Search Publications
The shocked outflow in NGC 4051 - momentum-driven feedback, ultrafast outflows and warm absorbers
King, A. R.; Pounds, K. A.
An extended XMM-Newton observation of the Seyfert 1 galaxy NGC 4051 in 2009 revealed an unusually rich absorption spectrum with outflow velocities, in both Reflection Grating Spectrometers and EPIC spectra, up to ∼9000 km s-1. Evidence was again seen for a fast ionized wind with velocity ∼0.12c. Detailed modelling with the XSTAR photoio…
Mass, shape and thermal properties of Abell 1689 using a multiwavelength X-ray, lensing and Sunyaev-Zel'dovich analysis
Umetsu, Keiichi; Sereno, Mauro; Ettori, Stefano +1 more
Knowledge of the mass and concentration of galaxy clusters is crucial for an understanding of their formation and evolution. Unbiased estimates require an understanding of the shape and orientation of the halo as well as its equilibrium status. We propose a novel method to determine the intrinsic properties of galaxy clusters from a multiwavelengt…
Mars ionosphere total electron content analysis from MARSIS subsurface data
Amata, E.; Orosei, R.; Picardi, G. +6 more
We describe a method to estimate the total electron content (TEC) of the Mars ionosphere from the output parameters of an algorithm, called the Contrast Method (Picardi, G., Sorge, S. [2000]. Proc. SPIE. Eighth International Conference on Ground Penetrating Radar, vol. 4084, pp. 624-629; Ilyushin, Ya.A., Kunitsyn, V.E. [2004]. J. Commun. Technol. …
Distant galaxy clusters in the XMM Large Scale Structure survey
Chiappetti, L.; Valtchanov, I.; Ilbert, O. +12 more
Distant galaxy clusters provide important tests of the growth of large-scale structure in addition to highlighting the process of galaxy evolution in a consistently defined environment at large look-back time. We present a sample of 22 distant (z > 0.8) galaxy clusters and cluster candidates selected from the 9 deg2 footprint of the …
The High-latitude Branch of the Solar Torsional Oscillation in the Rising Phase of Cycle 24
Thompson, M. J.; Howe, R.; Komm, R. +5 more
We use global heliseismic data from the Global Oscillation Network Group, the Michelson Doppler Imager on board the Solar and Heliospheric Observatory, and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, to examine the behavior, during the rising phase of Solar Cycle 24, of the migrating zonal flow pattern known as th…
Low-Resolution Spectrum of the Extragalactic Background Light with the AKARI InfraRed Camera
Sakon, Itsuki; Matsuura, Shuji; Wada, Takehiko +2 more
The Extragalactic Background Light (EBL) as integrated light from outside of our Galaxy includes information about the early universe and the Dark Ages. We analyzed spectral data of the astrophysical diffuse emission obtained with the low-resolution spectroscopy mode on the AKARI Infra-Red Camera (IRC) in the
Discovery of GeV Emission from the Circinus Galaxy with the Fermi Large Area Telescope
Stawarz, Łukasz; Madejski, Greg M.; Cheung, Chi C. +7 more
We report the discovery of γ-ray emission from the Circinus galaxy using the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. Circinus is a nearby (~4 Mpc) starburst with a heavily obscured Seyfert-type active nucleus, bipolar radio lobes perpendicular to the spiral disk, and kpc-scale jet-like structures. Our analysis of 0…
The Morphology of the Ejecta in Supernova 1987A: A Study over Time and Wavelength
Fransson, Claes; Kirshner, Robert P.; Leibundgut, Bruno +9 more
We present a study of the morphology of the ejecta in Supernova 1987A based on images and spectra from the Hubble Space Telescope (HST) as well as integral field spectroscopy from VLT/SINFONI. The HST observations were obtained between 1994 and 2011 and primarily probe the outer H-rich zones of the ejecta. The SINFONI observations were obtained in…
Ripple effects and oscillations in the broad Fe Kα line as a probe of massive black hole mergers
Haiman, Z.; Ford, K. E. S.; McKernan, B. +1 more
When a sufficiently massive satellite (or secondary) black hole is embedded in a gas disc around a (primary) supermassive black hole, it can open an empty gap in the disc. A gap-opening secondary close to the primary will leave an imprint in the broad component of the Fe Kα emission line, which varies in a unique and predictable manner. If the gap…
Testing Galaxy Formation Models with the GHOSTS Survey: The Color Profile of M81's Stellar Halo
Bell, Eric F.; Holwerda, Benne W.; Monachesi, Antonela +6 more
We study the properties of the stellar populations in M81's outermost part, which hereafter we will call the stellar halo, using Hubble Space Telescope (HST) Advanced Camera for Surveys observations of 19 fields from the GHOSTS survey. The observed fields probe the stellar halo out to a projected distance of ~50 kpc from the galactic center. Each …