Introducing a real-time interactive GUI tool for visualization of galaxy spectra

To aid the understanding of the nonlinear relationship between galaxy properties and predicted spectral energy distributions (SED), we present a new interactive graphical user interface tool pipes_vis based on Bagpipes. It allows for real-time manipulation of a model galaxy's star formation history, dust and other relevant properties through sliders and text boxes, with each change's effect on the predicted SED reflected instantaneously. We hope the tool will assist in building intuition about what affects the SED of galaxies, potentially helping to speed up fitting stages such as prior construction, and aid in undergraduate and graduate teaching. pipes_vis is available online (pipes_vis is maintained and documented online at https://github.com/HinLeung622/pipes_vis, or version 0.4.1 is archived in Zenodo (Leung 2021) and also available for installation through pip install pipes_vis).PostprintNon peer reviewe

Ballistic Impact Mitigation Pad

In our senior design project we have decided to work under Dr. Jon Gerhardt on creating a gel pad to mitigate blunt force behind bulletproof vests. Extensive research on injury, materials, manufacturing methods, and NIJ standards was completed during this project. Through the use of advanced modeling software and additive manufacturing, we prototyped a functioning pad to test and compare to a pad that is currently available in today\u27s market. The results proved to be very successful, but there are many areas to improve upon down the road

The Explosive Weapons Trauma Care Collective (Extracct): A Roadmap For Reducing Preventable Death Among Civilian Casualties Of Explosive Injury

In a previous issue of The Journal of Conventional Weapons Destruction, we introduced the rationale underpinning the need for increased emphasis on point-of-injury care as well as enhanced engagement between humanitarian mine action (HMA) and emergency care services for civilian casualties of explosive ordnance (EO).1 The initial working group under which this conceptual foundation was developed was called the Mine Action Trauma Care Collaborative. In the intervening months, that initiative was reconceived as the Explosive Weapons Trauma Care Collective (EXTRACCT) to encompass the broad range of EO and explosive weapons (EW) that inflict harm on civilians in conflict and post-conflict settings.2,3 In this article, we present an overview of EXTRACCT’s approach to reducing preventable death and disability among civilian victims of EO/EW with a focus on low-resource settings (LRS)

Chemical evolution of local post-starburst galaxies: Implications for the mass-metallicity relation

We use the stellar fossil record to constrain the stellar metallicity evolution and star-formation histories of the post-starburst regions within 45 local post-starburst galaxies from the MaNGA survey. The direct measurement of the regions' stellar metallicity evolution is achieved by a new two-step metallicity model that allows for stellar metallicity to change at the peak of the starburst. We also employ a Gaussian process noise model that accounts for correlated errors introduced by the observational data reduction or inaccuracies in the models. We find that a majority of post-starburst regions (69% at $>1\sigma$ significance) increased in stellar metallicity during the recent starburst, with an average increase of 0.8 dex and a standard deviation of 0.4 dex. A much smaller fraction of PSBs are found to have remained constant (22%) or declined in metallicity (9%, average decrease 0.4 dex, standard deviation 0.3 dex). The pre-burst metallicities of the post-starburst galaxies are in good agreement with the mass-metallicity relation of local star-forming galaxies. These results are consistent with hydrodynamic simulations, which suggest that mergers between gas-rich galaxies are the primary formation mechanism of local PSBs, and rapid metal recycling during the starburst outweighs the impact of dilution by any gas inflows. The final mass-weighted metallicities of the post-starburst galaxies are consistent with the mass-metallicity relation of local passive galaxies. Our results suggest that rapid quenching following a merger-driven starburst is entirely consistent with the observed gap between the stellar mass-metallicity relations of local star-forming and passive galaxies.Comment: 18+4 pages, 8+2 figures, submitted to MNRA

Chemical evolution of local post-starburst galaxies : implications for the mass-metallicity relation

We use the stellar fossil record to constrain the stellar metallicity evolution and star-formation histories of the post-starburst (PSB) regions within 45 local PSB galaxies from the MaNGA survey. The direct measurement of the regions’ stellar metallicity evolution is achieved by a new two-step metallicity model that allows for stellar metallicity to change at the peak of the starburst. We also employ a Gaussian process noise model that accounts for correlated errors introduced by the observational data reduction or inaccuracies in the models. We find that a majority of PSB regions (69 per cent at >1σ significance) increased in stellar metallicity during the recent starburst, with an average increase of 0.8 dex and a standard deviation of 0.4 dex. A much smaller fraction of PSBs are found to have remained constant (22 per cent) or declined in metallicity (9 per cent, average decrease 0.4 dex, standard deviation 0.3 dex). The pre-burst metallicities of the PSB galaxies are in good agreement with the mass–metallicity (MZ) relation of local star-forming galaxies. These results are consistent with hydrodynamic simulations, which suggest that mergers between gas-rich galaxies are the primary formation mechanism of local PSBs, and rapid metal recycling during the starburst outweighs the impact of dilution by any gas inflows. The final mass-weighted metallicities of the PSB galaxies are consistent with the MZ relation of local passive galaxies. Our results suggest that rapid quenching following a merger-driven starburst is entirely consistent with the observed gap between the stellar mass–metallicity relations of local star-forming and passive galaxies.Peer reviewe

The Mine Action Trauma Care Collaborative: Enhancing Coordination Between Humanitarian Mine Action and the Emergency Health Response to Civilian Casualties of Explosive Ordnance

Modern armed conflict is characterized by the use of a wide variety of explosive weapons (EW), creating complex injury patterns with need for rapid first aid including hemorrhage control close to the point of injury. Yet, in many places where these injuries occur, formal trauma systems are weakened by conflict and resource limitations. In conflict zones, where immediate trauma care is often challenging to access for civilian casualties of EW, the humanitarian mine action (HMA) sector’s unique position and capabilities present a critical opportunity to bridge this gap—a potential that has been realized with the creation of the Mine Action Trauma Care Collaborative (MA-TCC). By fostering collaboration between the mine action sector and health responders, the MA-TCC aims to leverage HMA’s extensive field presence and expertise to enhance trauma care delivery, ensuring a more coordinated, effective response to the urgent medical needs of those injured by EW

Radio AGN in spiral galaxies

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.Radio AGN in the nearby Universe are more likely to be found in galaxies with early-type morphology, the detection rate in spiral or late-type galaxies (LTGs) being around an order of magnitude lower. We combine the mJy Imaging VLBA Exploration at 20cm (mJIVE-20) survey with the Sloan Digital Sky Survey (SDSS), to study the relatively rare population of AGN in LTGs that have nuclear radio luminosities similar to that in their early-type counterparts. The LTG AGN population is preferentially hosted by galaxies that have high stellar masses (M* > 10^10.8 MSun), red colours and low star-formation rates, with little dependence on the detailed morphology or local environment of the host LTG. The merger fraction in the LTG AGN is around 4 times higher than that in the general LTG population, indicating that merging is an important trigger for radio AGN in these systems. The red colours of our systems extend recent work which indicates that merger-triggered AGN in the nearby Universe appear after the peak of the associated starburst, implying that they do not strongly regulate star formation. Finally, we find that in systems where parsec-scale jets are clearly observed in our VLBI images, the jets are perpendicular to the major axis of the galaxy, indicating alignment between the accretion disc and the host galaxy stellar disc.Peer reviewe