We present the discovery of 18 narrow line Seyfert 1 galaxies (NLS1). The optical spectra show the Balmer lines only slightly broader than the forbidden lines and contain strong Fe Ⅱ emission. No particularly soft X ...We present the discovery of 18 narrow line Seyfert 1 galaxies (NLS1). The optical spectra show the Balmer lines only slightly broader than the forbidden lines and contain strong Fe Ⅱ emission. No particularly soft X ray spectral slopes can be seen compared to a normal Seyfert 1 galaxies sample.展开更多
We present and analyze the variability of three Seyfert galaxies on intra-day timescales. We have analyzed in a uniform manner the 38 longest(> 30 ks) observations made for NGC 4051, MCG-06–30–15 and NGC 4151 by ...We present and analyze the variability of three Seyfert galaxies on intra-day timescales. We have analyzed in a uniform manner the 38 longest(> 30 ks) observations made for NGC 4051, MCG-06–30–15 and NGC 4151 by XMM-Newton between 2000 and 2015. The nuclei were quite active during essentially all of these observations and the overall X-ray fluxes(0.3–10 keV) varied by an order of magnitude. Most of the observations do appear to show characteristic timescales, estimated through their auto-correlation functions, ranging between ~2.9 ks and ~45.3 ks. The hard(2–10 keV) and soft(0.3–2.0 keV) bands are very well correlated but consideration of their hardness ratios shows that the sources typically soften during flares. We also provide new estimates of the central black hole masses for these three AGNs that support the hypothesis that Narrow Line Seyfert 1 galaxies have relatively small central black holes.展开更多
文摘We present the discovery of 18 narrow line Seyfert 1 galaxies (NLS1). The optical spectra show the Balmer lines only slightly broader than the forbidden lines and contain strong Fe Ⅱ emission. No particularly soft X ray spectral slopes can be seen compared to a normal Seyfert 1 galaxies sample.
基金funded by ESA Member States and NASAsupport from the China Scholarship Council (CSC, Grant 2016GXZR89)+2 种基金supported by the Chinese Academy of Sciences (CAS) President’s International Fellowship Initiative (PIFI, Grant 2016VMB073)supported by the National Natural Science Foundation of China (Grant Nos. 11873073, 11473054 and U1531245)by the Science and Technology Commission of Shanghai Municipality (14ZR 1447100)
文摘We present and analyze the variability of three Seyfert galaxies on intra-day timescales. We have analyzed in a uniform manner the 38 longest(> 30 ks) observations made for NGC 4051, MCG-06–30–15 and NGC 4151 by XMM-Newton between 2000 and 2015. The nuclei were quite active during essentially all of these observations and the overall X-ray fluxes(0.3–10 keV) varied by an order of magnitude. Most of the observations do appear to show characteristic timescales, estimated through their auto-correlation functions, ranging between ~2.9 ks and ~45.3 ks. The hard(2–10 keV) and soft(0.3–2.0 keV) bands are very well correlated but consideration of their hardness ratios shows that the sources typically soften during flares. We also provide new estimates of the central black hole masses for these three AGNs that support the hypothesis that Narrow Line Seyfert 1 galaxies have relatively small central black holes.
