Search Publications
Identifying AGN Balmer absorptions and stratified narrow emission-line region kinematics in SDSS J112611.63+425246.4
Wang, J.; Xu, D. W.
Context. Balmer absorption is a rare phenomenon in active galactic nuclei (AGNs). So far, only seven Balmer-absorption AGNs have been reported in the literature.
Aims: We here report the identification of SDSS J112611.63+425246 as a new Balmer-absorption AGN through our spectral analysis and study the kinematics of its narrow emission-line re…
Stellar rotation, binarity, and lithium in the open cluster IC 4756
Strassmeier, K. G.; Weber, M.; Granzer, T. +3 more
Context. An important aspect in the evolutionary scenario of cool stars is their rotation and the rotationally induced magnetic activity and interior mixing. Stars in open clusters are particularly useful tracers for these aspects because of their known ages.
Aims: We aim to characterize the open cluster IC 4756 and measure stellar rotation p…
Short-term variability of inner-source pickup ions at 1 AU. SOHO/CELIAS observations
Wimmer-Schweingruber, R. F.; Berger, L.; Drews, C. +1 more
Context. In 1995 a second extended source of pickup ions in the inner heliosphere was discovered. Since then this so-called inner source has been characterised in many studies, and various scenarios for its nature have been proposed. But to this day, the detailed nature of the inner source is still unknown.
Aims: Although it seems most likely…
Calibrating the α parameter of convective efficiency using observed stellar properties
Wang, L.; Zhao, G.; Grupp, F. +3 more
Context. Synthetic model atmosphere calculations are still the most commonly used tool when determining precise stellar parameters and stellar chemical compositions. Besides three-dimensional models that consistently solve for hydrodynamic processes, one-dimensional models that use an approximation for convective energy transport play the major ro…
The HIFI spectral survey of AFGL 2591 (CHESS). III. Chemical structure of the protostellar envelope
van der Tak, F. F. S.; van der Wiel, M. H. D.; Semenov, D. A. +2 more
Aims: The aim of this work is to understand the richness of chemical species observed in the isolated high-mass envelope of AFGL 2591, a prototypical object for studying massive star formation.
Methods: Based on HIFI and JCMT data, the molecular abundances of species found in the protostellar envelope of AFGL 2591 were derived with a Mon…
Hubble Space Telescope ultraviolet spectroscopy of the hottest known helium-rich pre-white dwarf KPD 0005+5106
Rauch, T.; Werner, K.
We present a model-atmosphere analysis of the ultraviolet echelle spectra of KPD 0005+5106 taken with the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope. The star is the hottest known pre-white dwarf (Teff = 200 000 ± 20 000 K, log g= 6.7 ± 0.3 (cm/s2)). Its atmosphere is composed of helium with trace …
Witnessing a merging bullet being stripped in the galaxy cluster RXCJ2359.3-6042
Böhringer, Hans; Chon, Gayoung
We report the discovery of the merging cluster, RXCJ2359.3-6042, from the REFLEX II cluster survey and present our results from all three detectors combined in the imaging and spectral analysis of the XMM-Newton data. Also known as Abell 4067, this is a unique system, where a compact bullet penetrates an extended, low density cluster at redshift z…
Herschel HIFI observations of the Sgr A +50 km s-1 Cloud. Deep searches for O2 in emission and foreground absorption
Liseau, R.; Roueff, E.; Pagani, L. +8 more
Context. The Herschel Oxygen Project (HOP) is an open time key program, awarded 140 h of observing time to search for molecular oxygen (O2) in a number of interstellar sources. To date O2 has definitely been detected in only two sources, namely ρ Oph A and Orion, reflecting the extremely low abundance of O2 in the …
The CoRoT chemical peculiar target star HD 49310
Paunzen, E.; Weiss, W. W.; Fröhlich, H. -E. +2 more
Context. The magnetic chemically peculiar (CP) stars of the upper main sequence are well-suited laboratories for investigating the influence of local magnetic fields on the stellar surface because they produce inhomogeneities (spots) that can be investigated in detail as the star rotates.
Aims: We studied the inhomogeneous surface structure o…
A weak lensing analysis of the PLCK G100.2-30.4 cluster
Dahle, H.; Aghanim, N.; Arnaud, M. +12 more
We present a mass estimate of the Planck-discovered cluster PLCK G100.2-30.4, derived from a weak lensing analysis of deep Subaru griz images. We perform a careful selection of the background galaxies using the multi-band imaging data, and undertake the weak lensing analysis on the deep (1 h) r -band image. The shape measurement is based on the Ka…