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B. L. Fleshman, K. M. Leighly (The University of Oklahoma), C. Matsumoto (Nagoya University), D. Grupe (Pennsylvania State University)
Narrow-line Seyfert 1 galaxies with high luminosities are likely to be among the highest specific accretion rate objects in the Universe. This is because if the width of the H\beta line is related to the dynamical mass, then the specific accretion rate \dot{M}/\dot{M}Edd\propto v-2L1/2.
We present new and archival X-ray and UV observations of the two luminous NLS1s RX~J0439.7-4540 and PHL 1092 (MV=-22.7 and -24.3 respectively). The X-ray spectra are very similar, consisting of a power law plus a prominent soft excess that can be modelled approximately by a black body. RX~J0439.7-4540 experiences remarkable spectral variability between the ASCA observation made in 1997 and the XMM-Newton observation made in 2005: the flux decreased by a factor of >10, and the photon index flattened from \Gamma=2.32 ± 0.09 to \Gamma=1.56 ±0.09.
Despite the similarity in X-ray properties, the UV spectra are spectacularly different. PHL 1092 shows weak, strongly blueshifted high-ionization lines, and strong low-ionization emission from \ion{Fe}{2}, similar to several other luminous NLS1s including PHL~1811. In contrast, RX~J0439.7-4540 has rather strong high-ionization lines, and weak \ion{Fe}{2}, more typical of a bright broad-line quasar.
Results and discussion of these similarities and differences will be presented.
This research is supported by NASA XMM-Newton grant NNG05GD01G and StSCI grant HST-GO-09894.01-A.
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Bulletin of the American Astronomical Society, 37 #4
© 2005. The American Astronomical Soceity.