Search Publications
Magnetic fields near spacecraft-explored comets: 3D MHD numerical simulation
Baranov, V. B.; Alexashov, D. B.; Lebedev, M. G.
The magnetohydrodynamic (MHD) model of the interaction between the solar wind and a cometary ionosphere is presented. The model accounts for photoionization of the neutral component of the cometary outflow and the resonance charge exchange between charged and neutral particles, together with the interplanetary magnetic field. The numerical impleme…
Cold galaxies
Clements, David L.; Rowan-Robinson, Michael
We use 350 µm angular diameter estimates from Planck to test the idea that some galaxies contain exceptionally cold (10-13 K) dust, since colder dust implies a lower surface brightness radiation field illuminating the dust, and hence a greater physical extent for a given luminosity. The galaxies identified from their spectral energy distribu…
Herschel Hi-GAL imaging of massive young stellar objects
Pezzuto, S.; de Wit, W. -J.; Molinari, S. +5 more
We used Herschel Hi-GAL (Herschel infrared Galactic Plane survey) data to determine whether massive young stellar objects (MYSOs) are resolved at 70 µm and to study their envelope density distribution. Our analysis of three relatively isolated sources in the l = 30° and 59° Galactic fields show that the objects are partially resolved at 70 &…
X-rays from the oxygen-type Wolf-Rayet binary WR 30a
Skinner, Stephen L.; Zhekov, Svetozar A.
We present an analysis of XMM-Newton X-ray data of WR 30a (WO+O), a close massive binary that harbours an oxygen-rich Wolf-Rayet star. Its spectrum is characterized by the presence of two well-separated broad peaks, or `bumps', one peaking at energies between 1 and 2 keV and the other between 5 and 7 keV. A two-component model is required to match…
Planetary host stars: evaluating uncertainties in cool model atmospheres
Scholz, A.; Helling, Ch.; Bozhinova, I.
M-dwarfs are emerging in the literature as promising targets for detecting low-mass, Earth-like planets. An important step in this process is to determine the stellar parameters of the M-dwarf host star as accurately as possible. Different well-tested stellar model atmosphere simulations from different groups are widely applied to undertake this t…
The discrepancy in the mid-infrared continuum and the features of polycyclic aromatic hydrocarbons for Spitzer and Herschel SWIRE-field galaxies
Wu, Hong; Zhu, Yi-Nan
On the basis of observations by Spitzer and Herschel, we present and analyse the correlations between various monochromatic infrared (IR) luminosities for star-forming galaxies, selected from two northern Spitzer Wide-area InfraRed Extragalactic Survey (SWIRE) fields. The 24- and 70-µm luminosities (L[24] and L[70]), which are dominated by t…
X-ray outbursts from a new transient in NGC 55
Jithesh, V.; Wang, Zhongxiang
We report the outbursts from a newly discovered X-ray transient in the Magellanic-type, SB(s)m galaxy NGC 55. The transient source, XMMU J001446.81-391123.48, was undetectable in the 2001 XMM-Newton and 2004 Chandra observations, but detected in a 2010 XMM-Newton observation at a significance level of 9σ in the 0.3-8 keV energy band. The XMM-Newto…
The subsurface of Pluto from submillimetre observations.
Bendo, G. J.; Greaves, J. S.; Whitelaw, A. C. M.
Surface areas on Pluto change in brightness and colour, at optical to infrared wavelengths, over time-scales as short as years. The subsurface contains a reservoir of frozen volatiles, but little is known about it because Pluto is out of reach for cm-radar. Here we present a 0.85 mm wavelength light curve of the Pluto system, from archival data ta…
Predicted multiply imaged X-ray AGNs in the XXL survey
Surdej, J.; Horellou, C.; Melnyk, O. +3 more
We estimate the incidence of multiply imaged active galactic nuclei (AGNs) among the optical counterparts of X-ray selected point-like sources in the XXL field. We also derive the expected statistical properties of this sample, such as the redshift distribution of the lensed sources and of the deflectors that lead to the formation of multiple imag…
XMM-Newton view of a hard X-ray transient IGR J17497-2821
Dewangan, Gulab C.; Alam, Md. Shah; Mukherjee, Dipanjan +3 more
We present spectral and energy-dependent timing characteristics of the hard X-ray transient IGR J17497-2821 based on XMM-Newton observations performed five and nine days after its outburst on 2006 September 17. We find that the source spectra can be well described by a hard (Γ ∼ 1.50) power law and a weak multicolour disc blackbody with inner disc…