Search Publications
Insight into Active Galactic Nucleus and Host Galaxy Co-evolution from Hard X-Ray Emission
Wang, J.; Wei, J. Y.; Zhou, X. L.
We study the issue of active galactic nucleus (AGN) and host co-evolution by focusing on the correlation between the hard X-ray emission from central AGNs and the stellar populations of the host galaxies. Focusing on galaxies with strong Hα line emission (EW(Hα) > 5 Å), both X-ray and optical spectral analyses are performed on 67 (partially) ob…
Long-Term Variability of the O VII Line Intensity toward the Lockman Hole Observed with Suzaku from 2006 to 2011
Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; Sakai, Kazuhiro +3 more
Long-term time variabilities of the O VII (0.57 keV) emission in the soft X-ray diffuse background were studied using six Suzaku annual observations of the blank sky towards the Lockman Hole made from 2006 to 2011. After time intervals in which the emission was enhanced on time scales of a few tens of ks were removed, the O VII intensity was found…
Herschel observations of the debris disc around HIP 92043
Krivov, A. V.; Eiroa, C.; Löhne, T. +16 more
Context. Typical debris discs are composed of particles ranging from several micron sized dust grains to km sized asteroidal bodies, and their infrared emission peaks at wavelengths 60-100 µm. Recent Herschel DUNES observations have identified several debris discs around nearby Sun-like stars (F, G and K spectral type) with significant exces…
ODIN: a new model and ephemeris for the Pluto system
Colas, F.; Lainey, V.; Robert, V. +2 more
Because of Pluto's distance from the Sun, the Pluto system has not yet completed a revolution since its discovery, hence an uncertain heliocentric distance. In this paper, we present the fitting of our dynamical model ODIN (Orbite, Dynamique et Intégration Numérique) to observations. The small satellites P4 and P5 are not taken into account. We fi…
The Second Ultraluminous X-Ray Source Transient in M31: Chandra, Hubble Space Telescope, and XMM Observations, and Evidence for an Extended Corona
Murray, S. S.; Barnard, R.; Garcia, M.
XMMU J004243.6+412519 is a transient X-ray source in M31, first discovered 2012 January 15. Different approaches to fitting the brightest follow-up observation gave luminosities 1.3-2.5 × 1039 erg s-1, making it the second ultraluminous X-ray source (ULX) in M31, with a probable black hole accretor. These different models rep…
Herschel-ATLAS/GAMA: the environmental density of far-infrared bright galaxies at z ≤ 0.5
Ivison, R. J.; Cooray, A.; Ibar, E. +21 more
We compare the environmental and star formation properties of far-infrared detected and non-far-infrared detected galaxies out to z ∼ 0.5. Using optical spectroscopy and photometry from the Galaxy And Mass Assembly (GAMA) and Sloan Digital Sky Survey, with far-infrared observations from the Herschel Astrophysical Terahertz Large Area Survey (ATLAS…
Discovery of an Hα Emitting Disk around the Supermassive Black Hole of M31
Ricci, T. V.; Steiner, J. E.; Menezes, R. B.
Due to its proximity, the mass of the supermassive black hole in the nucleus of the Andromeda galaxy (M31), the most massive black hole in the Local Group of galaxies, has been measured by several methods involving the kinematics of a stellar disk which surrounds it. We report here the discovery of an eccentric Hα emitting disk around the black ho…
A report on the X-ray properties of the τ Sco-like stars
Massa, D.; Oskinova, L. M.; Ignace, R.
An increasing number of OB stars have been shown to possess magnetic fields. Although the sample remains small, it is surprising that the magnetic and X-ray properties of these stars appear to be far less correlated than expected. This contradicts model predictions, which generally indicate that the X-rays from magnetic stars are harder and more l…
VLT/FORS2 observations of four high-luminosity ULX candidates
Fabian, A. C.; Miniutti, G.; Roberts, T. P. +4 more
We obtained Very Large Telescope/FOcal Reducer and low dispersion Spectrograph spectra of the optical counterparts of four high-luminosity (LX ≥ 1040 erg s-1) Ultraluminous X-ray sources (ULX) candidates from the catalogue of Walton et al. We first determined accurate positions for the X-ray sources from archival C…
Studies of NGC 6720 with Calibrated HST/WFC3 Emission-line Filter Images. III. Tangential Motions using AstroDrizzle Images
O'Dell, C. R.; Henney, W. J.; Ferland, G. J. +1 more
We have been able to compare with astrometric precision AstroDrizzle processed images of NGC 6720 (the Ring Nebula) made using two cameras on the Hubble Space Telescope. The time difference of the observations was 12.925 yr. This large time base allowed the determination of tangential velocities of features within this classic planetary nebula. In…