Search Publications
On the nature of the UV turnup in early-type galaxies.
Alloin, D.; Pastoriza, M. G.; Bonatto, C. +1 more
We study the UV turnup in early-type galaxies from coadded IUE spectra reaching an unprecedented signal to noise ratio. Some spectral groups resulted with strong or moderate UV turnup, while in others it is very weak or absent. We study the relationships of the UV turnup intensity with absolute magnitude, X-ray and Hα luminosities. Galaxies in the…
ISO LWS measurement of the far-infrared spectrum of Saturn.
Ade, P. A. R.; Lellouch, E.; Encrenaz, T. +24 more
The spectrum of Saturn from 43 to 197µm was measured with the ISO Long Wavelength Spectrometer (LWS) during the performance verification phase of the mission. The measurements were made using the LWS in grating mode, with spectral resolutions of 0.29µm from 43 to 90µm and 0.6µm from 90 to 197µm. The spectrum was compa…
The ISO/LWS spectrum of the EGG nebula, AFGL 2688.
Omont, A.; Ade, P. A. R.; Burgdorf, M. +35 more
We present an ISO Long Wavelength Spectrometer (LWS) grating spectrum of the carbon-rich proto-planetary nebula AFGL 2688 between 43 and 194µm. The far-infrared spectrum of AFGL 2688 is dominated by strong rotational transitions of CO which are detected from J=14-13 up to J=23-22. The atomic fine structure lines [O I] and [C II] are not dete…
Coronal radio sounding with Ulysses: dual-frequency phase scintillation spectra in coronal holes and streamers.
Bird, M. K.; Karl, J.; Paetzold, M.
Dual-frequency Doppler measurements of the Ulysses downlink carrier signals were recorded during the spacecraft's 1995 solar conjunction. In this paper we present power spectra derived from phase fluctuations of the radio signals passing through the corona for different solar latitudes. It is possible to (a) distinguish clearly between spectra for…
Analysis of the ISOPHOT FIR maps of M51 and M101.
Lemke, D.; Telesco, C. M.; Kinkel, U. +6 more
The far-IR ISOPHOT maps of the spiral galaxies M51 and M101 at 60, 100, and at 175µm are analysed. For all areas in these galaxies the spectral energy distributions can be fitted with a single-temperature emission curve. Colours and dust temperatures were estimated for interesting sub-fields. The temperatures vary between 33K for HII regions…
A study on the nature of the peculiar supergiant HD 101584.
Waters, L. B. F. M.; Lamers, H. J. G. L. M.; Trams, N. R. +3 more
We present a study of low- and high-resolution ultraviolet, high-resolution optical CAT/CES spectra and ultraviolet, optical and infrared photometry of the peculiar supergiant HD 101584. From the photometry we learn that the ultraviolet and optical energy distribution cannot be fitted in a consistent way and we need a model in which the UV and opt…
Coronal radio sounding with Ulysses: solar wind electron density near 0.1AU during the 1995 conjunction.
Bird, M. K.; Asmar, S. W.; Paetzold, M. +2 more
Dual-frequency ranging measurements were recorded for a three-week interval during the 1995 solar conjunction of the Ulysses spacecraft. The unusual occultation geometry resulting from the high inclination Ulysses orbit enabled coronal radio sounding from the solar South Pole to the heliographic equator at solar ray path offsets near 0.1AU. The el…
ISO observations of hot dust in the nucleus of the S0 galaxy NGC 3998.
Rupen, M. P.; Fich, M.; Knapp, G. R. +2 more
ISOCAM maps of the Seyfert 1 S0 galaxy NGC 3998 between 4.5µm and 15µm detect both extended emission from the bulge stars and strong point source emission from the nucleus. The inner regions of NGC 3998 appear to contain a few thousand solar masses of warm (~200K) dust, probably associated with the AGN.
A damped Lyα candidate at z~0.1 towards Q0439-433.
Petitjean, P.; Smette, A.; Theodore, B. +1 more
We report on the detection of a Z_gal_=0.101 galaxy projected on the sky at 4.2arcsec (or 5.2h^-1^_100_kpc for q_0_=0.5) from the quasar Q 0439-433 (z_em_=0.594). The HST spectrum of the quasar shows strong Mg II, Fe II, Si II, Al II and C IV absorption lines at the same redshift as the galaxy. The equivalent width ratios of the low ionization lin…
Langmuir waves associated with discontinuities in the solar wind: a statistical study.
Tsurutani, B. T.; Kellogg, P. J.; MacDowall, R. J. +2 more
We have reported previously that short bursts of Langmuir waves are frequently observed in the solar wind in isolated local depressions in the magnetic field magnitude, which are called "magnetic holes". The magnetic depression regions are often bounded by directional discontinuities (DDs). To study the relation between the waves and the discontin…