MAPPING THE ACCRETION DISC WITH IONISED PLASMAS IN DIPPING SOURCES
We propose a 50 ks observation of the high-inclination dipping low-mass X-ray binary (LMXB) 4U 1916 (minimal) and a 50 ks of the dipping LMXB 4U 1624 (ideal). We will characterise the absorbers throughout the orbit (column densities, degree of ionisation and velocity width and shift) and determine their density and location. We will use the changes in the absorbers' properties to model the complex spectral changes throughout the orbit, including during dips, and to trace the variability of the absorber associated with changes in the source luminosity and hardness. We will use this information to make a full map of the accretion disc and identify potential zones of wind launching in LMXBs, shielded regions in the disc or zones that attenuate the central emission such as hot coronae.
TELESCOP= 'XRISM ' / Mission name INSTRUME= 'RESOLVE ' / Instrument name FILTER = 'OPEN ' / Filter name used OBS_ID = '300040010' / Observation identification string OBJECT = '4U1624-490' / Object name OBSERVER= 'XRISM Collaboration' / PI name OBS_MODE= 'POINTING' / POINTING or SLEW or ALL RA_OBJ = 247.01177083 / [deg] Object Right ascension DEC_OBJ = -49.1985028 / [deg] Object Declination RA_PNT = 247.006653068255 / Pointing RA DEC_PNT = -49.1960128021251 / Pointing DEC RA_NOM = 247.012046872943 / [deg] Nominal aspect point R.A. DEC_NOM = -49.1980824833496 / [deg] Nominal aspect point Dec. PA_NOM = 126.996998389255 / [deg] Nominal aspect point roll. TELAPSE = 93969.9812319875 / Elapsed time DATE-OBS= '2024-03-29T23:56:18.009047' / Start date DATE-END= '2024-03-31T02:02:27.990279' / Stop date ONTIME = 67756.843318 / On-source time EXPOSURE= 67756.843318 / 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 = '2024-09-26T14:48:46' / Date and time this file was created or updated SIB2_VER= / SIB2 version JAXA