VELA_X-1
We propose a 40-ks XRISM observation of the wind-fed High-Mass X-ray Binary (HMXB) Vela X-1 at orbital phase 0.43-0.53 where we expect the largest changes in absorption as the accretion structure crosses and obstructs our line of sight. By tracing the onset of this structure, we obtain an in-depth view of the stellar wind complexity in this source. In particular, the moderate absorption combined with strong continuum emission happening at these orbital phases will reveal emission lines below 12 keV, even with the gate valve closed. We will follow absorption variability and iron line energy shifts down to the pulse period of the neutron star to probe the onset of the accretion wake on our line of sight and radial velocities of the wind.
obsid = 201131010 / Unique Observation/Sequence Number
object = VELA_X-1 / Object name
pi_name = DIEZ CAMILLE / Proposal Principal Investigator Name
ra = 135.527956395938 / Right Ascension (Pointing Position) (deg)
dec = -40.5542773939656 / Declination (Pointing Position) (deg)
roll_angle = 111.343800298812 / Roll Angle (deg)
start_time = 2024-11-19T00:25:04 / Start Time of the Observation
stop_time = 2024-11-20T07:37:04 / Stop Time of the Observation
exposure = 61312.89049047 / Effective Total Observation Exposure (s)
public_date= 2025-12-11 / Public Date