Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2018

San Jose State University

Discipline
Keyword
Publication
Publication Type

Articles 1 - 30 of 121

Full-Text Articles in Physical Sciences and Mathematics

Proposing An Optimized Algorithm For Consolidating Electric-Powered Shared Scooters Into Hubs For Efficiently Managing Their Charging And Maintenance Operations, Ojen Goshtasb Dec 2018

Proposing An Optimized Algorithm For Consolidating Electric-Powered Shared Scooters Into Hubs For Efficiently Managing Their Charging And Maintenance Operations, Ojen Goshtasb

Master's Projects

The use of vehicles other than ones containing combustion engines have been adopted significantly over the past few years and the direction it’s taking seems to be the future of urban transportation. The hottest vehicle of choice currently is the electric scooter. They are small and portable, fast, and less costly compared to getting in a cab from Lyft or Uber to get around town. The goal of this paper is to make a proposal to drive the creation of a safe, efficient system for these scooters’ management. This must be beneficial to all parties involved; the rider, non-riders, and …


Management And Security Of Iot Systems Using Microservices, Tharun Theja Kammara Dec 2018

Management And Security Of Iot Systems Using Microservices, Tharun Theja Kammara

Master's Projects

Devices that assist the user with some task or help them to make an informed decision are called smart devices. A network of such devices connected to internet are collectively called as Internet of Things (IoT). The applications of IoT are expanding exponentially and are becoming a part of our day to day lives. The rise of IoT led to new security and management issues. In this project, we propose a solution for some major problems faced by the IoT devices, including the problem of complexity due to heterogeneous platforms and the lack of IoT device monitoring for security and …


Virtual Robot Climbing Using Reinforcement Learning, Ujjawal Garg Dec 2018

Virtual Robot Climbing Using Reinforcement Learning, Ujjawal Garg

Master's Projects

Reinforcement Learning (RL) is a field of Artificial Intelligence that has gained a lot of attention in recent years. In this project, RL research was used to design and train an agent to climb and navigate through an environment with slopes. We compared and evaluated the performance of two state-of-the-art reinforcement learning algorithms for locomotion related tasks, Deep Deterministic Policy Gradients (DDPG) and Trust Region Policy Optimisation (TRPO). We observed that, on an average, training with TRPO was three times faster than DDPG, and also much more stable for the locomotion control tasks that we experimented. We conducted experiments and …


Deep Visual Recommendation System, Raksha Sunil Dec 2018

Deep Visual Recommendation System, Raksha Sunil

Master's Projects

Recommendation system is a filtering system that predicts ratings or preferences that a user might have. Recommendation system is an evolved form of our trivial information retrieval systems. In this paper, we present a technique to solve new item cold start problem. New item cold start problem occurs when a new item is added to a shopping website like Amazon.com. There is no metadata for this item, no ratings and no reviews because it’s a new item in the system. Absence of data results in no recommendation or bad recommendations. Our approach to solve new item cold start problem requires …


Pantry: A Macro Library For Python, Derek Pang Dec 2018

Pantry: A Macro Library For Python, Derek Pang

Master's Projects

Python lacks a simple way to create custom syntax and constructs that goes outside of its own syntax rules. A paradigm that allows for these possibilities to exist within languages is macros. Macros allow for a shorter set of syntax to expand into a longer set of instructions at compile-time. This gives the capability to evolve the language to fit personal needs.

Pantry, implements a hygienic text-substitution macro system for Python. Pantry achieves this through the introduction of an additional preparsing step that utilizes parsing and lexing of the source code. Pantry proposes a way to simply declare a pattern …


Intra-Exchange Cryptocurrency Arbitrage Bot, Eric Han Dec 2018

Intra-Exchange Cryptocurrency Arbitrage Bot, Eric Han

Master's Projects

Cryptocurrencies are defined as a digital currency in which encryption techniques are utilized to regulate generation of units of currency and verify the transfer of funds, independent of a central governing body such as a bank. Due to the large number of cryptocurrencies currently available, there inherently exists many price discrepancies due to market inefficiencies. Market inefficiencies occur when the price of assets do not reflect their true value. In fact, these types of pricing discrepancies exist in other financial markets, including fiat currency exchanges and stock exchanges. However, these discrepancies are more significant in the cryptocurrency domain due to …


Variations On A Theme: Using Amino Acid Sequences To Generate Music, Aaron Kosmatin Dec 2018

Variations On A Theme: Using Amino Acid Sequences To Generate Music, Aaron Kosmatin

Master's Projects

In this project, we explore using a musical space to represent the properties of amino acids. We consider previous mappings and explore the limitations of these mappings. In this exploration, we will propose a new method of mapping into musical spaces that extends the properties that can be represented. For this work, we will use amino acid sequences as our example mapping. The amino acid properties we will use include mass, charge, structure, and hydrophobicity. Finally, we will show how the different musical properties can be compared for similarity.


Gradubique: An Academic Transcript Database Using Blockchain Architecture, Thinh Nguyen Dec 2018

Gradubique: An Academic Transcript Database Using Blockchain Architecture, Thinh Nguyen

Master's Projects

Blockchain has been widely adopted in the last few years even though it is in its infancy. The first well-known application built on blockchain technology was Bitcoin, which is a decentralized and distributed ledger to record crypto-currency transactions. All of the transactions in Bitcoin are anonymously transferred and validated by participants in the network. Bitcoin protocol and its operations are so reliable that technologists have been inspired to enhance blockchain technologies and deploy it outside of the crypto-currency world. The demand for private and non-crypto-currency solutions have surged among consortiums because of the security and fault tolerant features of blockchain. …


Interactions Between Disciplinary Practices And Joint Work In Undergraduate Physics Research Experiences, Gina Quan, Chandra Turpen, Andrew Elby Dec 2018

Interactions Between Disciplinary Practices And Joint Work In Undergraduate Physics Research Experiences, Gina Quan, Chandra Turpen, Andrew Elby

Faculty Publications

We analyze how participating in undergraduate research experiences (UREs) influenced physics students’ trajectories of participation within the community of practice of physics researchers. Students in the study participated in an elective seminar in which they were paired with graduate student and faculty mentors on physics research projects and participated in weekly discussions about research. Using video data from student interviews and mentor interviews, we characterize two aspects of students’ engagement in the physics community of practice. First, we find variations in their engagement in physics practice, which we characterize as physics activities that are connected and purposeful. Second, we characterize …


Mirach’S Goblin: Discovery Of A Dwarf Spheroidal Galaxy Behind The Andromeda Galaxy, David Martínez-Delgado, Eva Grebel, Behnam Javanmardi, Walter Boschin, Nicolas Longeard, Julio Carballo-Bello, Dmitry Makarov, Michael Beasley, Giuseppe Donatiello, Martha Haynes, Duncan Forbes, Aaron Romanowsky Dec 2018

Mirach’S Goblin: Discovery Of A Dwarf Spheroidal Galaxy Behind The Andromeda Galaxy, David Martínez-Delgado, Eva Grebel, Behnam Javanmardi, Walter Boschin, Nicolas Longeard, Julio Carballo-Bello, Dmitry Makarov, Michael Beasley, Giuseppe Donatiello, Martha Haynes, Duncan Forbes, Aaron Romanowsky

Faculty Publications

Context. It is of broad interest for galaxy formation theory to carry out a full inventory of the numbers and properties of dwarf galaxies, both satellite and isolated, in the Local Volume.Aims. Ultra-deep imaging in wide areas of the sky with small amateur telescopes can help to complete the census of these hitherto unknown low-surface-brightness galaxies, which cannot be detected by the current resolved stellar population and HI surveys. We report the discovery of Donatiello I, a dwarf spheroidal galaxy located one degree from the star Mirach (β And) in a deep image taken with an amateur telescope.Methods. The color-magnitude …


Angular Momentum And Galaxy Formation Revisited: Scaling Relations For Disks And Bulges, S. Michael Fall, Aaron Romanowsky Dec 2018

Angular Momentum And Galaxy Formation Revisited: Scaling Relations For Disks And Bulges, S. Michael Fall, Aaron Romanowsky

Faculty Publications

We show that the stellar specific angular momentum j, mass M, and bulge fraction of normal galaxies of all morphological types are consistent with a simple model based on a linear superposition of independent disks and bulges. In this model, disks and bulges follow scaling relations of the form and with but offset from each other by a factor of 8 ± 2 over the mass range . Separate fits for disks and bulges alone give and , respectively. This model correctly predicts that galaxies follow a curved 2D surface in the 3D space of , , and . We …


Nba 2k, Joseph Saludo Dec 2018

Nba 2k, Joseph Saludo

ART 108: Introduction to Games Studies

The NBA 2K games have come a long way from an emerging basketball game to now becoming the biggest basketball game ever created. From its graphics, gameplay, community, and many more reasons why the game became so successful today, NBA 2K has evolved into the best basketball game by improving its overall structure every year-round.


Calibration Of The Vertical Cavity Surface Emitting Laser (Vcsel) Water Vapor Hydrometer, Minghui Diao Nov 2018

Calibration Of The Vertical Cavity Surface Emitting Laser (Vcsel) Water Vapor Hydrometer, Minghui Diao

Faculty Publications, Meteorology and Climate Science

No abstract provided.


The Dragonfly Nearby Galaxies Survey. V. Hst/Acs Observations Of 23 Low Surface Brightness Objects In The Fields Of Ngc 1052, Ngc 1084, M96, And Ngc 4258, Yotam Cohen, Pieter Van Dokkum, Shany Danieli, Aaron Romanowsky, Roberto Abraham, Allison Merritt, Jielai Zhang, Lamiya Mowla, J. Diederik Kruijssen, Charlie Conroy, Asher Wasserman Nov 2018

The Dragonfly Nearby Galaxies Survey. V. Hst/Acs Observations Of 23 Low Surface Brightness Objects In The Fields Of Ngc 1052, Ngc 1084, M96, And Ngc 4258, Yotam Cohen, Pieter Van Dokkum, Shany Danieli, Aaron Romanowsky, Roberto Abraham, Allison Merritt, Jielai Zhang, Lamiya Mowla, J. Diederik Kruijssen, Charlie Conroy, Asher Wasserman

Faculty Publications

We present Hubble Space Telescope/Advanced Camera for Surveys (ACS) imaging of 23 very low surface brightness (μ e,V ~ 25–27.5) galaxies detected in the fields of four nearby galaxy groups. These objects were selected from deep optical imaging obtained with the Dragonfly Telephoto Array. Seven are newly identified, while most of the others had been seen previously in visual surveys of deep photographic plates and more recent surveys. Few have previously been studied in detail. From the ACS images, we measure distances to the galaxies using both the tip of the red giant branch method and the surface brightness fluctuations …


Remains Of The 19th Century: Deep Storage Of Contaminated Hydraulic Mining Sediment Along The Lower Yuba River, California, Tyler Nakamura, Michael Bliss Singer, Emmanuel Gabet Nov 2018

Remains Of The 19th Century: Deep Storage Of Contaminated Hydraulic Mining Sediment Along The Lower Yuba River, California, Tyler Nakamura, Michael Bliss Singer, Emmanuel Gabet

Faculty Publications

Since the onset of hydraulic gold mining in California’s Sierra Nevada foothills in 1852, the environmental damage caused by displacement and storage of hydraulic mining sediment (HMS) has been a significant ecological problem downstream. Large volumes of mercury-laden HMS from the Yuba River watershed were deposited within the river corridor, creating the anthropogenic Yuba Fan. However, there are outstanding uncertainties about how much HMS is still contained within this fan. To quantify the deep storage of HMS in the Yuba Fan, we analyzed mercury concentrations of sediment samples collected from borings and outcrops at multiple depths. The mercury concentrations served …


Observing Change In Students’ Attitudes Towards Mathematics: Contrasting Quantitative And Qualitative Approaches, Wes Maciejewski Nov 2018

Observing Change In Students’ Attitudes Towards Mathematics: Contrasting Quantitative And Qualitative Approaches, Wes Maciejewski

Faculty Research, Scholarly, and Creative Activity

A student’s attitude towards mathematics affects how they learn and perform in mathematics. What exactly is meant by attitude and how this interacts with mathematics education is a current debate in the mathematics education research community. Regardless, practitioners often acknowledge a consideration of improving students’ attitudes towards mathematics in their course design. This creates an impetus to study attitudes towards mathematics in a way that lends itself to observing changes over a course in mathematics. The current study draws on two approaches to observing and measuring attitudes towards mathematics in an effort to contrast disparate approaches and deepen an investigation …


The Extended Planetary Nebula Spectrograph (Epn.S) Early-Type Galaxy Survey: The Kinematic Diversity Of Stellar Halos And The Relation Between Halo Transition Scale And Stellar Mass, C. Pulsoni, O. Gerhard, M. Arnaboldi, L. Coccato, A. Longobardi, N. Napolitano, E. Moylan, C. Narayan, V. Gupta, A. Burkert, M. Capaccioli, A. Chies-Santos, A. Cortesi, K. Freeman, K. Kuijken, M. Merrifield, Aaron Romanowsky, C. Tortora Oct 2018

The Extended Planetary Nebula Spectrograph (Epn.S) Early-Type Galaxy Survey: The Kinematic Diversity Of Stellar Halos And The Relation Between Halo Transition Scale And Stellar Mass, C. Pulsoni, O. Gerhard, M. Arnaboldi, L. Coccato, A. Longobardi, N. Napolitano, E. Moylan, C. Narayan, V. Gupta, A. Burkert, M. Capaccioli, A. Chies-Santos, A. Cortesi, K. Freeman, K. Kuijken, M. Merrifield, Aaron Romanowsky, C. Tortora

Faculty Research, Scholarly, and Creative Activity

Context. In the hierarchical two-phase formation scenario, the halos of early type galaxies (ETGs) are expected to have different physical properties from the galaxies’ central regions.Aims. The ePN.S survey characterizes the kinematic properties of ETG halos using planetary nebulae (PNe) as tracers, overcoming the limitations of absorption line spectroscopy at low surface brightness.Methods. We present two-dimensional velocity and velocity dispersion fields for 33 ETGs, including fast (FRs) and slow rotators (SRs). The velocity fields were reconstructed from the measured PN velocities using an adaptive kernel procedure validated with simulations, and extend to a median of 5.6 effective radii (Re). We …


Wide-Field Kinematics Of Globular Clusters In The Leo I Group (Corrigendum), G. Bergond, S. Zepf, Aaron Romanowsky, R. Sharples, K. Rhode Oct 2018

Wide-Field Kinematics Of Globular Clusters In The Leo I Group (Corrigendum), G. Bergond, S. Zepf, Aaron Romanowsky, R. Sharples, K. Rhode

Faculty Publications

No abstract provided.


Dynamic Hierarchical Cache Management For Cloud Ran And Multi- Access Edge Computing In 5g Networks, Deepika Pathinga Rajendiran Oct 2018

Dynamic Hierarchical Cache Management For Cloud Ran And Multi- Access Edge Computing In 5g Networks, Deepika Pathinga Rajendiran

Master's Projects

Cloud Radio Access Networks (CRAN) and Multi-Access Edge Computing (MEC) are two of the many emerging technologies that are proposed for 5G mobile networks. CRAN provides scalability, flexibility, and better resource utilization to support the dramatic increase of Internet of Things (IoT) and mobile devices. MEC aims to provide low latency, high bandwidth and real- time access to radio networks. Cloud architecture is built on top of traditional Radio Access Networks (RAN) to bring the idea of CRAN and in MEC, cloud computing services are brought near users to improve the user’s experiences. A cache is added in both CRAN …


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 Oct 2018

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 …


Origins Of Ultradiffuse Galaxies In The Coma Cluster – Ii. Constraints From Their Stellar Populations, Anna Ferre-Mateu, Adebusola Alabi, Duncan Forbes, Aaron Romanowsky, Jean Brodie, Viraj Pandya, Ignacio Mart´In-Navarro, Sabine Bellstedt, Asher Wasserman, Maria Stone, Nobuhiro Okabe Oct 2018

Origins Of Ultradiffuse Galaxies In The Coma Cluster – Ii. Constraints From Their Stellar Populations, Anna Ferre-Mateu, Adebusola Alabi, Duncan Forbes, Aaron Romanowsky, Jean Brodie, Viraj Pandya, Ignacio Mart´In-Navarro, Sabine Bellstedt, Asher Wasserman, Maria Stone, Nobuhiro Okabe

Faculty Publications

In this second paper of the series we study, with new Keck/DEIMOS spectra, the stellar populations of seven spectroscopically confirmed ultradiffuse galaxies (UDGs) in the Coma cluster. We find intermediate to old ages (∼7 Gyr), low metallicities ([Z/H] ∼ −0.7 dex) and mostly supersolar abundance patterns ([Mg/Fe] ∼ 0.13 dex). These properties are similar to those of low-luminosity (dwarf) galaxies inhabiting the same area in the cluster and are mostly consistent with being the continuity of the stellar mass scaling relations of more massive galaxies. These UDGs’ star formation histories imply a relatively recent infall into the Coma cluster, consistent …


Academic Job Tips By Costanza Rampini - Phone Interview, Costanza Rampini Oct 2018

Academic Job Tips By Costanza Rampini - Phone Interview, Costanza Rampini

Faculty Publications, Environmental Studies

If you are on the academic job market, particularly in the fields of environmental studies/geography, I would be happy to share tips and questions from phone and on-campus interviews. I realize that Ph.D. advisors should provide this type of coaching, but they don't always do it...and some haven't been on the job market for a long time. It helps to speak to someone who just went through it...and has fresh notes from it! I was so much more prepared and had much more articulated answers by the time I had my 8th phone interview as compared to my first. Some …


A Framework For Detecting Injected Influence Attacks On Microblog Websites Using Change Detection Techniques, Vishnu S. Pendyala, Yuhong Liu, Silvia M. Figueira Sep 2018

A Framework For Detecting Injected Influence Attacks On Microblog Websites Using Change Detection Techniques, Vishnu S. Pendyala, Yuhong Liu, Silvia M. Figueira

Faculty Research, Scholarly, and Creative Activity

Presidential elections can impact world peace, global economics, and overall well-being. Recent news indicates that fraud on the Web has played a substantial role in elections, particularly in developing countries in South America and the public discourse, in general. To protect the trustworthiness of the Web, in this paper, we present a novel framework using statistical techniques to help detect veiled Web fraud attacks in Online Social Networks (OSN). Specific examples are used to demonstrate how some statistical techniques, such as the Kalman Filter and the modified CUSUM, can be applied to detect various attack scenarios. A hybrid data set, …


Little Lasting Impact Of The Paleocene-Eocene Thermal Maximum On Shallow Marine Molluscan Faunas, Linda Ivany, Carlie Pietsch, John Handley, Rowan Lockwood, Warren Allmon, Jocelyn Sessa Sep 2018

Little Lasting Impact Of The Paleocene-Eocene Thermal Maximum On Shallow Marine Molluscan Faunas, Linda Ivany, Carlie Pietsch, John Handley, Rowan Lockwood, Warren Allmon, Jocelyn Sessa

Faculty Publications

Global warming, acidification, and oxygen stress at the Paleocene-Eocene Thermal Maximum (PETM) are associated with severe extinction in the deep sea and major biogeographic and ecologic changes in planktonic and terrestrial ecosystems, yet impacts on shallow marine macrofaunas are obscured by the incompleteness of shelf sections. We analyze mollusk assemblages bracketing (but not including) the PETM and find few notable lasting impacts on diversity, turnover, functional ecology, body size, or life history of important clades. Infaunal and chemosymbiotic taxa become more common, and body size and abundance drop in one clade, consistent with hypoxia-driven selection, but within-clade changes are not …


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 Sep 2018

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 into …


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

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 in currently available Hubble Space …


The Importance Of Solvent Effects On The Mechanism Of The Pfeiffer Effect, Jamie Lunkley, Ngoc Nguyen, Kristina Tuminaro, Dana Margittai, Gilles Muller Aug 2018

The Importance Of Solvent Effects On The Mechanism Of The Pfeiffer Effect, Jamie Lunkley, Ngoc Nguyen, Kristina Tuminaro, Dana Margittai, Gilles Muller

Faculty Publications, Chemistry

The Pfeiffer effect is observed when an optically active compound such as an amino acid is introduced to a solution containing a labile racemic metal complex, and an equilibrium shift is obtained. The “perturbation” results in an excess of one enantiomer over the other. The shift is a result of a preferential outer sphere interaction between the introduced chiral species and one enantiomeric form (Λ or ∆) of a labile metal complex. Speculations regarding the mechanism of the Pfeiffer effect have attributed observations to a singular factor such as pH, solvent polarity, or numerous other intermolecular interactions. Through the use …


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 Aug 2018

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 use …


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 Aug 2018

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 …


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 Aug 2018

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.