INVESTIGATING THE COMPOSITION AND STATE OF IRON IN THE INTERSTELLAR MEDIUM USING X-RAY ABSORPTION SPECTROSCOPY
Recent analyses of extraterrestrial materials returned by sample return missions have refined our understanding of solar composition. However, the elemental composition within the Milky Way, historically estimated from meteorites and the Sun's photosphere, faces scrutiny for potentially underrepresenting heavy elements compared to interstellar space. This proposal aims to utilize XRISM to accurately quantify the total abundance of heavy elements, including iron, in both gaseous and solid states in the interstellar medium towards GX~5-1, a Low-Mass X-ray Binary, overcoming limitations of traditional methods.
TELESCOP= 'XRISM ' / Mission name INSTRUME= 'RESOLVE ' / Instrument name FILTER = 'ND ' / Filter name used OBS_ID = '201060010' / Observation identification string OBJECT = 'GX5-1 ' / Object name OBSERVER= 'TASUKU HAYASHI' / PI name OBS_MODE= 'POINTING' / POINTING or SLEW or ALL RA_OBJ = 270.2842 / [deg] Object Right ascension DEC_OBJ = -25.0782 / [deg] Object Declination RA_PNT = 270.27977525129 / Pointing RA DEC_PNT = -25.0787253551612 / Pointing DEC RA_NOM = 270.284264195198 / [deg] Nominal aspect point R.A. DEC_NOM = -25.0783055851588 / [deg] Nominal aspect point Dec. PA_NOM = 90.6818100818163 / [deg] Nominal aspect point roll. TELAPSE = 89331.002207011 / Elapsed time DATE-OBS= '2025-04-15T14:30:19.983082' / Start date DATE-END= '2025-04-16T15:19:10.985289' / Stop date ONTIME = 51126.856683 / On-source time EXPOSURE= 51126.856683 / Exposure time PROCVER = '03.00.013.010' / 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= 'gen20241115_xtd20241115_rsl20241115' / Version of CALDB used DATE = '2025-04-23T06:49:08' / Date and time this file was created or updated SIB2_VER= 'V03.01 ' / SIB2 version JAXA