Search Publications
Recent results on the parameters of the interstellar helium from the ULYSSES/GAS experiment
Rosenbauer, H.; Witte, M.; Banaszkiewicz, M.
Velocity and direction of the flow of the interstellar helium and its temperature and density have been determined from the measurements of the ULYSSES/GAS experiment for two different epochs: during the in-ecliptic path of ULYSSES, representing solar maximum conditions, and during the south to the north pole transition (11/94-6/95), close to the …
SWS spectroscopy of small grain features across the M17-Southwest photodissociation front.
Falgarone, E.; Wright, C. M.; Drapatz, S. +3 more
We present SWS spectra taken across the M17-Southwest photodissociation front and discuss spectral properties of PAHs and VSGs. We report new features at 4.65, 6.35, 8.7 and 11µm which we interpret as PAHs and/or VSGs emission. From feature intensity ratios along the cut, we find PAHs are mainly ionized and almost fully hydrogenated.
Corotating and Transient Solar Wind Flows in Three Dimensions
Gosling, J. T.
Two types of flows dominate the large-scale structure of the solar wind: corotating flows and transient disturbances. Corotating flows are associated with spatial variability in the coronal expansion and solar rotation, whereas transient disturbances are associated with episodic ejections of material into interplanetary space from coronal regions …
The life-cycle of star formation in distant clusters
Smail, I.; Barger, A. J.; Ellis, R. S. +3 more
We analyse the detailed distribution of star-forming and post-starburst members in three distant (z=0.31) galaxy clusters in terms of evolutionary sequences that incorporate secondary bursts of star formation on pre-existing stellar populations. Using the number density of spectroscopically confirmed members of the EW(Hdelta) versus B-R plane from…
Disk M Dwarf Luminosity Function from Hubble Space Telescope Star Counts
Gould, Andrew; Bahcall, John N.; Flynn, Chris
We study a sample of 257 Galactic disk M dwarfs (8 ≤ Mv ≤ 18.5) found in images obtained using the Hubble Space Telescope (HST). These include 192 stars in 22 fields imaged with the repaired Wide Field Camera (WFC2) with mean limiting mag I = 23.7 and 65 stars in 162 fields imaged with the prerepair Planetary Camera (PC 1) with mean lim…
Spectrophotometry of UIR bands in the diffuse emission of the galactic disk.
Lemke, D.; Laureijs, R. J.; Lehtinen, K. +5 more
The spectrum of the unidentified infrared (UIR) emission bands between 5.8 and 11.6µm has been observed for the first time for the diffuse emission of the galactic disk where the interstellar radiation field (ISRF) is quite low. The UIR bands at 6.2, 7.7, 8.6, and 11.3µm have absolute intensities which are ~1/10th of the values observe…
HST Observations of Jets from Young Stars
Mundt, Reinhard; Ray, Thomas P.; Raga, Alejandro C. +2 more
We report on Hubble Space Telescope (HST) emission line ([S II] lambda lambda 6716,6731, H alpha , and [O I] lambda 6300) and nearby continuum imaging of the HL Tau and HH 30 jets from our own HST program as well as a study of HST Archive [S II] lambda lambda 6716,6731 images of the HH 1 and HH 34 jets. It is found in all cases that these jets are…
HST Snapshot Survey of 3CR Radio Source Counterparts. I. Intermediate Redshifts
Baum, Stefi A.; Sparks, William B.; Miley, George K. +5 more
We have obtained images of 267 3CR radio galaxies and quasars by conducting a snapshot survey with HST's WFPC2 through a broadband red (F702W) filter. This is the first in a series of papers resulting from this survey, describing and presenting the basic data. Here we focus on the 77 radio galaxies within the redshift range 0.1 <z < 0.5 (91%…
Sub-galactic clumps at a redshift of 2.39 and implications for galaxy formation
Keel, W. C.; Odewahn, S. C.; Windhorst, R. A. +1 more
A large number of very faint, compact objects have been found at a redshift of 2.39 in optical images of the distant Universe. The objects appear to be star-forming spheroids smaller than the bulge of a spiral galaxy; they are much smaller and fainter than typical galaxies seen today. These objects may be part of a reservoir from which many of tod…
Evidence for two classes of comets from their polarimetric properties at large phase angles.
Levasseur-Regourd, A. C.; Hadamcik, E.; Renard, J. B.
The dependence of the linear polarization of solar light scattered by cometary dust upon the phase angle has been studied, through appropriate fits, from a data base of 22 comets and 750 points (mainly in the green and red spectral domains). Although the whole coma polarization is found to slightly increase with the wavelength, all the data obtain…