Search Publications
Luminosity dependence of the cyclotron line and evidence for the accretion regime transition in V 0332+53
Doroshenko, Victor; Tsygankov, Sergey S.; Mushtukov, Alexander A. +4 more
We report on the analysis of NuSTAR observations of the Be-transient X-ray pulsar V 0332+53 during the giant outburst in 2015 and another minor outburst in 2016. We confirm the cyclotron-line energy-luminosity correlation previously reported in the source and the line energy decrease during the giant outburst. Based on 2016 observations, we find t…
Using dust, gas and stellar mass-selected samples to probe dust sources and sinks in low-metallicity galaxies
Baes, M.; Dunne, L.; Maddox, S. +8 more
We combine samples of nearby galaxies with Herschel photometry selected on their dust, metal, H I and stellar mass content, and compare these to chemical evolution models in order to discriminate between different dust sources. In a companion paper, we used an H I-selected sample of nearby galaxies to reveal a subsample of very gas-rich (gas fract…
The slight spin of the old stellar halo
Gómez, Facundo A.; Marinacci, Federico; Pakmor, Rüdiger +4 more
We combine Gaia data release 1 astrometry with Sloan Digital Sky Survey (SDSS) images taken some ∼10-15 years earlier, to measure proper motions of stars in the halo of our Galaxy. The SDSS-Gaia proper motions have typical statistical errors of 2 mas yr-1 down to r ∼ 20 mag, and are robust to variations with magnitude and colour. Armed …
Hunting black holes with Gaia
Loeb, Abraham; Mashian, Natalie
We predict the number of black holes with stellar companions that are potentially detectable with Gaia astrometry over the course of its 5-yr mission. Our model estimates that nearly 2 × 105 astrometric binaries hosting black holes and stellar companions brighter than Gaia's detection threshold, G ∼ 20, should be discovered with 5σ sens…
Spectroscopic properties of luminous Ly α emitters at z ≈ 6-7 and comparison to the Lyman-break population
Sobral, David; Mobasher, Bahram; Darvish, Behnam +5 more
We present spectroscopic follow-up of candidate luminous Ly α emitters (LAEs) at z = 5.7-6.6 in the SA22 field with VLT/X-SHOOTER. We confirm two new luminous LAEs at z = 5.676 (SR6) and z = 6.532 (VR7), and also present HST follow-up of both sources. These sources have luminosities LLy α ≈ 3 × 1043 erg s-1, very h…
Massive post-starburst galaxies at z > 1 are compact proto-spheroids
Simpson, Chris; Wild, Vivienne; Almaini, Omar +6 more
We investigate the relationship between the quenching of star formation and the structural transformation of massive galaxies, using a large sample of photometrically selected post-starburst galaxies in the UKIDSS Ultra-Deep Survey field. We find that post-starburst galaxies at high redshift (z > 1) show high Sérsic indices, significantly highe…
WISDOM Project - II. Molecular gas measurement of the supermassive black hole mass in NGC 4697
Sarzi, Marc; Cappellari, Michele; Davis, Timothy A. +3 more
As part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) project, we present an estimate of the mass of the supermassive black hole (SMBH) in the nearby fast-rotating early-type galaxy NGC 4697. This estimate is based on Atacama Large Millimeter/submillimeter Array (ALMA) cycle-3 observations of the 12CO(2-1) emissio…
The evolving far-IR galaxy luminosity function and dust-obscured star formation rate density out to z≃5.
Scott, D.; McLure, R. J.; Dunlop, J. S. +5 more
We present a new measurement of the evolving galaxy far-IR luminosity function (LF) extending out to redshifts z ≃ 5, with resulting implications for the level of dust-obscured star formation density in the young Universe. To achieve this, we have exploited recent advances in sub-mm/mm imaging with SCUBA-2 on the James Clerk Maxwell Telescope and …
Lens models under the microscope: comparison of Hubble Frontier Field cluster magnification maps
Coe, Dan; Liesenborgs, Jori; Williams, Liliya L. R. +2 more
Using the power of gravitational lensing magnification by massive galaxy clusters, the Hubble Frontier Fields provide deep views of six patches of the high-redshift Universe. The combination of deep Hubble imaging and exceptional lensing strength has revealed the greatest numbers of multiply-imaged galaxies available to constrain models of cluster…
The high-Eddington NLS1 Ark 564 has the coolest corona
Fabian, A. C.; Reynolds, C. S.; Lohfink, A. +4 more
Ark 564 is an archetypal narrow-line Seyfert 1 that has been well observed in soft X-rays from 0.3-10 keV, revealing a steep spectrum, strong soft excess, iron K emission line and dramatic variability on the order of hours. Because of its very steep spectrum, observations of the source above 10 keV have been sparse. We report here on the first NuS…