THE ORIGIN OF THE NEUTRAL FE LINE IN THE GALACTIC CENTER EXPLORED BY NEW SPECTRAL FEATURES
The most characteristic spectral features of the Galactic center are bright fluorescence X-rays at 6.4 keV emitted from neutral Fe atoms in molecular clouds. Photoionization by X-rays from Sagittarius A* has been considered as its origin (the XRNe scenario). On the other hand, the Galactic center should have a high density of low-energy cosmic rays (CRs), and thus there is still a strong possibility that the neutral Fe line is due to CR bombardment. In this observation, we will explore new spectral features that could never be observed by X-ray CCD energy resolutions, and measure neutral emission lines from other elements so that we will quantitatively clarify the ratio of the XRNe and CR origins.
TELESCOP= 'XRISM ' / Mission name INSTRUME= 'RESOLVE ' / Instrument name FILTER = 'OPEN ' / Filter name used OBS_ID = '201052010' / Observation identification string OBJECT = 'RADIO_ARC' / Object name OBSERVER= 'KUMIKO NOBUKAWA' / PI name OBS_MODE= 'POINTING' / POINTING or SLEW or ALL RA_OBJ = 266.5968 / [deg] Object Right ascension DEC_OBJ = -28.895 / [deg] Object Declination RA_PNT = 266.591799742205 / Pointing RA DEC_PNT = -28.896843423727 / Pointing DEC RA_NOM = 266.596274365475 / [deg] Nominal aspect point R.A. DEC_NOM = -28.8956773631294 / [deg] Nominal aspect point Dec. PA_NOM = 80.0005030676141 / [deg] Nominal aspect point roll. TELAPSE = 258734.181407005 / Elapsed time DATE-OBS= '2025-03-16T16:54:16' / Start date DATE-END= '2025-03-19T16:46:30.181407' / Stop date ONTIME = 119813.21672 / On-source time EXPOSURE= 119813.21672 / 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 = '2025-03-29T01:06:39' / Date and time this file was created or updated SIB2_VER= 'V03.01 ' / SIB2 version JAXA