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ISO LWS Spectroscopy of M82: A Unified Evolutionary Model
Smith, Howard A.; Satyapal, Shobita; Spinoglio, Luigi +9 more
We present the first complete far-infrared spectrum (43-197 µm) of M82, the brightest infrared galaxy in the sky, taken with the Long Wavelength Spectrometer of the Infrared Space Observatory (ISO). We detected seven fine structure emission lines, [O I] 63 and 145 µm, [O III] 52 and 88 µm , [N II] 122 µm, [N III] 57 µ…
The ionizing cluster of 30 Doradus. III. Star-formation history and initial mass function
Terlevich, R.; Bosch, G.; Selman, F. +1 more
A new method is presented and used to determine the IMF of the starburst cluster NGC2070. A new correction, the magnitude-limit correction is introduced, and shown to be crucial when attempting to derive the IMF in the presence of variable reddening when the photometry is not several magnitudes deeper than the fainter stars analyzed. Failure to ap…
A barred spiral at the centre of the giant elliptical radio galaxy Centaurus A
Sanders, D. B.; Cesarsky, C.; Sauvage, M. +7 more
We report observations at mid-infrared and sub-millimeter wavelengths of Centaurus A (Cen A, NGC 5128), the giant elliptical galaxy that harbors the closest radio loud Active Galactic Nucleus (AGN) to Earth. The dust emission from the deep interior of Cen A reveals a bisymmetric structure with a diameter of 5(') (5 kpc), centred at the AGN. This s…
Dynamical models of NGC 3115
Bacon, Roland; Emsellem, Eric; Dejonghe, Herwig
We present new dynamical models of the S0 galaxy N3115, making use of the available published photometry and kinematics as well as two-dimensional TIGER spectrography. The models are based on a detailed model of the luminosity distribution built using an MGE fit on HST/WFPC2 and ground-based photometric data. We first examined the kinematics in th…
Heliospheric magnetic field polarity inversions at high heliographic latitudes
Balogh, A.; Horbury, T. S.; Lucek, E. A. +2 more
The heliospheric magnetic field over the poles of the sun has been examined to identify intervals when the polarity of the magnetic field deviates significantly from the calculated Parker spiral, using Ulysses observations in 1994 and 1995, near solar minimum. Intervals with deviation > 90° have been identified, corresponding to magnetic field …
High-Redshift Supernovae in the Hubble Deep Field
Phillips, M. M.; Gilliland, Ronald L.; Nugent, Peter E.
Two supernovae detected in the Hubble Deep Field (HDF) using the original 1995 December epoch and data from a shorter (63,000 s in F814W) 1997 December visit with HST are discussed. The supernovae (SNe) are both associated with distinct galaxies at redshifts of 0.95 (spectroscopic) from Cohen et al. and 1.32 (photometric) from the work of Fernánde…
HST images and properties of the most distant radio galaxies
Pentericci, L.; Macchetto, F.; Spinrad, H. +4 more
With the Hubble Space Telescope we have obtained images of 9 of the most distant radio galaxies. The galaxies, which have redshifts between z=2.3 and z=3.6, were observed with the WFPC2 camera in a broad band filter (F606W or F707W, roughly equivalent to V or R-band), corresponding to the near ultraviolet emission in the rest frame of the radio ga…
The NE BT VIII (lambda 770) resonance line: solar wavelengths determined by SUMER on SOHO
Wilhelm, K.; Curdt, W.; Dammasch, I. E. +1 more
The investigation of the source and acceleration of the solar wind was among the prime scientific goals of SOHO - ESA's and NASA's Solar and Heliospheric Observatory. For the coronal regions closest to the Sun, the bright extreme ultraviolet (EUV) resonance lines of the Ne viii spectrum at 770 { Angstroms} and 780 { Angstroms} with a formation tem…
Newly Synthesized Elements and Pristine Dust in the Cassiopeia A Supernova Remnant
Dwek, E.; Arendt, R. G.; Moseley, S. H.
Spectroscopic observations at 2.4-45 µm of the young supernova remnant Cas A with the Infrared Space Observatory (ISO) Short Wavelength Spectrometer reveal strong emission lines of O, Ne, Si, S, and Ar. These lines are observed at high velocities (several 103 km s-1) and are therefore associated with the supernova eject…
Morphology of the Quiet Solar Upper Atmosphere in the 4×104<Te<1.4×106 K Temperature Regime
Warren, H. P.; Feldman, U.; Widing, K. G.
Studies on the morphology of the solar upper atmosphere began over three decades ago. Early models assumed that the temperature structure of the solar upper atmosphere was continuous with a thin transition region connecting the chromosphere with the corona. Over the years it became apparent that the original depiction of the solar upper atmosphere…