to each galaxy in each band independently with a fully automated Markov chain Monte Carlo analysis: a single Sérsic model, a Sérsic plus exponential and a point source plus exponential. After fitting the galaxies, we perform model selection and flag galaxies for which none of our models are appropriate (mainly mergers/Irregular galaxies). The fit quality is assessed by visual inspections, comparison …

Highlighting The Beauty Of Science, Erik Johnson

Natural Science Faculty

Each fall and spring, the William M. Staerkel Planetarium hosts speakers who talk about their corner of the world of science. The James B. Kaler Science Lecture Series is named after a professor emeritus at the University of Illinois's astronomy department who delivered an annual talk for the series for about 30 years.

This academic year, the planetarium will begin the series with the premiere of a full dome show followed by a Q&A session with one of the show's producers. Tickets for Kaler Science Lectures are $2 for all attendees and are free for members of the Friends of …

An Automated System For Strain Engineering And Straintronics Of 2d Materials, Onur Çakıroğlu, Joshua O. Island, Yong Xie, Riccardo Frisenda, Andres Castellanos-Gomez

Physics & Astronomy Faculty Research

This work presents an automated three-point bending apparatus that can be used to study strain engineering and straintronics in 2D materials. This work benchmarks the system by reporting reproducible strain tuned micro-reflectance, Raman, and photoluminescence spectra for monolayer molybdenum disulfide (MoS2). These results are in good agreement with reported literature using conventional bending apparatus. This work further utilizes the system to automate strain investigations of straintronic devices by measuring the piezoresistive effect and the strain effect on photoresponse in an MoS2 electrical device. The details of the construction of the straightforward system are given and it is anticipated that it …

Distance Estimates To Evolved Stars Using Infrared Emission And Verification And Validation Of The Plasma Code Empire, Brandon M. Medina

Physics & Astronomy ETDs

Gaining insight into the structure and dynamics of the Milky Way is important for understanding the universe on a large scale. Evolved stars on the Asymptotic Giant Branch are useful for studying the Milky Way because their emission is peaked in the infrared, where interstellar extinction effects are not as dominant. To further understand the physical properties of these objects like luminosity and investigate the Galaxy's structure, we need distance estimates. Obtaining distance estimates for these evolved stars via trigonometric parallax measurements is time-consuming, so infrared surveys studying Asymptotic Giant Branch stars can benefit from other distance estimate methods. In …

Review On 11 Years Of Implementation Of Strategic Priority Program (Spp) On Space Science And Its Prospect, Ji Wu, Chi Wang, Quanlin Fan

Bulletin of Chinese Academy of Sciences (Chinese Version)

The Strategic Priority Program (SPP) on space science is a series scientific satellites program implemented by Chinese Academy of Science (CAS) since 2011. Since then, it has become the only and systematic space science satellite series of China. The article reviews the major scientific outcomes and technological breakthroughs in its first phase (2011-2016), the ongoing mission developments of its second phase (2017-2024), and the selected mission proposals for future space science program up to 2030. In 2016, President Xi has addressed:"to promote full developments of space science, space technology and space application," where he put space science in the first …

On Index System Of Space Science Strength And Its Enlightenment, Quanlin Fan, Tingting Song, Peng Shi, Haiyan Wei, Xiaoli Chen, Xuezhao Wang, Shijie Guo

Bulletin of Chinese Academy of Sciences (Chinese Version)

Major achievements of space science and technology are important symbols of a country's scientific and technological level and ability. The basic consensus of the aerospace community is that China's space technology has been well-developed, space applications need to be strengthened, and space science is relatively the less-developed. Thus, it is extremely urgent for China to build a strong country in space science and tackle the "bottleneck". Here we elaborate the internal logic among the strength of S&T, aerospace, and space science, expound the connotation of space science strength, investigate the index system, and suggest the three-tier system scientifically for the …

Thoughts On Space Science Development, Yidong Gu

Bulletin of Chinese Academy of Sciences (Chinese Version)

Space science is a large-scale activity by using space vehicles to explore the universe and natural laws and carry out special experiments, which has made great contributions to the development of contemporary science. This paper outlines the major breakthroughs in international space science, analyzes the context and new trends of space science and manned exploration activities, reviews the development achievements of space science in China in the past 20 years, puts forward existing problems and gaps, and emphasizes the strategic position of space science and its importance to China's science and technology, aerospace and the national long-term development. It is …

Prospects Of Global Space Science Breakthroughs And China’S Contributions, Chi Wang

Bulletin of Chinese Academy of Sciences (Chinese Version)

Space science is a frontier interdisciplinary subject that probes the macroscopic and microscopic worlds with spacecraft as a platform. Since the 1960s, many Nobel Prize-level discoveries and original achievements have been spawned in related basic science, breaking through the boundaries of human cognition of the nature, and expanding the human knowledge graph continuously. In the 21st century, with a new round of scientific and technological revolution brewing, space science has also entered a new era of revolutionary advancements. Here we review the major progress in global space science in the past ten years, as well as the trend of space …

Connecting The Last Mile To Speed Up Space Science Development Of China—Review And Prospect Of The Funding Practices For Space Science By Nsfc, Zengqian Hou, Yupeng Yao, Guoxuan Dong, Sheng Yu

Bulletin of Chinese Academy of Sciences (Chinese Version)

Strengthening the basic scientific research in an all-round way and achieving more breakthroughs from zero to one as soon as possible are the major strategic needs of building a world leading power in science and technology in the new era. As the main channel funding basic research in China, the National Natural Science Foundation of China (NSFC) has always focused on the basic frontiers and major scientific issues in space science, carried out strategic research on the planning of relevant disciplines, sorted out key scientific questions, defined the priority development direction, and provided continuous and stable funding through major, key, …

Reverberation Mapping Of Markarian 421 Using V,R, I, And Ha Filters, Alex Whitman

Honors Program Theses and Projects

Active Galactic Nuclei (AGN) at their most basic level are supermassive blackholes that emit light. While that sounds paradoxical, it speaks volumes to how little we know about these extraordinary objects. One technique that can be used, and was used here to better understand these objects is reverberation mapping. We employed this method on the AGN Markarian 421 (Mrk 421) at Bridgewater State University (BSU). Mrk 421 was chosen because it is the brightest known AGN, averaging 12.7 magnitudes, and the observational abilities of BSU are best suited for objects brighter than 18 magnitudes in optical wavelengths. We observed Mrk …

Dissipation In Global Simulations Of Accretion Disks, Catherine Gibson, Theodore Dezen Phd

Creative Collaborations: Annual Showcase of Undergraduate Research

Abstract: We perform general relativistic magneto-hydrodynamic simulations to study the dynamics of and radiation from accretion onto stellar mass black holes. Recent theoretical work suggested magnetic torques exerted at the innermost stable circular orbit can drive significant bulk vertical energy transport in regions close to the black hole, and hence dissipate a larger fraction of accretion power near the photosphere compared to standard models. This additional heating in turn may lead to the non-thermal high-energy (into several hundred keVs) radiation observed in some systems. We analyze time-dependent global simulations to further assess the feasibility of such models and illuminate the …

X-Ray Properties Of Early-Type Stars In The Tarantula Nebula From T-Rex, Paul A. Crowther, Patrick S. Broos, Leisa K. Townsley, Andy M. T. Pollock, Katie A. Tehrani, Marc Gagné

Earth & Space Sciences Faculty Publications

We reassess the historical L-X/L-Bol relation for early-type stars from a comparison between T-ReX, the Chandra ACIS X-ray survey of the Tarantula Nebula in the Large Magellanic Cloud (LMC), and contemporary spectroscopic analysis of massive stars obtained primarily from VLT/FLAMES, VLT/MUSE, and HST/STIS surveys. For 107 sources in common (some host to multiple stars), the majority of which are bolometrically luminous (40 per cent exceed 10(6)L(circle dot)), we find an average log L-X/L-Bol = -6.90 +/- 0.65. Excluding extreme systems Mk 34 (WN5h+WN5h), R140a (WC4+WN6+), and VFTS 399 (O9 IIIn+?), plus four WR sources with anomalously hard X-ray components (R130, …

Continuum Damping Effects In Nuclear Collisions, Hossein Sadeghi, Mahdieh Ghafouri

Karbala International Journal of Modern Science

The Time-Dependent Skyrme Hartree-Fock (TDSHF) calculations have been conducted to study 100Sn+16O, 116Sn+16O, and 122Sn+16O collisions on a 3-Dimensional (3D) mesh with SV-bas SF. For the 100Sn+16O collision, the continuum damping width of the rotational amplitudes in Ecm = 100, 150, 200, and 250 MeV has been achieved around 108, 185, 277, and 318, with the time evolution width for z2 around 15/5, 13/5, 13/9, or 14/3 fm2. The quadrupole deformation, kinetic energy, and rotational amplitude are studied. It is seen that the compound nucleus becomes uniform and spherical as time grows. The results of the time evolution show the …

Search For Continuous Gravitational Wave Emission From The Milky Way Center In O3 Ligo-Virgo Data, R. Abbott, H. Abe, F. Acernese, M. G. Benjamin, Teviet Creighton, Mario C. Diaz, F. Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

We present a directed search for continuous gravitational wave (CW) signals emitted by spinning neutron stars located in the inner parsecs of the Galactic Center (GC). Compelling evidence for the presence of a numerous population of neutron stars has been reported in the literature, turning this region into a very interesting place to look for CWs. In this search, data from the full O3 LIGO-Virgo run in the detector frequency band [10,2000]  Hz have been used. No significant detection was found and 95% confidence level upper limits on the signal strain amplitude were computed, over the full search band, with …

Galaxy And Mass Assembly: Galaxy Zoo Spiral Arms And Star Formation Rates, R Porter-Temple, Benne Holwerda, A M. Hopkins, L E. Porter, C Henry, T Geron, B Simmons, K Masters, S Kruk

Faculty and Staff Scholarship

Understanding the effect spiral structure has on star formation properties of galaxies is important to complete our picture of spiral structure evolution. Previous studies have investigated connections between spiral arm properties and star formation, but the effect that the number of spiral arms has on this process is unclear. Here, we use the Galaxy And Mass Assembly (GAMA) survey paired with the citizen science visual classifications from the Galaxy Zoo project to explore galaxies’ spiral arm number and how it connects to the star formation process. We use the votes from the GAMA-Kilo Degree Survey Galaxy Zoo classification to investigate …