15 research outputs found
A new look at spherical accretion in High Mass X-ray Binaries
Currently used model of spherical accretion onto a magnetized rotating
neutron star encounters major difficulties in explaining the entry rate of
accreting material into the stellar field and spin evolution of long-period
X-ray pulsars. These difficulties can be, however, avoided if the magnetic
field of the material captured by the neutron star is incorporated into the
model. The magnetic field of the flow itself under certain conditions controls
the accretion process and significantly affects the parameters of the accreting
material. The mode by which the accretion flow enters the stellar magnetosphere
in that case can be associated with Bohm (or turbulent) diffusion and the
torque applied to the neutron star appears to be substantially higher than that
evaluated in the non-magnetized accretion scenario.Comment: published in Proc. of WISAP 2011 Conference 'Waves and Instabilities
in Space and Astrophysical Plasmas', P.-L. Sulem & M. Mond (eds.), Eilat,
Israel, June 19-24, 201
The KPNO International Spectroscopic Survey. IV. H-alpha-selected Survey List 2
The KPNO International Spectroscopic Survey (KISS) is an objective-prism
survey for extragalactic emission-line objects. It combines many of the
features of previous slitless spectroscopic surveys with the advantages of
modern CCD detectors, and is the first purely digital objective-prism survey
for emission-line galaxies. Here we present the second list of emission-line
galaxy candidates selected from our red spectral data, which cover the
wavelength range 6400 to 7200 A. In most cases, the detected emission line is
H-alpha. The current survey list covers a 1.6-degree-wide strip located at
Dec(1950) = 43d 30' and spans the RA range 11h 55m to 16h 15m. The survey strip
runs through the center of the Bootes Void, and has enough depth to adequately
sample the far side of the void. An area of 65.8 sq. deg. is covered. A total
of 1029 candidate emission-line objects have been selected for inclusion in the
survey list (15.6 per sq. deg.). We tabulate accurate coordinates and
photometry for each source, as well as estimates of the redshift and
emission-line flux and equivalent width based on measurements of the digital
objective-prism spectra. The properties of the KISS emission-line galaxies are
examined using the available observational data. Although the current survey
covers only a modest fraction of the total volume of the Bootes Void, we
catalog at least twelve objects that appear to be located within the void. Only
one of these objects has been recognized previously as a void galaxy.Comment: Accepted for publication in the Astronomical Journal (April 2004); 20
pages, 12 figure