V18

Presentation Title: Initial results of solar flare observing sounding rocket FOXSI-4
Author(s): Noriyuki Narukage, Lindsay Glesener, Kazuki Ampuku, Yumi Bamba, Wayne Baumgartner, Stephen Bongiorno, Juan Camilo Buitrago-Casas, Patrick R. Champey, Steven Christe, Kristopher Cooper, Sasha Courtade, Tamar Ervin, Ryuto Fujii, Tadashi Hirose, Hunter Kanniainen, Sota Kashima, Sam Krucker, Kanya Kusano, Juan Carlos Martinez Oliveros, Takahiro Minami, Ikuyuki Mitsuishi, Shunsaku Nagasawa, Athanasios Pantazides, Eliad Peretz, Savannah Perez Piel, Orlando Romeo, Taro Sakao, Koki Sakuta, Yoshiaki Sato, Sabrina Savage, Riko Shimizu, Daniel Ryan, Tadayuki Takahashi, Juliana Therese Vievering, Shin Watanabe, Yusuke Yoshida, Yixian Zhang, Flare Campaign Team and Hi-C FLARE team

Abstract:

On April 17, 2024, two sounding rockets, FOXSI-4 and Hi-C FLARE, were launched and successfully observed an M-class solar flare.
FOXSI-4 (4th flight of the Focusing Optics X-ray Solar Imager) has realized the world's first X-ray focusing imaging spectroscopic observation of a solar flare with seven pairs of high-precision electroformed Wolter type I mirrors and high-speed X-ray cameras, which enable photon-counting type measurements from soft to hard X-ray ranges. In this observation, each X-ray photon emitted from a solar flare was individually measured. Thus, the entire solar flare region can be investigated with spatial, temporal, and energy resolution. FOXSI-4 has detected at least 10 million photons in the soft X-ray range (up to 10 keV), from which we can investigate the spatial distribution and temporal evolution of the temperature and density of the flaring plasmas. In the hard X-ray range (up to 20 keV), at least 10 thousand photons have been detected, which is expected to enable the investigation of the behavior of high-energy electrons.
For this solar flare observation with sounding rockets whose observation time is limited to 5 minutes (called a "Solar Flare Sounding Rocket Campaign"), we have established a method of launching rockets shortly after the onset of a large flare using real-time monitoring of solar activity in X-rays and EUV light and flare size prediction based on the photospheric magnetic field data and a kappa-scheme.
Coordinating observation with the Hinode satellite was also conducted in this solar flare campaign.
In this talk, the initial results of FOXSI-4 will be introduced, along with a brief summary of FOXSI-4 instruments, flare campaign, and coordinate observation with Hi-C FLARE and Hinode satellite.