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Imaging of the protoelliptical NGC 1700 and its globular cluster system
Forbes, Duncan A.; Brodie, Jean P.; Kissler-Patig, Markus +1 more
An excellent candidate for a young elliptical, or `protoelliptical' galaxy is NGC 1700. Here we present new B-, V- and I-band imaging using the Keck telescope, and reanalyse existing V- and I-band images from the Hubble Space Telescope. After subtracting a model of the galaxy from the Keck images, NGC 1700 reveals two symmetric tidal tail-like str…
Radiometric Validation of the Midcourse Space Experiment's (MSX) Point Source Catalogs and the MSX Properties of Normal Stars
Cohen, Martin; Hammersley, Peter L.; Egan, Michael P.
We describe our methods to validate the absolute calibration of the infrared (IR) radiometry of the Midcourse Space Experiment (MSX) Point Source Catalog, version 1.2 (PSC1.2). These are based upon stars drawn from our current all-sky network of absolute calibrators and upon other stars that also support the calibration of ESA's Infrared Space Obs…
Hubble Space Telescope Observations of the Wolf-Rayet Nebula NGC 6888
Hester, J. Jeff; Scowen, Paul A.; Moore, Brian D.
We present Hubble Space Telescope Wide Field Planetary Camera 2 images of a portion of the bright northeast rim of NGC 6888, the nebular shell physically associated with the Wolf-Rayet star HD 192163. The exposures are taken in the light of Hα λ6563, [O III] λ5007, and [S II] λλ6717, 6731. The images are used to constrain models of the ionization …
Far infrared extragalactic background radiation --- I. Source counts with ISOPHOT
Juvela, M.; Lemke, D.; Mattila, K.
As a part of the ISOPHOT CIRB (Cosmic Infrared Background Radiation) project we have searched for point-like sources in eight fields mapped at two or three wavelengths between 90 µm and 180 µm. Most of the 55 sources detected are suspected to be extragalactic and cannot be associated with previously known objects. It is probable, also …
Hubble Space Telescope Observations of the Interacting Galaxies NGC 2207 and IC 2163
Bond, Howard E.; Brinks, Elias; Struck, Curtis +11 more
Hubble Space Telescope (HST) images of the galaxies NGC 2207 and IC 2163 show star formation and dust structures in a system that has experienced a recent grazing encounter. Tidal forces from NGC 2207 compressed and elongated the disk of IC 2163, forming an oval ridge of star formation along a caustic where the perturbed gas rebounded after its in…
The Globular Cluster Systems in the Coma Ellipticals. II. Metallicity Distribution and Radial Structure in NGC 4874 and Implications for Galaxy Formation
Kavelaars, J. J.; Harris, William E.; Hesser, James E. +2 more
Deep Hubble Space Telescope WFPC2 images in V and I are used to investigate the globular cluster system (GCS) in NGC 4874, the central cD galaxy of the Coma cluster. Although the luminosity function of the clusters displays its normal Gaussian-like shape and turnover level, other features of the system are surprising. We find the GCS to be (a) spa…
The Temperature and Cooling Age of the White Dwarf Companion to the Millisecond Pulsar PSR B1855+09
Kulkarni, S. R.; van Kerkwijk, M. H.; Kaspi, V. M. +1 more
We report on Keck and Hubble Space Telescope observations of the binary millisecond pulsar PSR B1855+09. We detect its white dwarf companion and measure mF555W=25.90+/-0.12 and mF814W=24.19+/-0.11 (Vega system). From the reddening-corrected color, (mF555W-mF814W)0=1.06+/-0.21, we infer a tempe…
Acoustic Imaging of Solar Active Regions - (Invited Review)
Chou, Dean-Yi
Acoustic imaging is a new method to construct the acoustic signal at a point on the solar surface or in the solar interior with the signals measured at the solar surface. The constructed signals contain both intensity information and phase information. The intensity is computed by summing the squared amplitude of the constructed signal over time. …
Hubble Space Telescope Imaging Spectrograph Observations of the Hot White Dwarf in the Close Binary Feige 24
Vennes, Stéphane; Thorstensen, John R.; Polomski, Elisha F. +3 more
We obtained and analyzed two Hubble Space Telescope Imaging Spectrograph spectra of the white dwarf in the DA plus dMe binary Feige 24. The spectra, obtained at orbital quadratures, provide new estimates of the white dwarf motion and gravitational redshift resulting in revised white dwarf parameters. An analysis of interstellar absorption lines re…
An infrared study of the L1551 star formation region
Liseau, R.; White, G. J.; Ceccarelli, C. +14 more
Spectroscopic observations using the Infrared Space Observatory are reported towards the two well known infrared sources and young stellar objects L1551 IRS 5 and L1551 NE, and at a number of locations in the molecular outflow. The ISO spectrum contains several weak gas-phase lines of O I, C II, [Fe II] and [Si II], along with solid state absorpti…