scholarly journals X-Ray Sources of Cosmological Relevance

1983 ◽  
Vol 104 ◽  
pp. 7-18
Author(s):  
T. Maccacaro ◽  
I. M. Gioia
Keyword(s):  
Proportional Counter ◽  
Extragalactic Astronomy ◽  
X Ray ◽  
Einstein Observatory

The imaging and spectroscopic instruments onboard the Einstein Observatory (Giacconi et al. 1979) have been extensively used to study in detail the X-ray properties of a large variety of astronomical objects. In this paper we will briefly discuss some of the most relevant results on extragalactic astronomy obtained mainly with the Imaging Proportional Counter (IPC).

scholarly journals X-ray observations of symbiotic stars

1982 ◽  
Vol 70 ◽  
pp. 115-116
Author(s):  
David A. Allen
Keyword(s):  
Steady State ◽  
Proportional Counter ◽  
White Dwarfs ◽  
Symbiotic Stars ◽  
X Ray ◽  
The Past ◽  
Accretion Process ◽  
Einstein Observatory

AbstractObservations are reported of 19 symbiotic stars made with the imaging proportional counter of the Einstein Observatory. Three of the objects (HM Sge, V 1016 Cyg and RR Tel) were detected as soft X-ray sources. All three have shown slow-nova eruptions in the past 40 years. The data are interpreted as support of a model for slow novae involving thermonuclear events on white dwarfs which accrete from M giant companions. Symbiotic stars in their steady state, not being detected X-ray sources, are presumed to be powered by the accretion process alone.

scholarly journals Small-Scale Fluctuations and Anisotropies in the 1–3 keV X-Ray Background

1990 ◽  
Vol 139 ◽  
pp. 408-409
Author(s):  
X. Barcons ◽  
A. C. Fabian
Keyword(s):  
Spatial Distribution ◽  
Probability Distribution ◽  
Proportional Counter ◽  
Flux Distribution ◽  
Small Scale ◽  
X Ray ◽  
Deep Survey ◽  
X Ray Background ◽  
Einstein Observatory ◽  
Source Number

The spatial distribution of the 1–3 keV X-ray background (XRB) in five Einstein Observatory Imaging Proportional Counter fields has been analyzed. The autocorrelation function does not exceed 9% on scales ~5′. The observed count probability distribution is then used to check the source number-flux distribution at faint levels. Agreement with the Einstein Observatory deep survey is obtained. A cutoff in the number-flux distribution for a Euclidean population of sources at a flux approximately one-half of the deep survey limit, previously suggested by Hamilton and Helfand (1987), is also inferred.

X-ray observations of LMC X-3 with the monitor proportional counter aboard the HEAO 2 Einstein observatory - A comparison with Cygnus X-1

1983 ◽  
Vol 274 ◽  
pp. L65 ◽  
Author(s):  
M. C. Weisskopf ◽  
W. A. Darbro ◽  
R. F. Elsner ◽  
A. C. Williams ◽  
S. M. Kahn ◽  
...  
Keyword(s):  
Proportional Counter ◽  
X Ray ◽  
Einstein Observatory

scholarly journals X-Ray Observations of M87’s Halo

1980 ◽  
Vol 5 ◽  
pp. 689-693
Author(s):  
D. Fabricant ◽  
M. Lecar ◽  
P. Gorenstein
Keyword(s):  
Proportional Counter ◽  
Total Mass ◽  
Precise Determination ◽  
Virgo Cluster ◽  
Field Of View ◽  
Two Dimensional ◽  
X Ray ◽  
Einstein Observatory ◽  
Extended Emission

We briefly describe the soft X-ray image of M87 obtained using the imaging proportional counter aboard the Einstein Observatory. These data provide further strong evidence for the existence of a massive halo of dark matter surrounding M87 and allow a much more precise determination of its mass. Two pointing positions of the satellite were analyzed; one centered on M87, the other 63’ south and 25’ east of M87. The field of view of the imaging proportional counter is 60’ × 60’, and it attains a two dimensional spatial resolution of ˜ 1.5’ in a spectral range spanning 0.1 to 4.5 keV.As previous reports had suggested (Gorenstein et al. 1977; Fabricant et al. 1978), the present observations show M87 to be a strong, very extended, thermal X-ray source with a temperature near 2 keV, surrounded by weaker and still more extended emission from hotter gas associated with the Virgo cluster as a whole (Davison, 1978; Lawrence, 1978). We find M87 to have a total 0.5-4.5 keV X-ray luminosity of about 2 × 1043 ergs/sec, and an extrapolated 2-6 keV luminosity of approximately 1 × 1043 ergs/sec. The total mass of gas inferred from the X-ray measurement exceeds 1012 solar masses.

scholarly journals Review of Recent Observations of Cluster X-Ray Sources Using the Einstein Observatory

1980 ◽  
Vol 5 ◽  
pp. 727-734
Author(s):  
Stephen S. Murray
Keyword(s):  
Energy Resolution ◽  
Proportional Counter ◽  
Field Of View ◽  
Clusters Of Galaxies ◽  
X Ray ◽  
Moderate Energy ◽  
Einstein Observatory

In this contribution I shall review briefly some of the recent research being carried out at the Harvard-Smithsonian Center for Astrophysics in the study of X-ray emission from clusters of galaxies. This work is being done by several of us at CFA, and I particularly wish to thank Drs. Christine Jones, William Forman, and J. Patrick Henry for permission to discuss their results. The data have been obtained from the Einstein X-ray Observatory (HEAO-2) using the imaging instruments, and in particular the Imaging Proportional Counter (IPC). This gives X-ray images with about l½ arc minute resolution over a field of view of ½° × ½° and moderate energy resolution over a band from 0.5 to 3.0 keV. (For further details see Giacconi et al. 1979).

X-ray observations of GX 1 + 4 with the monitor proportional counter on board the Einstein Observatory

1985 ◽  
Vol 297 ◽  
pp. 288 ◽  
Author(s):  
R. F. Elsner ◽  
M. C. Weisskopf ◽  
K. M. V. Apparao ◽  
W. Darbro ◽  
B. D. Ramsey ◽  
...  
Keyword(s):  
Proportional Counter ◽  
X Ray ◽  
Einstein Observatory

scholarly journals Einstein Observations of the SNRs IC443, W44 and W49B

1983 ◽  
Vol 101 ◽  
pp. 273-280
Author(s):  
M.G. Watson ◽  
R. Willingale ◽  
J. P. Pye ◽  
D. P. Rolf ◽  
N. Wood ◽  
...  
Keyword(s):  
High Resolution ◽  
Proportional Counter ◽  
Molecular Clouds ◽  
Differential Absorption ◽  
Temperature Variations ◽  
X Ray ◽  
Einstein Observatory ◽  
Spatial Temperature

We present soft x-ray observations made with the Einstein Observatory Imaging Proportional Counter (IPC) of IC443, W44 and W49B (for details of the observatory and instruments see Giacconi et al. 1979). The x-ray emission from IC443 and W44 is clearly concentrated within the interior of the remnant with little or no evidence for a limb-brightened shell. Significant spectral differences are found across the x-ray images in both remnants which are interpreted as being due to a combination of differential absorption by molecular clouds and intrinsic spatial temperature variations. The distant remnant W49B is only just resolved in the IPC observations, but additional observations with the High Resolution Imager (HRI) indicate a similar “infilled” morphology to IC443 and W44.

scholarly journals Hard X-Ray Properties of Cataclysmic Variables

1979 ◽  
Vol 53 ◽  
pp. 135-138
Author(s):  
J.H. Swank
Keyword(s):  
Solid State ◽  
Proportional Counter ◽  
Cataclysmic Variables ◽  
High Energy ◽  
X Rays ◽  
Dwarf Novae ◽  
X Ray ◽  
Upper Limits ◽  
Energy Detectors ◽  
Einstein Observatory

The production of hard X-rays in accretion onto degenerate dwarfs appears manifested by such sources as the magnetic variables AM Herculis and 3U0311-227 and the dwarf novae SS Cygni, EX Hydrae and U Geminorum. Upper limits on flux above 2 keV from Ariel 5 (Watson, Sherrington and Jameson 1978) and from the high energy detectors of the HEAO A2 experiment show that only a few others usually exhibit more than ~10-11 ergs cm-2s-1 or ~ 1031 ergs s-1. However, while there are only a few sources that these experiments could study, their behavior is complex (Swank et al. 1977a; Ricketts, King and Raine 1979; Swank et al. 1978; Mason, Cordova and Swank 1979). This paper is a brief summary of results for AM Her, EX Hya, SS Cyg and U Gem obtained with the high energy detectors of the HEAO A2 experiment from 2-60 keV and the Solid State Spectrometer Experiment (SSS) with the Monitor Proportional Counter (MPC) on the Einstein Observatory.

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