4U1700-37
We aim to study 4U 1700-377, a high-mass X-ray binary system, to better understand how matter behaves around its bright companion star and address the ``mass-gap'' mystery. Depending on its true nature, 4U 1700-377 could either be the heaviest neutron star without detected pulsations or the smallest black hole ever found. Using XRISM's detailed spectral analysis, we plan to measure the central energies and the profiles of the neutral and ionized iron lines with unprecedented accuracy.
obsid = 201064010 / Unique Observation/Sequence Number object = 4U1700-37 / Object name pi_name = YAMADA SHINYA / Proposal Principal Investigator Name ra = 255.987135717979 / Right Ascension (Pointing Position) (deg) dec = -37.8436520403796 / Declination (Pointing Position) (deg) roll_angle = 88.5869835772094 / Roll Angle (deg) start_time = 2025-02-10T11:46:04 / Start Time of the Observation stop_time = 2025-02-11T22:09:04 / Stop Time of the Observation exposure = 58719.802638 / Effective Total Observation Exposure (s) public_date= 2026-02-19 / Public Date