ABELL 754: CAPTURING THE HYDRODYNAMIC MOTION PERPENDICULAR TO THE MERGER AXIS
We propose two-pointing deep observations for a sloshing main gas halo (100 ksec) and a subhalo on the verge of destruction (200ksec) in a nearby violent merger, Abell 754, of which the merger axis is almost aligned on the sky plane. Edge-on observation allows us to separate hydrodynamic motion perpendicular to the merger axis from the merger-induced inflow motion. The perpendicular motion acting on disrupting gas halos is only induced in the gas by its collisional nature. Our observation will reveal mixing and incorporating processes of the gas, that is, a scene of hierarchical structure formation. Together with merger parameters derived from weak-lensing mass distribution from Subaru/HSC and galaxy dynamics, a direct measurement of the gas motion and X-ray thermodynamics give us a compr
TELESCOP= 'XRISM ' / Mission name INSTRUME= 'RESOLVE ' / Instrument name FILTER = 'FE55 ' / Filter name used OBS_ID = '201015010' / Observation identification string OBJECT = 'ABELL754_MAIN' / Object name OBSERVER= 'NOBUHIRO OKABE' / PI name OBS_MODE= 'POINTING' / POINTING or SLEW or ALL RA_OBJ = 137.3326 / [deg] Object Right ascension DEC_OBJ = -9.6887 / [deg] Object Declination RA_PNT = 137.327799979245 / Pointing RA DEC_PNT = -9.68682719226038 / Pointing DEC RA_NOM = 137.331804145264 / [deg] Nominal aspect point R.A. DEC_NOM = -9.68788892068503 / [deg] Nominal aspect point Dec. PA_NOM = 111.632758592845 / [deg] Nominal aspect point roll. TELAPSE = 215636.765625 / Elapsed time DATE-OBS= '2024-11-20T07:49:24.234375' / Start date DATE-END= '2024-11-22T19:43:21' / Stop date ONTIME = 5422.8348922 / On-source time EXPOSURE= 5422.8348922 / 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 = '2024-12-02T03:26:15' / Date and time this file was created or updated SIB2_VER= 'V03.01 ' / SIB2 version JAXA