Search Publications
A fast matching algorithm for sheared stellar samples: k-d match
Heyl, Jeremy S.
This paper presents new and efficient algorithms for matching stellar catalogues, where the transformation between the coordinate systems of the two catalogues is unknown and might include shearing. The discovery of a given object, whether a star or asterism, from a first catalogue in a second catalogue is logarithmic in time rather than polynomia…
Detection of Hα emission from z > 3.5 submillimetre luminous galaxies with AKARI-FUHYU spectroscopy
Oyabu, Shinki; Smail, Ian; Pearson, Chris +9 more
We present tentative Hα emission line detections of four submillimetre-detected galaxies at z > 3.5: the radio galaxies 8C1909+722 and 4C60.07 at signal-to-noise ratios (SNRs) of 3.1 and 2.5, and two submillimetre-selected galaxies (SMGs) near the first of these at SNRs of 10.0 and 2.4, made with the AKARI space telescope as part of the Follow-…
A photospheric metal line profile analysis of hot DA white dwarfs with circumstellar material
Barstow, M. A.; Welsh, B. Y.; Dickinson, N. J.
Some hot DA white dwarfs have circumstellar high ion absorption features in their spectra, in addition to those originating in the photosphere. In many cases, the line profiles of these absorbing components are unresolved. Given the importance of the atmospheric composition of white dwarfs to studies of stellar evolution, extra-solar planetary sys…
Numerical simulations of wind-equatorial gas interaction in η Carinae
Soker, Noam; Tsebrenko, Danny; Akashi, Muhammad
We perform 3D gas-dynamical simulations and show that the asymmetric morphology of the blue- and red-shifted components of the outflow at hundreds of astronomical units from the massive binary system η Carinae can be accounted for from the collision of the free primary stellar wind with the slowly expanding dense equatorial gas. Owing to the very …
XMM-Newton discovery of transient 285.4 s X-ray pulsar XMMU J013359.5+303634 in M33
Trudolyubov, S. P.
I report on the discovery and analysis of the first transient X-ray pulsar detected in the Local Group galaxy M33. The 2010 July-August deep XMM-Newton observations of M33 fields revealed a new bright X-ray source XMMU J013359.5+303634 exhibiting pulsations with a period P ∼ 285.4 s and pulsed fraction ∼47 per cent in the 0.3-10 keV energy range. …
Searching for evidence of jet-cloud interaction in radio galaxies. First results for 3C 381
Feinstein, C.; Reynaldi, V.
We present results of Gemini spectroscopy and Hubble Space Telescope imaging of the 3C 381 radio galaxy. Possible ionizing mechanisms for the extended emission-line region were studied through state-of-the-art diagnostic analysis employing line ratios. Photoionization from the central engine as well as mixed medium photoionization models fail in r…
Probing the fast outflow in IRAS 15452 - 5459 with ATCA observations of OH, H2O and SiO masers
Menten, K. M.; Cerrigone, L.; Wiesemeyer, H.
Maser lines of OH, H2O and SiO are commonly observed in O-rich asymptotic giant branch (AGB) stars, but their presence after the end of the AGB phase is linked to non-spherical mass-loss processes. IRAS 15452 - 5459 is a post-AGB star with an hourglass nebula whose maser lines are quite peculiar. We observed all of the three maser speci…
The low-mass companion of HIP 45314 (HR 3672)
Neuhäuser, R.; Schmidt, T. O. B.; Mugrauer, M. +2 more
We report the discovery of a very low mass companion to HIP 45314 (HR 3672) located about 2.7 arcsec north-west of HR 3672 A. With four years of epoch difference between the two observations obtained with the Very Large Telescope we can reject by more than 4σ that B would be a non-moving background object unrelated to A. HR 3672 A is a B 7-8 main-…
Light curves of six bright soft X-ray transients in M31
Nooraee, Nakisa
Disc irradiation is thought to be capable of explaining the global behaviour of the light curves of soft X-ray transients (SXTs). Depending on the strength of the central X-ray emission in irradiating the disc, the light curve may exhibit an exponential or a linear decay. The model predicts that in brighter transients a transition from exponential…
A multi-wavelength study of nuclear activity and environment of low-power radio galaxy CTD 86
Singh, K. P.; Dewangan, G. C.; Pandge, M. B. +1 more
We present an X-ray study of the nuclear and extended emission of a nearby Fanaroff & Riley class I (FR-I) radio galaxy CTD 86 based on the XMM-Newton observations. Two different components observed are: diffuse thermal emission from hot gas (kT ∼ 0.79 keV, ne ∼ 10-3 cm-3, LX ∼ 5 × 1042 er…