DISK IONIZATION AND PLANET FORMATION STUDIED BY OBSERVATIONS OF THE PROTOSTAR ELIAS 29 AND 9 PRE-MAIN-SEQUENCE STARS
Stellar X-ray activity can induce chemical reactions in the protoplanetary disk and affect planet formation. The low-ionized Fe line at ~ 6.4 keV can be a good tracer of the X-ray penetration depth toward the disk, which can reveal the ionization process of surrounding envelope and disk by coronal X-rays. We propose a 100 ks observation of the protostar Elias 29 with Resolve to estimate the X-ray penetration depth and confirm the Fe line is formed from the disk. Using the same pointing, we also use Xtend, which simultaneously observes 9 surrounding pre-main-sequence stars. From this, we can provide the constraint on the line formation region from another viewpoint, by combining the Fe line equivalent widths and the disk inclination angles from the high spatially-resolved ALMA data.
TELESCOP= 'XRISM ' / Mission name INSTRUME= 'XTEND ' / Instrument name OBS_ID = '201047010' / Observation identification string OBJECT = 'ELIAS29 ' / Object name OBSERVER= 'SHUN INOUE' / PI name OBS_MODE= 'POINTING' / POINTING or SLEW or ALL RA_OBJ = 246.7893 / [deg] Object Right ascension DEC_OBJ = -24.6219 / [deg] Object Declination RA_PNT = 246.792046161864 / Pointing RA DEC_PNT = -24.6203088544854 / Pointing DEC RA_NOM = 246.789949973169 / [deg] Nominal aspect point R.A. DEC_NOM = -24.6220331005363 / [deg] Nominal aspect point Dec. PA_NOM = 278.055210444295 / [deg] Nominal aspect point roll. TELAPSE = 68857.1991789937 / Elapsed time DATE-OBS= '2025-08-13T01:07:12.800821' / Start date DATE-END= '2025-08-13T20:14:50' / Stop date ONTIME = 36396.000677 / On-source time EXPOSURE= 36396.000677 / Exposure time PROCVER = '03.02.014.010' / Processing script version MKFFF = 'ISAS/JAXA' / Origin of First FITS file ORIGIN = 'GSFC/NASA' / Origin of Processed FITS file SOFTVER = 'Hea_12Mar2025_V6.35_XRISM_28Feb2025_V002' / Version of HEADAS used CALDBVER= 'gen20241115_xtd20241115_rsl20241115' / Version of CALDB used DATE = '2025-08-21T07:08:02' / Date and time this file was created or updated SIB2_VER= 'V04.00 ' / SIB2 version JAXA