scholarly journals On Uncertainties in Cross‐Correlation Lags and the Reality of Wavelength‐dependent Continuum Lags in Active Galactic Nuclei

1998 ◽  
Vol 110 (748) ◽  
pp. 660-670 ◽  
Author(s):  
Bradley M.  Peterson ◽  
Ignaz  Wanders ◽  
Keith  Horne ◽  
Stefan  Collier ◽  
Tal  Alexander ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Cross Correlation ◽  
Galactic Nuclei

scholarly journals XMM–Newton study of X-ray sources in the field of Willman 1 dwarf spheroidal galaxy★

2020 ◽  
Vol 499 (3) ◽  
pp. 3111-3129
Author(s):  
Sara Saeedi ◽  
Manami Sasaki
Keyword(s):  
Active Galactic Nuclei ◽  
Cross Correlation ◽  
Flux Ratio ◽  
Galactic Nuclei ◽  
Symbiotic Star ◽  
X Ray ◽  
Dwarf Spheroidal Galaxies ◽  
Infrared Wavelengths ◽  
Optical Flux ◽  
M Dwarf

ABSTRACT We present the results of the analysis of three XMM–Newton observations of the Willman 1 dwarf spheroidal galaxy (Wil 1). X-ray sources are classified on the basis of spectral analysis, hardness ratios, X-ray-to-optical flux ratio, X-ray variability, and cross-correlation with available catalogues in optical and infrared wavelengths. We catalogued 97 sources in the field of Wil 1. Our classification shows the presence of a β-type symbiotic star in Wil 1. We classified one M dwarf foreground star in the field of Wil 1. Moreover, 54 sources are classified as background active galactic nuclei and galaxies. Our study shows that the luminosity of the X-ray sources of Wil 1 does not exceed ∼1034 erg s−1 in the energy range of 0.2–12.0 keV, which is similar to observed luminosities of sources in nearby dwarf spheroidal galaxies.

INVESTIGATION OF INTRADAY VARIABILITY OF ACTIVE GALACTIC NUCLEI IN OPTICAL AND RADIO RANGES

2010 ◽  
Vol 1 (2) ◽  
pp. 111-115
Author(s):  
O. E. Volvach ◽  
L. N. Volvach ◽  
V. S. Bichkova ◽  
M. S. Kardashev ◽  
M. G. Larionov ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Intraday Variability

Hubble Space Telescopeand Ground‐based Observations of I Zw 1 and MRK 486 and the Variability of Polarization in Radio‐quiet Active Galactic Nuclei

1997 ◽  
Vol 488 (1) ◽  
pp. 202-215 ◽  
Author(s):  
Paul S. Smith ◽  
Gary D. Schmidt ◽  
Richard G. Allen ◽  
Dean C. Hines
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei

Polarization Variability of Active Galactic Nuclei and X‐Ray Binaries

1997 ◽  
Vol 487 (1) ◽  
pp. 142-152 ◽  
Author(s):  
Gang Bao ◽  
Petr Hadrava ◽  
Paul J. Wiita ◽  
Ying Xiong
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
X Ray ◽  
X Ray Binaries
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