Search Publications
Molecular hydrogen from z = 0.0963 DLA towards the QSO J1619+3342
Muzahid, S.; Srianand, R.; Mohan, V. +1 more
We report the detection of H2 in a zabs = 0.0963 Damped Lyman α (DLA) system towards zem = 0.4716 QSO J1619+3342. This DLA has log N(H I) = 20.55 ± 0.10, 18.13 ≤ log N(H2) ≤ 18.40, [S/H] = -0.62 ± 0.13, [Fe/S] = -1.00 ± 0.17 and the molecular fraction - 2.11 ≤ log[f(H2)] ≤ -1.85. The inferred …
The nature of massive black hole binary candidates - II. Spectral energy distribution atlas
Hogg, David W.; Decarli, R.; Lusso, E. +5 more
Recoiling supermassive black holes (SMBHs) are considered one plausible physical mechanism to explain high velocity shifts between narrow and broad emission lines sometimes observed in quasar spectra. If the sphere of influence of the recoiling SMBH is such that only the accretion disc is bound, the dusty torus would be left behind, hence the SED …
X-ray time delays from the Seyfert 2 galaxy IRAS 18325-5926
Vaughan, S.; Alston, W. N.; Lobban, A. P.
Using new XMM-Newton observations we detect hard X-ray time lags in the rapid variability of the Compton-thin Seyfert 2 galaxy IRAS 18325-5926. The higher-energy X-ray variations lag behind correlated lower-energy variations by up to ∼3 ks and the magnitude of the lag increases clearly with energy separation between the energy bands. We find that …
Near-infrared Hubble Space Telescope polarimetry of a complete sample of narrow-line radio galaxies
Tadhunter, C. N.; Ramírez, E. A.; Axon, D. +5 more
We present an analysis of 2.05 µm Hubble Space Telescope polarimetric data for a sample of 13 nearby Fanaroff-Riley type II (FRII) 3CR radio sources (0.03 < z < 0.11) that are classified as narrow-line radio galaxies (NLRG) at optical wavelengths. We find that the compact cores of the NLRG in our sample are intrinsically highly polariz…
GALAPAGOS-C: analysis of galaxy morphologies using high-performance computing methods
Kelvin, Lee S.; Barden, Marco; Häußler, Boris +2 more
We present GALAPAGOS-C, a code designed to process a complete set of survey images through automation of source detection (via SEXTRACTOR), postage stamp cutting, object mask preparation, sky background estimation and complex two-dimensional light profile Sérsic modelling (via GALFIT). GALAPAGOS-C is designed around the concept of MPI-parallelizat…
A new HCN maser in IRAS 15082-4808
Zijlstra, A. A.; Fuller, G. A.; Smith, C. L.
We have identified a new vibrational HCN maser at 89.087 GHz in the asymptotic giant branch (AGB) star IRAS 15082-4808, a maser which is thought to trace the innermost region of an AGB envelope. The observations of this maser at three epochs are presented: two positive detections and one null detection. The line profile has varied between the posi…
The void in the Sculptor group spiral galaxy NGC 247
Wagner-Kaiser, R.; Sarajedini, A.; De Maio, T. +1 more
The dwarf galaxy NGC 247, located in the Sculptor Filament, displays an apparent void on the north side of its spiral disc. The existence of the void in the disc of this dwarf galaxy has been known for some time, but the exact nature and cause of this strange feature has remained unclear. We investigate the properties of the void in the disc of NG…
Milky Way dust extinction measured with QSOs
Wolf, Christian
We investigate reddening by Milky Way dust in the low-extinction regime of E(B - V) < 0.15. Using over 50 000 QSOs at 0.5 < z < 2.5 from the Sloan Digital Sky Survey (SDSS) data release 7 (DR7) QSO Catalogue, we probe the residual SDSS colours after dereddening and correcting for the known spectroscopic redshifts. We find that the extinct…
Herschel-ATLAS/GAMA: How does the far-IR luminosity function depend on galaxy group properties?
Ivison, R. J.; Dunne, L.; Eales, S. +15 more
We use the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) Phase I data to study the conditional luminosity function of far-IR (250 µm) selected galaxies in optically selected galaxy groups from the Galaxy And Mass Assembly (GAMA) spectroscopic survey, as well as environmental effects on the far-IR-to-optical colour. We applied …
Episodic star formation in a group of LAEs at z = 5.07.
Mas-Hesse, J. M.; Cava, A.; Gonzalez-Martin, O. +10 more
We are undertaking a search for high-redshift low-luminosity Lyman Alpha sources in the SHARDS (Survey for High-z Absorption Red and Dead Sources) survey. Among the pre-selected Lyman Alpha sources two candidates were spotted, located 3.19 arcsec apart, and tentatively at the same redshift. Here, we report on the spectroscopic confirmation with Gr…