Polarization angle accuracy for future CMB experiments. The COSMOCal project and its prototype in the 1mm band

The Cosmic Microwave Background (CMB) radiation offers a unique window into the early Universe, facilitating precise examinations of fundamental cosmological theories. However, the quest for detecting B-modes in the CMB, predicted by theoretical models of inflation, faces substantial challenges in terms of calibration and foreground modeling. The COSMOCal (COsmic Survey of Millimeter wavelengths Objects for CMB experiments Calibration) project aims at enhancing the accuracy of the absolute calibration of the polarization angle $\psi$ of current and future CMB experiments. The concept includes the build of a very well known artificial source emitting in the frequency range [20-350] GHz that would act as an absolute calibrator for several polarization facilities on Earth. A feasibility study to place the artificial source in geostationary orbit, in the far field for all the telescopes on Earth, is ongoing. In the meanwhile ongoing hardware work is dedicated to build a prototype to test the technology, the precision and the stability of the polarization recovering in the 1 mm band (220-300 GHz). High-resolution experiments as the NIKA2 camera at the IRAM 30m telescope will be deployed for such use. Once carefully calibrated ($\Delta\psi$ < 0.1 degrees) it will be used to observe astrophysical sources such as the Crab nebula, which is the best candidate in the sky for the absolute calibration of CMB experiments.Comment: to appear in Proc. of the mm Universe 2023 conference, Grenoble (France), June 2023, published by F. Mayet et al. (Eds), EPJ Web of conferences, EDP Science

Venus night side measurements of winds at 115 km altitude from NO bright patches tracking.

N and O atoms produced by photo-dissociation of CO2 and N2 on the day side of Venus are transported to the night side in the thermospheric circulation. When the air parcel is descending, the recombination N+O→ NO produces the famous γ and δ bands of NO emission. Pioneer Venus (1978) suggested that the statistical center of the emission is off from the anti-solar point, about one- two hours in Local time after midnight. This is confirmed from SPICAV/VEX results, and the explanation generally accepted is the influence of retrograde super rotation. However, the emission takes place at 115 km, while VIRTIS/VEX, with maps of O2 emission (peak altitude 95 km) in the night side of Venus (recombination of O+O coming from the day side), has shown that the maximum of emission is statistically centered on the antisolar point. Therefore, there is no influence of super-rotation at 95 km. One way to explain this paradox is that the cause of the super rotation is different at 115 km and in the lower atmosphere. Alternately, some gravity waves could propagate from below, crossing the altitude 95 km with minimal interaction, and breaking around 115, depositing their momentum. Another consideration is that the altitude of N2 photo-dissociation is higher in the thermosphere than CO2, therefore the thermospheric circulation pattern may be different for the transport of N atoms, and O atoms. We have started building maps of the NO emission by moving around the spacecraft along its orbit on the night side. The idea is that NO emission is concentrated generally in rather well defined patches of light. Therefore, by comparing maps taken at 1 hour or 24 hr interval, we can make a “bright patch tracking”, and derive directly the velocity of the moving air parcel containing N and O (we are aware that a part of the motion could be due to a phase shift of a gravity wave, if it has some influence on the NO emission). Preliminary results from this exercise with Venus Express will be presented and discussed

BIRDY : BIRDY: an interplanetary CubeSat to collect radiation data on the way to Mars and back

International audienceThe studies of the space radiations are facing a lack of observational data. Simultaneous measurements from multiple locations in the solar system are necessary to properly assess the knowledge about the solar wind and the cosmic rays. A specialized CubeSat is a smart and cheap solution to take part in the global effort: a new concept for autonomous space probes will be demonstrated by BIRDY. Moreover the &quot;CubeSat&quot; standard allows numerous students to get involved in the BIRDY team, managed by two major institutions for space science and technology, in France at the Paris Observatory and in Taiwan at the National Cheng Kung University. A prototype shall be ready to fly in Geostationary Transfer Orbit from 2018, before a flight model being sent on a free-return Earth-Mars-Earth trajectory

Low frequency radioastronomy of the inner heliosphere: the way

Item does not contain fulltext40th COSPAR Scientific Assembly, 2-10 August 2014, in Moscow, Russi

BIRDY : BIRDY: an interplanetary CubeSat to collect radiation data on the way to Mars and back

International audienceThe studies of the space radiations are facing a lack of observational data. Simultaneous measurements from multiple locations in the solar system are necessary to properly assess the knowledge about the solar wind and the cosmic rays. A specialized CubeSat is a smart and cheap solution to take part in the global effort: a new concept for autonomous space probes will be demonstrated by BIRDY. Moreover the &quot;CubeSat&quot; standard allows numerous students to get involved in the BIRDY team, managed by two major institutions for space science and technology, in France at the Paris Observatory and in Taiwan at the National Cheng Kung University. A prototype shall be ready to fly in Geostationary Transfer Orbit from 2018, before a flight model being sent on a free-return Earth-Mars-Earth trajectory

BIRDY : BIRDY: an interplanetary CubeSat to collect radiation data on the way to Mars and back

International audienceThe studies of the space radiations are facing a lack of observational data. Simultaneous measurements from multiple locations in the solar system are necessary to properly assess the knowledge about the solar wind and the cosmic rays. A specialized CubeSat is a smart and cheap solution to take part in the global effort: a new concept for autonomous space probes will be demonstrated by BIRDY. Moreover the &quot;CubeSat&quot; standard allows numerous students to get involved in the BIRDY team, managed by two major institutions for space science and technology, in France at the Paris Observatory and in Taiwan at the National Cheng Kung University. A prototype shall be ready to fly in Geostationary Transfer Orbit from 2018, before a flight model being sent on a free-return Earth-Mars-Earth trajectory

Low frequency radioastronomy of the inner heliosphere: the way forward.

International audienc

Characterization of the chemical diversity of Sextonia rubra fruits by MALDI-CASI-FT-ICR imaging and molecular networks

International audienc

Characterization of the chemical diversity of Sextonia rubra fruits by MALDI-CASI-FT-ICR imaging and molecular networks

International audienc