NEAR-INFRARED IMAGING OF A z = 6.42 QUASAR HOST GALAXY WITH THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3*

摘要: We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z = 6.42 quasar J1148+5251 to attempt detect rest-frame near-ultraviolet emission from host galaxy. These observations included contemporaneous a nearby star similar colors measure temporal variations in telescope instrument point-spread function (PSF). subtract point source using both this direct PSF model PSF. Using subtraction, we an upper limit for galaxy mJ > 22.8 mH 23.0 AB mag (2 σ). After subtracting our best PSF, limiting surface brightness 03 05 radius μ J 23.5 H 23.7 arcsec–2 test ability subtraction method recover flux by simulating galaxies with varying integrated magnitude, effective radius, Sersic index, conducting same analysis. models indicate that (μ arcsec–2) corresponds 22-23 mag, consistent method. Combined existing far-infrared observations, gives infrared excess log (IRX) 1.0 corresponding ultraviolet spectral slope β –1.2 ± 0.2. values match those most local luminous galaxies, but are redder than almost all star-forming 6 Lyman break galaxies.