GX1+4
One of the big questions in neutron stars is how the strong magnetic field is formed and evolved. We propose a 40 ks observation of a low-mass X-ray binary pulsar GX 1+4, which has long been suspected to have a very high magnetic field strength, perhaps ~ 1e14 G. Thanks to the excellent energy resolution of the Resolve, the proposed observation enables us for the first time to resolve the profile of the Fe K alpha lines and to measure the magnetic field strength above 1e13 G, which is impossible to probe using the cyclotron resonance scattering feature (CRSF). From this observation we can determine whether or not the source is the first magnetar binary ever detected. Moreover, Resolve may provide a unique opportunity to search for the proton CRSF.
obsid = 201018010 / Unique Observation/Sequence Number
object = GX1+4 / Object name
pi_name = TAKAGI TOSHIHIRO / Proposal Principal Investigator Name
ra = 263.007525585089 / Right Ascension (Pointing Position) (deg)
dec = -24.7452375802524 / Declination (Pointing Position) (deg)
roll_angle = 93.0802889869987 / Roll Angle (deg)
start_time = 2025-03-25T05:12:04 / Start Time of the Observation
stop_time = 2025-03-26T13:50:04 / Stop Time of the Observation
exposure = 47378.86731 / Effective Total Observation Exposure (s)
public_date= 2026-04-16 / Public Date