scholarly journals The Diffuse Emission and a Variable Ultraluminous X‐Ray Point Source in the Elliptical Galaxy NGC 3379

2005 ◽  
Vol 635 (2) ◽  
pp. 1053-1061 ◽  
Author(s):  
Laurence P. David ◽  
Christine Jones ◽  
William Forman ◽  
Steven S. Murray
Keyword(s):  
Point Source ◽  
Elliptical Galaxy ◽  
Diffuse Emission ◽  
X Ray

scholarly journals Chandra observations of the dwarf starburst and Wolf-Rayet galaxies NGC 4449 and NGC 5253

2003 ◽  
Vol 212 ◽  
pp. 751-752
Author(s):  
Lesley K. Summers ◽  
Ian R. Stevens ◽  
David K. Strickland ◽  
Timothy M. Heckman
Keyword(s):  
Point Source ◽  
Massive Stars ◽  
Stellar Winds ◽  
Diffuse Emission ◽  
X Ray ◽  
Complex Morphology ◽  
Hα Emission ◽  
Supernova Explosions ◽  
Source Populations

We present an analysis of the Chandra observations of two dwarf starburst, Wolf-Rayet galaxies (NGC 4449 and NGC 5253). We have identified at least three different classes of objects within the X-ray point source populations, and we have found the diffuse emission, resulting from the stellar winds and supernova explosions of massive stars, to have a complex morphology and to consist of several components. Comparison with the Hα emission suggests the presence of ~ kpc-scale wind-blown bubbles and ruptured superbubbles.

XRMF applications of a monolithic, polycapillary, focusing x-ray optic

1996 ◽  
Vol 54 ◽  
pp. 240-241
Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla
Keyword(s):  
Trace Elements ◽  
Point Source ◽  
Focal Spot ◽  
Fluorescence Analysis ◽  
X Rays ◽  
Focal Distance ◽  
Spot Diameter ◽  
X Ray ◽  
Focal Spot Diameter

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.

CHANDRAOBSERVATIONS OF THE X-RAY POINT SOURCE POPULATION IN NGC 4636

2009 ◽  
Vol 695 (2) ◽  
pp. 1094-1110 ◽  
Author(s):  
Jennifer Posson-Brown ◽  
Somak Raychaudhury ◽  
William Forman ◽  
R. Hank Donnelly ◽  
Christine Jones
Keyword(s):  
Point Source ◽  
Source Population ◽  
X Ray

X-ray Microscopy in your Lab

2013 ◽  
Vol 21 (2) ◽  
pp. 7-7
Author(s):  
Charles Lyman
Keyword(s):  
Grain Size ◽  
Point Source ◽  
Visible Light ◽  
Light Microscope ◽  
Construction Materials ◽  
X Rays ◽  
X Ray ◽  
Projection Images ◽  
Straight Lines

Using X rays to produce magnified images of objects has been a goal for 150 years. Ever since Ernst Abbe declared in 1873 that light microscope resolution was limited by the wavelength of light, the search was on for a microscopy medium with a wavelength shorter than visible light (<500 nm). When Roentgen discovered X rays in 1895, it was thought that the new medium may have been found. Soon it was clear, however, that it was not easy to construct a physical lens for X rays because the rays penetrated all lens construction materials. X-ray “radiography images” of a few times magnification were possible but only as projection images, formed as X rays from millimeter-sized sources traveled in straight lines through the specimen to be captured on film. Unfortunately, even in the best cases, useful magnification was limited by the relatively large “point source” of X rays and the large grain size of X-ray film (both about 0.1–1.0 mm).

Suzaku Detection of the Charge Exchange Emission and Observation for the Soft X-ray Diffuse Emission

2009 ◽  
Author(s):  
N. Y. Yamasaki ◽  
K. Mitsuda ◽  
Y. Ezoe ◽  
T. Hagihara ◽  
K. Kimura ◽  
...  
Keyword(s):  
Charge Exchange ◽  
Diffuse Emission ◽  
X Ray

Electron Acceleration in Collapsing Magnetic Traps during the Solar Flare on July 19, 2012: Observations and Models

2017 ◽  
Vol 13 (S335) ◽  
pp. 90-93
Author(s):  
P. A. Gritsyk ◽  
B. V. Somov
Keyword(s):  
Point Source ◽  
Solar Flares ◽  
High Efficiency ◽  
Reverse Current ◽  
Electron Acceleration ◽  
Thick Target ◽  
Two Dimensions ◽  
Magnetic Traps ◽  
Thin Target ◽  
X Ray

AbstractUsing the appropriate kinetic equation, we considered the problem of propagation of accelerated electrons into the solar corona and chromosphere. Its analytical solution was used for modelling the M7.7 class limb flare occurred on July 19, 2012. Coronal above-the-loop-top hard X-Ray source was interpreted in the thin-target approximation, the foot-point source - in the thick-target approximation with account of the reverse-current electric field. For the foot-point source we found a good accordance with the RHESSI observations. For the coronal source we also got very accurate estimate of the power-law spectral index, but significant differences between the modelled and observed hard X-ray intensities were noticed. The last discrepancy was solved by adding the coronal magnetic trap model to the thin target model. The former one implies that the trap collapses in two dimensions, locks and accelerates particles inside itself. In our report, we confirm an existence and high efficiency of the electron acceleration in collapsing magnetic traps during solar flares. Our new results represent (e.g. for RHESSI observations) the theoretical prediction of the double step particle acceleration in solar flares, when the first step is the acceleration in reconnection area and the second one – the acceleration in coronal trap.

scholarly journals ROSAT observation of the HII region RCW 49 Possible discovery of a new Wolf-Rayet ring nebula

1995 ◽  
Vol 163 ◽  
pp. 76-77
Author(s):  
S. Mereghetti ◽  
T. Belloni
Keyword(s):  
Optical Emission ◽  
Young Star ◽  
Star Cluster ◽  
X Rays ◽  
Diffuse Emission ◽  
Hii Region ◽  
X Ray ◽  
Ring Nebula

We have observed the southern HII region RCW 49 with the ROSAT PSPC instrument. Part of the diffuse X-ray and optical emission present in this region might be associated with the X-ray selected WR star Th35-42 (WR20c). The young star cluster Westerlund 2 (which contains WR20a) is seen in X-rays as a centrally peaked, resolved source, surrounded by fainter diffuse emission.

A Centaurus A : Spectra of the Optical Filament

1975 ◽  
Vol 2 (6) ◽  
pp. 366-367 ◽  
Author(s):  
B.A. Peterson ◽  
R.J. Dickens ◽  
R.D. Cannon
Keyword(s):  
Radio Source ◽  
Elliptical Galaxy ◽  
Brightness Distribution ◽  
Radio Brightness ◽  
Dust Lane ◽  
X Ray ◽  
The Galaxy ◽  
Centaurus A

The radio source, Cen A, is large and complex with many peaks in the brightness distribution over an area about 4 x 10 degrees. The peculiar elliptical galaxy NGC 5128 lies between the two strong inner radio brightness peaks and is centred on a weaker central radio source. This radio source is in the centre of the dust lane which divides the galaxy and may be related to the infrared, X-ray and γ-ray sources.

scholarly journals Magnetic Fields & Ionized Gas in Elliptical Galaxy Halos

1990 ◽  
Vol 140 ◽  
pp. 459-462
Author(s):  
Richard G. Strom
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Elliptical Galaxy ◽  
Radio Sources ◽  
Early Type ◽  
Ionized Gas ◽  
X Ray ◽  
Galaxy Halos ◽  
Field Strengths

Faraday depolarization estimates of thermal densities within the components of double radio sources agree well with estimates from X-ray observations of hot halos around early-type galaxies, provided magnetic field strengths are close to their equipartition values. Internal Faraday dispersion is the main cause of the depolarization observed.

Sign in / Sign up

Export Citation Format

Share Document