Elbereth conference 2024

Session

Session 6

29 févr. 2024, 12:00

Amphithéâtre Henri Mineur (Institut d'Astrophysique de Paris)

6. Dust dynamics during the gravitational collapse

Gabriel Verrier (CEA Saclay)

29/02/2024 12:00

Oral presentation

Interstellar dust is about one percent of the mass of the interstellar medium. However, its presence significantly impacts stellar formation scenarios and observations in the visible, the infrared and the sub-mm, e.g. via the dust grains opacity, the surface chemistry, the coupling with the gas and the magnetic field, and the formation of planetary cores.

We are currently working on...

36. Detection of interstellar radio recombination lines with NenuFAR

Lucie Cros (LPENS - équipe astrophysique)

29/02/2024 12:15

Oral presentation

We report detection of the low frequency carbon radio recombination lines (RRLs) towards several galactic radio sources using the NenuFAR array. Based at Nançay Radio astronomy station, NenuFAR (New Extension in Nançay Upgrading LOFAR) is a LOFAR extension and SKA precursor that can detect Carbon atoms at quantum numbers between n = 400 and n = 850, thanks to its frequency range spanning from...

49. Simulated methane clouds in the Titan troposphere with the TITAN PCM

BRUNO DE BATZ DE TRENQUELLEON

29/02/2024 12:30

Oral presentation

On Titan, methane is at the origin of all characteristics of the climate and the prebiotic chemistry that take place there. Methane and minor gases from photochemistry, produce clouds and precipitation that sculpt the satellite's landscape. Despite the many observations made by Cassini and Huygens, we still have a limited understanding of the couplings between the different cycles taking place...

13. Reanalysis of trace species in Titan’s lower atmosphere measured by Cassini Huygens

Koyena Das (LATMOS)

29/02/2024 12:45

Oral presentation

In Titan, the two major gases nitrogen (N2) and methane (CH4) are ionized and/or photolyzed at high altitudes by the sunlight and the energetic particles from Saturn's magnetosphere, resulting in rich atmospheric chemistry and a wide variety of carbon and nitrogen-bearing atmospheric compounds. In the present work, we focus on studying the vertical profiles of trace species in the lower...

22. Sub-Kelvin cryogenic developments for future CMB projects

Mme Anaïs Besnard (Institut d'Astrophysique Spatiale (IAS))

29/02/2024 13:00

Oral presentation

In order to reach a greater sensitivity, future CMB missions will need to have their focal plane to be cooled down to 100 mK typically. This will require a 2 µW cooling power delivered in a continuous and stable way. The current cooling technologies do not meet these requirements anymore. To achieve those goals, a Closed-Cycle Dilution Refrigerator is in development, using a mixture of 3He and...

52. Shack-Hartmann wavefront sensor design for optical communications in strong scintillation conditions

Timothée Vène (ONERA DOTA)

29/02/2024 13:15

Oral presentation

In the case of an optical link with a LEO satellite, it is crucial to maximize the duration of the downlink,
even at low elevations, in order to transfer the largest amount of data possible at each pass. However, in
this context, amplitude fluctuations (or scintillation) are challenging the operation of Adaptive Optics
(AO) systems, starting with their wavefront sensing subsystems.
Indeed,...