Joss Bland‐Hawthorn
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View article: H <scp>i</scp> terminal velocity curves − Lessons learned from N-body/hydrodynamic ‘surrogate’ models of the Milky Way
H <span>i</span> terminal velocity curves − Lessons learned from N-body/hydrodynamic ‘surrogate’ models of the Milky Way Open
The development of an N-body/hydrodynamic ‘surrogate’ model of the Milky Way (MW) − a model that resembles the MW in several key aspects after many Gyrs of evolution − would be extremely beneficial for Galactic Archaeology. Here we present…
View article: Turbulent Gas-rich Disks at High Redshift: Origin of Thick Stellar Disks Through 3D “Baryon Sloshing”
Turbulent Gas-rich Disks at High Redshift: Origin of Thick Stellar Disks Through 3D “Baryon Sloshing” Open
In response to recent observations from JWST and Atacama Large Millimeter Array, we explore a new class of dynamically self-consistent models that mimics a plausible progenitor of the Milky Way over a wide range of disk gas fractions, f ga…
View article: The GECKOS Survey: resolved, multiphase observations of mass loading and gas density in the galactic wind of NGC 4666
The GECKOS Survey: resolved, multiphase observations of mass loading and gas density in the galactic wind of NGC 4666 Open
We present a multiphase, resolved study of the galactic wind extending from the nearby starburst galaxy NGC 4666. For this, we use VLT/MUSE observations from the GECKOS program and H i data from the WALLABY survey. We identify both ionized…
View article: Deep Extragalactic VIsible Legacy Survey (DEVILS): first data release covering the D10 (COSMOS) region
Deep Extragalactic VIsible Legacy Survey (DEVILS): first data release covering the D10 (COSMOS) region Open
The Deep Extragalactic VIsible Legacy Survey (DEVILS) is a deep, high-completeness multiwavelength survey based around spectroscopic observations using the Anglo-Australian Telescope’s AAOmega spectrograph. The survey covers $\sim 4.5$ deg…
View article: The GECKOS survey: Jeans anisotropic models of edge-on discs uncover the impact of dust and kinematic structures
The GECKOS survey: Jeans anisotropic models of edge-on discs uncover the impact of dust and kinematic structures Open
The central regions of disc galaxies host a rich variety of stellar structures: nuclear discs, bars, bulges, and boxy-peanut bulges. These components are often difficult to disentangle, both photometrically and kinematically, particularly …
View article: The GALAH survey: Improving chemical abundances using star clusters
The GALAH survey: Improving chemical abundances using star clusters Open
Large spectroscopic surveys aim to consistently compute stellar parameters of very diverse stars, while minimizing systematic errors. We explore the use of stellar clusters as benchmarks to verify the precision of spectroscopic parameters …
View article: The GECKOS Survey: Resolved, multiphase observations of mass-loading and gas density in the galactic wind of NGC 4666
The GECKOS Survey: Resolved, multiphase observations of mass-loading and gas density in the galactic wind of NGC 4666 Open
We present a multiphase, resolved study of the galactic wind extending from the nearby starburst galaxy NGC 4666. For this we use VLT/MUSE observations from the GECKOS program and HI data from the WALLABY survey. We identify both ionised a…
View article: Galactic seismology: can the <i>Gaia</i> ‘phase spiral’ co-exist with a clumpy, turbulent interstellar medium?
Galactic seismology: can the <i>Gaia</i> ‘phase spiral’ co-exist with a clumpy, turbulent interstellar medium? Open
The Gaia satellite revealed a remarkable spiral pattern (‘phase spiral’, PS) in the $z\!-\!V_{z}$ phase–plane throughout the solar neighbourhood, where z and $V_{z}$ are the displacement and velocity of a star perpendicular to the Galactic…
View article: The GECKOS survey: Identifying kinematic sub-structures in edge-on galaxies
The GECKOS survey: Identifying kinematic sub-structures in edge-on galaxies Open
The vertical evolution of galactic discs is governed by the sub-structures within them. Several of these features, including bulges and kinematically distinct discs, are best studied in edge-on galaxies, as the viewing angle allows the eas…
View article: Sifting for a Stream: The Morphology of the $300S$ Stellar Stream
Sifting for a Stream: The Morphology of the $300S$ Stellar Stream Open
Stellar streams are sensitive laboratories for understanding the small-scale structure in our Galaxy's gravitational field. Here, we analyze the morphology of the $300S$ stellar stream, which has an eccentric, retrograde orbit and thus cou…
View article: Galactic seismology: can the Gaia 'phase spiral' co-exist with a clumpy, turbulent interstellar medium?
Galactic seismology: can the Gaia 'phase spiral' co-exist with a clumpy, turbulent interstellar medium? Open
The Gaia satellite revealed a remarkable spiral pattern ('phase spiral', PS) in the z-Vz phase-plane throughout the solar neighbourhood, where z and Vz are the displacement and velocity of a star perpendicular to the Galactic plane. As dem…
View article: The emergence of galactic thin and thick discs across cosmic history
The emergence of galactic thin and thick discs across cosmic history Open
Present-day disc galaxies often exhibit distinct thin and thick discs. The formation mechanisms of the two discs and the timing of their onset remain open questions. To address these questions, we select edge-on galaxies from flagship JWST…
View article: Optical spectroscopic signatures of the red giant evolutionary state
Optical spectroscopic signatures of the red giant evolutionary state Open
Modern spectroscopic surveys output large data volumes. Theoretical models provide a means to transform the information encoded in these data to measurements of physical stellar properties. However, in detail, the models are incomplete and…
View article: Optical spectroscopic signatures of the red giant evolutionary state
Optical spectroscopic signatures of the red giant evolutionary state Open
Modern spectroscopic surveys output large data volumes. Theoretical models provide a means to transform the information encoded in these data to measurements of physical stellar properties. However, in detail the models are incomplete and …
View article: Cryoscope: A Cryogenic Infrared Survey Telescope in Antarctica
Cryoscope: A Cryogenic Infrared Survey Telescope in Antarctica Open
We present Cryoscope, a new 50 deg 2 field-of-view, 1.2 m aperture, K dark survey telescope to be located at Dome C, Antarctica. Cryoscope has an innovative optical–thermal design wherein the entire telescope is cryogenically cooled. Cryos…
View article: Flipping of the Tidal Tails of the Ophiuchus Stream due to the Decelerating Galactic Bar
Flipping of the Tidal Tails of the Ophiuchus Stream due to the Decelerating Galactic Bar Open
The Ophiuchus stellar stream presents a puzzle due to its complicated morphology, with a substructure perpendicular to the main track (spur), a broadened tail (fanning), and a shorter than expected angular extent given its old stellar popu…
View article: The SAMI Galaxy Survey: large-scale environment affects galaxy spin amplitudes and the formation of slow rotators
The SAMI Galaxy Survey: large-scale environment affects galaxy spin amplitudes and the formation of slow rotators Open
We explore the impact of the large-scale 3D density field, as defined by deep, wide-field galaxy surveys, on stellar spin ($\lambda _{\rm R_e}$) and the distributions of fast and slow rotators. We use the Galaxy And Mass Assembly spectrosc…
View article: The SAMI Galaxy Survey: large-scale environment affects galaxy spin amplitudes and the formation of slow rotators
The SAMI Galaxy Survey: large-scale environment affects galaxy spin amplitudes and the formation of slow rotators Open
We explore the impact of the large-scale 3D density field, as defined by deep, wide-field galaxy surveys, on stellar spin ($λ_{\rm R_e}$) and the distributions of fast and slow rotators. We use the GAMA spectroscopic redshift survey to rec…
View article: Signatures of simulated spiral arms on radial actions
Signatures of simulated spiral arms on radial actions Open
Context. Spiral arms play a key role in the evolution of disc galaxies, defining their morphology, star formation, chemistry, and dynamics. Among their various implications, it has been observed in the Milky Way disc that the distribution …
View article: Cryoscope: A Cryogenic Infrared Survey Telescope in Antarctica
Cryoscope: A Cryogenic Infrared Survey Telescope in Antarctica Open
We present Cryoscope--a new 50 deg$^2$ field-of-view, 1.2 m aperture, $K_{dark}$ survey telescope to be located at Dome C, Antarctica. Cryoscope has an innovative optical-thermal design wherein the entire telescope is cryogenically cooled.…
View article: Turbulent gas-rich discs at high redshift: origin of thick stellar discs through 3D 'baryon sloshing'
Turbulent gas-rich discs at high redshift: origin of thick stellar discs through 3D 'baryon sloshing' Open
In response to recent observations from JWST and ALMA, we explore a new class of dynamically self-consistent models using our AGAMA/Ramses hydrodynamic N-body framework (Nexus) that mimics a plausible progenitor of the Milky Way over a wid…
View article: The GALAH Survey: Stellar parameters and abundances for 800 000 <i>Gaia</i> RVS spectra using GALAH DR4 and <i>The Cannon</i>
The GALAH Survey: Stellar parameters and abundances for 800 000 <i>Gaia</i> RVS spectra using GALAH DR4 and <i>The Cannon</i> Open
Analysing stellar parameters and abundances from nearly one million Gaia Data Release 3 (DR3) Radial Velocity Spectrometer (RVS) spectra poses challenges due to the limited spectral coverage (restricted to the infrared Ca ii triplet) and v…
View article: The GALAH survey: Improving chemical abundances using star clusters
The GALAH survey: Improving chemical abundances using star clusters Open
Large spectroscopic surveys aim to consistently compute stellar parameters of very diverse stars while minimizing systematic errors. We explore the use of stellar clusters as benchmarks to verify the precision of spectroscopic parameters i…
View article: The GALAH survey: Data release 4
The GALAH survey: Data release 4 Open
The stars of the Milky Way carry the chemical history of our Galaxy in their atmospheres as they journey through its vast expanse. Like barcodes, we can extract the chemical fingerprints of stars from high-resolution spectroscopy. The four…
View article: Hector Galaxy Survey: Data processing, quality control, and early science
Hector Galaxy Survey: Data processing, quality control, and early science Open
The Hector Galaxy Survey is a new optical integral field spectroscopy (IFS) survey currently using the Anglo-Australian Telescope to observe up to 15 000 galaxies at low redshift ( $z \lt 0.1$ ). The Hector instrument employs 21 optical fi…
View article: findAbar: How astronomers may perceive the bar in galaxies differently
findAbar: How astronomers may perceive the bar in galaxies differently Open
Bars are ubiquitous morphological features in the observed distribution of galaxies. There are similarly many methods for classifying these features and, without a strict theoretical definition or common standard practice, this is often le…
View article: <i>S</i><sup>5</sup>: New insights from deep spectroscopic observations of the tidal tails of the globular clusters NGC 1261 and NGC 1904
<i>S</i><sup>5</sup>: New insights from deep spectroscopic observations of the tidal tails of the globular clusters NGC 1261 and NGC 1904 Open
As globular clusters (GCs) orbit the Milky Way, their stars are tidally stripped and form tidal tails that follow the orbit of the cluster around the Galaxy. The morphology of these tails is complex and shows correlations with the phase of…
View article: Efficient, ultra-high attenuation fiber Bragg grating filter for photon noise suppression
Efficient, ultra-high attenuation fiber Bragg grating filter for photon noise suppression Open
Precision optical filters are key components for current and future photonic technologies. Here, we demonstrate a low loss spectral filter consisting of an ultrasteep bandpass feature with a maximum gradient of (90.6$\pm$0.7) dB/GHz, centr…
View article: First Resolution of Microlensed Images of a Binary-lens Event
First Resolution of Microlensed Images of a Binary-lens Event Open
We resolve the multiple images of the binary-lens microlensing event ASASSN-22av using the GRAVITY instrument of the Very Large Telescope Interferometer (VLTI). The light curves show weak binary-lens perturbations, complicating the analysi…
View article: $S^5$: New insights from deep spectroscopic observations of the tidal tails of the globular clusters NGC 1261 and NGC 1904
$S^5$: New insights from deep spectroscopic observations of the tidal tails of the globular clusters NGC 1261 and NGC 1904 Open
As globular clusters (GCs) orbit the Milky Way, their stars are tidally stripped forming tidal tails that follow the orbit of the clusters around the Galaxy. The morphology of these tails is complex and shows correlations with the phase of…