Merge pull request #72 from aew10/nb/soc-stars

Trying to fix the website

Author: nborsato

assets/data/SiN_AEW11_Information.csv

@@ -173,7 +173,7 @@ Characterising High Amplitude Delta Scuti Stars using TESS data,"Delta Scuti sta
 
 I used lightcurves from the TESS spacecraft to explore the distribution of the amplitudes of the main pulsation in stars in the delta Scuti region of the HR diagram.  I found a discontinuity at the high amplitude end of the distribution lying at a frequency semi-amplitude of 15 ppt, corresponding to a peak to peak lightcurve amplitude of around 0.04 mag.  This is substantially below the traditional HADS threshold.  This statistical finding is a starting point for exploring the physical properties of HADS defined with the new threshold.",Tom Love,University of Southern Queensland,Stars
 Accretion disks simulations in pre-common envelope systems (X-ray binaries progenitors),"A critical phase in the formation and evolution of X-ray binaries is the moment when stable mass transfer from the giant donor becomes unstable and non-conservative, leading to a common envelope binary interaction. We simulate the formation and evolution of the accretion disk around a 1.4 Msun neutron star as mass transfers from a 7 Msun red supergiant from the early Roche lobe overflow phase to when mass transfer intensifies just ahead of a likely in-spiral. We compare our results, obtained with a Lagrangian code, with a similar simulation carried out with a different, Eulerian code, discussing the challenges in these simulations also in light of results from the recent literature. We use these simulations to demonstrate several characteristics of the mass transfer phase and determine the disk parameters such as size, mass, scale height and longevity in view of the viscous evolution of the disk and the ability to sustain a jet before and during the common envelope. We discuss our ability to acquire critical knowledge that can inform phases of stellar evolution that will be routinely observed as transient events.",Ana Lourdes Juarez Garcia,Macquarie University,Stars
-Alpha-Enhanced Disrupted Dwarfs: Nature or Nurture?,"Alpha-element abundances provide a powerful diagnostic of star formation histories in galaxies, tracing fundamental properties such as initial mass, gas retention, and star formation timescales and intensities. We present a comparative analysis of α-element (Mg, Ca) abundances in six tidally disrupted dwarf galaxies, derived from high-resolution spectra obtained by the Southern Stellar Stream Spectroscopic Survey (S5), and compare them with literature data for surviving dwarf spheroidals. Our observations show that stars in stellar streams exhibit systematically higher [α/Fe] at fixed [Fe/H] than their intact counterparts, indicating more rapid early enrichment and distinct evolutionary pathways. These results pose challenges to current models of disruption and quenching timescales. We discuss potential formation and environmental mechanisms that could account for the observed chemical differences.",Aldo Mura Guzmán,Macquarie University,Stars
+Alpha-Enhanced Disrupted Dwarfs: Nature or Nurture?,"Alpha-element abundances provide a powerful diagnostic of star formation histories in galaxies, tracing fundamental properties such as initial mass, gas retention, and star formation timescales and intensities. We present a comparative analysis of α-element (Mg, Ca) abundances in six tidally disrupted dwarf galaxies, derived from high-resolution spectra obtained by the Southern Stellar Stream Spectroscopic Survey (S5), and compare them with literature data for surviving dwarf spheroidals. Our observations show that stars in stellar streams exhibit systematically higher [α/Fe] at fixed [Fe/H] than their intact counterparts, indicating more rapid early enrichment and distinct evolutionary pathways. These results pose challenges to current models of disruption and quenching timescales. We discuss potential formation and environmental mechanisms that could account for the observed chemical differences.",Aldo Mura Guzman,Macquarie University,Stars
 Unveiling the ISM with Spectrospatial Models: Continuous Maps of Weak Metal Recombination Lines in the Rosette Nebula with SDSS-V Local Volume Mapper,"The SDSS-V Local Volume Mapper (LVM) integral field unit survey is delivering unprecedented spectroscopic information about our galaxy, enabling detailed studies of star formation and stellar feedback across a wide range of spatial scales. LVM is uniquely positioned to map how stars inject energy and momentum into their surroundings, shaping chemical abundances and the thermal structure of the interstellar medium, down to 0.05 parsecs. Weak auroral and metal recombination lines are essential for robust measurements and for addressing the longstanding abundance discrepancy problem (ADP): a 50+ year systematic disagreement between abundance determination methods. Yet their very low signal-to-noise, even with LVM’s depth, remains a significant challenge for existing methods. We developed a spatially coherent model that infers emission line properties continuously across the sky, fitting tens of thousands of spectra at once. By exploiting the similarity of nearby spectra, it is especially effective at recovering weak emission lines. We demonstrate the power of this approach through its first application to the LVM Rosette Nebula dataset, recovering spatially resolved maps of faint auroral and metal recombination lines. These maps are among the first of their kind, and they provide a clear path to resolving the ADP.",Thomas Hilder,Monash University,Stars
 Exact Nonlinear Decomposition of Ideal-MHD Waves Using Eigenenergies,"Precise tracking and measurement of the energy carried by the individual magnetohydrodynamic (MHD) modes has important implications and utility in both astrophysical and laboratory plasmas. Previously, this was only achievable in limited linear MHD cases in the β ≪ 1 or β ≫ 1 regimes. In this talk, I willl introduce the Eigenenergy Decomposition Method (or EEDM) and derive exact analytical expressions for the modal energy components—called eigenenergies—of nonlinear 3D disturbances governed by the inhomogeneous ideal MHD equations. I will also provide detailed guidelines for applying the decomposition scheme to any general inhomogeneous quasi-linear partial differential equations that possess a globally conserved quantity, beyond the realm of MHD. Furthermore, it is shown that the eigenenergies can be used to locate and measure nonlinear mode conversions, which is an additional feature of the method. Finally, well-categorized context for the application of the method to simulation and a discussion on possible numerical inaccuracies that may inevitably arise owing to discretization will be provided.",Axel Raboonik,University of Newcastle,Stars
 An old open cluster in the TESS continuous viewing zone: gyrochronology of NGC1901 ,"An open cluster consists of stars sharing the same age, distance and initial metallicity. Characterising its members deepens our understanding of stellar formation and evolution. NGC1901 is an 891-Myr-old open cluster confirmed using Gaia data and located in the TESS southern continuous viewing zone (CVZ). It is the third cluster discovered within this region, enabling a thorough investigation due to extensive available data. Our main goal is to measure the most precise age estimate of this cluster to date, using gyrochronology. Age-dating an open cluster is challenging, as different methods often yield different values. Similar analysis of UBC-1, another CVZ cluster, by Fritzewski et al. (2024), suggests how promising the approach is, when addressing targets within the CVZ. Long-duration TESS observations allow accurate measurements of rotation periods, and this is the first time NGC1901 is comprehensively characterised. As a preliminary task, we refine the NGC1901 membership list using spatial and kinematic filtering of Gaia DR3 data, and compare it to that from Hunt & Reffert (2023). We explore stellar lightcurves from TESS cycles 1, 3 and 5 to search for brightness variability indicative of rotation. The next step involves deriving the cluster's age through gyrochronology, a technique based on how rotation periods evolve with time. G, K and M-type dwarfs experience strong magnetic braking, and therefore spin down as they age. When plotted as function of colour, rotation periods highlight age-dependent sequences. In this context, we compare NGC1901's distribution to those of NGC6811 and Praesepe, which are 1 Gyr (Curtis et al. 2019) and 670 Myr old (Rampalli et al. 2021), respectively. Future work will combine gyrochronology with an independent age estimate from the asteroseismology of pulsating stars to enhance the precision of NGC 1901's age.",Mara Bernizzoni,The University of Sydney,Stars