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ATEL # 1375; P. Parisi, N. Masetti, R. Landi (INAF/IASF, Bologna), A. Bazzano (INAF/IASF, Rome), A.J. Bird (Univ. Southampton) and R. Walter (ISDC, Versoix)
on 1 Feb 2008; 15:26 UT
Password Certification: Nicola Masetti (email@example.com)
Subjects: Optical, X-ray, Gamma Ray, AGN
We report on an optical spectroscopic follow-up observation of source USNO-A2.0 1500_00589511, positionally coincident with the Swift/XRT and Chandra/HRC-I X-ray source #1 reported in Landi et al. (ATel #1322) and in Jonker & Kuiper (ATel #1326) respectively, and likely associated with the INTEGRAL source IGR J00333+6122/J00335+6126 (Kuiper et al. ATel #939; Bird et al. 2007, ApJS, 170, 175).
The observations were performed on 2008 January 5, starting at 22:34 UT, with the William Herschel Telescope (located in Canary Islands, Spain) plus ISIS-Red Arm using Grism R158R and a 1.5 arcsec slit. The total exposition time was 2000 s. The optical spectrum, which covers the useful range 5300-9000 Angstroms, shows several emission features, among which a very broad (observed FWZI ~ 680 Angstroms) Halpha+[NII] complex as well as narrow [OIII] lines. Using the narrow emission features, we determine a redshift z=0.105+-0.001 for the source.
The Swift/XRT and Chandra/HRC-I X-ray source #2 (Landi et al. ATel #1322; Jonker & Kuiper, ATel #1326) within the IBIS error circle of IGR J00333+6122 is instead associated with star TYC 4015-206-1 of intermediate spectral type without peculiar spectral features (Masetti et al., ATel #941). This, together with its soft X-ray spectrum points out that this source is not a symbiotic X-ray binary, but more likely a star with coronal emission, and rules out its association with IGR J00333+6122.
From all of the above we thus identify the hard X-ray source IGR J00333+6122 with the Seyfert 1 AGN USNO-A2.0 1500_00589511.
We thank P. Rodriguez-Gil and A. Cardwell for Service Programme observations performed with the WHT.