Search Publications
Discovery of an Optical Synchrotron Jet in 3C 15
Baum, Stefi A.; McCarthy, Patrick J.; Sparks, William B. +6 more
We report the discovery of a new optical synchrotron jet in the radio galaxy 3C 15. This brings to nine the number of known optical synchrotron jets in nearby radio galaxies. The jet is well resolved in both length and width and extends to a projected metric distance of ~5 kpc from the galaxy nucleus. The host galaxy shows complex inner structure,…
Unveiling the Hidden Nucleus of IC 5063 with NICMOS
Colina, L.; Calzetti, D.; Axon, D. +16 more
We present high-resolution near-infrared images of the Seyfert 2 galaxy IC 5063 obtained using the Near-Infrared Camera and Multiobject Spectrometer (NICMOS) in broadband filters at 1.1, 1.6, and 2.2 µm (FWHM ~ 0.21" at 2.2 µm). The images show a very red, unresolved point source at the center of the galaxy, confirming the existence of…
Molecular Gas in the Inner 100 Parsecs of M51
Yun, M. S.; Armus, L.; Scoville, N. Z. +1 more
We report imaging of CO (2-1) emission in the nucleus of M51 at 1'' (47 pc) resolution. Molecular gas is found closely associated with the nuclear radio jet and the X-shaped dust absorption feature seen in the Hubble Space Telescope images. The CO emission lies along the side of the nuclear radio continuum ``jet.'' The strongest molecul…
The Height Structure of the Solar Atmosphere from the Extreme-Ultraviolet Perspective
Kundu, M. R.; White, S. M.; Zhang, Jie
We investigate the structure of the solar chromosphere and transition region using full Sun images obtained with the Extreme-Ultraviolet Imaging Telescope (EIT) aboard the Solar and Heliospheric Observatory spacecraft. The limb seen in the EIT coronal images (taken in lines of Fe IX/X at 171 Å, Fe XII at 195 Å, and Fe XV at 284 Å) is an absorption…
The Hubble Space Telescope Extragalactic Distance Scale Key Project. IX. The Discovery of Cepheids in NGC 2090
Illingworth, Garth D.; Huchra, John P.; Kennicutt, Robert C. +15 more
We report on the discovery of 34 Cepheid variables in NGC 2090, with periods ranging between 5 and 58 days. Apparent V and I period-luminosity relations for Cepheids with P >= 10 days have been constructed, assuming a fiducial distance modulus, µ0, of 18.50 +/- 0.10 mag and a reddening, E(B-V), of 0.10 mag for the Large Magella…
High-Resolution Mid-Infrared Imaging of the Nucleus of NGC 1068
Bock, J. J.; Marsh, K. A.; Ressler, M. E. +1 more
We have obtained mid-infrared images of the nucleus of NGC 1068 from the Hale 5 m telescope at Mount Palomar with diffraction-limited resolution and high sensitivity at λ=8.8, 10.3, and 12.5 µm. Deconvolved images show that the infrared emission extends north to south in the inner 2", consisting of a central peak, a component extending 1" no…
Absolute Vacuum Ultraviolet Oscillator Strengths in CO II and the Interstellar Cobalt Abundance
Federman, S. R.; Lawler, J. E.; Mullman, K. L. +1 more
We report the first laboratory measurements of 10 absolute oscillator strengths (f-values) for vacuum ultraviolet lines of Co II. The oscillator strengths are measured with the High-Sensitivity Absorption Spectroscopy Experiment at the University of Wisconsin. The measurements serve as a test of theoretical work on Co II f-values and set an absolu…
Hubble Space Telescope Observations of NGC 121: First Detection of Blue Stragglers in an Extragalactic Globular Cluster
Fall, S. Michael; Rich, R. Michael; Shara, Michael M. +1 more
We have resolved stars in the core of the old SMC globular cluster NGC 121 with images from the refurbished Hubble Space Telescope and Wide Field Planetary Camera 2. Our photometry reaches 1.5 mag below the main-sequence turnoff, with negligible field contamination. A blue straggler star (BSS) sequence of 42 candidates is clearly seen--the first s…
High-Metallicity Mg II Absorbers in the z < 1 Lyα Forest of PKS 0454+039: Giant Low Surface Brightness Galaxies?
Churchill, Christopher W.; Le Brun, Vincent
We report the discovery of two iron-group enhanced high-metallicity Mg II absorbers in a search through 28 Lyα forest clouds along the PKS 0454+039 sight line. Based upon our survey and the measured redshift number densities of Wr(Mg II) <= 0.3 Å absorbers and Lyα absorbers at z ~ 1, we suggest that roughly 5% of Lyα absorbers at z &…
Latitudinal Variation of Solar Subsurface Rotation Inferred from p-Mode Frequency Splittings Measured with SOI-MDI and GONG
Kosovichev, A. G.; Birch, A. C.
Analysis of p-mode frequency splittings as measured by the Solar Oscillations Investigation-Michelson Doppler Imager (SOI-MDI) on board the Solar and Heliospheric Observatory and the ground-based Global Oscillations Network Group (GONG) experiment reveal that the symmetric component of the solar rotation rate in the upper 4% by radius and closer t…