Search Publications
Investigation of Dual Active Nuclei, Outflows, Shock-heated Gas, and Young Star Clusters in Markarian 266
Sturm, E.; Veilleux, S.; Sanders, D. B. +24 more
Results of observations with the Spitzer, Hubble, GALEX, Chandra, and XMM-Newton space telescopes are presented for the luminous infrared galaxy (LIRG) merger Markarian 266. The SW (Seyfert 2) and NE (LINER) nuclei reside in galaxies with Hubble types SBb (pec) and S0/a (pec), respectively. Both companions are more luminous than L* galaxies and th…
A newly discovered young massive star cluster at the far end of the Galactic Bar
Figer, Donald F.; Davies, Ben; Najarro, Francisco +4 more
We present a near-infrared study of the candidate star cluster Mercer 81, located at the centre of the G338.4+0.1 H II region and close to the TeV gamma-ray source HESS 1640-465. Using Hubble Space Telescope/NICMOS imaging and VLT/ISAAC spectroscopy, we have detected a compact and highly reddened cluster of stars, although the bright stars in the …
Time Delays in Quasi-periodic Pulsations Observed during the X2.2 Solar Flare on 2011 February 15
Schmutz, W.; Zhukov, A. N.; Berghmans, D. +10 more
We report observations of quasi-periodic pulsations (QPPs) during the X2.2 flare of 2011 February 15, observed simultaneously in several wavebands. We focus on fluctuations on timescale 1-30 s and find different time lags between different wavebands. During the impulsive phase, the Reuven Ramaty High Energy Solar Spectroscopic Imager channels in t…
Broad-band study of hard X-ray-selected absorbed active galactic nuclei
de Rosa, A.; Ubertini, P.; Landi, R. +6 more
In this paper we report on the broad-band X-ray properties of a complete sample of absorbed Seyfert galaxies hard X-ray selected with INTEGRAL. Our sample is composed of 33 sources, of which 15 are newly discovered active galactic nuclei (AGN) above 20 keV (IGR sources), while 18 are already known type 2 AGN ('known'). For 17 sources (15 IGR + 2 '…
Assessing the long-term variability of Venus winds at cloud level from VIRTIS-Venus Express
Hueso, R.; Sánchez-Lavega, A.; Peralta, J.
The Venus Express (VEX) mission has been in orbit to Venus for more than 4 years now. The Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument onboard VEX observes Venus in two channels (visible and infrared) obtaining spectra and multi-wavelength images of the planet that can be used to sample the atmosphere at different altitude…
Ground-based Near-infrared Emission Spectroscopy of HD 189733b
Drossart, P.; Waldmann, I. P.; Tinetti, G. +3 more
We investigate the K- and L-band dayside emission of the hot-Jupiter HD 189733b with three nights of secondary eclipse data obtained with the SpeX instrument on the NASA Infrared Telescope Facility. The observations for each of these three nights use equivalent instrument settings and the data from one of the nights have previously been reported b…
Optical constants of Titan's stratospheric aerosols in the 70-1500 cm-1 spectral range constrained by Cassini/CIRS observations
Bézard, Bruno; Vinatier, Sandrine; de Kok, Remco +3 more
We utilized aerosol extinction coefficient inferred from Cassini/CIRS spectra in the far and mid infrared region to derive the extinction cross-section near an altitude of 190 km at 15°S (from far-IR) and 20°S (from mid-IR). By comparing the extinction cross section that are derived from observations with theoretical calculations for a fractal agg…
The Star Formation History of Leo T from Hubble Space Telescope Imaging
Bell, Eric F.; Dolphin, Andrew E.; Williams, Benjamin F. +9 more
We present the star formation history (SFH) of the faintest known star-forming galaxy, Leo T, based on deep imaging taken with the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2). The HST/WFPC2 color-magnitude diagram (CMD) of Leo T is exquisitely deep, extending ~2 mag below the oldest main-sequence turnoff, permitting excellen…
Dynamical properties of the Venus mesosphere from the radio-occultation experiment VeRa onboard Venus Express
Pätzold, M.; Häusler, B.; Tellmann, S. +4 more
The dynamics of Venus' mesosphere (60-100 km altitude) was investigated using data acquired by the radio-occultation experiment VeRa on board Venus Express. VeRa provides vertical profiles of density, temperature and pressure between 40 and 90 km of altitude with a vertical resolution of few hundred meters of both the Northern and Southern hemisph…
The First Observations of Low-redshift Damped Lyα Systems with the Cosmic Origins Spectrograph: Chemical Abundances and Affiliated Galaxies
Lehner, N.; Jenkins, E. B.; Prochaska, J. X. +6 more
We present Cosmic Origins Spectrograph (COS) measurements of metal abundances in eight 0.083 < z abs < 0.321 damped Lyα (DLA) and sub-DLA absorption systems serendipitously discovered in the COS-Halos survey. We find that these systems show a large range in metallicities, with -1.10 < [Z/H] < 0.31, similar to the spread foun…