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Astrophysics and Astronomy

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2016

Florida Institute of Technology

Articles 1 - 18 of 18

Full-Text Articles in Physical Sciences and Mathematics

A Dynamical Analysis Of The Kepler-80 System Of Five Transiting Planets, Mariah G. Macdonald, Darin A. Ragozzine Oct 2016

A Dynamical Analysis Of The Kepler-80 System Of Five Transiting Planets, Mariah G. Macdonald, Darin A. Ragozzine

Aerospace, Physics, and Space Science Faculty Publications

Kepler has discovered hundreds of systems with multiple transiting exoplanets which hold tremendous potential both individually and collectively for understanding the formation and evolution of planetary systems. Many of these systems consist of multiple small planets with periods less than ~50 days known as Systems with Tightly spaced Inner Planets, or STIPs. One especially intriguing STIP, Kepler-80 (KOI-500), contains five transiting planets: f, d, e, b, and c with periods of 1.0, 3.1, 4.6, 7.1, and 9.5 days, respectively. We provide measurements of transit times and a transit timing variation (TTV) dynamical analysis. We find that TTVs cannot reliably detect …

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A Deep Search For Additional Satellites Around The Dwarf Planet Haumea, Luke D. Burkhart, Darin Ragozzine, Michael E. Brown Jun 2016

A Deep Search For Additional Satellites Around The Dwarf Planet Haumea, Luke D. Burkhart, Darin Ragozzine, Michael E. Brown

Aerospace, Physics, and Space Science Faculty Publications

Haumea is a dwarf planet with two known satellites, an unusually high spin rate, and a large collisional family, making it one of the most interesting objects in the outer solar system. A fully self-consistent formation scenario responsible for the satellite and family formation is still elusive, but some processes predict the initial formation of many small moons, similar to the small moons recently discovered around Pluto. Deep searches for regular satellites around Kuiper belt objects are difficult due to observational limitations, but Haumea is one of the few for which sufficient data exist. We analyze Hubble Space Telescope (HST) …

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Dynamic Flaring Non-Potential Fields On Quiet Sun Networks Scales, David L. Chesney, Hakeem M. Oluseyi, Norton B. Orange May 2016

Dynamic Flaring Non-Potential Fields On Quiet Sun Networks Scales, David L. Chesney, Hakeem M. Oluseyi, Norton B. Orange

Aerospace, Physics, and Space Science Faculty Publications

We report on the identification of dynamic flaring non-potential structures on quiet Sun (QS) supergranular network scales. Data from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory allow for the high spatial and temporal resolution of this diverse class of compact structures. The rapidly evolving nonpotential events presented here, with lifetimes <10 minutes, are on the order of 10″ in length. Thus, they contrast significantly with well-known active region (AR) non-potential structures such as high-temperature X-ray and EUV sigmoids (>100″) and micro-sigmoids (>10″) with lifetimes on the order of hours to days. The photospheric magnetic field environment derived from the Helioseismic and Magnetic Imager shows a lack of evidence for these flaring non-potential fields being associated with significant concentrations of bipolar magnetic elements. Of much …

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Geological Conditions Required For The Fluvial Erosion Of Titan’S Impact Craters, Rebeca M. Kinser May 2016

Geological Conditions Required For The Fluvial Erosion Of Titan’S Impact Craters, Rebeca M. Kinser

Theses and Dissertations

In comparison to other icy satellites, Titan has a small number of impact craters on its surface. Its dense atmosphere screens smaller impactors from the surface, but this alone does not account for the lack of impact craters, especially at large diameters. This suggests that Titan has a relatively young surface and/or erosional processes have effectively removed craters from its surface. For example, fluvial erosion could degrade craters such that they would be unrecognizable from an orbiting spacecraft such as Cassini. The amount of erosion, however, will depend on a number of factors including the geological and meteorological conditions of …

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Double Power Laws In The Event-Integrated Solar Energetic Particle Spectrum, Lulu Zhao, Ming Zhang, Hamid K. Rassoul Apr 2016

Double Power Laws In The Event-Integrated Solar Energetic Particle Spectrum, Lulu Zhao, Ming Zhang, Hamid K. Rassoul

Aerospace, Physics, and Space Science Faculty Publications

A double power law or a power law with exponential rollover at a few to tens of MeV nucleon−1 of the eventintegrated differential spectra has been reported in many solar energetic particle (SEP) events. The rollover energies per nucleon of different elements correlate with a particleʼs charge-to-mass ratio (Q/A). The probable causes are suggested as residing in shock finite lifetimes, shock finite sizes, shock geometry, and an adiabatic cooling effect. In this work, we conduct a numerical simulation to investigate a particleʼs transport process in the inner heliosphere. We solve the focused transport equation using a time-backward Markov stochastic approach. …

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Efficient Geometric Probabilities Of Multi-Transiting Exoplanetary Systems From Corbits, Joshua Brakensiek, Darin Ragozzine Apr 2016

Efficient Geometric Probabilities Of Multi-Transiting Exoplanetary Systems From Corbits, Joshua Brakensiek, Darin Ragozzine

Aerospace, Physics, and Space Science Faculty Publications

NASA’s Kepler Space Telescope has successfully discovered thousands of exoplanet candidates using the transit method, including hundreds of stars with multiple transiting planets. In order to estimate the frequency of these valuable systems, it is essential to account for the unique geometric probabilities of detecting multiple transiting extrasolar planets around the same parent star. In order to improve on previous studies that used numerical methods, we have constructed an efficient, semi-analytical algorithm called the Computed Occurrence of Revolving Bodies for the Investigation of Transiting Systems (CORBITS), which, given a collection of conjectured exoplanets orbiting a star, computes the probability that …

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Reverberation Mapping Of The Dusty Torus In Active Galactic Nuclei, Erich Franz Geisert Apr 2016

Reverberation Mapping Of The Dusty Torus In Active Galactic Nuclei, Erich Franz Geisert

Theses and Dissertations

The Dusty Torus is a structure that is believed to exist in Active Galactic Nuclei. The Torus is physically too small to be spatially resolved, so Reverberation Mapping can be performed in order to replace spatial resolution with temporal resolution, yielding observations that can unravel the mystery of the Dusty Torus. One of the unknowns about the Torus is how the dust is distributed. The two competing theories are that either the dust resides in discrete clouds or that there is a solid wall of dust. This thesis presents the results of a year long observation program, starting in August …

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A Normal Supermassive Black Hole In Ngc 1277, Alister W. Graham, Mark Durré, Giulia A.D. Savorgnan, Anne M. Medling, Dan Batcheldor, Nicholas Scott, Beverly Watson, Alessandro Marconi Mar 2016

A Normal Supermassive Black Hole In Ngc 1277, Alister W. Graham, Mark Durré, Giulia A.D. Savorgnan, Anne M. Medling, Dan Batcheldor, Nicholas Scott, Beverly Watson, Alessandro Marconi

Aerospace, Physics, and Space Science Faculty Publications

The identification of galaxies with “overly massive” black holes requires two measurements: a black hole mass (Mbh) and a host spheroid mass (Msph,*). Here we provide our measurements for NGC 1277. Our structural decomposition reveals that NGC 1277 is dominated by a “classical” spheroid with a Sérsic index n = 5.3, a half-light radius Rₑmajor: You have a new taskSpace: You have a new task,major = 2.1 kpc, and a stellar mass of 2.7 10^11 11 M⊙ (using M*/ LV = 11.65, Martín-Navarro et al.). This mass is an order of magnitude greater than originally reported. Using the latest Mbh–n, …

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Kepler Eclipsing Binary Stars. Vii. The Catalog Of Eclipsing Binaries Found In The Entire Kepler Data Set, Brian Kirk, Darin Ragozzine Mar 2016

Kepler Eclipsing Binary Stars. Vii. The Catalog Of Eclipsing Binaries Found In The Entire Kepler Data Set, Brian Kirk, Darin Ragozzine

Aerospace, Physics, and Space Science Faculty Publications

The primary Kepler Mission provided nearly continuous monitoring of ∼200,000 objects with unprecedented photometric precision. We present the final catalog of eclipsing binary systems within the 105 deg2 Kepler field of view. This release incorporates the full extent of the data from the primary mission (Q0-Q17 Data Release). As a result, new systems have been added, additional false positives have been removed, ephemerides and principal parameters have been recomputed, classifications have been revised to rely on analytical models, and eclipse timing variations have been computed for each system. We identify several classes of systems including those that exhibit tertiary eclipse …

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An Hst Proper-Motion Study Of The Large Scale Jet Of 3c273, Eileen T. Meyer, William B. Sparks, Markos Georganopoulos, Jay Anderson, Roeland Van Der Marel, John Biretta, Sangmo Tony Sohn, Marco Chiaberge, Eric S. Perlman, Colin Norman Feb 2016

An Hst Proper-Motion Study Of The Large Scale Jet Of 3c273, Eileen T. Meyer, William B. Sparks, Markos Georganopoulos, Jay Anderson, Roeland Van Der Marel, John Biretta, Sangmo Tony Sohn, Marco Chiaberge, Eric S. Perlman, Colin Norman

Aerospace, Physics, and Space Science Faculty Publications

The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly relativistic on sub-parsec scales, with apparent proper motions up to 15c observed by very long baseline interferometry. In contrast, we find that the kiloparsec-scale knots are compatible with being stationary, with a mean speed of -0.2 ±0.5c over the whole jet. Assuming …

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Measurement Of Higher Cumulants Of Net-Charge Multiplicity Distributions In Au + Au Collisions At √Snn =7.7-200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, Phenix Collaboration Jan 2016

Measurement Of Higher Cumulants Of Net-Charge Multiplicity Distributions In Au + Au Collisions At √Snn =7.7-200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, Phenix Collaboration

Aerospace, Physics, and Space Science Faculty Publications

We report the measurement of cumulants (Cn,n=1,...,4) of the net-charge distributions measured within pseudorapidity (|η|<0.35) in Au+Au collisions at √sNN=7.7-200GeV with the PHENIX experiment at the Relativistic Heavy Ion Collider. The ratios of cumulants (e.g., C₁/C₂, C₃/C₁) of the net-charge distributions, which can be related to volume independent susceptibility ratios, are studied as a function of centrality and energy. These quantities are important to understand the quantum-chromodynamics phase diagram and possible existence of a critical end point. The measured values are very well described by expectation from negative binomial distributions. We do not observe any nonmonotonic behavior in the ratios of the cumulants as a function of collision energy. The measured values of C₁/C₂ and C₃/C₁ can be directly compared to lattice quantum-chromodynamics calculations and thus allow extraction of both the chemical freeze-out temperature and the baryon chemical potential at each center-of-mass energy. The extracted baryon chemical potentials are in excellent agreement with a thermal-statistical analysis model.

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A Search For Brief Optical Flashes Associated With The Seti Target Kic 8462852, A U. Abeysekara, Jamie A. Holder Jan 2016

A Search For Brief Optical Flashes Associated With The Seti Target Kic 8462852, A U. Abeysekara, Jamie A. Holder

Aerospace, Physics, and Space Science Faculty Publications

The F-type star KIC 8462852 has recently been identified as an exceptional target for search for extraterrestrial intelligence (SETI) observations. We describe an analysis methodology for optical SETI, which we have used to analyze nine hours of serendipitous archival observations of KIC→8462852 made with the VERITAS gamma-ray observatory between 2009 and 2015. No evidence of pulsed optical beacons, above a pulse intensity at the Earth of approximately 1 photon m-2, is found. We also discuss the potential use of imaging atmospheric Cherenkov telescope arrays in searching for extremely short duration optical transients in general.

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Transit Timing Observations From Kepler. Ix. Catalog Of The Full Long-Cadence Data Set, Tomer Holczer, Tsevi Mazeh, Gil Nachmani, Daniel Jontof-Hutter, Eric B. Ford, Daniel Fabrycky, Darin Ragozzine, Mackenzie Kane, Jason H. Steffen Jan 2016

Transit Timing Observations From Kepler. Ix. Catalog Of The Full Long-Cadence Data Set, Tomer Holczer, Tsevi Mazeh, Gil Nachmani, Daniel Jontof-Hutter, Eric B. Ford, Daniel Fabrycky, Darin Ragozzine, Mackenzie Kane, Jason H. Steffen

Aerospace, Physics, and Space Science Faculty Publications

We present a new transit timing catalog of 2599 Kepler Objects of Interest (KOIs), using the PDC-MAP long-cadence light curves that include the full 17 quarters of the mission (ftp://wise-ftp.tau.ac.il/pub/tauttv/TTV/ver-112). The goal is to produce an easy-to-use catalog that can stimulate further analyses of interesting systems. For 779 KOIs with high enough S/N, we derived the timing, duration, and depth of 69,914 transits. For 1820 KOIs with lower SNR, we derived only the timing of 225,273 transits. After removal of outlier timings, we derived various statistics for each KOI that were used to indicate significant variations. Including systems found by …

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Evidence Of Magnetic Field Decay In Massive Main-Sequence Stars, Luca Fossati, Fabian R.N. Schneider, Norberto Castro, Norbert Langer, Sergio Simón-Díaz, André Luís Müller, Alex De Koter, Thierry Morel, Véronique Petit, Hugues Sana, Gregg A. Wade Jan 2016

Evidence Of Magnetic Field Decay In Massive Main-Sequence Stars, Luca Fossati, Fabian R.N. Schneider, Norberto Castro, Norbert Langer, Sergio Simón-Díaz, André Luís Müller, Alex De Koter, Thierry Morel, Véronique Petit, Hugues Sana, Gregg A. Wade

Aerospace, Physics, and Space Science Faculty Publications

A significant fraction of massive main-sequence stars show strong, large-scale magnetic fields. The origin of these fields, their lifetimes, and their role in shaping the characteristics and evolution of massive stars are currently not well understood. We compile a catalogue of 389 massive main-sequence stars, 61 of which are magnetic, and derive their fundamental parameters and ages. The two samples contain stars brighter than magnitude 9 in the V-band and range in mass between 5 and 100 M⊙. We find that the fractional main-sequence age distribution of all considered stars follows what is expected for a magnitude limited sample, while …

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The Puzzling Properties Of The Magnetic O Star Tr16-22, Yaël Nazé, Rodolfo Barbá, Stefano Bagnulo, Nidia Morrell, Roberto Gamen, Véronique Petit, Coralie Neiner Jan 2016

The Puzzling Properties Of The Magnetic O Star Tr16-22, Yaël Nazé, Rodolfo Barbá, Stefano Bagnulo, Nidia Morrell, Roberto Gamen, Véronique Petit, Coralie Neiner

Aerospace, Physics, and Space Science Faculty Publications

Context. The detection of bright, hard, and variable X-ray emission in Tr16-22 prompted spectropolarimetric observations of this star, which in turn led to the discovery of a surface magnetic field. Aims. We want to further constrain the properties of this star, in particular to verify whether X-ray variations are correlated to changes in optical emission lines and magnetic field strength, as expected from the oblique rotator model that is widely accepted for magnetic O stars. Methods. We have obtained new low-resolution spectropolarimetric and long-term high-resolution spectroscopic monitoring of Tr16-22, and we also analyse new, serendipitous X-ray data. Results. The new …

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Powerful Activity In The Bright Ages. I. A Visible/Ir Survey Of High Redshift 3c Radio Galaxies And Quasars, Bryan Hilbert, Eric S. Perlman Jan 2016

Powerful Activity In The Bright Ages. I. A Visible/Ir Survey Of High Redshift 3c Radio Galaxies And Quasars, Bryan Hilbert, Eric S. Perlman

Aerospace, Physics, and Space Science Faculty Publications

We present new rest-frame UV and visible observations of 22 high-z (1 < z < 2.5) 3C radio galaxies and QSOs obtained with the Hubble Space Telescope's Wide Field Camera 3 instrument. Using a custom data reduction strategy in order to assure the removal of cosmic rays, persistence signal, and other data artifacts, we have produced high-quality science-ready images of the targets and their local environments. We observe targets with regions of UV emission suggestive of active star formation. In addition, several targets exhibit highly distorted host galaxy morphologies in the rest frame visible images. Photometric analyses reveal that brighter QSOs generally tend to be redder than their dimmer counterparts. Using emission line fluxes from the literature, we estimate that emission line contamination is relatively small in the rest frame UV images for the QSOs. Using archival VLA data, we have also created radio map overlays for each of our targets, allowing for analysis of the optical and radio axes alignment.

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Scaling Properties Of Fractional Momentum Loss Of High- Pt Hadrons In Nucleus-Nucleus Collisions At √Snn From 62.4 Gev To 2.76 Tev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki, Phenix Collaboration Jan 2016

Scaling Properties Of Fractional Momentum Loss Of High- Pt Hadrons In Nucleus-Nucleus Collisions At √Snn From 62.4 Gev To 2.76 Tev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki, Phenix Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Measurements of the fractional momentum loss (Sloss ≡ δpT/pT) of high-transverse-momentum-identified hadrons in heavy-ion collisions are presented. Using π⁰ in Au+Au and Cu+Cu collisions at √sNN=62.4 and 200 GeV measured by the PHENIX experiment at the Relativistic Heavy Ion Collider and and charged hadrons in Pb+Pb collisions measured by the ALICE experiment at the Large Hadron Collider, we studied the scaling properties of Sloss as a function of a number of variables: the number of participants, Npart, the number of quark participants, Nqp, the charged-particle density, dNch/dη, and the Bjorken energy density times the equilibration time, ᵋᵦjτ₀. We find that …

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Transverse Energy Production And Charged-Particle Multiplicity At Midrapidity In Various Systems From √Snn =7.7 To 200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki Jan 2016

Transverse Energy Production And Charged-Particle Multiplicity At Midrapidity In Various Systems From √Snn =7.7 To 200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki

Aerospace, Physics, and Space Science Faculty Publications

Measurements of midrapidity charged-particle multiplicity distributions, dNch/dη, and midrapidity transverse-energy distributions, dET/dη, are presented for a variety of collision systems and energies. Included are distributions for Au+Au collisions at sNN=200, 130, 62.4, 39, 27, 19.6, 14.5, and 7.7 GeV, Cu+Cu collisions at √sNN=200 and 62.4 GeV, Cu+Au collisions at √sNN=200 GeV, U+U collisions at √sNN=193 GeV, d+Au collisions at √sNN=200 GeV, ³He+Au collisions at √sNN=200 GeV, and p+p collisions at √sNN=200 GeV. Centrality-dependent distributions at midrapidity are presented in terms of the number of nucleon participants, Npart, and the number of constituent quark participants, Nqp. For all A+A collisions down …

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