OBSERVATIONS OF SS CYGNI IN QUIESCENCE AND OUTBURST
SS Cygni is one of the prototypical dwarf novae, which shows transitions between an optically quiescent state and an outburst state. In the outburst state, hard X-ray emission is thought to arise from coronae over an accretion disc, but their location is unclear. We will understand the corona geometry by measuring profiles of the coronal emission lines with the Resolve. In the quiescent state, on the other hand, it is commonly understood that the hard X-ray emission emanates from the optically thin boundary layer, yet its heating mechanism and radial profile of the BL plasma are both poorly understood. We will try to make them clear by means of spectroscopy of the emission lines from the plasma and the fluorescent iron K-alpha emission line with the Resolve.
TELESCOP= 'XRISM ' / Mission name INSTRUME= 'RESOLVE ' / Instrument name FILTER = 'FE55 ' / Filter name used OBS_ID = '300042010' / Observation identification string OBJECT = 'SS_CYGNI' / Object name OBSERVER= 'XRISM Collaboration' / PI name OBS_MODE= 'POINTING' / POINTING or SLEW or ALL RA_OBJ = 325.67829 / [deg] Object Right ascension DEC_OBJ = 43.58611 / [deg] Object Declination RA_PNT = 325.673487358664 / Pointing RA DEC_PNT = 43.5833269225871 / Pointing DEC RA_NOM = 325.678044313503 / [deg] Nominal aspect point R.A. DEC_NOM = 43.5857375035493 / [deg] Nominal aspect point Dec. PA_NOM = 60.4387760821783 / [deg] Nominal aspect point roll. TELAPSE = 359280.735987008 / Elapsed time DATE-OBS= '2024-06-04T20:27:48.003066' / Start date DATE-END= '2024-06-09T00:15:48.739053' / Stop date ONTIME = 13297.931884 / On-source time EXPOSURE= 13297.931884 / 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 = '2024-09-26T13:47:59' / Date and time this file was created or updated SIB2_VER= / SIB2 version JAXA