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INTEGRAL observation of the high-mass X-ray transient V 0332+53 during the 2005 outburst decline
Rodriguez, J.; Mowlavi, N.; Wilms, J. +7 more
The decline of the high mass X-ray transient V 0332+53 during the Dec. 2004 to Feb. 2005 outburst is analysed from the data recorded by INTEGRAL. The flux is shown to decrease exponentially until 2005 Feb. 10, with a decay time scale of ~30 days above 20 keV and ~20 days at lower energies, and to decrease linearly thereafter. The energy spectrum i…
The Circumstellar Environments of NML Cygni and the Cool Hypergiants
Humphreys, Roberta M.; Marengo, Massimo; Schuster, Michael T.
We present high-resolution HST WFPC2 images of compact nebulosity surrounding the cool M-type hypergiants NML Cyg, VX Sgr, and S Per. The powerful OH/IR source NML Cyg exhibits a peculiar bean-shaped asymmetric nebula that is coincident with the distribution of its H2O vapor masers. We show that NML Cyg's circumstellar envelope is likel…
Long-lived geomagnetic storms and coronal mass ejections
Gopalswamy, N.; Yashiro, S.; Lara, A. +3 more
Coronal mass ejections (CMEs) are major solar events that are known to cause large geomagnetic storms (Dst < -100 nT). Isolated geomagnetic storms typically have a main phase of 3-12 hours and a recovery phase of around 1 day. However, there are some storms with main and recovery phases exceeding ∼3 days. We trace the origin of these long-lived…
The Fundamental Plane for z = 0.8-0.9 Cluster Galaxies
Jørgensen, Inger; Chiboucas, Kristin; Barr, Jordi +3 more
We present the fundamental plane (FP) for 38 early-type galaxies in the two rich galaxy clusters RX J0152.7-1357 (z=0.83) and RX J1226.9+3332 (z=0.89), reaching a limiting magnitude of MB=-19.8 in the rest frame of the clusters. While the zero-point offset of the FP for these high-redshift clusters relative to our low-redshift sample is…
The Low-z Intergalactic Medium. II. Lyβ, O VI, and C III Forest
Shull, J. Michael; Danforth, Charles W.; Stocke, John T. +1 more
We present the results of a large survey of H I, O VI, and C III absorption lines in the low-redshift (z<0.3) intergalactic medium (IGM). We begin with 171 strong Lyα absorption lines (Wλ>=80 mÅ) in 31 AGN sight lines studied with the Hubble Space Telescope and measure corresponding absorption from higher order Lyman lines with FU…
Measuring M Dwarf Winds with DAZ White Dwarfs
Debes, John H.
Hydrogen atmosphere white dwarfs with metal lines, so-called DAZs, show evidence for ongoing accretion of material onto their surfaces. Some DAZs are known to have unresolved M dwarf companions, which could account for the observed accretion through a stellar wind. I combine observed Ca abundances of the DAZs with information on the orbital separa…
Probing the Faintest Stars in a Globular Star Cluster
Anderson, Jay; Rich, R. Michael; Stetson, Peter B. +10 more
NGC 6397 is the second closest globular star cluster to the Sun. Using 5 days of time on the Hubble Space Telescope, we have constructed an ultradeep color-magnitude diagram for this cluster. We see a clear truncation in each of its two major stellar sequences. Faint red main-sequence stars run out well above our observational limit and near to th…
Testing the inverse-Compton catastrophe scenario in the intra-day variable blazar S5 0716+71 . I. Simultaneous broadband observations during November 2003
Lähteenmäki, A.; Smith, N.; Chen, W. P. +72 more
Context.Some intra-day variable, compact extra-galactic radio sources show brightness temperatures severely exceeding 1012 K, the limit set by catastrophic inverse-Compton (IC) cooling in sources of incoherent synchrotron radiation. The violation of the IC limit, actually possible under non-stationary conditions, would lead to IC avalan…
The XMM-Newton survey of the ELAIS-S1 field. I. Number counts, angular correlation function and X-ray spectral properties
Berta, S.; D'Elia, V.; Fiore, F. +16 more
Aims.The formation and evolution of cosmic structures can be probed by studying the evolution of the luminosity function of the Active Galactic Nuclei (AGNs), galaxies and clusters of galaxies and of the clustering of the X-ray active Universe, compared to the IR-UV active Universe.
Methods: .To this purpose, we have surveyed with XMM-Newton t…
Thermodynamic structure of collision-dominated expanding plasma: Heating of interplanetary coronal mass ejections
Liu, Y.; Richardson, J. D.; Kasper, J. C. +2 more
We investigate the thermodynamic structure of interplanetary coronal mass ejections (ICMEs) using combined surveys of the ejecta between 0.3 and 20 AU. ICMEs are shown to have a moderate expansion in the solar wind compared with theoretical predictions. The expansion seems to be governed by a polytrope with γ ∼ 1.3 in this distance range. We find …