Search Publications
QUIJOTE scientific results - II. Polarisation measurements of the microwave emission in the Galactic molecular complexes W43 and W47 and supernova remnant W44
Lasenby, A.; Martínez-González, E.; Rebolo, R. +11 more
We present Q-U-I JOint TEnerife (QUIJOTE) intensity and polarisation maps at 10-20 GHz covering a region along the Galactic plane 24° ≲ l ≲ 45°, |b| ≲ 8°. These maps result from 210 h of data, have a sensitivity in polarisation of ≈40 µK beam-1 and an angular resolution of ≈1°. Our intensity data are crucial to confirm the presenc…
The Gaia DR1 mass-radius relation for white dwarfs
Gänsicke, B. T.; Jordan, S.; Tremblay, P. -E. +9 more
The Gaia Data Release 1 (DR1) sample of white dwarf parallaxes is presented, including six directly observed degenerates and 46 white dwarfs in wide binaries. This data set is combined with spectroscopic atmospheric parameters to study the white dwarf mass-radius relationship (MRR). Gaia parallaxes and G magnitudes are used to derive model atmosph…
The HST large programme on ω Centauri - I. Multiple stellar populations at the bottom of the main sequence probed in NIR-Optical
Apai, D.; Anderson, J.; Milone, A. P. +7 more
As part of a large investigation with Hubble Space Telescope to study the faintest stars within the globular cluster ω Centauri, in this work we present early results on the multiplicity of its main sequence (MS) stars, based on deep optical and near-infrared observations. By using appropriate colour-magnitude diagrams, we have identified, for the…
Comparative analysis of Debrecen sunspot catalogues
Ludmány, A.; Baranyi, T.; Győri, L.
Sunspot area data are important for studying solar activity and its long-term variations. At the Debrecen Heliophysical Observatory, we compiled three sunspot catalogues: the Debrecen Photoheliographic Data (DPD), the SDO/HMI Debrecen Data (HMIDD) and the SOHO/MDI Debrecen Data. For comparison, we also compiled an additional sunspot catalogue, the…
Revealing the ultrafast outflow in IRAS 13224-3809 through spectral variability
Fabian, A. C.; Reynolds, C. S.; Pinto, C. +6 more
We present an analysis of the long-term X-ray variability of the extreme narrow-line Seyfert 1 galaxy IRAS 13224-3809 using principal component analysis (PCA) and fractional excess variability (Fvar) spectra to identify model-independent spectral components. We identify a series of variability peaks in both the first PCA component and F…
Nature of the absorbing gas associated with a galaxy group at z∼0.4
Pettini, Max; York, Donald G.; Husemann, Bernd +6 more
We present new Multi Unit Spectroscopic Explorer observations of quasar field Q2131-1207 with a log N(H I} = 19.50 ± 0.15 sub-damped Lyman α at zabs = 0.42980. We detect four galaxies at a redshift consistent with that of the absorber where only one was known before this study. Two of these are star-forming galaxies, while the ones furt…
The metallicity of the intracluster medium over cosmic time: further evidence for early enrichment
Allen, Steven W.; Simionescu, Aurora; Werner, Norbert +4 more
We use Chandra X-ray data to measure the metallicity of the intracluster medium (ICM) in 245 massive galaxy clusters selected from X-ray and Sunyaev-Zel'dovich (SZ) effect surveys, spanning redshifts 0 < z < 1.2. Metallicities were measured in three different radial ranges, spanning cluster cores through their outskirts. We explore trends in…
The Galaxy End Sequence
Smith, Matthew W. L.; Eales, Stephen; Ciesla, Laure +4 more
A common assumption is that galaxies fall in two distinct regions of a plot of specific star formation rate (SSFR) versus galaxy stellar mass: a star-forming galaxy main sequence (GMS) and a separate region of 'passive' or 'red and dead galaxies'. Starting from a volume-limited sample of nearby galaxies designed to contain most of the stellar mass…
A population of faint low surface brightness galaxies in the Perseus cluster core
Wittmann, Carolin; Kotulla, Ralf; Lisker, Thorsten +7 more
We present the detection of 89 low surface brightness (LSB), and thus low stellar density galaxy candidates in the Perseus cluster core, of the kind named 'ultra-diffuse galaxies', with mean effective V-band surface brightnesses 24.8-27.1 mag arcsec-2, total V-band magnitudes -11.8 to -15.5 mag, and half-light radii 0.7-4.1 kpc. The can…
The Gaia ultracool dwarf sample - I. Known L and T dwarfs and the first Gaia data release
Caballero, J. A.; Sarro, L. M.; Marocco, F. +5 more
We identify and investigate known ultracool stars and brown dwarfs that are being observed or indirectly constrained by the Gaia mission. These objects will be the core of the Gaia ultracool dwarf sample composed of all dwarfs later than M7 that Gaia will provide direct or indirect information on. We match known L and T dwarfs to the Gaia first da…