Search Publications
Energy-angle dispersion of accelerated heavy ions at 67P/Churyumov-Gerasimenko: implication in the mass-loading mechanism
Yamauchi, M.; Behar, E.; Nilsson, H. +4 more
The Rosetta spacecraft studied the comet 67P/Churyumov-Gerasimenko for nearly two years. The Ion Composition Analyzer instrument on board Rosetta observed the positive ion distributions in the environment of the comet during the mission. A portion of the comet's neutral coma is expected to get ionized, depending on the comet's activity and positio…
The effect of unresolved contaminant stars on the cross-matching of photometric catalogues
Wilson, Tom J.; Naylor, Tim
A fundamental process in astrophysics is the matching of two photometric catalogues. It is crucial that the correct objects be paired, and that their photometry does not suffer from any spurious additional flux. We compare the positions of sources in Wide-field Infrared Survey Explorer (WISE), INT Photometric H α Survey, Two Micron All Sky Survey …
A catalogue of white dwarf candidates in VST ATLAS
Hermes, J. J.; Raddi, Roberto; Gänsicke, Boris T. +6 more
The Sloan Digital Sky Survey (SDSS) has created a knowledge gap between the Northern and the Southern hemispheres, which is very marked for white dwarfs: Only ≃15 per cent of the known white dwarfs are south of the equator. Here, we make use of the VLT Survey Telescope (VST) ATLAS survey, one of the first surveys obtaining deep, optical, multiband…
Near-infrared variability study of the central 2.3 arcmin × 2.3 arcmin of the Galactic Centre - I. Catalogue of variable sources
Morris, Mark R.; Williams, Benjamin F.; Do, Tuan +7 more
We used 4-yr baseline Hubble Space Telescope/Wide Field Camera 3 IR observations of the Galactic Centre in the F153M band (1.53 µm) to identify variable stars in the central ∼2.3 arcmin × 2.3 arcmin field. We classified 3845 long-term (periods from months to years) and 76 short-term (periods of a few days or less) variables among a total sam…
Optical and ultraviolet spectroscopic analysis of SN 2011fe at late times
Filippenko, Alexei V.; Foley, Ryan J.; Pan, Yen-Chen +16 more
We present optical spectra of the nearby Type Ia supernova SN 2011fe at 100, 205, 311, 349 and 578 d post-maximum light, as well as an ultraviolet (UV) spectrum obtained with the Hubble Space Telescope at 360 d post-maximum light. We compare these observations with synthetic spectra produced with the radiative transfer code phoenix. The day +100 s…
Gas inflows towards the nucleus of NGC 1358
Robinson, Andrew; Schnorr-Müller, Allan; Storchi-Bergmann, Thaisa +2 more
We use optical spectra from the inner 1.8 × 2.5 kpc2 of the Seyfert 2 galaxy NGC 1358, obtained with the GMOS integral field spectrograph on the Gemini South telescope at a spatial resolution of ≈ 165 pc, to assess the feeding and feedback processes in this nearby active galaxy. Five gaseous kinematical components are observed in the em…
Post-perihelion observations of comet 67P/Churyumov-Gerasimenko at the 6 m BTA telescope: optical spectroscopy
Afanasiev, V. L.; Kiselev, N. N.; Ivanova, O. V. +2 more
In the framework of the worldwide ground-based campaign, long-slit spectroscopy of comet 67P/Churyumov-Gerasimenko was performed at the 6 m BTA telescope of the Special Astrophysical Observatory RAS in the post-perihelion period from 2015 November to 2016 April at a heliocentric distance from 1.61 to 2.72 au. Strong CN and relatively weak C2<…
Counter-evidence against multiple frequency nature of 0.75 mHz oscillation in V4743 Sgr
Ness, J. -U.; Dobrotka, A.
All X-ray light curves of nova V4743 Sgr (2002), taken during and after outburst, contain a 0.75 mHz periodic signal that can most plausibly be interpreted as being excited by the rotation of the white dwarf in an intermediate polar system. This interpretation faces the challenge of an apparent multifrequency nature of this signal in the light cur…
Unveiling the AGN in IC 883: discovery of a parsec-scale radio jet
Bondi, M.; Muxlow, T. W. B.; Argo, M. K. +12 more
IC 883 is a luminous infrared galaxy (LIRG) classified as a starburst-active galactic nucleus (AGN) composite. In a previous study, we detected a low-luminosity AGN (LLAGN) radio candidate. Here, we report on our radio follow-up at three frequencies that provides direct and unequivocal evidence of the AGN activity in IC 883. Our analysis of archiv…
Unusual void galaxy DDO 68: implications of the HST-resolved photometry
Makarova, L. N.; Makarov, D. I.; Pustilnik, S. A. +1 more
DDO 68 (UGC 5340) is an unusual dwarf galaxy with extremely low gas metallicity [12 + log (O/H) = 7.14] residing in the nearby Lynx-Cancer void. Despite its apparent isolation, it shows both optical and H I morphological evidence for strong tidal disturbance. Here, we study the resolved stellar populations of DDO 68 using deep images from the HST …