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Addendum: Hubble Space Telescope Evidence for an Intermediate-Mass Black Hole in the Globular Cluster M15. II. Kinematic Analysis and Dynamical Modeling [Astron. J. 124, 3270 (2002)]
Gerssen, Joris; van der Marel, Roeland P.; Gebhardt, Karl +3 more
In Paper II, we reported the existence of a dark and compact mass component near the center of M15, based on an analysis of new data from the Hubble Space Telescope. Possible explanations for this mass component include (1) a single, intermediate-mass black hole (BH) and (2) a collection of dark remnants (e.g., neutron stars) that have sunk to the…
A self-consistent treatment of radiation in coronal loop modelling
Mason, H. E.; Bradshaw, S. J.
We perform a hydrodynamic simulation of a cooling coronal loop and calculate the time-dependent ion populations of the most abundant elements of the solar atmosphere at each time-step. We couple the time-dependent ion balance equations to the hydrodynamic equations in order to treat the energy loss through radiation in a self-consistent way by all…
Entropy scaling in galaxy clusters: Insights from an XMM-Newton observation of the poor cluster A1983
Arnaud, M.; Pratt, G. W.
An XMM-Newton observation of the cool (kT =2.1 keV ) cluster A1983, at z=0.044, is presented. Gas density and temperature profiles are calculated over the radial range up to 500 h50-1 kpc, corresponding to ~ 0.35 rv . The outer regions of the surface brightness profile are well described with a beta -model with beta =0.74, bu…
Using an MHD simulation to interpret the global context of a coronal mass ejection observed by two spacecraft
Lario, D.; Odstrcil, D.; Riley, Pete +4 more
In late February 1999 the ACE spacecraft observed a coronal mass ejection (CME) at 1 AU, in the ecliptic plane. Thirteen days later, Ulysses observed a CME at 5 AU and 22°S. We present a detailed analysis of the plasma, magnetic field, and composition signatures of these two events. On the basis of this comparison alone, it is not clear that the t…
3D dynamical evolution of the interstellar gas in the Gould Belt
Grenier, I. A.; Perrot, C. A.
The dynamical evolution of the Gould Belt has been modelled in 3D and compared to the spatial and velocity distributions of all HI and H2 clouds found within a few hundred parsecs from the Sun and to the Hipparcos distances of the nearby OB associations. The model describes the expansion of a shock wave that sweeps momentum from the amb…
Dust Grain Size Distributions from MRN to MEM
Sofia, Ulysses J.; Gordon, K. D.; Clayton, Geoffrey C. +2 more
Employing the maximum entropy method (MEM) algorithm, we fit interstellar extinction measurements that span the wavelength range 0.125-3 µm. We present a uniform set of MEM model fits, all using the same grain materials, optical constants, and abundance constraints. In addition, we are taking advantage of improved UV and IR data and better e…
An ISOCAM survey through gravitationally lensing galaxy clusters. I. Source lists and source counts for A370, A2218 and A2390
Kneib, J. -P.; Altieri, B.; Elbaz, D. +11 more
ESA's Infrared Space Observatory (ISO) was used to perform a deep survey with ISOCAM through three massive gravitationally lensing clusters of galaxies. The total area surveyed depends on source flux, with nearly seventy square arcminutes covered for the brighter flux levels in maps centred on the three clusters Abell 370, Abell 2218 and Abell 239…
A Multitransition CO Study of the Antennae Galaxies NGC 4038/9
Kuno, Nario; Zhu, Ming; Seaquist, E. R.
For the Antennae interacting galaxy pair, we have obtained high-quality, fully sampled 12CO J=1-0 and 3-2 maps of the regions surrounding the nuclei and the area of overlap between the two galaxies. The maps possess an angular resolution of 15" or 1.5 kpc, so far the highest resolution maps available at both the J=1-0 and 3-2 transition…
Observational evidence of new current sheets trailing coronal mass ejections
Webb, D. F.; Riley, P.; Burkepile, J. +1 more
Field line reconnection in the wake of coronal mass ejections (CMEs) is a fundamental aspect of some magnetically driven eruptive flare/CME models, e.g., the standard reconnection model [cf. Svestka and Cliver, 1992]. This model features a growing hot loop arcade beneath a rising X-type neutral point that is connected to the retreating CME. In mod…
Caught in the act: A helium-reionizing quasar near the line of sight to Q0302-003
Reimers, D.; Jakobsen, P.; Jansen, R. A. +1 more
We report the discovery of a quasar at z=3.050+/-0.003, closely coincident in redshift with the isolated low-opacity feature seen near z =~ 3.056 in the otherwise black portion of the He Ii Gunn-Peterson absorption trough seen toward the z=3.286 background quasar Q0302-003, located 6farcm5 away on the sky. We explore plausible models for the He Ii…