Search Publications
H_2_ infrared line emission from S 140: a warm PDR.
Draine, B. T.; Bertoldi, F.; Sternberg, A. +4 more
ISO SWS spectra of H_2_ pure rotational and ro-vibrational transitions, as well as [FeII], and [SiII] fine structure lines were obtained for one position on the photodissociation region (PDR) adjacent to the bright rim of the S 140 HII region. The gas density is =~10^4^cm^-3^ and the incident UV flux χ=~400 at the location of the ionization front.…
ISO-SWS spectrophotometry of galactic Wolf-Rayet stars: preliminary results.
Beintema, D. A.; de Graauw, T.; Morris, P. W. +12 more
ISO-SWS spectra of seven late-type galactic Wolf-Rayet stars are discussed. A high resolution spectrum (2.3-29.6µm, λ/{DELTA}λ=~820-1700) of the WC8 star WR11 (γ^2^ Vel) is shown and its Ne abundance is discussed. Medium resolution spectra (λ/{DELTA}λ=~250-600) of the WC8-9 stars WR48a, WR98a, WR104, WR112 and WR118 show the broad circumstel…
The infrared spectrum of comet C/1995 O1 (Hale-Bopp) at 4.6 AU from the Sun.
Altieri, B.; Jorda, L.; Lamy, P. L. +7 more
Comet C/1995 O1 (Hale-Bopp) was observed on 27 April 1996 with the ISOPHOT instrument of ISO when it was at 4.6 AU from the Sun. The 2.5-12µm spectrum was recorded at low resolution. We present here the preliminary results of this observation. The 2.5-5µm spectrum shows emission in the CO_2_ ν_3_ band. The CO_2_ production rate is abou…
Discovery of four white dwarfs with strong magnetic fields by the Hamburg/ESO Survey.
Reimers, D.; Jordan, S.; Bade, N. +3 more
Four magnetic white dwarfs have been found in the course of the Hamburg/ESO Survey for bright QSOs. The objects have been selected as QSO candidate on the basis of its blue continuum and the apparent absence of strong hydrogen or helium lines. One star, HE1211-1707, shows a rather fast spectral variability: both the strength and the position of th…
SWS spectroscopy of the colliding galaxies NGC4038/39.
Lutz, D.; Genzel, R.; Sturm, E. +8 more
We present mid-infrared spectroscopy of the prototypical interacting galaxies NGC 4038/39 (the `Antennae') obtained with the ISO Short Wavelength Spectrometer (SWS). Our observations focus on the interaction zone where the two galaxies overlap, providing new constraints on the properties of the young and vigorous extranuclear starburst triggered b…
Secular variations in the Z source CygnusX-2.
van der Klis, M.; Kuulkers, E.; Vaughan, B. A.
We analyzed the X-ray spectral variations of the low-mass X-ray binary CygX-2 on time scales longer than one day using EXOSAT data. We describe these variations in terms of the shifts and shape changes of the "Z" pattern in X-ray colour-colour and hardness-intensity diagrams. CygX-2 varies between three intensity "levels": "high", "medium" and "lo…
The ISO-SWS spectrum of NML Cyg.
Waters, L. B. F. M.; Beintema, D. A.; Izumiura, H. +9 more
The high resolution spectrum of NML Cyg observed with the ISO-SWS in its slow-speed grating mode (2.4-45µm) shows a wealth of features never seen before in previous observations. These include ro-vibrational lines of H_2_O at 2.7 and 6.2µm, of OH between 3 and 3.5µm and a deep absorption band of CO_2_ at 4.26µm. We also rep…
The Sombrero galaxy. II. Colours, kinematics and line strengths of the central region.
Emsellem, E.; Bacon, R.; Monnet, G. +1 more
We present photometric (pre-COSTAR HST and ground-based) and new two-dimensional TIGER spectrographic data of the central region of the Sombrero galaxy (NGC 4594, M 104). This gives B-V and V-R_C_ images, as well as 2D line strengths and kinematical maps (LOSVDs). Analysis of these data lets us draw a clearer picture of the morphology of the Sombr…
The mass distribution of CL0939+4713 obtained from a `weak' lensing analysis of a WFPC2 image.
Kneib, J. -P.; Schneider, P.; Seitz, S. +1 more
The image distortions of high-redshift galaxies caused by gravitational light deflection of foreground clusters of galaxies can be used to reconstruct the two-dimensional surface mass density of these clusters. We apply an unbiased parameter-free reconstruction technique to the cluster CL0939+4713 (Abell 851), observed with the WFPC2 on board of t…
The ISO LWS grating spectrum of NGC 7027.
Walker, H. J.; Omont, A.; Ade, P. A. R. +39 more
We present a high signal-to-noise ISO Long Wavelength Spectrometer (LWS) grating spectrum of the planetary nebula NGC 7027 from 43-194µm. In total 40 emission lines have been detected, with 30 identified. From the ionized region, we observe fine-structure lines from [N II], [N III] and [O III]. The [O I] and [C II] fine-structure lines from …