Search Publications
Searching for visual companions of close Cepheids. VLT/NACO lucky imaging of Y Oph, FF Aql, X Sgr, W Sgr, and η Aql
Kervella, P.; Mérand, A.; Girard, J. H. V. +4 more
Aims: High-resolution imaging in several photometric bands can provide color and astrometric information of the wide-orbit component of Cepheid stars. Such measurements are needed to understand the age and evolution of pulsating stars. In addition, binary Cepheids have the potential to provide direct and model-independent distances and masses…
Unveiling the environment surrounding low-mass X-ray binary SAX J1808.4-3658
Kaastra, J. S.; Costantini, E.; Fabian, A. C. +2 more
Context. Low-mass X-ray binaries (LMXBs) are a natural workbench to study accretion disk phenomena and optimal background sources to measure elemental abundances in the interstellar medium (ISM). In high-resolution XMM-Newton spectra, the LMXB SAX J1808.4-3658 in the past showed a neon column density significantly higher than expected given its sm…
Mass profile and dynamical status of the z ~ 0.8 galaxy cluster LCDCS 0504
Ilbert, O.; Schrabback, T.; Schirmer, M. +34 more
Context. Constraints on the mass distribution in high-redshift clusters of galaxies are currently not very strong.
Aims: We aim to constrain the mass profile, M(r), and dynamical status of the z ~ 0.8 LCDCS 0504 cluster of galaxies that is characterized by prominent giant gravitational arcs near its center.
Methods: Our analysis is based…
Characterizing AGB stars in Wide-field Infrared Survey Explorer (WISE) bands
Kong, Xu; Zhu, Qingfeng; He, Jinhua +1 more
Aims: Since asymptotic giant branch (AGB) stars are bright and extended infrared objects, most Galactic AGB stars saturate the Wide-field Infrared Survey Explorer (WISE) detectors and therefore the WISE magnitudes that are restored by applying point-spread-function fitting need to be verified. Statistical properties of circumstellar envelopes…
Dust composition and mass-loss return from the luminous blue variable R71 in the LMC
Waters, L. B. F. M.; Tielens, A. G. G. M.; Meixner, M. +3 more
Context. We present an analysis of mid- and far-infrared (IR) spectrum and spectral energy distribution (SED) of the luminous blue variable (LBV) R71 in the Large Magellanic Cloud (LMC).
Aims: This work aims to understand the overall contribution of high-mass LBVs to the total dust-mass budget of the interstellar medium (ISM) of the LMC and c…
High-resolution ammonia mapping of the very young protostellar core Chamaeleon-MMS1
Walmsley, C. M.; Harju, J.; Miettinen, O. +4 more
Aims: The aim of this study is to investigate the structure and kinematics of the nearby candidate first hydrostatic core Cha-MMS1.
Methods: Cha-MMS1 was mapped in the NH3(1,1) line and the 1.2 cm continuum using the Australia Telescope Compact Array (ATCA). The angular resolution of the ATCA observations is 7″ (~1000 AU), and…
Extended warm gas in the ULIRG Mrk273: Galactic outflows and tidal debris
Veilleux, S.; Rupke, D. S. N.; Sparks, W. B. +6 more
We present new HST/ACS medium- and narrow-band images and optical Isaac Newton Telescope long-slit spectra of the merging system Mrk273. The HST observations sample the [OIII]λλ4959,5007 emission from the galaxy and the nearby continuum. These data were taken as a part of a larger study of ultraluminous infrared galaxies (ULIRGs) with the aim of i…
HESS J1818-154, a new composite supernova remnant discovered in TeV gamma rays and X-rays
Klochkov, D.; Santangelo, A.; Quirrenbach, A. +217 more
Composite supernova remnants (SNRs) constitute a small subclass of the remnants of massive stellar explosions where non-thermal radiation is observed from both the expanding shell-like shock front and from a pulsar wind nebula (PWN) located inside of the SNR. These systems represent a unique evolutionary phase of SNRs where observations in the rad…
Imaging the circumstellar environment of the young T Tauri star SU Aurigae
Jeffers, S. V.; Min, M.; Canovas, H. +2 more
The circumstellar environments of classical T Tauri stars are challenging to directly image because of their high star-to-disk contrast ratio. One method to overcome this is by using imaging polarimetry where scattered and consequently polarised starlight from the star's circumstellar disk can be separated from the unpolarised light of the central…
Herschel observations of gas and dust in comet C/2006 W3 (Christensen) at 5 AU from the Sun
de Graauw, Th.; Lara, L. M.; Küppers, M. +19 more
Context. Cometary activity at large heliocentric distances is thought to be driven by outgassing of molecular species more volatile than water that are present in the nucleus. The long-period comet C/2006 W3 (Christensen) was an exceptional target for a detailed study of its distant gaseous and dust activity.
Aims: We aimed to measure the H