Search Publications
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 …
Contribution of the first galaxies to the cosmic far-infrared/sub-millimeter background - I. Mean background level
De Rossi, María Emilia; Bromm, Volker
We study the contribution of the first galaxies to the far-infrared/sub-millimeter (FIR/sub-mm) extragalactic background light (EBL) by implementing an analytical model for dust emission. We explore different dust models, assuming different grain-size distributions and chemical compositions. According to our findings, observed reradiated emission …
The cosmic microwave background Cold Spot anomaly: the impact of sky masking and the expected contribution from the integrated Sachs-Wolfe effect
Lahav, Ofer; Benoit-Lévy, Aurélien; Naidoo, Krishna
We re-analyse the cosmic microwave background (CMB) Cold Spot (CS) anomaly with particular focus on understanding the bias a mask (contaminated by Galactic and point sources) may introduce. We measure the coldest spot, found by applying the Spherical Mexican Hat Wavelet transform on 100 000 cut-sky (masked) and full-sky CMB simulated maps. The CS …