XRISM RESOLVE observation 201094010

Quick-look products

Resolve spectrum

px1000: OPEN

px1000: OPEN

Resolve light curve

Light curve

Light curve

Title

THE NATURE OF THE CIRCUMNUCLEAR OBSCURING MEDIUM IN THE NEAREST VARIABLE COMPTON-THICK AGN NGC 4945

Abstract

NGC 4945 is the brightest Seyfert 2 in hard X-rays, and the best example of only a few Compton-thick AGN known to vary strongly >10 keV. The strong hard X-ray variability implies the intrinsic flux is not smeared out by the obscurer, requiring an atypically low torus covering factor. The cause remains unknown, but may be related to outflows depleting the sub-pc reflecting gas. Chandra has also resolved part of the reflector directly on extended scales of ~30pc rather than a classical sub-pc torus. These ill-understood reflector properties make NGC 4945 an ideal target for XRISM. We propose a 200ks observation to constrain the location, density and clumpiness of the obscurer with Resolve, and understand implications for the wider population from this prototype variable Compton-thick AGN.

FITS header

TELESCOP= 'XRISM   '           / Mission name
INSTRUME= 'RESOLVE '           / Instrument name
FILTER  = 'FE55    '           / Filter name used
OBS_ID  = '201094010'          / Observation identification string
OBJECT  = 'NGC4945 '           / Object name
OBSERVER= 'PETER BOORMAN'      / PI name
OBS_MODE= 'POINTING'           / POINTING or SLEW or ALL
RA_OBJ  =             196.3645 / [deg] Object Right ascension
DEC_OBJ =             -49.4682 / [deg] Object Declination
RA_PNT  =     196.373023975896 / Pointing RA
DEC_PNT =    -49.4687057601603 / Pointing DEC
RA_NOM  =     196.366735614155 / [deg] Nominal aspect point R.A.
DEC_NOM =    -49.4686251618704 / [deg] Nominal aspect point Dec.
PA_NOM  =     277.709655080787 / [deg] Nominal aspect point roll.
TELAPSE =     433116.238534003 / Elapsed time
DATE-OBS= '2025-06-23T02:40:12' / Start date
DATE-END= '2025-06-28T02:58:48.238534' / Stop date
ONTIME  =         13741.603182 / On-source time
EXPOSURE=         13741.603182 / 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    = '2025-07-13T04:48:09' / Date and time this file was created or updated
SIB2_VER= 'V04.00  '           / SIB2 version JAXA

Links