Search Publications
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…
A closer look at the `characteristic' width of molecular cloud filaments
Panopoulou, G. V.; Tassis, K.; Skalidis, R. +2 more
Filaments in Herschel molecular cloud images are found to exhibit a 'characteristic width'. This finding is in tension with spatial power spectra of the data, which show no indication of this characteristic scale. We demonstrate that this discrepancy is a result of the methodology adopted for measuring filament widths. First, we perform the previo…
Galaxy Zoo: morphological classifications for 120 000 galaxies in HST legacy imaging
Scarlata, Claudia; Schawinski, Kevin; Griffith, Roger L. +18 more
We present the data release paper for the Galaxy Zoo: Hubble (GZH) project. This is the third phase in a large effort to measure reliable, detailed morphologies of galaxies by using crowdsourced visual classifications of colour-composite images. Images in GZH were selected from various publicly released Hubble Space Telescope legacy programmes con…
Tracing the Hercules stream with Gaia and LAMOST: new evidence for a fast bar in the Milky Way
Famaey, Benoit; Kawata, Daisuke; Hunt, Jason A. S. +1 more
The length and pattern speed of the Milky Way bar are still controversial. Photometric and spectroscopic surveys of the inner Galaxy, as well as gas kinematics, favour a long and slowly rotating bar, with corotation around a Galactocentric radius of 6 kpc. On the other hand, the existence of the Hercules stream in local velocity space favours a sh…
The Complete Local Volume Groups Sample - I. Sample selection and X-ray properties of the high-richness subsample
Babul, Arif; Raychaudhury, Somak; Ponman, Trevor J. +7 more
We present the Complete Local-Volume Groups Sample (CLoGS), a statistically complete optically selected sample of 53 groups within 80 Mpc. Our goal is to combine X-ray, radio and optical data to investigate the relationship between member galaxies, their active nuclei and the hot intra-group medium (IGM). We describe sample selection, define a 26-…
Beyond the Kepler/K2 bright limit: variability in the seven brightest members of the Pleiades
Aigrain, S.; Grundahl, F.; Albrecht, S. +20 more
The most powerful tests of stellar models come from the brightest stars in the sky, for which complementary techniques, such as astrometry, asteroseismology, spectroscopy and interferometry, can be combined. The K2 mission is providing a unique opportunity to obtain high-precision photometric time series for bright stars along the ecliptic. Howeve…
Multiple stellar populations in Magellanic Cloud clusters - V. The split main sequence of the young cluster NGC 1866
Anderson, J.; Milone, A. P.; Marino, A. F. +7 more
One of the most unexpected results in the field of stellar populations of the last few years is the discovery that some Magellanic Cloud globular clusters younger than ∼400 Myr exhibit bimodal main sequences (MSs) in their colour-magnitude diagrams (CMDs). Moreover, these young clusters host an extended main-sequence turn-off (eMSTO) in close anal…
Galaxy populations in massive galaxy clusters to z = 1.1: colour distribution, concentration, halo occupation number and red sequence fraction
Benoit-Lévy, A.; D'Andrea, C. B.; Zenteno, A. +70 more
We study the galaxy populations in 74 Sunyaev-Zeldovich effect selected clusters from the South Pole Telescope survey, which have been imaged in the science verification phase of the Dark Energy Survey. The sample extends up to z ∼ 1.1 with 4 × 1014 M⊙ ≤ M200 ≤ 3 × 1015M⊙. Using the band conta…
A new, faint population of X-ray transients
Yang, Guang; Brandt, William N.; Schneider, Donald P. +22 more
We report on the detection of a remarkable new fast high-energy transient found in the Chandra Deep Field-South, robustly associated with a faint (mR = 27.5 mag, zph ∼ 2.2) host in the CANDELS survey. The X-ray event is comprised of 115^{+12}_{-11} net 0.3-7.0 keV counts, with a light curve characterized by an ≈100 s rise tim…