Tootfinder

Generalized Quasispecies Model with Time Delays and Periodic Fluctuations in Replication
Nolbert Morales, Edward A. Turner
https://arxiv.org/abs/2508.12424 https://

Generalized Quasispecies Model with Time Delays and Periodic Fluctuations in Replication
In this research, we present a generalized quasispecies model in which population growth is governed by an arbitrary nonlinear function incorporating time delays. We begin by demonstrating that, under the constant population constraint, the dynamics of the system with time delays remain confined to the invariant manifold for both forward and backward time evolution. Furthermore, we establish that in this modified quasispecies model, defined on a single-peak fitness landscape, in the presence of…

White Dwarfs with Infrared Excess in the HET Dark Energy Experiment
Rudy A. Morales, Barbara G. Castanheira, Jayden Blanchard, Detlev Koester, P\'eter N\'emeth, S. O. Kepler, Erin Mentuch Cooper, Karl Gebhardt
https://arxiv.org/abs/2509.12116

White Dwarfs with Infrared Excess in the HET Dark Energy Experiment
White dwarfs with infrared excess emission provide a window into the late stages of stellar evolution and the dynamics of circumstellar environments. Using data from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), we characterized 30 white dwarfs exhibiting infrared excess, including 29 DA and 1 DB stars. While an infrared excess can arise from dusty disks or cool (sub-)stellar companions, our sample is limited to stellar companions due to our selection based on SDSS photometry, whi…

X-SHOOTER Spectrum of Comet C/2025 N1: Insights into a Distant Interstellar Visitor
A. Alvarez-Candal, J. L. Rizos, L. M. Lara, P. Santos-Sanz, P. J. Gutierrez, J. L. Ortiz, N. Morales, J. de Le\'on
https://arxiv.org/abs/2507.07312

X-SHOOTER Spectrum of Comet C/2025 N1: Insights into a Distant Interstellar Visitor
Comets are primitive remnants of the early Solar System whose composition offers fundamental clues to their formation and evolution. High-resolution, broad-wavelength spectroscopy is crucial for identifying volatile species and constraining the physical conditions within the coma. We aim to characterize the gas composition and physical environment of the newly discovered comet C/2025 N1 through optical and near-infrared spectroscopy. We used a medium-resolution spectrum of comet C/2025 N1 with …

On the Efficiency of Producing Gamma-Ray Bursts from Isolated Population III Stars
Gibran Morales-Rivera, Ramandeep Gill, S. Jane Arthur, Paz Beniamini, Jonathan Granot
https://arxiv.org/abs/2508.03689

On the Efficiency of Producing Gamma-Ray Bursts from Isolated Population III Stars
The rate of long-duration gamma-ray bursts (GRBs) from isolated Pop III stars is not well known, as it depends on our poor understanding of their initial mass function (IMF), rotation rates, stellar evolution, and mass loss. A sub-population of massive ($M_{\rm ZAMS}\gtrsim20M_\odot$) Pop III stars is expected to suffer core-collapse and launch a relativistic jet that would power a GRB. In the collapsar scenario, a key requirement is that the pre-supernova star imparts sufficient angular moment…

Straddling Two Platforms: From Twitter to Mastodon, an Analysis of the Evolution of an Unfinished Social Media Migration
Sim\'on Pe\~na-Fern\'andez, Ainara Larrondo-Ureta, Jordi Morales-i-Gras
https://arxiv.org/abs/2508.17563

Straddling Two Platforms: From Twitter to Mastodon, an Analysis of the Evolution of an Unfinished Social Media Migration
Social media have been fundamental in the daily lives of millions of people, but they have raised concerns about content moderation policies, the management of personal data, and their commercial exploitation. The acquisition of Twitter (now X) by Elon Musk in 2022 generated concerns among Twitter users regarding changes in the platform's direction, prompting a migration campaign by some user groups to the federated network Mastodon. This study reviews the onboarding of users to this decentrali…

A transition from H$_2$O to C$_2$H$_2$ dominated spectra with decreasing stellar luminosity
Sierra L. Grant, Milou Temmink, Ewine F. van Dishoeck, Danny Gasman, Aditya M. Arabhavi, Beno\^it Tabone, Thomas Henning, Inga Kamp, Alessio Caratti o Garatti, Valentin Christiaens, Pac\^ome Esteve, Manuel G\"udel, Hyerin Jang, Till Kaeufer, Nicolas T. Kurtovic, Maria Morales-Calder\'on, Giulia Perotti, Kamber Schwarz, Andrew D. Sellek, Lucas M. Stapper, Marissa Vlasblom, L. B. F. M. Wa…

A transition from H$_2$O to C$_2$H$_2$ dominated spectra with decreasing stellar luminosity
The chemical composition of the inner regions of disks around young stars will determine the properties of planets forming there. Many disk physical processes drive the chemical evolution, some of which depend on/correlate with the stellar properties. We aim to explore the connection between stellar properties and inner disk chemistry, using mid-infrared spectroscopy. We use JWST-MIRI observations of a large, diverse sample of sources to explore trends between C$_2$H$_2$ and H$_2$O. Additionall…

SN 2024hpj: a perspective on SN 2009ip-like events
I. Salmaso, A. Pastorello, E. Borsato, S. Benetti, M. T. Botticella, Y. -Z. Cai, N. Elias-Rosa, A. Farina, M. Fraser, L. Galbany, M. Gonz\'alez-Ba\~nuelos, C. P. Guti\'errez, P. Lundqvist, T. Kangas, T. L. Killestein, T. Kravtsov, K. Matilainen, A. Morales-Garoffolo, A. Mura, G. Pignata, A. Reguitti, T. M. Reynolds, S. Smartt, S. Srivastav, L. Tartaglia, G. Valerin, Z. -Y. Wang

SN 2024hpj: a perspective on SN 2009ip-like events
Supernovae (SNe) IIn are terminal explosions of massive stars that are surrounded by a dense circumstellar medium (CSM). Among SNe IIn, a notable subset is the SNe 2009ip-like, which exhibit an initial, fainter peak attributed to stellar variability in the late evolutionary stages, followed by a brighter peak, interpreted as the SN explosion itself. We analyse the spectrophotometric evolution of SN 2024hpj, a SN IIn with signs of precursor activity. Comparing it with similar objects in the lite…

The Hot Neptune Initiative (HONEI) II. TOI-5795 b: A hot super-Neptune orbiting a metal-poor star
F. Manni, L. Naponiello, L. Mancini, S. Vissapragada, K. Biazzo, A. S. Bonomo, D. Polychroni, D. Turrini, D. Locci, A. Maggio, V. D Orazi, M. Damasso, C. Briceno, D. R. Ciardi, C. A. Clark, K. A. Collins, D. W. Latham, N. Law, M. Lopez-Morales, M. B. Lund, L. Malavolta, A. W. Mann, G. Mantovan, D. Nardiello, M. Pinamonti, D. J. Radford, R. P. Schwarz, A. Shporer, A. Sozzetti, C. N., Watki…

The Hot Neptune Initiative (HONEI) II. TOI-5795 b: A hot super-Neptune orbiting a metal-poor star
The formation of Neptune planets with orbital periods less than 10\,days remains uncertain. They might have developed similarly to longer-period counterparts, emerged from rare collisions between smaller planets, or could be the remnant cores of stripped giant planets. Characterizing a large number of them is important to advance our understanding of how they form and evolve. We aimed at confirming the planetary nature and characterizing the properties of a close-in Neptune-type transiting exop…