Search Publications
A re-analysis of the iron line in the XMM-Newton data from the low/hard state in GX339-4
Done, Chris; Diaz Trigo, Maria
The detection of an extremely broad iron line in XMM-Newton MOS data from the low/hard state of the black hole binary GX339-4 is the only piece of evidence which unambiguously conflicts with the otherwise extremely successful truncated disc interpretation of this state. However, it also conflicts with some aspect of observational data for all othe…
The Advanced Camera for Surveys Nearby Galaxy Survey Treasury. V. Radial Star Formation History of NGC 300
de Jong, Roelof S.; Williams, Benjamin F.; Gilbert, Karoline M. +13 more
We present new Hubble Space Telescope (HST) observations of NGC 300 taken as part of the Advanced Camera for Surveys Nearby Galaxy Survey Treasury (ANGST). Individual stars are resolved in these images down to an absolute magnitude of M F814W = 1.0 (below the red clump). We determine the star formation history of the galaxy in six rad…
Asymmetries of solar coronal extreme ultraviolet emission lines
Peter, H.
Context. The profiles of emission lines formed in the corona contain information on the dynamics and the heating of the hot plasma. Only recently has data with sufficiently high spectral resolution become available for investigating the details of the profiles of emission lines formed well above 106 K. These show enhanced emission in th…
Variations of the spectral index of dust emissivity from Hi-GAL observations of the Galactic plane
de Bernardis, P.; Masi, S.; Montier, L. +14 more
Context. Variations in the dust emissivity are critical for gas mass determinations derived from far-infrared observations, but also for separating dust foreground emission from the Cosmic Microwave Background (CMB). Hi-GAL observations allow us for the first time to study the dust emissivity variations in the inner regions of the Galactic plane a…
The intriguing nature of the high-energy gamma ray source XSS J12270-4859
Mukai, K.; Belloni, T.; de Martino, D. +7 more
Context. The nature of the hard X-ray source XSS J12270-4859 is still unclear. It was claimed to be a possible magnetic cataclysmic variable of the Intermediate Polar type from its optical spectrum and a possible 860 s X-ray periodicity in RXTE data. However, recent observations do not support the latter variability, leaving this X-ray source stil…
Cassini observations of a Kelvin-Helmholtz vortex in Saturn's outer magnetosphere
Coates, A. J.; Krupp, N.; Dougherty, M. K. +9 more
We present Cassini observations of a plasma vortex in Saturn's dayside outer magnetosphere. The vortex encounter took place on 13 December 2004 as Cassini was travelling toward the planet. The spacecraft crossed the magnetopause 3 times, before being immersed in the low-latitude boundary layer. During the transition between the boundary layer and …
Broad-line region physical conditions along the quasar eigenvector 1 sequence
Marziani, P.; Bachev, R.; Sulentic, J. W. +3 more
We compare broad emission-line profiles and estimate line ratios for all major emission lines between Lyα and Hβ in a sample of six quasars. The sources were chosen with two criteria in mind: the existence of high-quality optical and ultraviolet spectra and the possibility of sampling the spectroscopic diversity in the 4D eigenvector 1 (4DE1) cont…
Cross-calibrating X-ray detectors with clusters of galaxies: an IACHEC study
Guainazzi, M.; David, L.; Nevalainen, J.
Aims: We used a sample of 11 nearby relaxed clusters of galaxies observed with the X-ray instruments XMM-Newton (EPIC) pn and MOS, Chandra ACIS-S and ACIS-I and BeppoSAX MECS to examine the cross-calibration of the energy dependence and normalisation of the effective area of these instruments as of December 2009. We also examined the Fe XXV/X…
Physical Conditions in a Coronal Mass Ejection from Hinode, Stereo, and SOHO Observations
Raymond, J. C.; Landi, E.; Hara, H. +1 more
In the present work, we analyze multiwavelength observations from Hinode, Solar and Heliospheric Observatory (SOHO), and STEREO of the early phases of a coronal mass ejection (CME). We use Hinode/EIS and SOHO/UVCS high-resolution spectra to measure the physical properties of the CME ejecta as a function of time at 1.1 and 1.9 solar radii. Hinode/X…
Untangling the chemical evolution of Titan's atmosphere and surface-from homogeneous to heterogeneous chemistry
Kaiser, Ralf I.; Maksyutenko, Pavlo; Ennis, Courtney +6 more