Search Publications
Saturn's cloud structure and temporal evolution from ten years of Hubble Space Telescope images (1994 2003)
Sánchez-Lavega, A.; Rojas, J. F.; Pérez-Hoyos, S. +1 more
We present a study of the vertical structure of clouds and hazes in the upper atmosphere of Saturn's Southern Hemisphere during 1994-2003, about one third of a Saturn year, based on Hubble Space Telescope images. The photometrically calibrated WFPC2 images cover the spectral region between the near-UV (218-255 nm) and the near-IR (953-1042 nm), in…
Initiation of hot coronal loop oscillations: Spectral features
Solanki, S. K.; Curdt, W.; Innes, D. E. +1 more
We explore the excitation of hot loop oscillations observed with the SUMER spectrograph on SOHO by analysing Fe XIX and Fe XXI spectral line profiles in the initial phase of the events. We investigate all 54 Doppler shift oscillations in 27 flare-like events, whose physical parameters have been measured so far. In nearly 50% of the cases, the spec…
Kinetic vs. multi-fluid models of H atoms in the heliospheric interface: a comparison
Izmodenov, V.; Alexashov, D.
The goal of this paper is to illuminate similarities and differences in the kinetic and multi-fluid models of the heliospheric interface, the region of solar wind interaction with the Local Interstellar Cloud (LIC), and then to explore physical reasons for these differences. We present a detailed comparison of two types of models. The first type i…
Global cooling and densification of the plasma sheet during an extended period of purely northward IMF on October 22-24, 2003
Wing, S.; Balogh, A.; Fujimoto, M. +6 more
The October 22-24, 2003 interplanetary magnetic cloud was characterized by an exceptionally long interval (~32 hours) of nearly purely northward interplanetary magnetic field (IMF). Following the northward IMF turning Cluster observed a gradual transition to a cold (<1 keV) and dense (~1-2 cm-3) plasma sheet (CDPS). Cluster observed …
Optical Morphology Evolution of Infrared Luminous Galaxies in GOODS-N
Le Floc'h, E.; Koo, D. C.; Melbourne, J.
We combine optical morphologies and photometry from HST, redshifts from Keck, and mid-infrared luminosities from Spitzer for an optically selected sample of ~800 galaxies in GOODS-N to track the morphology evolution of luminous infrared galaxies (LIRGs) since redshift z=1. We find a 50% decline in the number of LIRGs from z~1 to lower redshift, in…
Relationship between X-ray and ultraviolet emission of flares from dMe stars observed by XMM-Newton
Raassen, A. J. J.; Mewe, R.; Audard, M. +6 more
We present simultaneous ultraviolet and X-ray observations of the dMe-type flaring stars
Gamma-Ray Burst-Selected High-Redshift Galaxies: Comparison to Field Galaxy Populations to z ~ 3
Kouveliotou, C.; Fruchter, A. S.; Vreeswijk, P. M. +6 more
We study the internal structural properties of 37 long-duration gamma-ray burst (GRB) host galaxies imaged with the Hubble Space Telescope (HST). Our goal is to gain insights in the types of galaxies that give rise to GRBs and the relationship of GRB hosts to high-redshift galaxies selected through more traditional photometric methods. We measure …
XMM-Newton observations of three poor clusters: Similarity in dark matter and entropy profiles down to low mass
Arnaud, M.; Pratt, G. W.
We present an analysis of the mass and entropy profiles of three poor galaxy clusters (A1991, A2717 and MKW9) observed with XMM-Newton. The clusters have very similar temperatures (kT= 2.65, 2.53 and 2.58 keV), and similar redshifts (0.04 ⪉ z ⪉ 0.06). We trace the surface brightness, temperature, entropy and integrated mass profiles with excellent…
The Advanced Camera for Surveys Virgo Cluster Survey. V. Surface Brightness Fluctuation Calibration for Giant and Dwarf Early-Type Galaxies
Jordán, Andrés; Tonry, John L.; Côté, Patrick +7 more
As part of the Advanced Camera for Surveys (ACS) Virgo Cluster Survey, we have measured surface brightness fluctuations (SBFs) in a sample of 100 early-type Virgo galaxies. Distances derived from these measurements are needed to explore the three-dimensional structure of the Virgo Cluster, study the intrinsic parameters of globular clusters associ…
X-ray absorption lines suggest matter infalling onto the central black-hole of Mrk 509
de Rosa, A.; Cappi, M.; Ponti, G. +2 more
Evidence for both red- and blue-shifted absorption lines due to ionized Fe in the X-ray spectrum of the Seyfert 1 galaxy Mrk 509 is reported. These features appear to be transient on time-scales as short as ~20 ks, and have been observed with two different satellites, BeppoSAX and XMM-Newton. The red- and blue-shifted lines are found at E∼5.5 keV …