Search Publications
Mid-infrared observations of the circumstellar disks around PDS 66 and CRBR 2422.8-3423
Wolf, S.; Gräfe, C.
Aims: We present mid-infrared observations and photometry of the circumstellar disks around
Stray-light correction in 2D spectroscopy
Franz, M.; Schlichenmaier, R.
Context. In solar physics, spectropolarimeters based on Fabry-Pérot interferometers are commonly used for high spatial resolution observations. In the data pipeline, corrections for scattered light may be performed on each narrow band image.
Aims: We elaborate on the effects of stray-light corrections on Doppler maps.
Methods: First, we …
Deep optical imaging of the γ-ray pulsar J1048-5832 with the VLT
Sollerman, J.; Kirichenko, A.; Zyuzin, D. +2 more
Context. PSR J1048-5832 is a young radio-pulsar that has recently been detected in γ-rays with Fermi, and also in X-rays with Chandra and XMM-Newton. It powers a compact pulsar wind nebula visible in X-rays and is in many ways similar to the Vela pulsar.
Aims: We present deep optical observations made with the ESO Very Large Telescope to sear…
Star forming regions in a sample of HST spiral galaxies
Dapergolas, A.; Kontizas, M.; Kontizas, E. +2 more
Aims: The presence of small- and large-scale star formation structures in a sample of six spiral Hubble Space Telescope (HST) galaxies is investigated to identify small structures of young stars known as OB associations and to tell whether they are formed inside larger scale star forming stellar structures in a hierarchical form.
Methods…
Cosmological model dependence of the galaxy luminosity function: far-infrared results in the Lemaître-Tolman-Bondi model
Berta, S.; Magnelli, B.; Nordon, R. +9 more
Aims: This is the first paper of a series aiming at investigating galaxy formation and evolution in the giant-void class of the Lemaître-Tolman-Bondi (LTB) models that best fits current cosmological observations. Here we investigate the luminosity function (LF) methodology, and how its estimates would be affected by a change on the cosmologic…
Astrometric mass ratios for three spectroscopic binaries
Sahlmann, J.; Fekel, F. C.
The orbits of five single-lined spectroscopic binaries have recently been determined. We now use astrometric measurements that were collected with the Hipparcos satellite to constrain the systems' mass ratios and secondary masses. The barycentric astrometric orbits of three binary systems, HD 140667, HD 158222, and HD 217924, are fully determined …
Herschel and IRAM-30 m observations of comet C/2012 S1 (ISON) at 4.5 AU from the Sun
Altieri, B.; Jorda, L.; Küppers, M. +9 more
Context. The sungrazer comet C/2012 S1 (ISON) (perihelion at rh = 0.0125 AU from the Sun) was bright and active when discovered in September 2012 at 6.3 AU from the Sun.
Aims: Our goal was to characterize the distant gaseous and dust activity of this comet, inbound, from observations of H2O, CO and the dust coma in the f…
Population gradients and photometric metallicities in early- and transition-type dwarf galaxies: Clues from the Sculptor group
Rejkuba, M.; Da Costa, G. S.; Grebel, E. K. +3 more
Aims: We focus on the resolved stellar populations of one early-type and four transition-type dwarf galaxies in the Sculptor group, with the aim to examine the potential presence of population gradients and place constraints on their mean metallicities.
Methods: We use deep Hubble Space Telescope images to construct color-magnitude diagr…
Evidence for partial Taylor relaxation from changes in magnetic geometry and energy during a solar flare
Bloomfield, D. S.; Gallagher, P. T.; Murray, S. A.
Context. Solar flares are powered by energy stored in the coronal magnetic field, a portion of which is released when the field reconfigures into a lower energy state. Investigation of sunspot magnetic field topology during flare activity is useful to improve our understanding of flaring processes.
Aims: Here we investigate the deviation of t…
Detection of X-rays from the jet-driving symbiotic star Hen 3-1341
Sokoloski, J. L.; Luna, G. J. M.; Stute, M. +1 more
Context. Hen 3-1341 is a symbiotic binary system consisting of a white dwarf and a red giant star that is one of about ten symbiotics that show hints of jets. The bipolar jets have been detected through displaced components of emission lines during its outburst from 1998 to 2004. These components disappeared when Hen 3-1341 reached quiescence. On …