Search Publications
Illuminating a Dark Lens : A Type Ia Supernova Magnified by the Frontier Fields Galaxy Cluster Abell 2744
Richard, Johan; Treu, Tommaso; Broadhurst, Tom +27 more
SN HFF14Tom is a Type Ia SN discovered at z=1.3457+/- 0.0001 behind the galaxy cluster Abell 2744 (z = 0.308). In a cosmology-independent analysis, we find that HFF14Tom is 0.77 ± 0.15 mag brighter than unlensed Type Ia SNe at similar redshift, implying a lensing magnification of {µ }{obs}=2.03+/- 0.29. This observed magnification…
Direct Imaging of an Asymmetric Debris Disk in the HD 106906 Planetary System
Murray-Clay, Ruth; Dong, Ruobing; Oppenheimer, Rebecca +53 more
We present the first scattered light detections of the HD 106906 debris disk using the Gemini/Gemini Planet Imager in the infrared and Hubble Space Telescope (HST)/Advanced Camera for Surveys in the optical. HD 106906 is a 13 Myr old F5V star in the Sco-Cen association, with a previously detected planet-mass candidate HD 106906b projected 650 AU f…
Comets as collisional fragments of a primordial planetesimal disk
Rickman, H.; Morbidelli, A.
Context. The Rosetta mission and its exquisite measurements have revived the debate on whether comets are pristine planetesimals or collisionally evolved objects.
Aims: We investigate the collisional evolution experienced by the precursors of current comet nuclei during the early stages of the solar system in the context of the so-called Nice…
Effect of primordial magnetic fields on the ionization history
Finelli, F.; Paoletti, D.; Rubiño-Martín, J. A. +1 more
Primordial magnetic fields (PMF) damp at scales smaller than the photon diffusion and free-streaming scale. This leads to heating of ordinary matter (electrons and baryons), which affects both the thermal and ionization history of our Universe. Here, we study the effect of heating due to ambipolar diffusion and decaying magnetic turbulence. We fin…
Low-level accretion in neutron star X-ray binaries
Altamirano, D.; Degenaar, N.; Wijnands, R. +5 more
We search the literature for reports on the spectral properties of neutron star low-mass X-ray binaries when they have accretion luminosities between 1034 and 1036 erg s-1, corresponding to roughly 0.01-1 per cent of the Eddington accretion rate for a neutron star. We found that in this luminosity range the photon …
Anatomy of the AGN in NGC 5548. II. The spatial, temporal, and physical nature of the outflow from HST/COS Observations
Kaastra, J. S.; Harrison, F. A.; Kriss, G. A. +30 more
Context. AGN outflows are thought to influence the evolution of their host galaxies and of super massive black holes. Our deep multiwavelength campaign on NGC 5548 has revealed a new, unusually strong X-ray obscuration, accompanied by broad UV absorption troughs observed for the first time in this object. The X-ray obscuration caused a dramatic de…
Hubble Space Telescope Proper Motion (HSTPROMO) Catalogs of Galactic Globular Clusters. III. Dynamical Distances and Mass-to-Light Ratios
Anderson, Jay; van der Marel, Roeland P.; Watkins, Laura L. +1 more
We present dynamical distance estimates for 15 Galactic globular clusters (GCs) and use these to check the consistency of dynamical and photometric distance estimates. For most of the clusters, this is the first dynamical distance estimate ever determined. We extract proper-motion (PM) dispersion profiles using cleaned samples of bright stars from…
Evolution in the Black Hole—Galaxy Scaling Relations and the Duty Cycle of Nuclear Activity in Star-forming Galaxies
Trump, Jonathan R.; Brandt, W. N.; Xue, Y. Q. +6 more
We measure the location and evolutionary vectors of 69 Herschel-detected broad-line active galactic nuclei (BLAGNs) in the {{M}BH}-{{M}*} plane. BLAGNs are selected from the COSMOS and CDF-S fields, and span the redshift range 0.2≤slant z\lt 2.1. Black hole masses are calculated using archival spectroscopy and single-epoch vi…
High-resolution imaging of the molecular outflows in two mergers: IRAS 17208-0014 and NGC 1614
Tacconi, L. J.; Hunt, L. K.; Colina, L. +11 more
Context. Galaxy evolution scenarios predict that the feedback of star formation and nuclear activity (AGN) can drive the transformation of gas-rich spiral mergers into (ultra) luminous infrared galaxies and, eventually, lead to the build-up of QSO/elliptical hosts.
Aims: We study the role that star formation and AGN feedback have in launching…
Statistical Evidence for Contributions of Flares and Coronal Mass Ejections to Major Solar Energetic Particle Events
Dudok de Wit, T.; Klein, K. -L.; Miteva, R. +2 more
Solar energetic particle (SEP) events are related to flares and coronal mass ejections (CMEs). This work is a new investigation of statistical relationships between SEP peak intensities - deka-MeV protons and near-relativistic electrons - and characteristic quantities of the associated solar activity. We consider the speed of the CME and quantitie…