TRACING A MISSING BRANCH IN THE SNR EVOLUTION: RECOMBINING PLASMA IN W49B
The Suzaku's discovery of recombining plasma in supernova remnants (SNRs) was a surprise because it is never expected in the fiducial Sedov model. We propose to observe the brightest recombining SNR W49B to reveal the origin of this new class of SNRs based on the high-resolution spectroscopy using XRISM/Resolve. We will identify the cooling process that formed the recombining state based on measurements of the electron temperature, ion temperature, and charge-state distribution. We will also constrain the progenitor type that regulates the SN environment, by bias-free measurements of the ejecta mass ratios of the Fe-group elements. Additionally, as an ideal goal, we will search for the signature of interaction with supra-thermal electrons and constrain the injection efficiency.
TELESCOP= 'XRISM ' / Mission name INSTRUME= 'RESOLVE ' / Instrument name FILTER = 'OPEN ' / Filter name used OBS_ID = '300055010' / Observation identification string OBJECT = 'W49B_East' / Object name OBSERVER= 'XRISM Collaboration' / PI name OBS_MODE= 'POINTING' / POINTING or SLEW or ALL RA_OBJ = 287.79758 / [deg] Object Right ascension DEC_OBJ = 9.10211 / [deg] Object Declination RA_PNT = 287.789924516771 / Pointing RA DEC_PNT = 9.09550512719468 / Pointing DEC RA_NOM = 287.793559639643 / [deg] Nominal aspect point R.A. DEC_NOM = 9.09746032225462 / [deg] Nominal aspect point Dec. PA_NOM = 67.9999800089688 / [deg] Nominal aspect point roll. TELAPSE = 674528.012205988 / Elapsed time DATE-OBS= '2024-04-23T03:03:20' / Start date DATE-END= '2024-04-30T22:25:28.012206' / Stop date ONTIME = 323494.44338 / On-source time EXPOSURE= 323494.44338 / 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 = '2024-09-26T00:38:23' / Date and time this file was created or updated SIB2_VER= / SIB2 version JAXA