Search Publications
NGC 1614: A Laboratory for Starburst Evolution
Rieke, G. H.; Alonso-Herrero, A.; Quillen, A. C. +2 more
The modest extinction and reasonably face-on viewing geometry make the luminous infrared galaxy NGC 1614 an ideal laboratory for the study of a powerful starburst. Hubble Space Telescope/near-infrared camera and multiobject spectrometer (NICMOS) observations show (1) deep CO stellar absorption, tracing a starburst nucleus about 45 pc in diameter (…
Hubble Space Telescope Proper-Motion Measurements of the η Carinae Nebula
Davidson, Kris; Bally, John; Balick, Bruce +3 more
We present proper-motion measurements of the bipolar lobes and equatorial disk features ejected from η Carinae during the last century and deduce their relative ages in order to determine the likelihood of multiple ejection events. Hubble Space Telescope Wide Field Planetary Camera 2 images taken in 1994, 1995, and 1999 were compared, and the moti…
NICMOS Observations of Extragalactic Cepheids. I. Photometry Database and a Test of the Standard Extinction Law
Calzetti, D.; Stetson, P. B.; Persson, S. E. +8 more
We present the results of near-infrared observations of extragalactic Cepheids made with the Near-Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope (HST). The variables are located in the galaxies IC 1613, IC 4182, M31, M81, M101, NGC 925, NGC 1365, NGC 2090, NGC 3198, NGC 3621, NGC 4496A, and NGC 4536. All fields w…
Discovery of Extended X-Ray Emission from the Planetary Nebula NGC 7027 by the Chandra X-Ray Observatory
Soker, Noam; Kastner, Joel H.; Vrtilek, Saeqa D.
We report the discovery of X-ray emission from NGC 7027, a prototypical object for the study of the formation and evolution of planetary nebulae. Observations with the Advanced CCD Imaging Spectrometer (ACIS) aboard the Chandra X-Ray Observatory show that the X-ray emission from NGC 7027 is extended and is bipolar in morphology. The ACIS spectrum …
M Dwarfs from Hubble Space Telescope Star Counts. IV.
Gould, Andrew; Salim, Samir; Bahcall, John N. +2 more
We study a sample of about 1400 disk M dwarfs that are found in 148 fields observed with the Wide Field Camera 2 (WFC2) on the Hubble Space Telescope and 162 fields observed with pre-repair Planetary Camera 1 (PC1), of which 95 of the WFC2 fields are newly analyzed. The method of maximum likelihood is applied to derive the luminosity function and …
Modeling the Interstellar Medium of Low Surface Brightness Galaxies: Constraining Internal Extinction, Disk Color Gradients, and Intrinsic Rotation Curve Shapes
Wood, Kenneth; Matthews, L. D.
We use a combination of three-dimensional Monte Carlo radiative transfer techniques and multiwavelength (BRHK, Hα) imaging data to investigate the nature of the interstellar medium (ISM) in the edge-on, low surface brightness (LSB) galaxy UGC 7321. Using realistic models that incorporate multiple scattering effects and clumping of the stars and th…
Near-Infrared Imaging and [O I] Spectroscopy of IC 443 using Two Micron All Sky Survey and Infrared Space Observatory
Reach, W. T.; Rho, Jeonghee; Jarrett, T. H. +1 more
We present near-infrared J (1.25 µm), H (1.65 µm), and Ks (2.17 µm) imaging of the entire supernova remnant IC 443 from the Two Micron All Sky Survey (2MASS), and Infrared Space Observatory (ISO) LWS observations of [O I] for 11 positions in the northeast. Near-infrared emission from IC 443 was detected in all three ba…
Structural Properties of Massive Young Clusters
Maíz-Apellániz, Jesús
We have retrieved multicolor WFPC2/Hubble Space Telescope data from the STScI archive for 27 nearby massive (>~3×104 Msolar) young (<20 Myr) star clusters (MYCs). The data represents the most complete sample of clearly resolved MYCs to date. We have analyzed their structural properties and have found that they can be cl…
Solid Carbon Dioxide in Regions of Low-Mass Star Formation
Whittet, D. C. B.; Gerakines, P. A.; Gibb, E. L. +2 more
We present high-resolution (R~1500-2000) spectra of the 4.27 µm asymmetric stretching feature of solid CO2 in eight lines of sight observed with the Short Wavelength Spectrometer of the Infrared Space Observatory. Two of the sources are field stars located behind the Taurus molecular cloud; the others are young stellar objects (YS…
Molecular Gas and the Modest Star Formation Efficiency in the ``Antennae'' Galaxies: Arp 244=NGC 4038/9
Gao, Yu; Lo, K. Y.; Lee, T. -H. +1 more
We report here a factor of 5.7 higher total CO flux in Arp 244 (the ``Antennae'' galaxies) than that previously accepted in the literature (thus a total molecular gas mass of 1.5×1010 Msolar), based on our fully sampled CO(1-0) observations at the NRAO 12 m telescope. Currently, much of the understanding and modeling of the s…