Search Publications
Nuclear Properties of Nearby Spiral Galaxies from Hubble Space Telescope NICMOS Imaging and STIS Spectroscopy
Marconi, A.; Capetti, A.; Carollo, C. M. +16 more
We investigate the central regions of 23 spiral galaxies using Space Telescope Imaging Spectrograph (STIS) spectroscopy and archival Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) imaging. The sample is taken from our program to determine the masses of central massive black holes (MBHs) in 54 nearby spiral galaxies. Stars are likely t…
Midcourse Space Experiment Observations of Small Solar System Bodies
Lisse, C. M.; Mäkinen, T.; Walker, R. G. +4 more
Eight comets, two transition objects (extinct comet candidates), and two near-Earth asteroids were imaged in four infrared bands with the SPIRIT III instrument on the Midcourse Space Experiment, namely, C/1996 B2 (Hyakutake), C/1995 O1 (Hale-Bopp), C/1996 Q1 (Tabur), 126P/IRAS, 22P/Kopff, 46P/Wirtanen, (3200) Phaethon, (4015) 107P/Wilson-Harringto…
HD 166181 = V815 Herculis, a Single-lined Spectroscopic Multiple System
Pourbaix, D.; Fekel, Francis C.; Scarfe, C. D. +2 more
We have obtained extensive spectroscopic and velocity spectrometer observations of HD 166181, a previously known single-lined spectroscopic binary. Our improved orbit for the G6 V primary has a period of 1.8098343 days and is circular. Although the lines of additional components have not been detected, radial velocity measurements confirm that the…
Resolving the Shocks in Radio Galaxy Nebulae: Hubble Space Telescope and Radio Imaging of 3C 171, 3C 277.3, and PKS 2250-41
Koekemoer, Anton M.; Baum, Stefi A.; O'Dea, Christopher P. +5 more
We present the results of Hubble Space Telescope (HST) WFPC2 medium-band and narrowband imaging and Very Large Array and MERLIN2 radio imaging of three powerful radio galaxies: 3C 171, 3C 277.3, and PKS 2250-41. We obtained images of the rest frame [O III] λ5007 and [O II] λ3727 line emission using the linear ramp filters on WFPC2. The correlation…
Polarization Measurements of Post-Asymptotic Giant Branch Candidates and Related Stars
Parthasarathy, M.; Jain, S. K.; Sarkar, G.
We have obtained UBVRI polarization measurements of 26 post-asymptotic giant branch (post-AGB) candidates and related stars. The extremely metal-poor post-AGB star HR 4049 has been observed several times. In most cases we find the objects to be intrinsically polarized. The polarization measurements presented in this paper indicate asymmetric circu…
On the Ga II and Ga III Resonance Lines and the Implication for Chemical Stratification in HgMn Stars
Nielsen, K. E.; Leckrone, D. S.; Wahlgren, G. M. +2 more
The gallium abundance in HgMn stars has been reported to be different for analyses conducted from spectral lines in the optical versus those from the ultraviolet. We pursue this ultraviolet-optical discrepancy from a line-blending perspective by investigating the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) spectrum of …
Escape of Lyα Emission in the Starburst Galaxy Markarian 357: a Wind's Far Side
Keel, William C.
Hubble Space Telescope imaging and slitless spectroscopy are used to examine where the strong Lyα emission escapes from the interstellar medium in the starburst galaxy Mrk 357. An Hα image shows that the ionized gas is mostly in a global wind, rather than associated with the individual star-forming regions seen in the optical and UV continuum. The…
Erupting Cataclysmic Variable Stars in the Nearest Globular Cluster, NGC 6397: Intermediate Polars?
Zurek, David R.; Knigge, C.; Hinkley, Sasha +2 more
NGC 6397 is the closest globular cluster and hence the ideal place to search for faint stellar populations such as cataclysmic variables (CVs). Hubble Space Telescope (HST) and Chandra observers have identified nine certain and likely CVs in this nearby cluster, including several magnetic CV candidates. We have combined our recent UV imagery with …
Far-Infrared and Millimeter Continuum Studies of K Giants: α Bootis and α Tauri
McMurry, A. D.; Lim, Tanya; Schulz, Bernhard +5 more
We have imaged two normal, noncoronal, infrared-bright K giants, α Tau and α Boo, in the 1.4 and 2.8 mm continua using BIMA. These stars have been used as important absolute calibrators for several infrared satellites. Our goals are (1) to establish whether these stars radiate as simple photospheres or possess long-wavelength chromospheres and (2)…
Dust Morphology and Composition in FU Orionis Systems
Woodward, Charles E.; Russell, Ray W.; Telesco, C. M. +7 more
FU Orionis stars are a small group of pre-main-sequence stars known for large-amplitude optical variability. These objects also exhibit multiwavelength phenomena suggestive of active accretion from a circumstellar disk. We present high spatial resolution mid-IR imaging and spectroscopy, submillimeter photometry, and 3-4 µm photometry of four…