Search Publications
The Chrysalis Opens? Photometry from the η Carinae Hubble Space Telescope Treasury Project, 2002-2006
Davidson, Kris; Martin, J. C.; Koppelman, M. D.
During the past decade η Car has brightened markedly, possibly indicating a change of state. Here we summarize photometry gathered by the Hubble Space Telescope (HST) as part of the HST Treasury Project on this object. Our data include Space Telescope Imaging Spectrograph (STIS) CCD acquisition images, Advanced Camera for Surveys HRC images in fou…
Structural Parameters for Globular Clusters in NGC 5128. II. Hubble Space Telescope ACS Imaging and New Clusters
Forbes, Duncan A.; Barmby, Pauline; Harris, William E. +2 more
We report the first results from an imaging program with the ACS on the Hubble Space Telescope designed to measure the structural characteristics of a wide range of globular clusters in NGC 5128, the nearest giant elliptical galaxy. From 12 ACS WFC fields we have measured a total of 62 previously known globular clusters and have discovered 69 new …
XMM-Newton and Optical Follow-up Observations of SDSS J093249.57+472523.0 and SDSS J102347.67+003841.2
Anderson, Scott F.; Brinkmann, J.; Szkody, Paula +5 more
We report follow-up XMM-Newton and ground-based optical observations of the unusual X-ray binary SDSS J102347.67+003841.2 (=FIRST J102347.6+003841) and a new candidate intermediate polar (IP) found in the Sloan Digital Sky Survey: SDSS J093249.57+472523.0. SDSS J1023 was observed in its low state, with similar magnitude/color (V=17.4 and B=17.9) a…
Image-Subtraction Photometry of Variable Stars in the Globular Clusters NGC 6388 and NGC 6441
Catelan, M.; Stetson, Peter B.; Pritzl, Barton J. +4 more
We have applied Alard's image-subtraction method (ISIS ver. 2.1) to the observations of the globular clusters NGC 6388 and NGC 6441 previously analyzed using standard photometric techniques (DAOPHOT and ALLFRAME). In this reanalysis of observations obtained at the Cerro Tololo Inter-American Observatory, besides recovering the variables previously…
Subarcsecond-Resolution Radio Maps of Nearby Spiral Galaxies
Meier, David S.; Turner, Jean L.; Beck, Sara C. +3 more
We report subarcsecond-resolution Very Large Array imaging of four nearby spiral galaxies: IC 342, Maffei II, NGC 2903, and NGC 6946. In each galaxy, compact radio continuum sources are identified in the central ~15''×15'' region. These compact sources are responsible for 20%-30% of the total emission from the central kilopar…
Light Curves of 20-100 km Kuiper Belt Objects Using the Hubble Space Telescope
Bernstein, Gary M.; Trilling, David E.
We report high-precision photometry of three small and one larger Kuiper Belt objects (KBOs) obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope. The three small bodies are the smallest KBOs for which light-curve measurements are available. The object 2003 BF91 has a diameter of 20 km (assuming 10% albedo) …
OB Stars in the Solar Neighborhood. II. Kinematics
Alfaro, E. J.; Cabrera-Caño, J.; Elias, F.
Using the spatial classification method and the structural parameters estimated for the Gould Belt (GB) and the local Galactic disk (LGD) from a previous paper, we have evaluated spatial membership probabilities for a sample of O and B stars from the Hipparcos catalog (Perryman and coworkers) with available proper motions and radial velocity data.…
Hubble Space Telescope Observations of Star Clusters in M101
Barmby, P.; Kuntz, K. D.; Huchra, J. P. +1 more
Hubble Space Telescope Advanced Camera for Surveys (ACS) images are used to identify and study star cluster candidates in the nearby spiral galaxy M101. About 3000 round, slightly resolved cluster candidates are identified in 10 ACS pointings covering an area of 106 arcmin2. The cluster candidates' color and size distributions are consi…
Photometric Identification of Type Ia Supernovae at Moderate Redshift
Johnson, Benjamin D.; Crotts, Arlin P. S.
Large photometric surveys with the aim of identifying many Type Ia supernovae (SNe) at moderate redshift are challenged in separating these SNe from other SN types. We are motivated to identify Type Ia SNe based only on broadband photometric information, since spectroscopic determination of the SN type, the traditional method, requires significant…
NICMOS2 Hubble Space Telescope Observations of the Embedded Cluster Associated with Mon R2: Constraining the Substellar Initial Mass Function
Dougados, C.; Andersen, M.; Meyer, M. R. +2 more
We have analyzed Hubble Space Telescope NICMOS2 F110W-, F160W-, F165M-, and F207M-band images covering the central 1'×1' region of the cluster associated with Mon R2 in order to constrain the initial mass function (IMF) down to 20MJ. The flux ratio between the F165M and F160W bands was used to measure the strength …