Short timescale UV variability study in NGC 4151 using IUE data
نویسندگان
چکیده
منابع مشابه
pattern recognition in maintenance data using methodologies data minitng (cade study isfahan regional power electric company)
فعالیت های نگهداری و تعمیرات اطلاعاتی را تولید می کند که می تواند در تعیین زمان های بیکاری و ارایه یک برنامه زمان بندی شده یا تعیین هشدارهای خرابی به پرسنل نگهداری و تعمیرات کمک کند. وقتی که مقدار داده های تولید شده زیاد باشند، فهم بین متغیرها بسیار مشکل می شوند. این پایان نامه به کاربردی از داده کاوی برای کاوش پایگاه های داده چندبعدی در حوزه نگهداری و تعمیرات، برای پیدا کردن خرابی هایی که موجب...
15 صفحه اولMultiwavelength Observations of Short Time-scale Variability in Ngc 4151. Ii. Optical Observations
We present the results of an intensive ground-based spectrophotometric monitoring campaign of the Seyfert galaxy NGC 4151 for a period of over two months, with a typical temporal resolution of one day. Light curves for four optical continuum bands and the Hα and Hβ emission lines are given. During the monitoring period, the continuum at 6925 Å varied by ∼17% while the continuum at 4600 Å varied...
متن کاملCombined Long and Short Timescale X-ray Variability of NGC 4051 with RXTE and XMM-Newton
We present a comprehensive examination of the X-ray variability of the narrow line Seyfert 1 (NLS1) galaxy NGC 4051, one of the most variable AGN in the sky. We combine over 6.5 years of frequent monitoring observations by RXTE with a > 100 ks continuous observation by XMM-Newton and so present an overall 2-10 keV powerspectral density (PSD) covering an unprecedent frequency range of over 6.5 d...
متن کاملOSSE Observations of NGC 4151
We report results of a two-week observation of the Seyfert galaxy NGC 4151 with the Oriented Scintillation Spectrometer Experiment (OSSE) instrument on the Compton Gamma Ray Observatory (GRO). The source had a very soft spectrum which is best represented by a broken power law or Sunyaev-Titarchuk thermal Comptonization model. It can be characterized by an exponential shape with an e-folding ene...
متن کاملMultiwavelength Observations of Short Time-scale Variability in Ngc 4151. Iii. X-ray and Gamma-ray Observations
A series of ROSAT, ASCA and Compton Gamma-Ray Observatory (CGRO) observations of the Seyfert galaxy NGC 4151 were carried out during the period 1993 November 30 to December 13 as part of an intensive campaign to study the multiwavelength spectral characteristics of its short time-scale variability. In the softest X-ray bands monitored by ROSAT (0.1–0.4 keV, 0.5–1.0 keV) the source flux remained...
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ژورنال
عنوان ژورنال: Journal of Astrophysics and Astronomy
سال: 2018
ISSN: 0250-6335,0973-7758
DOI: 10.1007/s12036-018-9539-0