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A hyperluminous galaxy at z=2.8 found in a deep submillimetre survey
Kneib, J. -P.; Ivison, R. J.; Smail, Ian +5 more
We present a detailed study of SMM02399-0136, a hyperluminous, active galaxy selected from a submm survey of the distant Universe. This galaxy is the brightest source in the fields of six rich, lensing clusters, with a total area of 0.01deg^2, that we have mapped with a sensitivity of ~2mJybeam^-1 at 850mum. We identify a compact optical counterpa…
Distance to M31 with the Hubble Space Telescope and HIPPARCOS Red Clump Stars
Garnavich, P. M.; Stanek, K. Z.
Following the approach by Paczyński & Stanek, we compare the red clump stars with parallaxes known to better than 10% in the Hipparcos catalog with the red clump stars observed in three fields in M31 using the Hubble Space Telescope. There are ~600 and ~6300 such stars in the two data sets, respectively. The local red clump luminosity function…
The Definitive Abundance of Interstellar Oxygen
Meyer, David M.; Jura, M.; Cardelli, Jason A.
Using the Goddard High Resolution Spectrograph (GHRS) onboard the Hubble Space Telescope, we have obtained high signal-to-noise (S/N) ratio echelle observations of the weak interstellar O I λ1356 absorption toward the stars γ Cas, ɛ Per, δ Ori, ɛ Ori, 15 Mon, τ CMa, and γ Ara. In combination with previous GHRS measurements in six other sight lines…
Infrared Observations of Nebular Emission Lines from Galaxies at Z ~= 3
Dickinson, Mark; Giavalisco, Mauro; Pettini, Max +3 more
We present the first results from a program of near-infrared spectroscopy aimed at studying the familiar rest-frame optical emission lines from the H II regions of Lyman break galaxies at z ~= 3. By targeting redshifts that bring the lines of interest into gaps between the strong OH sky emission, we have been successful in detecting Balmer and [O …
The Distribution of Nearby Stars in Velocity Space Inferred from HIPPARCOS Data
Dehnen, Walter
The velocity distribution f(v) of nearby stars is estimated, via a maximum likelihood algorithm, from the positions and tangential velocities of a kinematically unbiased sample of 14,369 stars observed by the Hipparcos satellite. The distribution f shows rich structure in the radial and azimuthal motions, v_R and v_phi, but not in the vertical vel…
The Sun's total irradiance: Cycles, trends and related climate change uncertainties since 1976
Fröhlich, Claus; Lean, Judith
A composite record of the Sun's total irradiance compiled from measurements made by five independent space-based radiometers since 1978 exhibits a prominent 11-year cycle with similar levels during 1986 and 1996, the two most recent minimum epochs of solar activity. This finding contradicts recent assertions of a 0.04% irradiance increase from the…
New models of Jupiter's magnetic field constrained by the Io flux tube footprint
Connerney, J. E. P.; Satoh, T.; Acuña, M. H. +1 more
Spherical harmonic models of the planetary magnetic field of Jupiter are obtained from in situ magnetic field measurements and remote observations of the position of the foot of the Io flux tube in Jupiter's ionosphere. The Io flux tube (IFT) footprint locates the ionospheric footprint of field lines traced from Io's orbital radial distance in the…
Detailed Mass Map of CL 0024+1654 from Strong Lensing
Tyson, J. Anthony; Kochanski, Greg P.; Dell'Antonio, Ian P.
We construct a high-resolution mass map of the z=0.39 cluster 0024+1654, based on a parametric inversion of the associated gravitational lens. The lens creates eight well-resolved subimages of a background galaxy, seen in deep imaging with the Hubble Space Telescope.1 Excluding mass concentrations centered on visible galaxies, more than 98% of the…
Steps toward interstellar silicate mineralogy. IV. The crystalline revolution
Waters, L. B. F. M.; Mutschke, H.; Henning, Th. +3 more
Mid- and far-infrared spectra gained by the Short Wavelength Spectrometer (SWS) of the Infrared Space Observatory (ISO) satellite have provided striking evidence for the presence of crystalline silicates in comets, circumstellar envelopes around young stars and, most of all, evolved stars and planetary nebulae. Since optical properties of astrophy…
The Age of Globular Clusters in Light of Hipparcos: Resolving the Age Problem?
Chaboyer, Brian; Demarque, P.; Kernan, Peter J. +1 more
We review five independent techniques that are used to set the distance scale to globular clusters, including subdwarf main-sequence fitting utilizing the recent Hipparcos parallax catalog. These data together all indicate that globular clusters are farther away than previously believed, implying a reduction in age estimates. We now adopt a best-f…