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The obscured mid-infrared continuum of NGC 4418: A dust- and ice-enshrouded AGN
Lutz, D.; Tielens, A. G. G. M.; Moorwood, A. F. M. +2 more
We report the detection of absorption features in the 6-8 mu m region superimposed on a featureless mid-infrared continuum in NGC 4418. For several of these features this is the first detection in an external galaxy. We compare the absorption spectrum of NGC 4418 to that of embedded massive protostars and the Galactic centre, and attribute the abs…
ISO LWS observations of planetary nebula fine-structure lines
Barlow, M. J.; Cohen, M.; Liu, X. -W. +7 more
We have obtained 43-198µm far-infrared (IR) spectra for a sample of 51 Galactic planetary nebulae (PN) and protoplanetary nebulae (PPN), using the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). Spectra were also obtained of the former PN candidate Lo 14. The spectra yield fluxes for the fine-structure lines…
Gas-grain chemical models of star-forming molecular clouds as constrained by ISO and SWAS observations
Ehrenfreund, P.; Charnley, S. B.; Rodgers, S. D.
We have investigated the gaseous and solid state molecular composition of dense interstellar material that periodically experiences processing in the shock waves associated with ongoing star formation. Our motivation is to confront these models with the stringent abundance constraints on CO2, H2O and O2, in both ga…
The New Solar Corona
Aschwanden, Markus J.; Rabin, Douglas M.; Poland, Arthur I.
We focus on new observational capabilities (Yohkoh, SoHO, TRACE), observations, modeling approaches, and insights into physical processes of the solar corona. The most impressive new results and problems discussed in this article can be appreciated from the movies available on the Annual Reviews website and at http://www.lmsal.com/pub/araa/araa.ht…
The Proper Motion, Parallax, and Origin of the Isolated Neutron Star RX J185635-3754
Walter, Frederick M.
The isolated neutron star RX J185635-3754 is the closest known neutron star to the Sun. Based on Hubble Space Telescope Wide Field Planetary Camera 2 observations over a 3 yr baseline, I report its proper motion (332+/-1 mas yr-1 at a position angle of 100.3d+/-0.1d) and parallax (16.5+/-2.3 mas, 61 pc). This proper motion brings the ne…
On-the-Disk Development of the Halo Coronal Mass Ejection on 1998 May 2
Thompson, B. J.; Pick, M.; Maia, D. +7 more
A halo coronal mass ejection (CME) was observed at 15:03 UT on 1998 May 2 by the Solar and Heliospheric Observatory Large-Angle Spectrometric Coronagraph. The observation of the CME was preceded by a major soft X-ray flare in NOAA Active Region 8210, characterized by a delta spot magnetic configuration and some activity in region 8214. A large tra…
The NGC 4839 group falling into the Coma cluster observed by XMM-Newton
Aghanim, N.; Arnaud, M.; Molendi, S. +7 more
We present here the first analysis of the XMM-Newton EPIC-MOS data of the galaxy group around
Cepheid Calibration of the Peak Brightness of Type Ia Supernovae. XI. SN 1998aq in NGC 3982
Panagia, N.; Saha, A.; Macchetto, F. D. +4 more
Repeated imaging observations have been made of NGC 3982 with the Hubble Space Telescope between 2000 March and May, over an interval of 53 days. Images were obtained on 12 epochs in the F555W band and on five epochs in the F814W band. The galaxy hosted the Type Ia supernova (SN Ia) SN 1998aq. A total of 26 Cepheid candidates were identified, with…
The M 31 double nucleus probed with OASIS. A natural vec m = 1 mode?
Combes, F.; Copin, Y.; Emsellem, E. +3 more
We present observations with the adaptive optics assisted integral field spectrograph OASIS of the M 31 double nucleus in the spectral domain around the Calcium triplet at a spatial resolution better than 0farcs5 FWHM. These data are used to derive the two-dimensional stellar kinematics within the central 2 arcsec. Archival WFPC2/HST images in the…
The ISO-SWS spectrum of planetary nebula NGC 7027
Pottasch, S. R.; Beintema, D. A.; Bernard Salas, J. +1 more
We present the infrared spectrum of the planetary nebula