Search Publications
The Circumstellar Disk HD 169142: Gas, Dust, and Planets Acting in Concert?
Pinte, C.; Ménard, F.; van der Plas, G. +34 more
HD 169142 is an excellent target for investigating signs of planet-disk interaction due to previous evidence of gap structures. We perform J-band (∼1.2 µm) polarized intensity imaging of HD 169142 with VLT/SPHERE. We observe polarized scattered light down to 0.″16 (∼19 au) and find an inner gap with a significantly reduced scattered-light fl…
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…
Exploring Dust around HD 142527 down to 0.″025 (4 au) Using SPHERE/ZIMPOL
Ménard, F.; Quanz, S. P.; Avenhaus, H. +25 more
We have observed the protoplanetary disk of the well-known young Herbig star HD 142527 using ZIMPOL polarimetric differential imaging with the very broad band (∼600-900 nm) filter. We obtained two data sets in 2015 May and 2016 March. Our data allow us to explore dust scattering around the star down to a radius of ∼0.″025 (∼4 au). The well-known o…
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…
ALMA Observations of Gas-rich Galaxies in z ∼ 1.6 Galaxy Clusters: Evidence for Higher Gas Fractions in High-density Environments
Cooper, M. C.; van Kampen, E.; Demarco, R. +16 more
We present ALMA CO (2-1) detections in 11 gas-rich cluster galaxies at z ∼ 1.6, constituting the largest sample of molecular gas measurements in z > 1.5 clusters to date. The observations span three galaxy clusters, derived from the Spitzer Adaptation of the Red-sequence Cluster Survey. We augment the >5σ detections of the CO (2-1) fluxes wi…
Explaining the rolling-pin distribution of suprathermal electrons behind dipolarization fronts
Cao, J. B.; Xu, Y.; Fu, H. S. +2 more
The rolling-pin distribution of suprathermal electrons (40-200 keV), showing electron pitch angles primarily at 0°, 90°, and 180°, has recently been reported behind dipolarization fronts (DFs) both in observations and simulations. The formation of such type of distribution, however, has been unclear so far. In this study, we present an observation…
Cosmic microwave background constraints on primordial black hole dark matter
Blum, Kfir; Flauger, Raphael; Aloni, Daniel
We revisit cosmic microwave background (CMB) constraints on primordial black hole dark matter. Spectral distortion limits from COBE/FIRAS do not impose a relevant constraint. Planck CMB anisotropy power spectra imply that primordial black holes with mBHgtrsim 5 Msolar are disfavored. However, this is susceptible to sizeable u…
Hubble Space Telescope Proper Motion (HSTPROMO) Catalogs of Galactic Globular Clusters. V. The Rapid Rotation of 47 Tuc Traced and Modeled in Three Dimensions
Anderson, J.; Piotto, G.; Vesperini, E. +5 more
High-precision proper motions of the globular cluster 47 Tuc have allowed us to measure for the first time the cluster rotation in the plane of the sky and the velocity anisotropy profile from the cluster core out to about 13‧. These profiles are coupled with prior measurements along the line of sight (LOS) and the surface brightness profile and f…
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…