Heavy atomic and molecular ions escaping from a planetary atmosphere can contribute to the long-term evolution of its composition. Here we have examined Cluster spacecraft data acquired by the CIS-CODIF ion mass spectrometer, obtained in the terrestrial inner magnetosphere. Analysis shows that the CIS-CODIF instrument detected, in upwelling ion beams and in the ring current, a series of energetic ion species including not only atomic ions as O+ but also molecular ions around ~30 amu. Given the 5-7 m/Δm mass resolution of the instrument, these could include N2+, NO+, or O2+. Their density, when these molecular ions were present, was from a few up to 28% of the O+ density. The events were during active periods, with CME arrivals followed by a northward rotation of the IMF. For four of these events, for which the orbital conditions were favourable, the observations by Cluster preceded the observations of outflowing heavy ions by the ARTEMIS spacecraft, at lunar distances in the terrestrial magnetotail, reported by Poppe et al. . The upwelling O+ fluxes, measured by Cluster in the inner magnetosphere, are consistent with the heavy ion fluxes measured by ARTEMIS. These events constitute the first coordinated heavy ion outflow observation in the Earth’s inner magnetosphere and at the Moon. They show the existence of a direct pathway of plasma, upwelling from the ionosphere and then transported and lost into the deep magnetotail. They show also that molecular ion escape, during active periods, is an additional escape mechanism (with respect to the atomic ion escape). Quantifying these mechanisms is important in order to understand the long-term (billion years scale) evolution of the atmospheric composition, and in particular the evolution of the N/O ratio, which is essential for habitability. Future missions should investigate in detail the mechanisms of atomic and molecular ion acceleration and escape, their link to the solar and magnetospheric activity, and their role in the magnetospheric dynamics and in the long-term evolution of the atmospheric composition. Our observations suggest also that terrestrial heavy ions, transported to the Moon, may have preserved samples of the Earth’s atmosphere of billions of years ago by their implantation in the near side lunar regolith. They show also the importance of the deep magnetotail of the Earth in monitoring outflowing heavy ions, as proposed in the FATE (Far Tail Explorer) mission.
Type Ia Supernovae (SN Ia) represent a very, perhaps even the most, important step on the extra-galactic distance ladder, and they have led to ground-breaking discoveries such as dark energy. Despite their outstanding importance, we still struggle to understand the details of the evolutionary pathways that produce SN Ia. It is clear that the progenitors of SN Ia are close binaries containing at least one white dwarf. The two main progenitor channels that have been proposed are the single degenerate channel in which the white dwarf accretes from a non-degenerate companion and the double degenerate channel which explains SN Ia explosions as the merger of two CO white dwarfs. However, whether nature has a strong preference for one of these channels, or whether a combination of several evolutionary channels contributes to the observed SN Ia rate, remains an open question.
I will discuss possible progenitor systems and present first results from the SN Ia pathway survey. This project has been especially designed to constrain theories of the formation and evolution of white dwarf binaries towards SN Ia by establishing a large sample of detached white dwarf + AFGK binaries.
Eclipsing Time Variations (ETVs) are observed in several types of
close binaries, and in some of them their nature is still uncertain.
Post-common-envelope binaries (PCEBs) are of particular interest in this context, as ~90% of them present ETVs on their O-C diagram of the eclipsing times. The planetary hypothesis attributes these variations to the presence of a third (and sometimes fourth) companion, but in some cases this solution has unstable orbits over short periods of time and searches for a third companion have failed. Another explanation links the ETVs to changes in the gravitational quadrupole moment of the magnetically active component of the binary during its magnetic cycle, thus changing the gravitational potential.
This is known as the Applegate mechanism. In this talk I will focus on this mechanism and our current efforts to link the ETVs to magnetic activity in PCEBs, particularly on theoretical and computational grounds.
Dust particles in space, like photons, carry information from remote
sites in space and time. From knowledge of the dust particles'
birthplace and their bulk properties, we can learn about the remote
environment out of which the particles formed. The in-situ analysis
of dust particles in space provides a window to planetary moons,
comets, the interplanetary dust cloud, and interstellar particles
from the ambient local interstellar cloud entering our solar system.
I will review the achievements of in-situ space dust measurements
in our planetary system and discuss future perspectives.
The last decade has seen immense advances in photonics based methods for imaging and manipulation. In this talk I will describe routes for obtaining wide field images that minimise photodamage and enable deeper penetration into tissue. I will describe the use of light sheet microscopy using propagation invariant light fields, particularly Airy beams and Bessel beams . This can be extended to new ways of imaging without aberration correction using attenuation compensation  and in three-photon mode . This increases depth penetration of light sheet microscopy. A more recent advance from our team involves the use of temporal focusing for multiphoton imaging at depth . This surprising approach allows us to retrieve images through tissue in the absence of any form of aberration correction and with no knowledge of the scattering tissue. It compares favourably with standard two photon microscopy.