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Candidate Type II Quasars from the Sloan Digital Sky Survey. III. Spectropolarimetry Reveals Hidden Type I Nuclei
Hall, Patrick B.; Strauss, Michael A.; Brinkmann, J. +7 more
We have conducted spectropolarimetry of 12 type II (obscured) quasar candidates selected from the spectroscopic database of the Sloan Digital Sky Survey on the basis of their emission-line properties. Polarization was detected in all objects, with nine being highly polarized (>3%) and with polarization reaching as high as 17% in two objects. Br…
Confirmation of Errors in Hipparcos Parallaxes from Hubble Space Telescope Fine Guidance Sensor Astrometry of the Pleiades
Soderblom, David R.; Benedict, G. Fritz; McArthur, Barbara +4 more
We present absolute trigonometric parallaxes and relative proper motions for three members of the Pleiades, obtained with the Hubble Space Telescope's Fine Guidance Sensor 1r, a white-light interferometer. We estimate spectral types and luminosity classes of the stars comprising the astrometric reference frame from R~2000 spectra, VJHK photometry,…
Hubble Space Telescope Advanced Camera for Surveys Coronagraphic Imaging of the AU Microscopii Debris Disk
Ford, H. C.; Demarco, R.; Infante, L. +38 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=0.75" and 15" (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 o…
The T Tauri Star Population of the Young Cluster NGC 2264
Simon, Theodore; Dahm, S. E.
An Hα emission survey of the young cluster NGC 2264 in the Mon OB1 association resulted in the detection of 490 Hα emission stars in a 25'×40' field approximately centered between the O7 V multiple star S Mon and the Cone Nebula. The survey was carried out with the wide-field grism spectrograph (WFGS) on the University of Haw…
The Near-Infrared Camera and Multi-Object Spectrometer Ultra Deep Field: Observations, Data Reduction, and Galaxy Photometry
Dickinson, Mark; Franx, Marijn; van Dokkum, Pieter +10 more
This paper describes the observations and data reduction techniques for the version 2.0 images and catalog of the Near-Infrared Camera and Multi-Object Spectrometer Ultra Deep Field (NICMOS UDF) Treasury program. All sources discussed in this paper are based on detections in the combined NICMOS F110W and F160W bands only. The NICMOS images are dri…
A Study of Edge-On Galaxies with the Hubble Space Telescope Advanced Camera for Surveys. II. Vertical Distribution of the Resolved Stellar Population
de Jong, Roelof S.; Seth, Anil C.; Dalcanton, Julianne J.
We analyze the vertical distribution of the resolved stellar populations in six low-mass (Vmax=67-131 km s-1), edge-on, spiral galaxies observed with the Hubble Space Telescope Advanced Camera for Surveys. In each galaxy we find evidence for an extraplanar stellar component extending up to 15 scale heights (3.5 kpc) above the…
An Infrared Coronagraphic Survey for Substellar Companions
Weinberger, Alycia J.; Schneider, Glenn; Hines, Dean C. +10 more
We have used the F160W filter (1.4-1.8 µm) and the coronagraph on the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) on the Hubble Space Telescope to survey 45 single stars with a median age of 0.15 Gyr, an average distance of 30 pc, and an average H magnitude of 7 mag. For the median age we were capable of detecting a 30MJ…
The Opacity of Spiral Galaxy Disks. IV. Radial Extinction Profiles from Counts of Distant Galaxies Seen through Foreground Disks
Allen, Ronald J.; Holwerda, B. W.; van der Kruit, P. C. +1 more
Dust extinction can be determined from the number of distant field galaxies seen through a spiral disk. To calibrate this number for the crowding and confusion introduced by the foreground image, González et al. and Holwerda et al. developed the Synthetic Field Method (SFM), which analyzes synthetic fields constructed by adding various deep exposu…
Hubble Space Telescope Imaging of the Primary Shock Front in the Cygnus Loop Supernova Remnant
Blair, William P.; Raymond, John C.; Sankrit, Ravi
We present Hubble Space Telescope WFPC2 narrowband Hα (F656N) and [O III] λ5007 (F502N) imaging of two fields on the northeastern limb of the Cygnus Loop supernova remnant. This region provides an outstanding example of the initial encounter between the primary blast wave and the surrounding interstellar medium. The Hα images show the primary nonr…
New Optical and Near-Infrared Surface Brightness Fluctuation Models. II. Young and Intermediate-Age Stellar Populations
Cantiello, M.; Capaccioli, M.; Brocato, E. +1 more
We present theoretical surface brightness fluctuation (SBF) amplitudes for single-burst stellar populations of young and intermediate age (25 Myr<=t<=5 Gyr) and metallicities Z=0.0003, 0.001, 0.004, 0.008, 0.01, 0.02, and 0.04. The fluctuation magnitudes and colors as expected in the Johnson-Cousins (UBVRIJHK) photometric system are provided…