4U1909+07
We propose a XRISM observation of the Compton-thick wind-fed Supergiant X-ray binary 4U 1909+07 for 50 ks. Taking advantage of the unprecedented spectral resolution and large collecting area of Resolve, we will probe large-scale (high density and velocity) structures threading the wind of the B0-3 I donor star by constraining the geometry and ionization structure of its Fe fluorescent region. Our aim is to perform the deepest search yet for the elusive Compton shoulder on the red wing of its strong Fe Kalpha line and constrain the Fe Kbeta/Kalpha ratio, which suggests ionized material. Our study also holds broader astrophysical relevance in characterizing the winds of early-type massive stars.
obsid = 202043010 / Unique Observation/Sequence Number
object = 4U1909+07 / Object name
pi_name = COLEY JOEL / Proposal Principal Investigator Name
ra = 287.70043803515 / Right Ascension (Pointing Position) (deg)
dec = 7.59745203035305 / Declination (Pointing Position) (deg)
roll_angle = 68.661059065961 / Roll Angle (deg)
start_time = 2026-05-05T13:30:04 / Start Time of the Observation
stop_time = 2026-05-06T20:19:04 / Stop Time of the Observation
exposure = 53809.948571 / Effective Total Observation Exposure (s)
public_date= 2099-12-31 / Public Date