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Astronomy For Educators, Daniel E. Barth 2019 University of Arkansas, Fayetteville

Astronomy For Educators, Daniel E. Barth

Open Educational Resources

Astronomy for Educators provides new and accomplished K-12 instructors with concepts and projects for low-cost, high-impact STEM classroom instruction that is built around the National Academies National Research Council's K-12 Framework for Science Education.


Bayesian Analysis Of Two Stellar Populations In Galactic Globular Clusters Ii: Ngc 5024, Ngc 5272, And Ngc 6352, Rachel Wagner-Kaiser, Ted von Hippel, David Stenning, Elliot Robinson, Ata Sarajedini, David van Dyk, Nathan Stein, William H. Jefferys 2018 University of Florida

Bayesian Analysis Of Two Stellar Populations In Galactic Globular Clusters Ii: Ngc 5024, Ngc 5272, And Ngc 6352, Rachel Wagner-Kaiser, Ted Von Hippel, David Stenning, Elliot Robinson, Ata Sarajedini, David Van Dyk, Nathan Stein, William H. Jefferys

Publications

We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival ACS Treasury observations of Galactic Globular Clusters to find and characterize two stellar populations in NGC 5024 (M53), NGC 5272 (M3), and NGC 6352. For these three clusters, both single and double-population analyses are used to determine a best fit isochrone(s). We employ a sophisticated Bayesian analysis technique to simultaneously fit the cluster parameters (age, distance, absorption, and metallicity) that characterize each cluster. For the two-population analysis, unique population level helium values are also fit to each distinct population of the cluster and the relative proportions of ...


Expected And Achievable Accuracy In Estimating Parameters Of Standing Accretion Shock Instability (Sasi) Fluctuations From Neutrinos And Gravitational Wave Oscillations, Colter Richardson, Jonathan Westhouse 2018 Embry-Riddle Aeronautical University

Expected And Achievable Accuracy In Estimating Parameters Of Standing Accretion Shock Instability (Sasi) Fluctuations From Neutrinos And Gravitational Wave Oscillations, Colter Richardson, Jonathan Westhouse

Undergraduate Research Symposium - Prescott

Core collapse supernovae are one of the most interesting sources of gravitational waves. When the progenitor star is particularly massive, hydrodynamic instability called standing accretion shock instability can develop and it is characterized by deterministic oscillations in the gravitational wave signal as well as in the neutrino luminosity with frequencies of 100hz. In this talk we will review current efforts to extract physical information from the SASI components of the gravitational wave and enhance the detectability of gravitational waves with such components both using laser interferometers and neutrino detectors.


Modeling And Detectability Of Gravitational Wave Waveform Memory From Core Collapse Supernovae, Pedro Jesus Quinonez, Emily Grimes 2018 Embry-Riddle Aeronautical University

Modeling And Detectability Of Gravitational Wave Waveform Memory From Core Collapse Supernovae, Pedro Jesus Quinonez, Emily Grimes

Undergraduate Research Symposium - Prescott

Ever since the discovery of gravitational waves by LIGO, studying these waves have become of utmost importance. This is because gravitational waves have the potential to carry information that have remain unseen by physicist in the past. For example, take the case of a core collapse supernovae. Any information transferred through electromagnetic waves that attempts to escape the inner core of a dying star is blocked out by the intense radiation of its outer shell. For this reason, astronomers have been unable to truly study what goes in the core. However, this is not the case for gravitational waves, which ...


Chromodynamical Analysis Of Lenticular Galaxies Using Globular Clusters And Planetary Nebulae, Emilio Zanatta, Arianna Cortesi, Ana Chies-Santos, Duncan Forbes, Aaron Romanowsky, Adebusola Alabi, Lodovico Coccato, Claudia Mendes de Oliveira, Jean Brodie, Michael Merrifield 2018 Universidade Federal do Rio Grande do Sul

Chromodynamical Analysis Of Lenticular Galaxies Using Globular Clusters And Planetary Nebulae, Emilio Zanatta, Arianna Cortesi, Ana Chies-Santos, Duncan Forbes, Aaron Romanowsky, Adebusola Alabi, Lodovico Coccato, Claudia Mendes De Oliveira, Jean Brodie, Michael Merrifield

Faculty Publications

Recovering the origins of lenticular galaxies can shed light on the understanding of galaxy and compare them with the kinematics of planetary nebulae (PNe). The PNe and GC data come from the Planetary Nebulae Spectrograph and the SLUGGS Surveys. Through photometric spheroid-disc decomposition and PNe kinematics. we find the probability for a given GC to belong to either the spheroid or the disc of its host galaxy or be rejected from the model. We find that there is no correlation between the components that the GCs are likely to belong to and their colours. Particularly, for NGC 2768, we find ...


A Bayesian Analysis Of The Ages Of Four Open Clusters, Elizabeth Jeffery, Ted von Hippel, David A. van Dyk, David C. Stenning, Elliot Robinson, Nathan Sten, William H. Jefferys 2018 BYU

A Bayesian Analysis Of The Ages Of Four Open Clusters, Elizabeth Jeffery, Ted Von Hippel, David A. Van Dyk, David C. Stenning, Elliot Robinson, Nathan Sten, William H. Jefferys

Publications

In this paper we apply a Bayesian technique to determine the best fit of stellar evolution models to find the main sequence turn off age and other cluster parameters of four intermediate-age open clusters: NGC 2360, NGC 2477, NGC 2660, and NGC 3960. Our algorithm utilizes a Markov chain Monte Carlo technique to fit these various parameters, objectively finding the best-fit isochrone for each cluster. The result is a high-precision isochrone fit. We compare these results with the those of traditional “by-eye” isochrone fitting methods. By applying this Bayesian technique to NGC 2360, NGC 2477, NGC 2660, and NGC 3960 ...


Chromodynamical Analysis Of Lenticular Galaxies Using Globular Clusters And Planetary Nebulae, Emilio J B Zanatta, Arianna Cortesi, Ana L. Chies-Santos, Duncan A. Forbes, Aaron J. Romanowsky, Adebusola B. Alabi, Lodovico Coccato, Claudia Mendes de Oliveira, Jean P. Brodie, Michael M. Merrifield 2018 Universidade Federal do Rio Grande do Sul

Chromodynamical Analysis Of Lenticular Galaxies Using Globular Clusters And Planetary Nebulae, Emilio J B Zanatta, Arianna Cortesi, Ana L. Chies-Santos, Duncan A. Forbes, Aaron J. Romanowsky, Adebusola B. Alabi, Lodovico Coccato, Claudia Mendes De Oliveira, Jean P. Brodie, Michael M. Merrifield

Aaron J. Romanowsky

Recovering the origins of lenticular galaxies can shed light on the understanding of galaxy and compare them with the kinematics of planetary nebulae (PNe). The PNe and GC data come from the Planetary Nebulae Spectrograph and the SLUGGS Surveys. Through photometric spheroid-disc decomposition and PNe kinematics. we find the probability for a given GC to belong to either the spheroid or the disc of its host galaxy or be rejected from the model. We find that there is no correlation between the components that the GCs are likely to belong to and their colours. Particularly, for NGC 2768, we find ...


Origins Of Ultradiffuse Galaxies In The Coma Cluster – I. Constraints From Velocity Phase Space, Adebusola Alabi, Anna Ferré-Mateu, Aaron Romanowsky, Jean Brodie, Duncan Forbes, Asher Wasserman, Sabine Bellstedt, Ignacio Martín-Navarro, Viraj Pandya, Maria Stone, Nobuhiro Okabe 2018 University of California Observatories

Origins Of Ultradiffuse Galaxies In The Coma Cluster – I. Constraints From Velocity Phase Space, Adebusola Alabi, Anna Ferré-Mateu, Aaron Romanowsky, Jean Brodie, Duncan Forbes, Asher Wasserman, Sabine Bellstedt, Ignacio Martín-Navarro, Viraj Pandya, Maria Stone, Nobuhiro Okabe

Faculty Publications

We use Keck/DEIMOS spectroscopy to confirm the cluster membership of 16 ultradiffuse galaxies (UDGs) in the Coma cluster, bringing the total number of spectroscopically confirmed UDGs from the Yagi et al. (Y16) catalogue to 25. We also identify a new cluster background UDG, confirming that most (∼95 per cent) of the UDGs in the Y16 catalogue belong to the Coma cluster. In this pilot study of Coma UDGs in velocity phase space, we find evidence of a diverse origin for Coma cluster UDGs, similar to normal dwarf galaxies. Some UDGs in our sample are consistent with being late infalls ...


Origins Of Ultradiffuse Galaxies In The Coma Cluster – I. Constraints From Velocity Phase Space, Adebusola B. Alabi, Anna Ferré-Mateu, Aaron J. Romanowsky, Jean P. Brodie, Duncan A. Forbes, Asher Wasserman, Sabine Bellstedt, Ignacio Martín-Navarro, Viraj Pandya, Maria B. Stone, Nobuhiro Okabe 2018 University of California Observatories

Origins Of Ultradiffuse Galaxies In The Coma Cluster – I. Constraints From Velocity Phase Space, Adebusola B. Alabi, Anna Ferré-Mateu, Aaron J. Romanowsky, Jean P. Brodie, Duncan A. Forbes, Asher Wasserman, Sabine Bellstedt, Ignacio Martín-Navarro, Viraj Pandya, Maria B. Stone, Nobuhiro Okabe

Aaron J. Romanowsky

We use Keck/DEIMOS spectroscopy to confirm the cluster membership of 16 ultradiffuse galaxies (UDGs) in the Coma cluster, bringing the total number of spectroscopically confirmed UDGs from the Yagi et al. (Y16) catalogue to 25. We also identify a new cluster background UDG, confirming that most (∼95 per cent) of the UDGs in the Y16 catalogue belong to the Coma cluster. In this pilot study of Coma UDGs in velocity phase space, we find evidence of a diverse origin for Coma cluster UDGs, similar to normal dwarf galaxies. Some UDGs in our sample are consistent with being late infalls ...


Dust Production And Depletion In Evolved Planetary Systems, J. Farihi, Ted von Hippel, Rik van Lieshout, P.W. Cauley, Erik Dennihy, Et al. 2018 University College London

Dust Production And Depletion In Evolved Planetary Systems, J. Farihi, Ted Von Hippel, Rik Van Lieshout, P.W. Cauley, Erik Dennihy, Et Al.

Publications

The infrared dust emission from the white dwarf GD 56 is found to rise and fall by 20 per cent peak-to-peak over 11.2 yr, and is consistent with ongoing dust production and depletion. It is hypothesized that the dust is produced via collisions associated with an evolving dust disc, temporarily increasing the emitting surface of warm debris, and is subsequently destroyed or assimilated within a few years. The variations are consistent with debris that does not change temperature, indicating that dust is produced and depleted within a fixed range of orbital radii. Gas produced in collisions may rapidly re-condense ...


The Distance Of The Dark Matter Deficient Galaxy Ngc 1052–Df2, Pieter van Dokkum, Shany Danieli, Yotam Cohen, Aaron Romanowsky, Charlie Conroy 2018 Yale University

The Distance Of The Dark Matter Deficient Galaxy Ngc 1052–Df2, Pieter Van Dokkum, Shany Danieli, Yotam Cohen, Aaron Romanowsky, Charlie Conroy

Faculty Publications

We recently inferred that the galaxy NGC 1052–DF2 has little or no dark matter and a rich system of unusual globular clusters. We assumed that the galaxy is a satellite of the luminous elliptical galaxy NGC 1052 at ≈20 Mpc, on the basis of its surface brightness fluctuations (SBFs) distance of 19.0 ± 1.7 Mpc, its radial velocity of ≈1800 km s−1, and its projected position. Here we analyze the color–magnitude diagram (CMD) of NGC 1052–DF2, following the suggestion by Trujillo et al. that the tip of the red giant branch (TRGB) can be detected ...


The Distance Of The Dark Matter Deficient Galaxy Ngc 1052–Df2, Pieter van Dokkum, Shany Danieli, Yotam Cohen, Aaron J. Romanowsky, Charlie Conroy 2018 Yale University

The Distance Of The Dark Matter Deficient Galaxy Ngc 1052–Df2, Pieter Van Dokkum, Shany Danieli, Yotam Cohen, Aaron J. Romanowsky, Charlie Conroy

Aaron J. Romanowsky

We recently inferred that the galaxy NGC 1052–DF2 has little or no dark matter and a rich system of unusual globular clusters. We assumed that the galaxy is a satellite of the luminous elliptical galaxy NGC 1052 at ≈20 Mpc, on the basis of its surface brightness fluctuations (SBFs) distance of 19.0 ± 1.7 Mpc, its radial velocity of ≈1800 km s−1, and its projected position. Here we analyze the color–magnitude diagram (CMD) of NGC 1052–DF2, following the suggestion by Trujillo et al. that the tip of the red giant branch (TRGB) can be detected ...


The Sluggs Survey: The Inner Dark Matter Density Slope Of The Massive Elliptical Galaxy Ngc 1407, Asher Wasserman, Aaron Romanowsky, Jean Brodie, Pieter van Dokkum, Charlie Conroy, Alexa Villaume, Duncan Forbes, Jay Strader, Adebusola Alabi, Sabine Bellstedt 2018 University of California, Santa Cruz

The Sluggs Survey: The Inner Dark Matter Density Slope Of The Massive Elliptical Galaxy Ngc 1407, Asher Wasserman, Aaron Romanowsky, Jean Brodie, Pieter Van Dokkum, Charlie Conroy, Alexa Villaume, Duncan Forbes, Jay Strader, Adebusola Alabi, Sabine Bellstedt

Faculty Publications

We investigate the dark matter density profile of the massive elliptical galaxy, NGC 1407, by constructing spherically symmetric Jeans models of its field star and globular cluster systems. Two major challenges in such models are the degeneracy between the stellar mass and the dark matter halo profiles, and the degeneracy between the orbital anisotropy of the tracer population and the total mass causing the observed motions. We address the first issue by using new measurements of the mass-to-light ratio profile from stellar population constraints that include a radially varying initial mass function. To mitigate the mass–anisotropy degeneracy, we make ...


The Sluggs Survey: The Inner Dark Matter Density Slope Of The Massive Elliptical Galaxy Ngc 1407, Asher Wasserman, Aaron J. Romanowsky, Jean Brodie, Pieter G. van Dokkum, Charlie Conroy, Alexa Villaume, Duncan A. Forbes, Jay Strader, Adebusola B. Alabi, Sabine Bellstedt 2018 University of California, Santa Cruz

The Sluggs Survey: The Inner Dark Matter Density Slope Of The Massive Elliptical Galaxy Ngc 1407, Asher Wasserman, Aaron J. Romanowsky, Jean Brodie, Pieter G. Van Dokkum, Charlie Conroy, Alexa Villaume, Duncan A. Forbes, Jay Strader, Adebusola B. Alabi, Sabine Bellstedt

Aaron J. Romanowsky

We investigate the dark matter density profile of the massive elliptical galaxy, NGC 1407, by constructing spherically symmetric Jeans models of its field star and globular cluster systems. Two major challenges in such models are the degeneracy between the stellar mass and the dark matter halo profiles, and the degeneracy between the orbital anisotropy of the tracer population and the total mass causing the observed motions. We address the first issue by using new measurements of the mass-to-light ratio profile from stellar population constraints that include a radially varying initial mass function. To mitigate the mass–anisotropy degeneracy, we make ...


A Deficit Of Dark Matter From Jeans Modeling Of The Ultra-Diffuse Galaxy Ngc 1052-Df2, Asher Wasserman, Aaron Romanowsky, Jean Brodie, Pieter van Dokkum, Charlie Conroy, Roberto Abraham, Yotam Cohen, Shany Danieli 2018 University of California, Santa Cruz

A Deficit Of Dark Matter From Jeans Modeling Of The Ultra-Diffuse Galaxy Ngc 1052-Df2, Asher Wasserman, Aaron Romanowsky, Jean Brodie, Pieter Van Dokkum, Charlie Conroy, Roberto Abraham, Yotam Cohen, Shany Danieli

Faculty Publications

The discovery of the ultra-diffuse galaxy NGC 1052-DF2 and its peculiar population of star clusters has raised new questions about the connections between galaxies and dark matter (DM) halos at the extremes of galaxy formation. In light of debates over the measured velocity dispersion of its star clusters and the associated mass estimate, we constrain mass models of DF2 using its observed kinematics with a range of priors on the halo mass. Models in which the galaxy obeys a standard stellar-halo mass relation are in tension with the data and also require a large central density core. Better fits are ...


A Deficit Of Dark Matter From Jeans Modeling Of The Ultra-Diffuse Galaxy Ngc 1052-Df2, Asher Wasserman, Aaron J. Romanowsky, Jean Brodie, Pieter van Dokkum, Charlie Conroy, Roberto Abraham, Yotam Cohen, Shany Danieli 2018 University of California, Santa Cruz

A Deficit Of Dark Matter From Jeans Modeling Of The Ultra-Diffuse Galaxy Ngc 1052-Df2, Asher Wasserman, Aaron J. Romanowsky, Jean Brodie, Pieter Van Dokkum, Charlie Conroy, Roberto Abraham, Yotam Cohen, Shany Danieli

Aaron J. Romanowsky

The discovery of the ultra-diffuse galaxy NGC 1052-DF2 and its peculiar population of star clusters has raised new questions about the connections between galaxies and dark matter (DM) halos at the extremes of galaxy formation. In light of debates over the measured velocity dispersion of its star clusters and the associated mass estimate, we constrain mass models of DF2 using its observed kinematics with a range of priors on the halo mass. Models in which the galaxy obeys a standard stellar-halo mass relation are in tension with the data and also require a large central density core. Better fits are ...


Polarized Bow Shock Nebulae Reveal Features Of The Winds And Environments Of Massive Stars, Manisha Shrestha 2018 University of Denver

Polarized Bow Shock Nebulae Reveal Features Of The Winds And Environments Of Massive Stars, Manisha Shrestha

Electronic Theses and Dissertations

Massive stars strongly affect their surroundings through their energetic stellar winds during their lifetime and through their energetic deaths as supernovae. When a stellar wind interacts with the local interstellar medium (ISM), if the relative velocity between wind and ISM is supersonic, then a stellar wind bow shock is formed. Bow shocks and related density enhancements produced by the winds of massive stars moving through the interstellar medium provide important information regarding the motions of the stars, the properties of their stellar winds, and the characteristics of the local medium. Since bow shock nebulae are aspherical structures, light scattering within ...


Erratum: The Sluggs Survey: A Comparison Of Total-Mass Profiles Of Early-Type Galaxies From Observations And Cosmological Simulations, To ∼4 Effective Radii, Sabine Bellstedt, Duncan Forbes, Aaron Romanowsky, Rhea-Silvia Remus, Adam Stevens, Jean Brodie, Adriano Poci, Richard McDermid, Adebusola Alabi, Leonie Chevalier, Caitlin Adams, Anna Ferré-Mateu, Asher Wasserman, Viraj Pandya 2018 Swinburne University of Technology

Erratum: The Sluggs Survey: A Comparison Of Total-Mass Profiles Of Early-Type Galaxies From Observations And Cosmological Simulations, To ∼4 Effective Radii, Sabine Bellstedt, Duncan Forbes, Aaron Romanowsky, Rhea-Silvia Remus, Adam Stevens, Jean Brodie, Adriano Poci, Richard Mcdermid, Adebusola Alabi, Leonie Chevalier, Caitlin Adams, Anna Ferré-Mateu, Asher Wasserman, Viraj Pandya

Faculty Publications

This is an erratum to the paper “The SLUGGS Survey: A comparison of total-mass profiles of early-type galaxies from observations and cosmological simulations, to ∼4 effective radii” that was published in 2018, MNRAS, 476, 4543, which we refer to as the original paper.


Strong Evidence For The Density-Wave Theory Of Spiral Structure From A Multi-Wavelength Study Of Disk Galaxies, Hamed Pour-Imani 2018 University of Arkansas, Fayetteville

Strong Evidence For The Density-Wave Theory Of Spiral Structure From A Multi-Wavelength Study Of Disk Galaxies, Hamed Pour-Imani

Theses and Dissertations

The density-wave theory of spiral structure, though first proposed as long ago as the mid-1960s by C.C. Lin and F. Shu (Lin & Shu, 1964; Bertin & Lin, 1996; Shu, 2016), continues to be challenged by rival theories, such as the manifold theory. One test of these theories which has been proposed is that the pitch angle of spiral arms for galaxies should vary with the wavelength of the image in the density-wave theory, but not in the manifold theory. The reason is that stars are born in the density wave but move out of it as they age. In this dissertation, I combined large ...


Erratum: The Sluggs Survey: A Comparison Of Total-Mass Profiles Of Early-Type Galaxies From Observations And Cosmological Simulations, To ∼4 Effective Radii, Sabine Bellstedt, Duncan A. Forbes, Aaron J. Romanowsky, Rhea-Silvia Remus, Adam R H Stevens, Jean P. Brodie, Adriano Poci, Richard McDermid, Adebusola B. Alabi, Leonie Chevalier, Caitlin Adams, Anna Ferré-Mateu, Asher Wasserman, Viraj Pandya 2018 Swinburne University of Technology

Erratum: The Sluggs Survey: A Comparison Of Total-Mass Profiles Of Early-Type Galaxies From Observations And Cosmological Simulations, To ∼4 Effective Radii, Sabine Bellstedt, Duncan A. Forbes, Aaron J. Romanowsky, Rhea-Silvia Remus, Adam R H Stevens, Jean P. Brodie, Adriano Poci, Richard Mcdermid, Adebusola B. Alabi, Leonie Chevalier, Caitlin Adams, Anna Ferré-Mateu, Asher Wasserman, Viraj Pandya

Aaron J. Romanowsky

This is an erratum to the paper “The SLUGGS Survey: A comparison of total-mass profiles of early-type galaxies from observations and cosmological simulations, to ∼4 effective radii” that was published in 2018, MNRAS, 476, 4543, which we refer to as the original paper.


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