arXiv subjects

Charly Feldman

Publications and source records attributed to Charly Feldman.

3 recordsLinked to original sources

arXiv2026

Design and in-orbit calibration of the MXT optics

The Microchannel X-ray Telescope (MXT) is one of four instruments on the Space-based multi-band astronomical Variable Objects Monitor (SVOM) satellite mission, launched on the 22nd June 2024. The MXT is a narrow-field-optimised, lobster eye X-ray focusing telescope, consisting of an array of 25 square MPOs, with a focal length of 1.14 m and working in the energy band 0.2 - 10 keV. The design of the MXT optic (MOP) is optimised to give a 1 degree FoV to match the detector size, but the optic has the unique characteristics of a lobster eye design, with a wide FoV of 6 degree diameter, and a PSF, which is constant over the entire FoV. The MPOs on the Flight Module (FM) MOP have a pore size of 40 um giving the optimum thicknesses across the aperture of 2.4 mm in the centre and 1.2 mm at the edges. Using specific target sources, the in-orbit calibration of the optic is here described, and compared to the extensive on-ground calibration, which was carried out at the PANTER test facility, MPE, Germany. The design and limitations of the electron diverter, situated directly behind the optic, are also discussed.

astro-ph.IM↗

arXiv2023

Revolutionary Solar System Science Enabled by the Line Emission Mapper X-ray Probe

The Line Emission Mapper's (LEM's) exquisite spectral resolution and effective area will open new research domains in Astrophysics, Planetary Science and Heliophysics. LEM will provide step-change capabilities for the fluorescence, solar wind charge exchange (SWCX) and auroral precipitation processes that dominate X-ray emissions in our Solar System. The observatory will enable novel X-ray measurements of historically inaccessible line species, thermal broadening, characteristic line ratios and Doppler shifts - a universally valuable new astrophysics diagnostic toolkit. These measurements will identify the underlying compositions, conditions and physical processes from km-scale ultra-cold comets to the MK solar wind in the heliopause at 120 AU. Here, we focus on the paradigm-shifts LEM will provide for understanding the nature of the interaction between a star and its planets, especially the fundamental processes that govern the transfer of mass and energy within our Solar System, and the distribution of elements throughout the heliosphere. In this White Paper we show how LEM will enable a treasure trove of new scientific contributions that directly address key questions from the National Academies' 2023-2032 Planetary Science and 2013-2022 Heliophysics Decadal Strategies. The topics we highlight include: 1. The richest global trace element maps of the Lunar Surface ever produced; insights that address Solar System and planetary formation, and provide invaluable context ahead of Artemis and the Lunar Gateway. 2. Global maps of our Heliosphere through Solar Wind Charge Exchange (SWCX) that trace the interstellar neutral distributions in interplanetary space and measure system-wide solar wind ion abundances and velocities; a key new understanding of our local astrosphere and a synergistic complement to NASA IMAP observations of heliospheric interactions...

astro-ph.IM↗

arXiv2022

Lobster Eye X-ray Optics

This chapter describes the history, principles, and recent developments of large field of view X-ray optics based on lobster eye designs. Most of grazing incidence (reflective) X-ray imaging systems used in astronomy and other applications, are based on the Wolter 1 (or modified) arrangement. But there are also other designs and configurations proposed for future applications for both laboratory and space environments. Kirkpatrick-Baez (K-B) based lenses as well as various types of lobster eye optics serve as an example. Analogously to Wolter lenses, all these systems use the principle that the X-rays are reflected twice to create focal images. Various future projects in X-ray astronomy and astrophysics will require large optics with wide fields of view. Both large Kirkpatrick-Baez modules and lobster eye X-ray telescopes may serve as solutions as these can offer innovations such as wide fields of view, low mass and reduced costs. The basic workings of lobster eye optics using Micro Pore Optics (MPOs) and their various uses are discussed. The issues and limiting factors of these optics are evaluated and current missions using lobster eye optics to fulfil their science objectives are reviewed. The Multi Foil Optics (MFO) approach represents a promising alternative. These arrangements can also be widely applied in laboratory devices. The chapter also examines the details of alternative applications for non-Wolter systems in other areas of science, where some of these systems have already demonstrated their advantages such as the K-B systems which have already found wide applications in laboratories and synchrotrons.

astro-ph.IM↗