Deep [ITAL]H[/ITAL]-Band Galaxy Counts and Half-Light Radii from [ITAL]Hubble Space Telescope[/ITAL]/NICMOS Parallel Observations

We present deep galaxy counts and half-light radii from F160W (λ c =1.6 μm) images obtained with the Near-Infrared Camera and Multiobject Spectrograph on the Hubble Space Telescope . Nearly 9 arcmin 2 have been imaged with camera 3, with 3 σ depths ranging from H =24.3 to 25.5 in a 0 6 diameter aperture. The slope of the counts fainter than H =20 is 0.31, and the integrated surface density to H ≤24.75 is 4 × 10 5 galaxies deg -2 . The half-light radii of the galaxies decline steeply with apparent magnitude. At H =24, we are limited by both the delivered FWHM and the detection threshold of the images.