PROBING THE WIND-COMPACT OBJECT INTERACTION IN VELA X-1
We propose to observe Vela X-1, the prototypical High Mass X-ray Binary in order to study the spectrum and its variability. The observation is designed to study the variability with the X-ray pulse and the variability with the binary orbit. This will allow constraints on the shape of the pulsar beam, which has previously been done only very crudely. It will allow us to determine the mean density of gas in the wind as it interacts with the pulsar, and to constrain iron peak abundances. We will search for pulsations in the lines, which will provide information about the pulsar beam as seen by many different lines of sight at once. Observations of Vela X-1 are virtually guaranteed to produce spectra which are of high statistical significance and rich in line features. They will provide
TELESCOP= 'XRISM ' / Mission name INSTRUME= 'RESOLVE ' / Instrument name FILTER = 'OPEN ' / Filter name used OBS_ID = '300057020' / Observation identification string OBJECT = 'VELA_X-1' / Object name OBSERVER= 'XRISM Collaboration' / PI name OBS_MODE= 'POINTING' / POINTING or SLEW or ALL RA_OBJ = 135.52833 / [deg] Object Right ascension DEC_OBJ = -40.55469 / [deg] Object Declination RA_PNT = 135.533738482364 / Pointing RA DEC_PNT = -40.5560314701969 / Pointing DEC RA_NOM = 135.528629936688 / [deg] Nominal aspect point R.A. DEC_NOM = -40.5547501930184 / [deg] Nominal aspect point Dec. PA_NOM = 294.847641325337 / [deg] Nominal aspect point roll. TELAPSE = 30885.9832240045 / Elapsed time DATE-OBS= '2024-05-22T13:05:42' / Start date DATE-END= '2024-05-22T21:40:27.983224' / Stop date ONTIME = 12968.858224 / On-source time EXPOSURE= 12968.858224 / Exposure time PROCVER = '03.00.013.009' / Processing script version MKFFF = 'ISAS/JAXA' / Origin of First FITS file ORIGIN = 'GSFC/NASA' / Origin of Processed FITS file SOFTVER = 'Hea_21Aug2024_V6.34_XRISM_21Aug2024_V001' / Version of HEADAS used CALDBVER= 'gen20240315_xtd20240815_rsl20240815' / Version of CALDB used DATE = '2024-09-24T16:03:36' / Date and time this file was created or updated SIB2_VER= / SIB2 version JAXA