Opening the era of quasar host studies at high redshift with JWST
Abstract
We measure the host galaxy properties of five quasars with z 1.6 - 3.5 selected from SDSS and AEGIS, which fall within the JWST/HST CEERS survey area. A PSF library is constructed based on stars in the full field-of-view of the data and used with the 2-dimensional image modeling tool galight to decompose the quasar and its host with multi-band filters available for HST ACS+WFC3 and JWST NIRCAM (12 filters covering HST F606W to JWST F444W). As demonstrated, JWST provides the first capability to detect quasar hosts at z>3 and enables spatially-resolved studies of the underlying stellar populations at z2 within morphological structures (spiral arms, bar) not possible with HST. Overall, we find quasar hosts to be disk-like, lack merger signatures, and have sizes generally more compact than typical star-forming galaxies at their respective stellar mass, thus in agreement with results at lower redshifts. The fortuitous face-on orientation of SDSSJ1420+5300A at z = 1.646 enables us to find higher star formation and younger ages in the central 2-4 kpc region relative to the outskirts, which may help explain the relatively compact nature of quasar hosts and pose a challenge to AGN feedback models.