Search Publications
The nuclear outflow in NGC 2110
Wilson, A. S.; Rosario, D. J.; Nelson, C. H. +1 more
We present a spectroscopic and optical/radio imaging study of the Seyfert NGC 2110 using the Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph (STIS), aiming to measure the dynamics and understand the nature of the nuclear outflow in the galaxy. Previous HST studies have revealed the presence of a linear structure in the narrow-lin…
Dynamics of Saturn's magnetodisk near Titan's orbit: Comparison of Cassini magnetometer observations from real and virtual Titan flybys
Dougherty, Michele K.; Kriegel, Hendrik; Simon, Sven +4 more
We analyze the variability of the ambient magnetospheric field along Titan's orbit at 20.3 Saturn radii. However, while our preceding study ( Simon et al., 2010) focused on Cassini magnetometer observations from the 62 Titan flybys (TA-T62) between October 2004 and October 2009, the present work discusses magnetic field data that were collected ne…
The enigmatic young brown dwarf binary FUTau: accretion and activity
Scholz, A.; Micela, G.; Stelzer, B. +1 more
FUTau belongs to a rare class of young, wide brown dwarf binaries. We have resolved the system in a Chandra X-ray observation and detected only the primary, FUTauA. Hard X-ray emission, presumably from a corona, is present but, unexpectedly, we also detect a strong and unusually soft component from FUTauA. Its X-ray properties, so far unique among…
Excitation of the molecular gas in the nuclear region of M 82
Martín-Pintado, J.; Morris, P.; Harris, A. I. +23 more
We present high-resolution HIFI spectroscopy of the nucleus of the archetypical starburst galaxy M 82. Six 12CO lines, 2 13CO lines and 4 fine-structure lines have been detected. Besides showing the effects of the overall velocity structure of the nuclear region, the line profiles also indicate the presence of multiple compon…
J0454-0309: evidence of a strong lensing fossil group falling into a poor galaxy cluster
Schrabback, T.; Schirmer, M.; Hildebrandt, H. +3 more
Aims: We have discovered a strong lensing fossil group (J0454) projected near the well-studied cluster MS0451-0305. Using the large amount of available archival data, we compare J0454 to normal groups and clusters. A highly asymmetric image configuration of the strong lens enables us to study the substructure of the system.
Methods: We u…
Multi-wavelength observations of a giant flare on CN Leonis. II. Chromospheric modelling with PHOENIX
Schmitt, J. H. M. M.; Hauschildt, P. H.; Fuhrmeister, B.
Aims: In M dwarfs, optical emission lines and continua are sensitive to changing chromospheric conditions, e.g., during flares. To study flare conditions for an observed spectrum, a comparison to synthesised spectra from model atmospheres is needed.
Methods: Using the stellar atmosphere code PHOENIX, we computed a set of 41 1D NLTE param…
Antiparallel magnetic reconnection rates at the Earth's magnetopause
Fuselier, S. A.; Trattner, K. J.; Petrinec, S. M.
Cluster observations at the Earth's high-latitude magnetopause are combined with magnetic field models to demonstrate that antiparallel reconnection was occurring at the magnetopause for an event on 3 December 2001. Over a 20 min period, the reconnection line passed over the spacecraft on two occasions. In between the encounters with the reconnect…
The spectral energy distribution of D-type symbiotic stars: the role of dust shells
Ciroi, S.; Rafanelli, P.; Angeloni, R. +1 more
We have collected continuum data of a sample of D-type symbiotic stars. By modelling their spectral energy distribution in a colliding-wind theoretical scenario we have found characteristics common to all the systems: (1) at least two dust shells are clearly present, one at ~1000K and the other at ~400K they dominate the emission in the infrared; …
Ground-based measurements of the methane distribution on Titan
Griffith, Caitlin A.; Penteado, Paulo F.
Using spectra taken with NIRSPEC (Near Infrared Spectrometer) and adaptive optics on the Keck II telescope, we resolved the latitudinal variation of the 3ν2 band of CHD at 1.56 µm. As CHD is less abundant than CH by a factor of 50±10×10-5, these CHD lines do not saturate in Titan's atmosphere, and are well characterized…
The Araucaria Project. Population Effects on the V- and I-band Magnitudes of Red Clump Stars
Udalski, Andrzej; Gieren, Wolfgang; Pietrzyński, Grzegorz +3 more
We present measurements of the V- and I-band magnitudes of red clump stars in 15 nearby galaxies obtained from recently published homogeneous Hubble Space Telescope photometry. Supplementing these results with similar data for another eight galaxies available in the literature, the populational effects on the V- and I-band magnitudes of red clump …