Search Publications
Evidence of accretion triggered oscillations in the pre-main-sequence interacting binary AK Sco.
Talavera, A.; Lopez-Santiago, J.; Gomez de, C. A. I.
Pre-main sequence (PMS) binaries are surrounded by circumbinary discs from which matter falls on to both components. The material dragged from the circumbinary disc flows on to each star through independent streams channelled by the variable gravitational field. The action of the bar-like potential is most prominent in high eccentricity systems ma…
X-ray and multiwavelength insights into the inner structure of high-luminosity disc-like emitters
Brandt, W. N.; Wu, Jian; Luo, B. +5 more
We present X-ray and multiwavelength studies of a sample of eight high-luminosity active galactic nuclei (AGN) with disc-like Hβ emission-line profiles selected from the Sloan Digital Sky Survey Data Release 7. These sources have higher redshift (z ≈ 0.6) than the majority of the known disc-like emitters, and they occupy a largely unexplored space…
Investigation of dust properties of the proto-planetary nebula IRAS 18276-1431
Maud, L. T.; Izumiura, H.; Murakawa, K. +1 more
We investigate the circumstellar dust properties of the oxygen-rich bipolar proto-planetary nebula (PPN) IRAS 18276-1431 by means of two-dimensional radiative transfer simulations of the circumstellar dust shell. The model geometry is assumed to have a torus and an envelope which consists of a pair of bipolar lobes and a spherical asymptotic giant…
A 20 GHz bright sample for δ > 72° - II. Multifrequency follow-up
Prandoni, I.; Ricci, R.; Massardi, M. +10 more
We present follow-up observations at 5, 8 and 30 GHz of the K-band Northern Wide Survey (KNoWS) 20 GHz Bright Sample, performed with the 32-m Medicina radio telescope and the 32-m Toruń radio telescope. The KNoWS sources were selected in the Northern Polar Cap (δ > 72°) and have a flux density limit S20 GHz = 115 mJy. We include NRAO…
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…