scholarly journals EUVE Observations of the Seyfert Galaxy MRK 279

1996 ◽  
Vol 152 ◽  
pp. 75-80
Author(s):  
C.-Y. Hwang ◽  
S. Bowyer ◽  
M. Lampton
Keyword(s):  
Seyfert Galaxy ◽  
Photometric Data ◽  
Collisional Excitation ◽  
X Ray ◽  
Euv Emission ◽  
Excitation Model ◽  
Intercloud Medium ◽  
Cloud Density ◽  
Over Time ◽  
Rule Out

We report EUVE spectral and photometric data of the Seyfert 1 galaxy MRK 279. The photometric data show large amplitude variations over time scales less than 10,000 s. The spectrum is characterized by several features between 80 and 100 Å. We compare the observed data with several models. We can rule out the possibility that the EUV emission is from a diffuse corona or intercloud medium. Models that assume the soft X-ray/EUV emission results from reprocessing in an optical BLR region are also inconsistent with the data. A collisional excitation model is consistent with the observations but requires a cloud density ≥ 1011 cm−3.

Transient collisional excitation X-ray laser generation with picoseconds laser pulses

2001 ◽  
Vol 11 (PR2) ◽  
pp. Pr2-39-Pr2-42 ◽  
Author(s):  
M. Kado ◽  
T. Kawachi ◽  
N. Hasegawa ◽  
M. Tanaka ◽  
K. Sukegawa ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Laser Generation ◽  
Collisional Excitation ◽  
X Ray

Gain profile of transient collisional excitation X-ray laser

2001 ◽  
Vol 11 (PR2) ◽  
pp. Pr2-55-Pr2-57
Author(s):  
M. Tanaka ◽  
T. Kawachi ◽  
M. Kado ◽  
N. Hasegawa ◽  
K. Sukegawa ◽  
...  
Keyword(s):  
Collisional Excitation ◽  
X Ray ◽  
Gain Profile

scholarly journals Review of the soft-X-ray laser research at CEL-V

1991 ◽  
Vol 9 (2) ◽  
pp. 493-499
Author(s):  
D. Naccache ◽  
J-L. Bourgade ◽  
P. Combis ◽  
C. J. Keane ◽  
J-P. Le Breton ◽  
...  
Keyword(s):  
Atomic Number ◽  
Collisional Excitation ◽  
X Ray ◽  
Order Of Magnitude ◽  
Laser Experiments ◽  
Magnitude Increase

We present some significant results of collisional excitation X-ray laser experiments in plasmas produced by a laser. We studied the amplification in Ne- and Ni-like ions by varying both the nature and the thickness of targets, the irradiation, and the wavelength of the driving laser. Some potentially interesting scalings as a function of the atomic number of the lasing element are demonstrated in the Ne-like system. An order-of-magnitude increase in gain in the Ni-like experiments was determined.

Transient collisional excitation X-ray lasers with 1-ps tabletop drivers

1999 ◽  
Vol 5 (6) ◽  
pp. 1441-1446 ◽  
Author(s):  
J. Dunn ◽  
A.I. Osterheld ◽  
Yuelin Li ◽  
J. Nilsen ◽  
V.N. Shlyaptsev
Keyword(s):  
Collisional Excitation ◽  
X Ray

A normal chest X-ray does not rule out the patient’s version

2021 ◽  
Author(s):  
Elena Forcén ◽  
María José Bernabé ◽  
Roberto Larrosa-Barrero
Keyword(s):  
X Ray ◽  
Normal Chest ◽  
Chest X Ray ◽  
Rule Out

Fractal X-ray time variability and spectral invariance of the Seyfert galaxy NGC5506

Nature ◽  
1987 ◽  
Vol 325 (6106) ◽  
pp. 696-698 ◽  
Author(s):  
Ian McHardy ◽  
Bozena Czerny
Keyword(s):  
Seyfert Galaxy ◽  
Time Variability ◽  
Spectral Invariance ◽  
X Ray

scholarly journals INTEGRAL observations of the GeV blazar PKS 1502+106 and the hard X-ray bright Seyfert galaxy Mkn 841

2011 ◽  
Vol 526 ◽  
pp. A125 ◽  
Author(s):  
E. Pian ◽  
P. Ubertini ◽  
A. Bazzano ◽  
V. Beckmann ◽  
D. Eckert ◽  
...  
Keyword(s):  
Seyfert Galaxy ◽  
X Ray

Comparative Study of Time-Dependent PAES and XPS on a Ni/Pd Surface

2017 ◽  
Vol 373 ◽  
pp. 313-316 ◽  
Author(s):  
Samantha Zimnik ◽  
Christian Piochacz ◽  
Sebastian Vohburger ◽  
Christoph Hugenschmidt
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Structural Changes ◽  
Time Dependent ◽  
Xps Analysis ◽  
Time Constants ◽  
X Ray ◽  
Residual Gas ◽  
Rule Out

We report on time-dependent Positron annihilation induced Auger Electron Spectroscopy (PAES) study on 0.5 monolayers (ML) Ni on polycrystalline Pd accompanied by complementary X-ray induced Photoelectron Spectroscopy (XPS). The normalized PAES spectra showed a significant decrease in the Ni intensity and an increase in the Pd intensity as a function of time. To rule out varying influence on the elements e.g. from surface contaminates due to the residual gas, a time-dependent XPS analysis was performed on pure Ni and Pd as well as to analyze the main contaminants C and O. The O fraction was found to be constant within the measurement time and the time constants for C significantly differ from those of Ni and Pd in the PAES data. Consequently, it was concluded that the PAES data show a superposition of C contamination and structural changes at the surface of Ni/Pd.

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