Search Publications
Resolving the Vela C ridge with P-ArTéMiS and Herschel
Hill, T.; Rodriguez, L.; André, Ph. +25 more
We present APEX/P-ArTéMiS 450 µm continuum observations of RCW 36 and the adjacent ridge, a high-mass high-column density filamentary structure at the centre of the Vela C molecular cloud. These observations, at higher resolution than Herschel/SPIRE camera, reveal clear fragmentation of the central star-forming ridge. Combined with PACS far-…
The CoRoT B-type binary HD 50230: a prototypical hybrid pulsator with g-mode period and p-mode frequency spacings⋆
Auvergne, M.; Baudin, F.; Poretti, E. +14 more
Context. B-type stars are promising targets for asteroseismic modelling, since their frequency spectrum is relatively simple.
Aims: We deduce and summarise observational constraints for the hybrid pulsator, HD 50230, earlier reported to have deviations from a uniform period spacing of its gravity modes. The combination of spectra and a high-q…
Rotating Wolf-Rayet stars in a post RSG/LBV phase. An evolutionary channel towards long-duration GRBs?
Harries, T. J.; Vink, J. S.; Gräfener, G. +1 more
Context. Wolf-Rayet (WR) stars with fast rotating cores are thought to be the direct progenitors of long-duration gamma-ray bursts (LGRBs). A well accepted evolutionary channel towards LGRBs is chemically-homogeneous evolution at low metallicities, which completely avoids a red supergiant (RSG), or luminous blue variable (LBV) phase. On the other …
A mid-IR study of the circumstellar environment of Herbig Be stars
Waters, L. B. F. M.; Pantin, E.; van Boekel, R. +7 more
Context. The study of the formation of massive stars is complicated because of the short times scales, large distances, and obscuring natal clouds. There are observational and theoretical indications that the circumstellar environment of Herbig Be (HBe) stars is substantially different from that of their lower mass counterparts, the T Tauri and He…
The XMM-Newton slew survey in the 2-10 keV band
Read, A. M.; Warwick, R. S.; Saxton, R. D.
Context. The on-going XMM-Newton Slew Survey (XSS) provides coverage of a significant fraction of the sky in a broad X-ray bandpass. Although shallow by contemporary standards, in the "classical" 2-10 keV band of X-ray astronomy, the XSS provides significantly better sensitivity than any currently available all-sky survey.
Aims: We investigat…
Detection and characterization of a 500 µm dust emissivity excess in the Galactic plane using Herschel/Hi-GAL observations
Bernard, J. -P.; Marshall, D. J.; Paladini, R. +7 more
Context. Past and recent observations have revealed unexpected variations in the far-infrared - millimeter (FIR-mm) dust emissivity in the interstellar medium. In the Herschel spectral range, those are often referred to as a 500 µm emission excess. Several dust emission models have been developed to interpret astrophysical data in the FIR-mm…
Bar pattern speed evolution over the last 7 Gyr
Aguerri, J. A. L.; Pérez, I.; Méndez-Abreu, J.
Context. The tumbling pattern of a bar is the main parameter characterising its dynamics. From numerical simulations, its evolution since bar formation is tightly linked to the dark halo in which the bar is formed through dynamical friction and angular momentum exchange. Observational measurements of the bar pattern speed with redshift can restric…
Pulsation spectrum of δ Scuti stars: the binary HD 50870 as seen with CoRoT and HARPS
Auvergne, M.; Amado, P. J.; Baudin, F. +14 more
Aims: We present the results obtained with the CoRoT satellite for HD 50870, a δ Sct star which was observed for 114.4 d. The aim of these observations was to evaluate the results obtained for HD 50844, the first δ Sct star monitored with CoRoT, on a longer time baseline.
Methods: The 307,570 CoRoT datapoints were analysed with different…
Frequency drifts of 3-min oscillations in microwave and EUV emission above sunspots
Nakariakov, V. M.; Shibasaki, K.; Yan, Y. +3 more
Aims: We analysed 3-min oscillations of microwave and extreme ultraviolet (EUV) emission generated at different heights of a sunspot atmosphere, studied the amplitude and frequency modulation of the oscillations, and its relationship with the variation of the spatial structure of the oscillations.
Methods: High-resolution data obtained w…
X-ray variations in the inner accretion flow of dwarf novae
Revnivtsev, M.; Balman, Ş.
Aims: We study the inner disk structure of dwarf novae (DNe; i.e., nonmagnetic cataclysmic variables).
Methods: We performed power spectral analysis of the X-ray light curves obtained using the Rossi X-ray Timing Explorer (RXTE) and X-ray Multi-mirror Mission (XMM-Newton) data. We fit the power spectra with a simple model that describes …