Lachlan Lancaster
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View article: Density-modulated star formation efficiency: implications for the observed abundance of ultraviolet luminous galaxies at <i>z</i> &gt; 10
Density-modulated star formation efficiency: implications for the observed abundance of ultraviolet luminous galaxies at <i>z</i> > 10 Open
The number density of UV luminous galaxies discovered by the James Webb Space Telescope at ultra high redshift ($z \gtrsim 10$) is higher, and declines much more slowly with increasing redshift, than expected from extrapolations of lower r…
View article: The Coevolution of Stellar Wind-blown Bubbles and Photoionized Gas. I. Physical Principles and a Semianalytic Model
The Coevolution of Stellar Wind-blown Bubbles and Photoionized Gas. I. Physical Principles and a Semianalytic Model Open
We propose a new framework for the simultaneous feedback of stellar winds and photoionizing radiation from massive stars, distinguishing the locations where forces are applied, and consequences for internal spatiotemporal evolution of the …
View article: The Coevolution of Stellar Wind-blown Bubbles and Photoionized Gas. II. 3D RMHD Simulations and Tests of Semianalytic Models
The Coevolution of Stellar Wind-blown Bubbles and Photoionized Gas. II. 3D RMHD Simulations and Tests of Semianalytic Models Open
In a companion paper (Paper I), we presented a coevolution model (CEM) in which to consider the evolution of feedback bubbles driven by massive stars through both stellar winds and ionizing radiation, outlining when either of these effects…
View article: The Co-Evolution of Stellar Wind-blown Bubbles and Photoionized Gas I: Physical Principles and a Semi-Analytic Model
The Co-Evolution of Stellar Wind-blown Bubbles and Photoionized Gas I: Physical Principles and a Semi-Analytic Model Open
We propose a new framework for the simultaneous feedback of stellar winds and photo-ionizing radiation from massive stars, distinguishing the locations where forces are applied, and consequences for internal spatio-temporal evolution of th…
View article: Suppression of Shock X-ray Emission in Novae from Turbulent Mixing with Cool Gas
Suppression of Shock X-ray Emission in Novae from Turbulent Mixing with Cool Gas Open
Shock interaction in classical novae occurs when a fast outflow from the white dwarf > 1000 km s/s collides with a slower, cooler shell of gas released earlier in the outburst. The shocks radiate across the electromagnetic spectrum, from r…
View article: Density modulated star formation efficiency: implications for the observed abundance of ultra-violet luminous galaxies at z>10
Density modulated star formation efficiency: implications for the observed abundance of ultra-violet luminous galaxies at z>10 Open
The number density of UV luminous galaxies discovered by the James Webb Space Telescope at ultra high redshift ($z \gtrsim 10$) is higher, and declines much more slowly with increasing redshift, than expected from extrapolations of lower r…
View article: Detection of Diffuse Hot Gas around the Young, Potential Superstar Cluster H72.97–69.39
Detection of Diffuse Hot Gas around the Young, Potential Superstar Cluster H72.97–69.39 Open
We present the first Chandra X-ray observations of H72.97–69.39, a highly embedded, potential superstar cluster in its infancy located in the star-forming complex N79 of the Large Magellanic Cloud. We detect particularly hard, diffuse X-ra…
View article: Geometry, Dissipation, Cooling, and the Dynamical Evolution of Wind-blown Bubbles
Geometry, Dissipation, Cooling, and the Dynamical Evolution of Wind-blown Bubbles Open
Bubbles driven by energy and mass injection from small scales are ubiquitous in astrophysical fluid systems and essential to feedback across multiple scales. In particular, O stars in young clusters produce high-velocity winds that create …
View article: The Interplay between the Initial Mass Function and Star Formation Efficiency through Radiative Feedback at High Stellar Surface Densities
The Interplay between the Initial Mass Function and Star Formation Efficiency through Radiative Feedback at High Stellar Surface Densities Open
The observed rest-UV luminosity function at cosmic dawn ( z ∼ 8–14) measured by JWST revealed an excess of UV-luminous galaxies relative to many prelaunch theoretical predictions. A high star formation efficiency (SFE) and a top-heavy init…
View article: Geometry, Dissipation, Cooling, and the Dynamical Evolution of Wind-Blown Bubbles
Geometry, Dissipation, Cooling, and the Dynamical Evolution of Wind-Blown Bubbles Open
Bubbles driven by energy and mass injection from small scales are ubiquitous in astrophysical fluid systems and essential to feedback across multiple scales. In particular, O stars in young clusters produce high velocity winds that create …
View article: The Interplay between the IMF and Star Formation Efficiency through Radiative Feedback at High Stellar Surface Densities
The Interplay between the IMF and Star Formation Efficiency through Radiative Feedback at High Stellar Surface Densities Open
The observed rest-UV luminosity function at cosmic dawn ($z \sim 8-14$) measured by JWST revealed an excess of UV-luminous galaxies relative to many pre-launch theoretical predictions. A high star-formation efficiency (SFE) and a top-heavy…
View article: Constraining the Diffusion Coefficient and Cosmic-Ray Acceleration Efficiency using Gamma-ray Emission from the Star-Forming Region RCW 38
Constraining the Diffusion Coefficient and Cosmic-Ray Acceleration Efficiency using Gamma-ray Emission from the Star-Forming Region RCW 38 Open
Stellar winds from massive stars may be significant sources of cosmic rays (CRs). To investigate this connection, we report a detailed study of gamma-ray emission near the young Milky Way star cluster ($\approx$ 0.5 Myr old) in the star-fo…
View article: Detection of Diffuse Hot Gas Around the Young, Potential Superstar Cluster H72.97-69.39
Detection of Diffuse Hot Gas Around the Young, Potential Superstar Cluster H72.97-69.39 Open
We present the first Chandra X-ray observations of H72.97-69.39, a highly-embedded, potential super-star cluster (SSC) in its infancy located in the star-forming complex N79 of the Large Magellanic Cloud. We detect particularly hard, diffu…
View article: Structure, Kinematics, and Observability of the Large Magellanic Cloud’s Dynamical Friction Wake in Cold versus Fuzzy Dark Matter
Structure, Kinematics, and Observability of the Large Magellanic Cloud’s Dynamical Friction Wake in Cold versus Fuzzy Dark Matter Open
The Large Magellanic Cloud (LMC) will induce a dynamical friction (DF) wake on infall to the Milky Way (MW). The MW’s stellar halo will respond to the gravity of the LMC and the dark matter (DM) wake, forming a stellar counterpart to the D…
View article: Structure, Kinematics, and Observability of the Large Magellanic Cloud's Dynamical Friction Wake in Cold vs. Fuzzy Dark Matter
Structure, Kinematics, and Observability of the Large Magellanic Cloud's Dynamical Friction Wake in Cold vs. Fuzzy Dark Matter Open
The Large Magellanic Cloud (LMC) will induce a dynamical friction (DF) wake on infall to the Milky Way (MW). The MW's stellar halo will respond to the gravity of the LMC and the dark matter (DM) wake, forming a stellar counterpart to the D…
View article: Cosmological structure formation and soliton phase transition in fuzzy dark matter with axion self-interactions
Cosmological structure formation and soliton phase transition in fuzzy dark matter with axion self-interactions Open
We investigate cosmological structure formation in fuzzy dark matter (FDM) with the attractive self-interaction (SI) with numerical simulations. Such a SI would arise if the FDM boson were an ultra-light axion, which has a strong CP symmet…
View article: Cosmological Structure Formation and Soliton Phase Transition in Fuzzy Dark Matter with Axion Self-Interactions
Cosmological Structure Formation and Soliton Phase Transition in Fuzzy Dark Matter with Axion Self-Interactions Open
We investigate cosmological structure formation in Fuzzy Dark Matter (FDM) with an attractive self-interaction (SI) with numerical simulations. Such a SI would arise if the FDM boson were an ultra-light axion, which has a strong CP symmetr…
View article: Ultra-diffuse Galaxies as Extreme Star-forming Environments. II. Star Formation and Pressure Balance in H i-rich UDGs
Ultra-diffuse Galaxies as Extreme Star-forming Environments. II. Star Formation and Pressure Balance in H i-rich UDGs Open
In addition to occupying the extreme, diffuse tail of the dwarf galaxy population, ultra-diffuse galaxies (UDGs) are themselves a key laboratory in which to study star formation in extreme low-density environments. In the second paper of t…
View article: Walter: A Tool for Predicting Resolved Stellar Population Observations with Applications to the Roman Space Telescope
Walter: A Tool for Predicting Resolved Stellar Population Observations with Applications to the Roman Space Telescope Open
Studies of resolved stellar populations in the Milky Way and nearby galaxies reveal an amazingly detailed and clear picture of galaxy evolution. Within the Local Group, the ability to probe the stellar populations of small and large galaxi…
View article: Ultra-Diffuse Galaxies as Extreme Star-forming Environments II: Star Formation and Pressure Balance in HI-Rich UDGs
Ultra-Diffuse Galaxies as Extreme Star-forming Environments II: Star Formation and Pressure Balance in HI-Rich UDGs Open
In addition to occupying the extreme, diffuse tail of the dwarf galaxy population, Ultra-Diffuse Galaxies (UDGs) are themselves a key laboratory in which to study star formation in extreme low-density environments. In the second paper of t…
View article: Star Formation Regulation and Self-pollution by Stellar Wind Feedback
Star Formation Regulation and Self-pollution by Stellar Wind Feedback Open
Stellar winds contain enough energy to easily disrupt the parent cloud surrounding a nascent star cluster, and for this reason they have long been considered candidates for regulating star formation. However, direct observations suggest mo…
View article: A Search for Wandering Black Holes in the Milky Way with Gaia and DECaLS
A Search for Wandering Black Holes in the Milky Way with Gaia and DECaLS Open
We present a search for “hypercompact” star clusters in the Milky Way using a combination of Gaia and the Dark Energy Camera Legacy Survey (DECaLS). Such putative clusters, with sizes of ∼1 pc and containing 500–5000 stars, are expected to…
View article: Galaxy formation with BECDM – II. Cosmic filaments and first galaxies
Galaxy formation with BECDM – II. Cosmic filaments and first galaxies Open
Bose–Einstein condensate dark matter (BECDM, also known as fuzzy dark matter) is motivated by fundamental physics and has recently received significant attention as a serious alternative to the established cold dark matter (CDM) model. We …
View article: A Mystery in Chamaeleon: Serendipitous Discovery of a Galactic Symbiotic Nova
A Mystery in Chamaeleon: Serendipitous Discovery of a Galactic Symbiotic Nova Open
We present the serendipitous discovery of a low optical-luminosity nova occurring in a D-type symbiotic binary star system in the Milky Way. We lay out the extensive archival data alongside new follow-up observations related to the stellar…
View article: First Star-Forming Structures in Fuzzy Cosmic Filaments
First Star-Forming Structures in Fuzzy Cosmic Filaments Open
In hierarchical models of structure formation, the first galaxies form in low-mass dark matter potential wells, probing the behavior of dark matter on kiloparsec scales. Even though these objects are below the detection threshold of curren…
View article: The halo’s ancient metal-rich progenitor revealed with BHB stars
The halo’s ancient metal-rich progenitor revealed with BHB stars Open
Using the data from the Sloan Digital Sky Survey and the Gaia satellite, we assemble a pure sample of ∼3000 Blue Horizontal Branch (BHB) stars with 7-D information, including positions, velocities and metallicities. We demonstrate that, as…
View article: The Halo's Ancient Metal-Rich Progenitor Revealed with BHB Stars
The Halo's Ancient Metal-Rich Progenitor Revealed with BHB Stars Open
This data represent properties of Blue Horizontal Branch stars in the Stellar Halo of the Milky Way with properties derived from the Sloan Digital Sky Survey's Data Release 8, the Gaia Mission's Data Release 2, and the work of Xue et al. 2…
View article: The Halo's Ancient Metal-Rich Progenitor Revealed with BHB Stars
The Halo's Ancient Metal-Rich Progenitor Revealed with BHB Stars Open
This data represent properties of Blue Horizontal Branch stars in the Stellar Halo of the Milky Way with properties derived from the Sloan Digital Sky Survey's Data Release 8, the Gaia Mission's Data Release 2, and the work of Xue et al. 2…
View article: Quantifying the smoothness of the stellar halo: a link to accretion history
Quantifying the smoothness of the stellar halo: a link to accretion history Open
We investigate the utility of the three-dimensional two-point correlation function (3D 2PCF) in quantifying substructure in the stellar halo of the Milky Way, particularly as a means of constraining the accretion history of our Galaxy. We …