RESOLVING RELATIVISTIC EFFECTS IN THE ACCRETION DISK OF SERPENS X-1
Serpens X-1 is a persistently accreting neutron star (NS) with the first confirmed relativistically broadened Fe line for such systems. However, there remains conflicting reports of key parameters, such as the position of the inner accretion disk and inclination. These quantities can be determined from resolving the red- and blue-wings of the Fe line profile, which are most sensitive to the gravitational redshift and Doppler effects, respectively. Further, the Fe line has a unique double-peaked profile which can be due to high disk density effects causing the Fe XXV and XXVI lines to be produced at a similar strength. We request a 300 ks observation of the source to reveal the Doppler and relativistic effects that shape the line profile and further our understanding of the accretion flow.
TELESCOP= 'XRISM ' / Mission name INSTRUME= 'XTEND ' / Instrument name OBS_ID = '201073010' / Observation identification string OBJECT = 'SERPENS_X-1' / Object name OBSERVER= 'RENEE LUDLAM' / PI name OBS_MODE= 'POINTING' / POINTING or SLEW or ALL RA_OBJ = 279.9898 / [deg] Object Right ascension DEC_OBJ = 5.036 / [deg] Object Declination RA_PNT = 280.002250510534 / Pointing RA DEC_PNT = 5.04447174285399 / Pointing DEC RA_NOM = 279.9903324117 / [deg] Nominal aspect point R.A. DEC_NOM = 5.03593618900277 / [deg] Nominal aspect point Dec. PA_NOM = 257.948230445558 / [deg] Nominal aspect point roll. TELAPSE = 347697.561981976 / Elapsed time DATE-OBS= '2024-10-17T22:25:46.398730' / Start date DATE-END= '2024-10-21T23:00:43.960712' / Stop date ONTIME = 19211.653311 / On-source time EXPOSURE= 19211.653311 / 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 = '2024-10-26T07:06:10' / Date and time this file was created or updated SIB2_VER= 'V03.01 ' / SIB2 version JAXA