George K Miley

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Multicolor coronagraphic images of the circumstellar disk around HD 141569A have been obtained with the Hubble Space Telescope Advanced Camera for Surveys. The B, V, and I images show that the disk's previously described multiple-ring structure is actually a continuous distribution of dust with a tightly wound spiral structure. Extending from the disk are(More)
We present Hubble Space Telescope Advanced Camera for Surveys multicolor coronagraphic images of the recently discovered edge-on debris disk around the nearby ($10 pc) M dwarf AU Microscopii. The disk is seen between r ¼ 0B75 and 15 00 (7.5–150 AU) from the star. It has a thin midplane with a projected FWHM thickness of 2.5–3.5 AU within r < 50 AU of the(More)
We present F435W (B), F606W (broad V), and F814W (broad I) coronagraphic images of the debris disk around Pictoris obtained with the Hubble Space Telescope's Advanced Camera for Surveys. These images provide the most photometrically accurate and morphologically detailed views of the disk between 30 and 300 AU from the star ever recorded in scattered light.(More)
Active galactic nuclei (AGNs) display many energetic phenomena--broad emission lines, X-rays, relativistic jets, radio lobes--originating from matter falling onto a supermassive black hole. It is widely accepted that orientation effects play a major role in explaining the observational appearance of AGNs. Seen from certain directions, circum-nuclear dust(More)
LOFAR (Low Frequency Array) is an innovative radio telescope optimized for the frequency range 30-240 MHz. The telescope is realized as a phased aperture array without any moving parts. Digital beam forming allows the telescope to point to any part of the sky within a second. Transient buffering makes retrospective imaging of explosive short-term events(More)
We measure the morphology–density relation (MDR) and morphology-radius relation (MRR) for galaxies in seven z ∼ 1 clusters that have been observed with the Advanced Camera for Surveys on board the Hubble Space Telescope. Simulations and independent comparisons of our visually derived morphologies indicate that ACS allows one to distinguish between E, S0,(More)
We present the discovery and detailed observations of the radio galaxy 1243+036 (=4C 03.24) at a redshift of z = 3.57. The radio source was selected on the basis of its extremely steep radio spectrum, suggesting that it might be very distant. The radio source was identified with a galaxy of R magnitude 22.5. Subsequent spectroscopy showed strong Lyman α and(More)
Imaging and spectroscopy with the Very Large Telescope have revealed 20 Lyα emitters within a projected distance of 1.3 Mpc and 600 km s −1 of the luminous radio galaxy TN J1338–1942 at z = 4.1. Compared to the field density of Lyα emitters, this implies an overdensity on the order of 15. The structure has a projected size of at least 2.7 Mpc × 1.8 Mpc and(More)
We present the results of a near infrared imaging program of a sample of 19 radio galaxies with redshift between 1.7 and 3.2, using the NICMOS Camera 2 on the Hubble Space Telescope. The galaxies were observed in H-band which, for 18 of the 19 targets, samples the rest-frame optical emission longwards of the 4000Å break. For many sources this band contains(More)
We report deep Keck narrow-band Lyα images of the luminous z > 3 radio galaxies 4C 41.17, 4C 60.07, and B2 0902+34. The images show giant, 100−200 kpc scale emission line nebulae, centered on these galaxies, which exhibit a wealth of morphological structure, including extended low surface brightness emission in the outer regions, radially directed(More)