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IR excesses around nearby Lambda Boo stars are caused by debris discs rather than ISM bow waves
Wyatt, M. C.; Venn, K. A.; Matthews, B. C. +3 more
Lambda Boo stars are predominately A-type stars with solar abundant C, N, O, and S, but up to 2 dex underabundances of refractory elements. The stars' unusual surface abundances could be due to a selective accretion of volatile gas over dust. It has been proposed that there is a correlation between the Lambda Boo phenomenon and IR excesses which a…
Numerical predictions for planets in the debris discs of HD 202628 and HD 207129
Maddison, S. T.; Thilliez, E.
Resolved debris disc images can exhibit a range of radial and azimuthal structures, including gaps and rings, which can result from planetary companions shaping the disc by their gravitational influence. Currently, there are no tools available to determine the architecture of potential companions from disc observations. Recent work by Rodigas, Mal…
Finest light curve details, physical parameters, and period fluctuations of CoRoT RR Lyrae stars
Derekas, A.; Szabó, R.; Sódor, Á. +1 more
The CoRoT satellite supplied the scientific community with a huge data base of variable stars. Among them the RR Lyrae stars have intensively been discussed in numerous papers in the last few years, but the latest runs have not been checked to find RR Lyrae stars up to now. Our main goal was to fill this gap and complete the CoRoT RR Lyrae sample.…
X-rays associated with the jet-cloud-interacting radio galaxy 3C 277.3 (Coma A): implications for energy deposition
Young, A. J.; Birkinshaw, M.; Worrall, D. M.
We report the discovery with Chandra of X-ray-emitting gas associated with the jet-cloud interaction in the radio galaxy 3C 277.3 (Coma A), a source that falls in the most important power range for radio-mode feedback in the Universe. This hot gas, heated by the jet, dominates the mass of the cloud which is responsible for an extreme projected def…
Masses of the components of SB2 binaries observed with Gaia - III. Accurate SB2 orbits for 10 binaries and masses of HIP 87895
Mazeh, T.; Tal-Or, L.; Halbwachs, J. -L. +9 more
In anticipation of the Gaia astrometric mission, a large sample of spectroscopic binaries has been observed since 2010 with the Spectrographe pour l'Observation des PHénomènes des Intérieurs Stellaires et des Exoplanètes spectrograph at the Haute-Provence Observatory. Our aim is to derive the orbital elements of double-lined spectroscopic binaries…
XMM-Newton discovery of mHz quasi-periodic oscillations in the high-mass X-ray binary IGR J19140+0951
Sidoli, L.; Esposito, P.; Motta, S. E. +2 more
We report on the discovery of mHz quasi-periodic oscillations (QPOs) from the high-mass X-ray binary (HMXB) IGR J19140+0951, during a 40 ks XMM-Newton observation performed in 2015, which caught the source in its faintest state ever observed. At the start of the observation, IGR J19140+0951 was at a low flux of 2 × 10-12 erg cm-2
The 2015 hard-state only outburst of GS 1354-64
Stiele, H.; Kong, A. K. H.
Since its outburst in 1997, GS 1354-64 stayed in quiescence. In 2015 June, renewed activity of GS 1354-64 was observed. Based on our analysis of energy spectra and timing properties obtained from Swift/X-ray telescope monitoring data, we found that GS 1354-64 stayed in the hard state during the entire outburst. Such a hard state only (or `failed' …
Major substructure in the M31 Outer Halo: the East Cloud
Mackey, A. D.; Martin, N. F.; Ferguson, A. M. N. +8 more
We present the first detailed analysis of the East Cloud, a highly disrupted diffuse stellar substructure in the outer halo of M31. The core of the substructure lies at a projected distance of ∼100 kpc from the centre of M31 in the outer halo, with possible extensions reaching right into the inner halo. Using Pan-Andromeda Archaeological Survey ph…
Chemical compositions and kinematics of the Hercules stream
Lambert, David L.; Reddy, Bacham E.; Ramya, P. +1 more
An abundance analysis is reported of 58-K giants identified by Famaey et al. (2005, A&A, 430, 165) as highly probable members of the Hercules stream selected from stars north of the celestial equator in the Hipparcos catalogue. The giants have compositions spanning the interval [Fe/H] from -0.17 to +0.42 with a mean value of +0.15 and relative…
Cluster mass profile reconstruction with size and flux magnification on the HST STAGES survey
Heymans, Catherine; Joachimi, Benjamin; Heavens, Alan F. +1 more
We present the first measurement of individual cluster mass estimates using weak lensing size and flux magnification. Using data from the HST STAGES (Space Telescope A901/902 Galaxy Evolution Survey) survey of the A901/902 supercluster we detect the four known groups in the supercluster at high significance using magnification alone. We discuss th…