SIMBAD references

We report identification of a narrow-line Seyfert 1 galaxy RX J1236.9+2656. X-ray emission from the NLS1 galaxy undergoes long-term variability with 0.1-2.0 keV flux changing by a factor of ∼2 within ∼3yr. The ROSAT PSPC spectrum of RX J1236.9+2656 is well represented by a power-law of Γ_X=3.7_–0.3^+0.5 absorbed by matter in our own Galaxy (N_H=1.33x10²⁰cm^–2 ). Intrinsic soft X-ray luminosity of the NLS1 galaxy is estimated to be ∼1.5x10⁴³erg/s in the energy band of 0.1-2.0keV. The optical spectrum of RX J1236.9+2656 is typical of NLS1 galaxies and shows narrow Balmer emission lines (1100km/s<FWHM<1700km/s) of Hβ, Hα, and forbidden lines of [O III] and [N II]. Fe II multiplets, usually present in optical spectra of NLS1 galaxies, are also detected in RX J1236.9+2656.