AGN and quasar science with aperture masking interferometry on the James
  Webb Space Telescope
  Due to feedback from accretion onto supermassive black holes (SMBHs), Active
Galactic Nuclei (AGNs) are believed to play a key role in LambdaCDM cosmology
and galaxy formation. However, AGNs' extreme luminosities and the small angular
size of their accretion flows create a challenging imaging problem. We show
James Webb Space Telescope's Near Infrared Imager and Slitless Spectrograph
(JWST-NIRISS) Aperture Masking Interferometry (AMI) mode will enable true
imaging (i.e. without any requirement of prior assumptions on source geometry)
at ~65 mas angular resolution at the centers of AGNs. This is advantageous for
studying complex extended accretion flows around SMBHs, and in other areas of
angular-resolution-limited astrophysics. By simulating data sequences
incorporating expected sources of noise, we demonstrate that JWST-NIRISS AMI
mode can map extended structure at a pixel-to-pixel contrast of ~10^{-2} around
an L=7.5 point source, using short exposure times (minutes). Such images will
test models of AGN feedback, fuelling and structure (complementary with ALMA
observations), and are not currently supported by any ground-based IR
interferometer or telescope. Binary point source contrast with NIRISS is
~10^{-4} (for observing binary nuclei in merging galaxies), significantly
better than current ground-based optical or IR interferometry. JWST-NIRISS'
seven-hole non-redundant mask has a throughput of 15%, and utilizes NIRISS'
F277W (2.77\micron), F380M (3.8\micron), F430M (4.3\micron), and F480M
(4.8\micron) filters. NIRISS' square pixels are 65mas per side, with a field of
view ~2\arcmin x 2\arcmin. We also extrapolate our results to AGN science
enabled by non-redundant masking on future 2.4m and 16m space telescopes
working at long-UV to near-IR wavelengths.
