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Ultraviolet Structure in the Lensed QSO 0957+561
Hutchings, J. B.
Imaging and spectra of the lensed QSO pair 0957+561 are presented and discussed. The data are principally those from the Space Telescope Imaging Spectrograph near-UV MAMA and cover rest wavelengths from 850 to 1350 Å. The QSOs are both extended over about 1", with morphology that matches with a small rotation and includes one feature aligned with …
Hubble Space Telescope NICMOS Multiband Photometry of Proteus and Puck
Dumas, Christophe; Terrile, Richard J.; Smith, Bradford A.
We report 1.1-2.4 µm multiband photometry of the small Uranian satellites Puck and Portia and of the small Neptunian satellite Proteus obtained with the Hubble Space Telescope and its near-infrared camera NICMOS. The surface of Puck (and likely Portia) displays an absorption feature matching the 2.0 µm band of water ice. In the case of…
The Wind of the B[e] Supergiant Henize S22 Viewed through a Reflection Nebula in DEM L106
Oey, M. S.; Nazé, Yaël; Chu, You-Hua +5 more
Narrowband HST WFPC2 images reveal a bow-shock-like halo around the H II region N30B toward the B[e] supergiant Hen S22 located within the larger DEM L106 nebula in the Large Magellanic Cloud. High-dispersion spectra of N30B show a narrow Hα emission component from the ionized gas; the velocity variations indicate a gas flow of -5 to -10 km s…
Astrophysics in 2002
Aschwanden, Markus J.; Trimble, Virginia
This has been the Year of the Baryon. Some low temperature ones were seen at high redshift, some high temperature ones were seen at low redshift, and some cooling ones were (probably) reheated. Astronomers saw the back of the Sun (which is also made of baryons), a possible solution to the problem of ejection of material by Type II supernovae (in w…
Structure and mass distribution of spiral galaxies at intermediate redshifts
Tamm, A.; Tenjes, P.
Using the HST archive WFPC2 observations and rotation curves measured by Vogt et al. (\cite{vogt1}), we constructed self-consistent light and mass distribution models for three disk galaxies at redshifts z=0.15, 0.90 and 0.99. The models consist of three components: the bulge, the disk and the dark matter. The light distribution of the galaxies in…
The stellar environment of SMC N81
Schaerer, D.; Heydari-Malayeri, M.; Charmandaris, V. +4 more
We present near infrared JHK imaging of the Small Magellanic Cloud compact H II region N81 using the ISAAC camera at the ESO Very Large Telescope (Antu). Our analysis of the stellar environment of this young massive star region reveals the presence of three new stellar populations in the surrounding field which are mainly composed of low mass star…
Nonthermal Mass Motions within the High-Temperature Plasmas above a Complex Solar Active Region
Curdt, W.; Landi, E.; Feldman, U.
We report on mass motions in high-temperature plasmas at radial distances of 1.06-1.20 Rsolar corresponding to 3.3×104-1.3×105 km above the west solar limb. The observations were conducted over a 53 hr time period while a complex active region moved across the west solar limb. We found that the nonthermal mass moti…
Extension of the ICRF for selected areas down to the 16th magnitude - II
Ducourant, C.; Le Campion, J. -F.; Teixeira, R. +3 more
In this paper we provide a major upgrade of the work presented in \citet{cam}, aiming at the extension of the ICRF at optical wavelengths in regions of special astronomical interest, using observations from the Bordeaux and Valinhos meridian circles. Along with the new fields, the main differences, when compared to the first release, are: a much l…
XMM-Newton observations of an absorbed z= 0.67 QSO: no dusty torus?
Georgakakis, A.; Georgantopoulos, I.; Griffiths, R. E. +4 more
We present XMM-Newton observations of AX J0341.4-4453, a mildly reddened AV < 7 quasi-stellar object (QSO) at a redshift of z= 0.672. The XMM-Newton spectrum shows a large obscuring column NH~ 1023 cm-2 corresponding to AV~ 70, in agreement with previous results based on the lower limit of …
How directions and helicity of erupted solar magnetic fields define geoeffectiveness of coronal mass ejections
Wang, Haimin; Yurchyshyn, Vasyl; Abramenko, Valentyna
In this study we report on the relationship between the projected speed of CMEs, measured at 20R from SOHO/LASCO images, and the hourly averaged magnitude of the southwardly directed magnetic field, B z, at the leading edge of interplanetary ejecta, as measured by the ACE magnetometer. We found that those CMEs that originate at the cent…