60 Milliarcsecond near-infrared imaging of 3C 273 with Altair and Gemini

We report data from the commissioning run of the Altair adaptive optics instrument on Gemini North. The bright QSO 3C 273 was observed at f/32 in the H and J bands, and at f/14 with J band, using the QSO itself as guide star. Resolution of approximately 60 mas full width at half-maximum (FWHM) was achieved in H band. The data and point-spread function are compared with those from the Hubble Space Telescope (HST). The Altair data allow a measurement of the spheroidal inner host galaxy to radii down to about 40 mas. A bright knot seen in visible wavelengths with the Advanced Camera for Surveys (ACS) instrument on HST is seen in the J but not the H band, and the dust lane seen with ACS is less visible, as expected. Other morphological features, and the jet, are discussed.