Search Publications
Intermediate-mass Elements in Young Supernova Remnants Reveal Neutron Star Kicks by Asymmetric Explosions
Katsuda, Satoru; Janka, Hans-Thomas; Tominaga, Nozomu +9 more
The birth properties of neutron stars (NSs) yield important information about the still-debated physical processes that trigger the explosion as well as on intrinsic neutron-star physics. These properties include the high space velocities of young neutron stars with average values of several 100 km s-1, with an underlying “kick” mechani…
The mean ultraviolet spectrum of a representative sample of faint z ∼ 3 Lyman alpha emitters
Ellis, Richard S.; Robertson, Brant E.; Nakajima, Kimihiko +2 more
We discuss the rest-frame ultraviolet (UV) emission line spectra of a large (∼100) sample of low luminosity redshift z ∼ 3.1 Lyman alpha emitters (LAEs) drawn from a Subaru imaging survey in the SSA22 survey field. Our earlier work based on smaller samples indicated that such sources have high [O III]/[O II] line ratios possibly arising from a har…
Ultrafast outflows disappear in high-radiation fields
Fabian, A. C.; Reynolds, C. S.; Pinto, C. +8 more
Ultrafast outflows (UFOs) are the most extreme winds launched by active galactic nuclei (AGN) due to their mildly relativistic speeds (∼0.1-0.3c) and are thought to significantly contribute to galactic evolution via AGN feedback. Their nature and launching mechanism are however not well understood. Recently, we have discovered the presence of a va…
Revisiting hypervelocity stars after Gaia DR2
Evans, N. W.; Hawkins, K.; Strader, J. +3 more
Hypervelocity stars are intriguing rare objects travelling at speeds large enough to be unbound from the Milky Way. Several mechanisms have been proposed for producing them, including the interaction of the Galaxy's supermassive black hole (SMBH) with a binary; rapid mass-loss from a companion to a star in a short-period binary; the tidal disrupti…
Two transitional type Ia supernovae located in the Fornax cluster member NGC 1404: SN 2007on and SN 2011iv
Challis, P.; Suntzeff, N. B.; Filippenko, A. V. +26 more
We present an analysis of ultraviolet (UV) to near-infrared observations of the fast-declining Type Ia supernovae (SNe Ia) 2007on and 2011iv, hosted by the Fornax cluster member NGC 1404. The B-band light curves of SN 2007on and SN 2011iv are characterised by Δm15 (B) decline-rate values of 1.96 mag and 1.77 mag, respectively. Although …
Exploring the Effects of Disk Thickness on the Black Hole Reflection Spectrum
Reynolds, Christopher S.; Taylor, Corbin
The relativistically broadened reflection spectrum, observed in both AGN and X-ray binaries, has proven to be a powerful probe of the properties of black holes and the environments in which they reside. Emitted from the innermost regions of the accretion disk, this X-ray spectral component carries with it information not only about the plasma that…
The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets
Giordano, Silvio; Raymond, John; Mann, Ingrid +16 more
This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information o…
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XV. The Dynamical Clock: Reading Cluster Dynamical Evolution from the Segregation Level of Blue Straggler Stars
Dalessandro, E.; Salaris, M.; Anderson, J. +17 more
The parameter A +, defined as the area enclosed between the cumulative radial distribution of blue straggler stars (BSSs) and that of a reference population, is a powerful indicator of the level of BSS central segregation. As part of the Hubble Space Telescope UV Legacy Survey of Galactic globular clusters (GCs), here we present the BSS…
Testing the Larson relations in massive clumps
Peretto, N.; Elia, D.; Schisano, E. +6 more
We tested the validity of the three Larson relations in a sample of 213 massive clumps selected from the Herschel infrared Galactic Plane (Hi-GAL) survey, also using data from the Millimetre Astronomy Legacy Team 90 GHz (MALT90) survey of 3-mm emission lines. The clumps are divided into five evolutionary stages so that we can also discuss the Lars…
ALMA Detection of Extended [C II] Emission in Himiko at z = 6.6
Maiolino, R.; Amorín, R.; Smit, R. +1 more
Himiko is one of the most luminous Lyα emitters at z = 6.595. It has three star-forming clumps detected in the rest-frame UV, with a total SFR = 20 M ⊙ yr-1. We report the Atacama Large Millimeter/submillimeter Array (ALMA) detection of the [C II]158 µm line emission in this Galaxy with a significance of 8σ. The total […