The Seyfert 1 AGN nature of IGR J20450+7530
ATel #2839; P. Parisi, N. Masetti, R. Landi, L. Bassani (INAF/IASF, Bologna), A. Bazzano (INAF/IASF, Rome), A. J. Bird (Univ. Southampton)
on 9 Sep 2010; 15:25 UT
Credential Certification: Nicola Masetti (email@example.com)
Subjects: Optical, X-ray, AGN
We report on an optical spectroscopic observation of object USNO-A2.0 1650-02316572 (RA(J2000) = 20h 44m
34.49s, Dec(J2000) = +75d 31m 58.9s), located in the Swift/XRT error box of the soft X-ray source #2 of
Landi et al. (ATel #2830). This object according to these authors, is the likely counterpart of the hard X-ray object IGR
J20450+7530 listed in the 4th IBIS Survey Catalog (Bird et al. 2010, ApJS, 186, 1).
The observations were performed under poor sky conditions (strong moon and thick cirrus) on 2010 August
2, starting at 23:54 UT with the BFOSC, installed on the 1.52m Loiano Telescope in Bologna, for a total
exposure time of 1800 s.
We found that the optical spectrum of the source shows broad (FWHM ~ 2800
km/s) Halpha and Hbeta emission lines at redshift z = 0.095 +/- 0.001, superimposed on a relatively flat
continuum. No narrow emissions are readily apparent.
From these features we thus identify IGR J20450+7530 as a Seyfert 1 Active Galactic Nucleus.
Considering the X-ray and optical properties of the object we can state that the
responsible of the hard X-ray emission detected with IBIS is source #2 of Landi et al. (ATel #2830).
We thank S. Galleti and Roberto Gualandi for the observation performed in service mode at the Loiano