Elbereth conference 2025

Session

Session 9

11 avr. 2025, 10:00

Amphithéâtre Evry Schatzman (Observatoire de Paris - Site de Meudon)

82. CO2 Ice Properties using CRISM Data: Implications for Martian Gullies Formation Mechanisms

Apolline Leclef (Institut d'Astrophysique Spatiale)

11/04/2025 10:00

Astrophysics

Oral presentation

The study of Martian ices provides key information into the formation mechanisms of gullies on Mars. Using infrared spectroscopy data from CRISM (Mars Reconnaissance Orbiter, NASA), this work focuses on seasonal CO2 ice deposits near Mars' poles, with particular attention to Sisyphi Cavi, where active gullies are observed. The properties of CO2 ice are characterized by evaluating its...

67. In situ research of organic matter on Mars surface using Gas Chromatograph and Mass Spectrometer (GCMS) with the SAM (MSL mission) and MOMA (ExoMars mission) space experiments

M. Théo Govekar (Laboratoire Atmosphères, Observations Spatiales)

11/04/2025 10:15

Astrophysics

Oral presentation

Mars’ surface is currently one of the environments in the solar system, where the research about prebiotic chemistry is the more active, because of the possibility of a past biologic activity considering Mars gathered the conditions required for the emergence of life at the time it arose on Earth [1].

In this context, a gas chromatograph mass spectrometers (GCMS) instrument was sent to Mars...

65. Effective theory reproducing MOND phenomenology based on a non-Abelian Yang-Mills graviphoton

Emeric Seraille (LPENS)

11/04/2025 10:30

Astrophysics

Oral presentation

Despite the remarkable success and relative simplicity of the standard ΛCDM model, some phenomena remain unexplained. Most notably, the puzzling relationship between galaxy rotation curves and the observed baryon density that motivated the development of MOND. However, most field theories attempting to reproduce MOND predictions have to rely on ad hoc free functions, preventing them from being...

66. On the shape of pancakes: post-collapse perturbation theory

Abineet Parichha (Institut d'Astrophysique de Paris - Sorbonne Université)

11/04/2025 10:45

Astrophysics

Oral presentation

Cold dark matter is typically modelled as a collisionless and self-gravitating fluid with negligible velocity dispersion and can be thought of as a 2D (3D) sheet of particles in 4D (6D) phase-space whose topology evolves as per the Lagrangian equations of motion of particles. The collapse of dark matter particles in the neighborhood of an initial overdensity into points of singularity, i.e....