Search Publications
Linking the X-ray and infrared properties of star-forming galaxies at z < 1.5
Magnelli, B.; Lutz, D.; Pannella, M. +16 more
We present the most complete study to date of the X-ray emission from star formation in high-redshift (median z = 0.7; z < 1.5), IR-luminous (LIR = 1010-1013 L⊙) galaxies detected by Herschel's PACS and SPIRE instruments. For our purpose, we take advantage of the deepest X-ray data to date, the Chandr…
Quiescent state and outburst evolution of SGR 0501+4516
Tiengo, A.; Götz, D.; Mereghetti, S. +9 more
We report on the quiescent state of the soft gamma repeater SGR 0501+4516 observed by XMM-Newton on 2009 August 30. The source exhibits an absorbed flux ∼75 times lower than that measured at the peak of the 2008 outburst, and a rather soft spectrum, with the same value of the blackbody temperature observed with ROSAT back in 1992. This new observa…
Water deuterium fractionation in the high-mass star-forming region G34.26+0.15 based on Herschel/HIFI data
Persson, C. M.; Lis, D. C.; Caux, E. +8 more
Understanding water deuterium fractionation is important for constraining the mechanisms of water formation in interstellar clouds. Observations of HDO and H_2^{18}O transitions were carried out towards the high-mass star-forming region G34.26+0.15 with the Heterodyne Instrument for the Far-Infrared (HIFI) instrument onboard the Herschel Space Obs…
Models of solar surface dynamics: impact on eigenfrequencies and radius
Morel, P.; Turck-Chièze, S.; Piau, L. +3 more
We study the effects of different descriptions of the solar surface convection on the eigenfrequencies of p modes. 1D evolution calculations of the whole Sun and 3D hydrodynamic and magnetohydrodynamic simulations of the current surface are performed. These calculations rely on realistic physics. Averaged stratifications of the 3D simulations are …
Molecular gas in the centre of nearby galaxies from VLT/SINFONI integral field spectroscopy - II. Kinematics
Saglia, R. P.; Nowak, N.; Thomas, J. +6 more
We present an analysis of the H2 emission-line gas kinematics in the inner ≲4 arcsec radius of six nearby spiral galaxies, based on adaptive optics-assisted integral-field observations obtained in the K band with SINFONI/VLT. Four of the six galaxies in our sample display ordered H2 velocity fields, consistent with gas moving…
Investigating evidence for different black hole accretion modes since redshift z ∼ 1
Cooper, M. C.; Georgakakis, A.; Salvato, M. +11 more
Chandra data in the COSMOS, AEGIS-XD and 4 Ms Chandra Deep Field South are combined with multiwavelength photometry available in those fields to determine the rest-frame U - V versus V - J colours of X-ray AGN hosts in the redshift intervals 0.1 < z < 0.6 (mean overline{z}=0.40) and 0.6 < z < 1.2 (mean overline{z}=0.85). This combinati…
Modelling the alumina abundance of oxygen-rich evolved stars in the Large Magellanic Cloud
Zijlstra, A. A.; McDonald, I.; Jones, O. C. +3 more
In order to determine the composition of the dust in the circumstellar envelopes of oxygen-rich asymptotic giant branch (AGB) stars, we have computed a grid of MODUST radiative-transfer models for a range of dust compositions, mass-loss rates, dust-shell inner radii and stellar parameters. We compare the resulting colours with the observed oxygen-…
Planet X revamped after the discovery of the Sedna-like object 2012 VP113?
Iorio, L.
The recent discovery of the Sedna-like dwarf planet 2012 VP113 by Trujillo and Sheppard has revamped the old-fashioned hypothesis that a still unseen trans-Plutonian object of planetary size, variously dubbed over the years as Planet X, Tyche and Telisto, might lurk in the distant peripheries of the Solar system. This time, the presence…
Search for X-ray occultations in active galactic nuclei
Salvati, M.; Risaliti, G.; Pietrini, P. +1 more
Recent time-resolved spectral studies of a few active galactic nuclei (AGNs) in hard X-rays revealed occultations of the X-ray primary source probably by broad-line region (BLR) clouds. An important open question on the structure of the circumnuclear medium of AGN is whether this phenomenon is common, i.e. whether a significant fraction of the X-r…
First detection and characterization of symbiotic stars in M31
Caldwell, Nelson; Mikołajewska, Joanna; Shara, Michael M.
Symbiotic binaries are putative progenitors of Type Ia supernovae. The census of Galactic symbiotic binaries is so incomplete that we cannot reliably estimate the total population of these stars, and use it to check whether that number is consistent with the observed Type Ia supernova rate in spiral galaxies. We have thus begun a survey of the nea…