Tootfinder

Build-up and survival of the disc: From numerical models of galaxy formation to the Milky Way
Matthew D. A. Orkney, Chervin F. P. Laporte
https://arxiv.org/abs/2509.09576 https:…

Build-up and survival of the disc: From numerical models of galaxy formation to the Milky Way
We study the build-up and survival of angular momentum in the stellar disc using a statistical suite of cosmological simulations of Milky Way-mass galaxies. Our results show that stellar kinematics at $z=0$ rarely recover the true times of disc spin-up, due to the disruptive impact of massive radial merger events. The proto-disc (i.e. Aurora) and kicked-up disc stars (the Splash) become indistinguishable at low metallicities, and the local fraction of kicked-up disc stars remains $<20$ per cent…

Reconstructing the origin of black hole mergers using sparse astrophysical models
V. Gayathri, Giuliano Iorio, Hiromichi Tagawa, Daniel Wysocki, Jeremiah Anglin, Imre Bartos, Shubhagata Bhaumik, Zolt'an Haiman, Michela Mapelli, R. O'Shaughnessy, LingQin Xue
https://arxiv.org/abs/2509.09647 …

Reconstructing the origin of black hole mergers using sparse astrophysical models
The astrophysical origin of binary black hole mergers discovered by LIGO and Virgo remains uncertain. Efforts to reconstruct the processes that lead to mergers typically rely on either astrophysical models with fixed parameters, or continuous analytical models that can be fit to observations. Given the complexity of astrophysical formation mechanisms, these methods typically cannot fully take into account model uncertainties, nor can they fully capture the underlying processes. Here, we present…

Good Morning #Canada
Finally, arriving at our our 10th province, Manitoba, and putting this series to rest means no more nightmares. Friendly Manitoba, it says so right on their license plates, also has hundreds of abandoned towns, but today we'll focus on Scarf. Named for William Scarf, not for winter clothing or the more recent term for eating quickly, the settlement began in the 1880s, started to flourish after train service arrived in 1907, and died slowly after train service stopped, with the last residents leaving in the 1980s. But in 2013, the regional mayor decided to sell parcels of land in the ghost town for $10. I wasn't able to find out if this plan to bring Scarf back from the dead was successful, but perhaps the area is cursed. In 2020, a tornado touched down near Scarf, killing two teenagers when their vehicle was swept off the road.
#CanadaIsAwesome #CanadianGhostTowns
https://www.cbc.ca/news/canada/manitoba/manitoba-rm-looks-to-sell-ghost-town-lots-for-10-1.2086700

FYI, here’s the exact language of 50 U.S.C. § 1702(b) which spells out how media mail is exempt:
https://kind.social/@wbwolf/115103183358864928

Unveiling the Bright Spot with Mie Scattering
Vin\'icius dos Passos de Souza, Antonio Alvaro Ranha Neves
https://arxiv.org/abs/2510.05948 https://arxiv…

Unveiling the Bright Spot with Mie Scattering
This work applies Mie scattering theory to provide a new perspective on the propagation of light through a spherical obstacle, offering a novel explanation for the formation of the Poisson spot (also known as the Arago or Fresnel spot). We demonstrate that the diffraction patterns generated by a sphere and by a circular disk can be understood as complementary outcomes of the same underlying scattering process. Our analysis highlights the constructive interference responsible for the bright cent…

Good Morning #Canada
I slept in this morning, getting an extra 90 minutes or so of extra #ZZZs. I usually get 7 to 8 hours of sleep, meeting the Canada Health recommendations, and apparently better than most Canadians. The attached article has some sleepy stats from a study commissioned by IKEA but doesn't address sleeplessness due to stress related furniture building. Some additional data:
- 60% of Canadians say they wake up “well rested”.
- Albertans are sleep-deprived as only 9% say they never find it hard to fall asleep. Compared to Saskatchewan and Manitoba (19%), Ontario (20%), B.C. and Atlantic Canada (27%), and Quebec (28%).
- 47% of us say money and financial matters affected our sleep.
- Quebec residents use more sleep medications (11.5%) than those in Ontario (6.7%), and we have Doug Ford.
- Only 5% of Canadians would give up intimate relations for better sleep.
(Data from Research Co., Leger, #StatsCan)
#CanadaIsAwesome #WakeUp
https://www.ctvnews.ca/health/article/canadians-are-losing-sleep-at-an-alarming-rate-recent-reports-suggest/

Unveiling Galactic substructures with M Giant stars: A kinematic and chemical study based on LAMOST DR9, Gaia DR3 and APOGEE DR17
Longfei Ding, Jing Li, Xiang-Xiang Xue, Hao Tian, Zhengzhou Yan, Gang Zhao
https://arxiv.org/abs/2509.07744

Unveiling Galactic substructures with M Giant stars: A kinematic and chemical study based on LAMOST DR9, Gaia DR3 and APOGEE DR17
Based on the updated M giant star catalog selected from LAMOST DR9, we iden-tify substructures within the integrals-of-motion space through Friends-of-Friends cluster-ing algorithm. We obtain members belonging to several known substructures: the Sagittarius stream, Galactic Anticenter Substructure (GASS), Gaia-Enceladus-Sausage (GES), Splash, and the high-α disk. Furthermore, we also identify two groups which cannot be clearly asso-ciated with previously known substructures. Our findings confi…