The Water-ice Feature in Near-infrared Disk-scattered Light around HD 142527:Micron-sized Icy Grains Lifted up to the Disk Surface?

We study the $3~\mu$m scattering feature of water ice detected in the outer disk of HD 142527 by performing radiative transfer simulations. We show that an ice mass abundance at the outer disk surface of HD 142527 is much lower than estimated in a previous study. It is even lower than inferred from far-infrared ice observations, implying ice disruption at the disk surface. Next, we demonstrate that a polarization fraction of disk-scattered light varies across the ice-band wavelengths depending on ice grain properties; hence, polarimetric spectra would be another tool for characterizing water-ice properties. Finally, we argue that the observed reddish disk-scattered light is due to grains with a few microns in size. To explain the presence of such grains at the disk surface, we need a mechanism that can efficiently oppose dust settling. If we assume turbulent mixing, our estimate requires $\alpha\gtrsim2\times10^{-3}$, where $\alpha$ is a non-dimensional parameter describing the vertical diffusion coefficient of grains. Future observations probing gas kinematics would be helpful to elucidate vertical grain dynamics in the outer disk of HD 142527.Comment: 21 pages, 14 figures, 1 table; Accepted for publication in Ap

Impact of Massive Binary Star and Cosmic Evolution on Gravitational Wave Observations I: Black Hole-Neutron Star Mergers

Mergers of black hole-neutron star (BHNS) binaries have now been observed by GW detectors with the recent announcement of GW200105 and GW200115. Such observations not only provide confirmation that these systems exist, but will also give unique insights into the death of massive stars, the evolution of binary systems and their possible association with gamma-ray bursts, $r$-process enrichment and kilonovae. Here we perform binary population synthesis of isolated BHNS systems in order to present their merger rate and characteristics for ground-based GW observatories. We present the results for 420 different model permutations that explore key uncertainties in our assumptions about massive binary star evolution (e.g. mass transfer, common-envelope evolution, supernovae), and the metallicity-specific star formation rate density, and characterize their relative impacts on our predictions. We find intrinsic local BHNS merger rates spanning $\mathcal{R}_{\rm{m}}^0 \approx 4$-$830\,\rm{Gpc}^{-3}\,\rm{yr}^{-1}$ for our full range of assumptions. This encompasses the rate inferred from recent BHNS GW detections, and would yield detection rates of $\mathcal{R}_{\rm{det}} \approx 1$-$180\, \rm{yr}^{-1}$ for a GW network consisting of LIGO, Virgo and KAGRA at design sensitivity. We find that the binary evolution and metallicity-specific star formation rate density each impact the predicted merger rates by order $\mathcal{O}(10)$. We also present predictions for the GW detected BHNS merger properties and find that all 420 model variations predict that $\lesssim 5\%$ of the BHNS mergers have BH masses $\gtrsim 18\,M_{\odot}$, total masses $\gtrsim 20\,M_{\odot}$, chirp masses $\gtrsim 5.5\,M_{\odot}$, mass ratios $\gtrsim 12$ or $\lesssim 2$. Moreover, we find that massive NSs $\gtrsim 2\,M_{\odot}$ are expected to be commonly detected in BHNS mergers in almost all our model variations.Comment: 38 pages, 18 figures, accepted to MNRAS. The authors welcome suggestions and feedback. All data and code to reproduce the results in this paper are publicly availabl

Reproduction package for the paper "Metal-poor atmosphere of a sub-Neptune planet progenitor"

This is a basic reproduction package for the paper Barat et al 2024

Reproduction Package for the paper "The early evolution of young massive clusters. II. The kinematic history of NGC 6618 / M 17"

- This reproduction package aims for open science, with the internal API designation of 'Gold' - Authors: M. Stoop, A. Derkink, L. Kaper, A. de Koter, C. Rogers, M.C. Ramírez-Tannus, D. Guo, N. Azatyan - Paper DOI: https://doi.org/10.1051/0004-6361/202347383 - Arxiv DOI: https://doi.org/10.48550/arXiv.2311.04174 - Zenodo DOI: http://doi.org/10.5281/zenodo.8120575 - Accepted for publication in Astronomy and Astrophysics (date of acceptance: 2023/10/27

Reproduction package for the paper "The effects of surface fossil magnetic fields on massive star evolution - III. The case of tau Sco"

This is a reproduction package for the paper "The effects of surface fossil magnetic fields on massive star evolution - III. The case of tau Sco" by Keszthelyi et al. (2021

Reproduction package for the paper "BH-BH mergers with & without EM counterpart: A model for stable tertiary mass transfer in hierarchical triple systems"

This is a reproduction package for the paper "BH-BH mergers with & without EM counterpart: A model for stable tertiary mass transfer in hierarchical triple systems" by Kummer et al. (2024). It aims to provide the most important data products and reproduce the Figures of the paper

Reproduction package for the paper "The effects of surface fossil magnetic fields on massive star evolution - II. Implementation of magnetic braking in MESA and implications for the evolution of surface rotation in OB stars "

This is a reproduction package for the paper "The effects of surface fossil magnetic fields on massive star evolution - II. Implementation of magnetic braking in MESA and implications for the evolution of surface rotation in OB stars" by Keszthelyi et al. (2020), https://doi.org/10.1093/mnras/staa23

Dataset: The Main Evolutionary Pathways of Massive Hierarchical Triple Stars

The following files contain the data and scripts to reproduce the figures presented in the paper: The Main Evolutionary Pathways of Massive Hierarchical Triple Stars 1. data_TRES_simulations.tar.gz: contains data files with reduced output from TRES simulations 2. plots.ipynb: contains scripts to create all plots in the paper mentioned above 3. README.txt: contains an explanation of the contents of the data_TRES_simulations.tar.gz fil

Reproduction package for the paper "Two waves of massive stars running away from the young cluster R136"

- This reproduction package aims for open science, with the internal API designation of 'Gold' - Authors: M. Stoop, A. de Koter, L. Kaper, S. Brands, S. Portegies Zwart, H. Sana, F. Stoppa, M. Gieles, L. Mahy, T. Shenar, D. Guo, G. Nelemans, S. Rieder - Paper DOI: https://doi.org/10.1038/s41586-024-08013-8 - Zenodo DOI: http://doi.org/10.5281/zenodo.10058762 - Published in Nature (date of publication: 2024/10/09

Analytic expressions for geometric cross-sections of fractal dust aggregates

This is a basic reproduction package for the paper "Analytic expressions for geometric cross-sections of fractal dust aggregates" by Tazaki (2021, MNRAS, submitted). In this repository, you will find the data files used to make figures in the paper. Source codes and scripts are included as well