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6,120 full-text articles. Page 7 of 184.

The Stellar Populations Of Two Ultra-Diffuse Galaxies From Optical And Near-Infrared Photometry, Viraj Pandya, Aaron J. Romanowsky, Seppo Laine, Jean Brodie, Benjamin Johnson, William Glaccum, Alexa Villaume, Jean-Charles Cuillandre, Stephen Gwyn, Jessica Krick, Ronald Lasker, Ignacio Martín-Navarro, David Martinez-Delgado, Pieter van Dokkum 2018 University of California, Santa Cruz

The Stellar Populations Of Two Ultra-Diffuse Galaxies From Optical And Near-Infrared Photometry, Viraj Pandya, Aaron J. Romanowsky, Seppo Laine, Jean Brodie, Benjamin Johnson, William Glaccum, Alexa Villaume, Jean-Charles Cuillandre, Stephen Gwyn, Jessica Krick, Ronald Lasker, Ignacio Martín-Navarro, David Martinez-Delgado, Pieter Van Dokkum

Faculty Publications

We present observational constraints on the stellar populations of two ultra-diffuse galaxies (UDGs) using optical through near-infrared (NIR) spectral energy distribution (SED) fitting. Our analysis is enabled by new Spitzer-IRAC 3.6 and 4.5 μm imaging, archival optical imaging, and the prospectorfully Bayesian SED fitting framework. Our sample contains one field UDG (DGSAT I), one Virgo cluster UDG (VCC 1287), and one Virgo cluster dwarf elliptical for comparison (VCC 1122). We find that the optical–NIR colors of the three galaxies are significantly different from each other. We infer that VCC 1287 has an old (7.7 ...


The Stellar Populations Of Two Ultra-Diffuse Galaxies From Optical And Near-Infrared Photometry, Viraj Pandya, Aaron J. Romanowsky, Seppo Laine, Jean P. Brodie, Benjamin D. Johnson, William Glaccum, Alexa Villaume, Jean-Charles Cuillandre, Stephen Gwyn, Jessica Krick, Ronald Lasker, Ignacio Martín-Navarro, David Martinez-Delgado, Pieter G. van Dokkum 2018 University of California, Santa Cruz

The Stellar Populations Of Two Ultra-Diffuse Galaxies From Optical And Near-Infrared Photometry, Viraj Pandya, Aaron J. Romanowsky, Seppo Laine, Jean P. Brodie, Benjamin D. Johnson, William Glaccum, Alexa Villaume, Jean-Charles Cuillandre, Stephen Gwyn, Jessica Krick, Ronald Lasker, Ignacio Martín-Navarro, David Martinez-Delgado, Pieter G. Van Dokkum

Aaron J. Romanowsky

We present observational constraints on the stellar populations of two ultra-diffuse galaxies (UDGs) using optical through near-infrared (NIR) spectral energy distribution (SED) fitting. Our analysis is enabled by new Spitzer-IRAC 3.6 and 4.5 μm imaging, archival optical imaging, and the prospectorfully Bayesian SED fitting framework. Our sample contains one field UDG (DGSAT I), one Virgo cluster UDG (VCC 1287), and one Virgo cluster dwarf elliptical for comparison (VCC 1122). We find that the optical–NIR colors of the three galaxies are significantly different from each other. We infer that VCC 1287 has an old (7 ...


Upper Limits On The Presence Of Central Massive Black Holes In Two Ultra-Compact Dwarf Galaxies In Centaurus A, Karina Voggel, Anil Seth, Nadine Neumayer, Steffen Mieske, Igor Chilingarian, Christopher Ahn, Holger Baumgardt, Michael Hilker, Dieu Nguyen, Aaron J. Romanowsky, Jonelle Walsh, Mark den Brok, Jay Strader 2018 University of Utah

Upper Limits On The Presence Of Central Massive Black Holes In Two Ultra-Compact Dwarf Galaxies In Centaurus A, Karina Voggel, Anil Seth, Nadine Neumayer, Steffen Mieske, Igor Chilingarian, Christopher Ahn, Holger Baumgardt, Michael Hilker, Dieu Nguyen, Aaron J. Romanowsky, Jonelle Walsh, Mark Den Brok, Jay Strader

Faculty Publications

The recent discovery of massive black holes (BHs) in the centers of high-mass ultra-compact dwarf galaxies (UCDs) suggests that at least some are the stripped nuclear star clusters of dwarf galaxies. We present the first study that investigates whether such massive BHs, and therefore stripped nuclei, also exist in low-mass (M < 107 M ⊙) UCDs. We constrain the BH masses of two UCDs located in Centaurus A (UCD 320 and UCD 330) using Jeans modeling of the resolved stellar kinematics from adaptive optics data obtained with the SINFONI integral field spectrograph at the Very Large Telescope (VLT/SINFONI). No massive BHs are ...


Upper Limits On The Presence Of Central Massive Black Holes In Two Ultra-Compact Dwarf Galaxies In Centaurus A, Karina T. Voggel, Anil C. Seth, Nadine Neumayer, Steffen Mieske, Igor Chilingarian, Christopher P. Ahn, Holger Baumgardt, Michael Hilker, Dieu D. Nguyen, Aaron J. Romanowsky, Jonelle L. Walsh, Mark den Brok, Jay Strader 2018 University of Utah

Upper Limits On The Presence Of Central Massive Black Holes In Two Ultra-Compact Dwarf Galaxies In Centaurus A, Karina T. Voggel, Anil C. Seth, Nadine Neumayer, Steffen Mieske, Igor Chilingarian, Christopher P. Ahn, Holger Baumgardt, Michael Hilker, Dieu D. Nguyen, Aaron J. Romanowsky, Jonelle L. Walsh, Mark Den Brok, Jay Strader

Aaron J. Romanowsky

The recent discovery of massive black holes (BHs) in the centers of high-mass ultra-compact dwarf galaxies (UCDs) suggests that at least some are the stripped nuclear star clusters of dwarf galaxies. We present the first study that investigates whether such massive BHs, and therefore stripped nuclei, also exist in low-mass (M < 107 M ) UCDs. We constrain the BH masses of two UCDs located in Centaurus A (UCD 320 and UCD 330) using Jeans modeling of the resolved stellar kinematics from adaptive optics data obtained with the SINFONI integral field spectrograph at the Very Large Telescope (VLT/SINFONI). No massive ...


Seeing An Exoplanet, Leo Moraczewski 2018 College of Saint Benedict/Saint John's University

Seeing An Exoplanet, Leo Moraczewski

Celebrating Scholarship and Creativity Day

In my experiment, I used the telescopes at the Saint John’s Observatory to measure the brightness of three stars that were expected to have exoplanets orbiting them. I was unable to take enough data on two of the stars, but was able to confirm the existence of an exoplanet around the third, HD189733.


Lunar Ice Cube: Development Of A Numerical Model For Attitude Control, Alexander Roberts, Benjamin Malphrus, Kevin Brown 2018 Morehead State University

Lunar Ice Cube: Development Of A Numerical Model For Attitude Control, Alexander Roberts, Benjamin Malphrus, Kevin Brown

Celebration of Student Scholarship Posters Archive

No abstract provided.


Msu And Citizen Cate: A High Definition Look At The Sun’S Inner Corona During The 2017 Solar Eclipse Over Hopkinsville, Kentucky., Jessie Anderson, Ethan Caudill 2018 Morehead State University

Msu And Citizen Cate: A High Definition Look At The Sun’S Inner Corona During The 2017 Solar Eclipse Over Hopkinsville, Kentucky., Jessie Anderson, Ethan Caudill

Celebration of Student Scholarship Posters Archive

No abstract provided.


Physics 516: Electromagnetic Phenomena (Spring 2018), Philip C. Nelson 2018 University of Pennsylvania

Physics 516: Electromagnetic Phenomena (Spring 2018), Philip C. Nelson

Department of Physics Papers

These course notes are made publicly available in the hope that they will be useful. All reports of errata will be gratefully received. I will also be glad to hear from anyone who reads them, whether or not you find errors: pcn@upenn.edu.


Primordial Black Hole Atoms, David Zwick, Tyler Hanover, Brian Nepper 2018 Rowan University

Primordial Black Hole Atoms, David Zwick, Tyler Hanover, Brian Nepper

Student Research Symposium Posters

Primordial black holes are thought to have been formed at the early stages of the universe in the presence of non-homogeneous density distributions of dark matter. We are working under the assumption that dark matter consists of elementary low mass particles, specifically, spin 1/2 fermions. We further assume that dark matter is electrically neutral, thus its main interaction is gravitational. We investigate dark matter spin 1/2 fermions in orbit around a black hole atom and consider mass ranges for which the quantum description is appropriate. Solutions to the Dirac equation are utilized to describe the radial mass distribution ...


High Resolution Spectroscopy Of The Hyades Giants, Antonio Martinez 2018 The Univeristy of Western Ontario

High Resolution Spectroscopy Of The Hyades Giants, Antonio Martinez

Electronic Thesis and Dissertation Repository

The four K0IIIHyades red clump giants, γ , δ , ϵ , and θ 1Tauri, are ideal candidates for cool star research. They are easily observable at a distance of only 47 pc and one star, ϵ Tauri, is a suspected Maunder minimum star. These stars also provide a useful opportunity to investigate the nature of the photospheric velocity field, and assess the effectiveness of a range of spectroscopic tools including the merits of the microturbulence-macroturbulence approach to the study of cool star spectra. High resolution (λ /Δ λ ∼ 100,000) exposures, taken from January 2001 to October 2008 in the 6250 Å ...


Design And Evaluation Of 3d-Printed Filar Micrometer, Emily Rull 2018 Olivet Nazarene University

Design And Evaluation Of 3d-Printed Filar Micrometer, Emily Rull

Scholar Week 2016 - present

This project sought to design and 3D-print a filar micrometer for double star measurements that amateur astronomers could produce cost effectively.

Double stars are celestial objects that allow the mass of stars to be calculated by assessing their orbits. Stellar mass affects every current model of stellar evolution, but the most accurate double star orbits can take decades to record. As a result of the long-term nature of such observations and lack of groundbreaking research in double star studies, professional astronomers are no longer focused on making these measurements. This allows amateur astronomers to pick up where professionals have left ...


Infrared Properties Of Stars In The Bulge Asymmetries And Dynamical Evolution Survey, Eddie Hilburn 2018 University of New Mexico

Infrared Properties Of Stars In The Bulge Asymmetries And Dynamical Evolution Survey, Eddie Hilburn

Physics & Astronomy ETDs

The Bulge Asymmetries and Dynamical Evolution (BAaDE) survey is an SiO maser survey of 28,062 infrared-selected evolved stars primarily in the Galactic plane. By cross-matching the BAaDE target sources with nine different infrared catalogs, we have constructed a catalog with wavelength coverage from 0.71 to 80 m. Using this catalog, we fit the data for each source to a model spectral energy distribution (SED) generated with the radiation transport program DUSTY in order to obtain characteristics such as bolometric flux, source effective temperature, and the optical depth of the circumstellar envelope.

The overall goal of the BAaDE survey ...


Does The Black Hole Shadow Probe The Event Horizon Geometry?, Pedro V. P. Cunha, Carlos A. R. Herdeiro, Maria J. Rodriguez 2018 Universidade de Lisboa

Does The Black Hole Shadow Probe The Event Horizon Geometry?, Pedro V. P. Cunha, Carlos A. R. Herdeiro, Maria J. Rodriguez

All Physics Faculty Publications

There is an exciting prospect of obtaining the shadow of astrophysical black holes (BHs) in the near future with the Event Horizon Telescope. As a matter of principle, this justifies asking how much one can learn about the BH horizon itself from such a measurement. Since the shadow is determined by a set of special photon orbits, rather than horizon properties, it is possible that different horizon geometries yield similar shadows. One may then ask how sensitive is the shadow to details of the horizon geometry? As a case study, we consider the double Schwarzschild BH and analyze the impact ...


Breaking The Habit: The Peculiar 2016 Eruption Of The Unique Recurrent Nova M31n 2008-12a, M. Henze, T. D. Oswalt, M. J. Darnley, S. C. Williams, M. Kato, et al. 2018 San Diego State University

Breaking The Habit: The Peculiar 2016 Eruption Of The Unique Recurrent Nova M31n 2008-12a, M. Henze, T. D. Oswalt, M. J. Darnley, S. C. Williams, M. Kato, Et Al.

Publications

Since its discovery in 2008, the Andromeda galaxy nova M31N 2008-12a has been observed in eruption every single year. This unprecedented frequency indicates an extreme object, with a massive white dwarf and a high accretion rate, which is the most promising candidate for the single-degenerate progenitor of a Type Ia supernova known to date. The previous three eruptions of M31N 2008-12a have displayed remarkably homogeneous multiwavelength properties: (i) from a faint peak, the optical light curve declined rapidly by two magnitudes in less than two days, (ii) early spectra showed initial high velocities that slowed down significantly within days and ...


Quantum Phase Space Representations And Their Negativities, Ninnat Dangniam 2018 University of New Mexico

Quantum Phase Space Representations And Their Negativities, Ninnat Dangniam

Physics & Astronomy ETDs

A classical simulation scheme of quantum computation given a restricted set of states and measurements may be---occasionally, but only occasionally---interpreted naturally as a statistical simulation of positive quasi-probability distributions on a phase space. In this dissertation, we explore phase space representations for finite-dimensional quantum systems and their negativities beyond the usual analogues of the Wigner function.

The first line of study focuses on a characterization tool for valid quasi-probability distributions of (possibly mixed) quantum states. A quantum generalization of Bochner's theorem from classical probability theory simultaneously characterizes both the set of valid Wigner functions and the subset of positive ...


The Subject Librarian Newsletter, Nanoscience, Fall 2016, Sandy Avila 2018 University of Central Florida

The Subject Librarian Newsletter, Nanoscience, Fall 2016, Sandy Avila

Sandy Avila

No abstract provided.


Planetary Candidates Observed By Kepler. Viii. A Fully Automated Catalog With Measured Completeness And Reliability Based On Data Release 25, Susan E. Thompson, Jeffrey L. Coughlin, Kelssey Hoffman, Fergal Mullally, Jessie L. Christiansen, Christopher J. Burke, Steve Bryson, Natalie Batalha, Michael R. Haas, Joseph Catanzarite, Jason F. Rowe, Geert Barentsen, Douglas A. Caldwell, Bruce D. Clarke, Jon M. Jenkins, Jie Li, David W. Latham, Jack J. Lissauer, Savita Mathur, Robert L. Morris, Shawn E. Seader, Jeffrey C. Smith, Todd C. Klaus, Joseph D. Twicken, Jeffrey E. Van Cleve, Bill Wohler, Rachel Akeson, David R. Ciardi, William D. Cochran, Christopher E. Henze, Steve B. Howell 2018 SETI Institute; NASA Ames Research Center; Space Telescope Science Institute

Planetary Candidates Observed By Kepler. Viii. A Fully Automated Catalog With Measured Completeness And Reliability Based On Data Release 25, Susan E. Thompson, Jeffrey L. Coughlin, Kelssey Hoffman, Fergal Mullally, Jessie L. Christiansen, Christopher J. Burke, Steve Bryson, Natalie Batalha, Michael R. Haas, Joseph Catanzarite, Jason F. Rowe, Geert Barentsen, Douglas A. Caldwell, Bruce D. Clarke, Jon M. Jenkins, Jie Li, David W. Latham, Jack J. Lissauer, Savita Mathur, Robert L. Morris, Shawn E. Seader, Jeffrey C. Smith, Todd C. Klaus, Joseph D. Twicken, Jeffrey E. Van Cleve, Bill Wohler, Rachel Akeson, David R. Ciardi, William D. Cochran, Christopher E. Henze, Steve B. Howell

Physics & Astronomy Faculty Publications

We present the Kepler Object of Interest (KOI) catalog of transiting exoplanets based on searching 4 yr of Kepler time series photometry (Data Release 25, Q1–Q17). The catalog contains 8054 KOIs, of which 4034 are planet candidates with periods between 0.25 and 632 days. Of these candidates, 219 are new, including two in multiplanet systems (KOI-82.06 and KOI-2926.05) and 10 high-reliability, terrestrial-size, habitable zone candidates. This catalog was created using a tool called the Robovetter, which automatically vets the DR25 threshold crossing events (TCEs). The Robovetter also vetted simulated data sets and measured how well it ...


"Water Fountain" Masers In Proto-Planetary Nebulae, Patrick R. Latimer 2018 University of New Mexico

"Water Fountain" Masers In Proto-Planetary Nebulae, Patrick R. Latimer

2018 Award Winners - Hulsman Undergraduate Library Research Award

No abstract provided.


Sdss-Iv Manga: Star Formation Cessation In Low-Redshift Galaxies. I. Dependence On Stellar Mass And Structural Properties, Enci Wang, Cheng Li, Ting Xiao, Lin Lin, Matthew Bershady, David R. Law, Michael Merrifield, Sebastian F. Sanchez, Rogemar A. Riffel, Rogerio Riffel, Renbin Yan 2018 University of Science and Technology of China, China

Sdss-Iv Manga: Star Formation Cessation In Low-Redshift Galaxies. I. Dependence On Stellar Mass And Structural Properties, Enci Wang, Cheng Li, Ting Xiao, Lin Lin, Matthew Bershady, David R. Law, Michael Merrifield, Sebastian F. Sanchez, Rogemar A. Riffel, Rogerio Riffel, Renbin Yan

Physics and Astronomy Faculty Publications

We investigate radial gradients in the recent star formation history (SFH) of 1917 galaxies with 0.01 < z < 0.14 from the Mapping Nearby Galaxies at Apache Point Observatory project. For each galaxy, we obtain two-dimensional maps and radial profiles for three spectroscopically measured parameters that are sensitive to the recent SFH: Dn (4000) (the 4000 Å break), EW(HδA), and EW(Hα) (the equivalent width of the Hδ absorption and the Hα emission line). The majority of the spaxels are consistent with models of a continuously declining star formation rate, indicating that starbursts occur rarely in local galaxies with regular morphologies. We classify the galaxies into three classes: fully star-forming (SF), partly quenched (PQ), and totally quenched (TQ). The galaxies that are less massive than 1010 M ...


Gravity Then And Now, Paul Ingraham 2018 Germanna Community College

Gravity Then And Now, Paul Ingraham

Student Writing

This paper discusses the theory of gravity from the time it was discovered by Sir Isaac Newton to present time with the discovery of gravitational waves by Albert Einstein, and the detection of gravitational waves. Stephen Hawking's and Leonard Mlodinow's recent book, The Grand Design, provides support for Edward Witten's M-theory. Gravity was the first of the four fundamental forces to be discovered, and that last to be detected. Einstein proposed that gravity was not only a force, but also could be characterized as a wave on the space-time continuum.


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