Swift observations of Swift J0911.2+4533

ATel #720; D. Grupe (PSU), J. Tueller (NASA/GSFC), C. Markwardt (U Md, NASA/GSFC), J. A. Kennea (PSU), A. Falcone (PSU), R. Mushotzky (NASA/GSFC), S. Barthelmy (NASA/GSFC), H. Krimm (NASA/GSFC), S. Campana (OAB), O. Godet (U Leicester), G. K. Skinner (CERS), K. Mukai (NASA/GSFC), S. T. Holland (NASA/GSFC), M. Ajello (MPE), J. Greiner (MPE), and T. Belloni (INAF)
on 3 Feb 2006; 16:02 UT
Credential Certification: Dirk Grupe (grupe@astro.psu.edu)

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We report on the X-ray detection in the 0.3-10 keV band of Swift J0911.2+4533. The source was detected in our ongoing Swift Burst Alert Telescope (BAT) hard X-ray survey (Tueller et al. ATEL #668 and #669, Kennea et al. ATEL #677, Ajello et al. ATEL #697). Swift J0911.2+4533 was observed on 2006-01-04 01:16 (UT start time) for a total of 5.5 ks and on 2005-01-07 17:36 (UT start time) for 8.9 ks with the X-ray Telescope (XRT) and UV/Optical Telescope (UVOT) on board Swift. We found a faint X-ray source at RA (2000) = 09 11 29.91 Dec (2000) = +45 28 02.1 with a position error of 4.0".

The position of this source coincides with 2MASX J091129.9+452806. Optical spectroscopy from the SDSS displays very strong [OIII] and [NII] emission lines which classify this source as a Seyfert 2 galaxy with a redshift z=0.0268. A combined power law fit to the BAT and XRT data shows that the X-ray spectrum of this AGN is highly absorbed with a column density of 3.7+1.8/-1.3 e23 cm-2 and a Photon index Gamma = 3.0+1.2/-0.8. The absorbed 0.2-10.0 keV flux is 1.7e-12 ergs/s/cm2, and corrected for absorption 1.5e-10 ergs/s/cm2. The intrinsic 0.2-10 keV luminosity is 3e44 ergs/s. The flux in the 15-150 keV band is 1.8e-11 ergs/s/cm2.

Swift J0911+4533 was not detected in the ROSAT All-Sky Survey in the 0.1-2.0 keV band, suggesting that it was also absorbed at the time of the RASS coverage in October 1990. This region was not observed by any other X-ray mission, either.

The UVOT analysis confirmed the strong reddening of this Seyfert 2 galaxy. We found the following magnitudes in the 6 UVOT filters:

V: 15.83+/-003

B: 16.89+/-0.06

U: 17.10+/-0.06

UVW1: 18.27+/-0.08

UVM2: 19.18+/-0.11

UVW2: 19.17+/-0.07

The UVOT image and the SDSS images suggest that the galaxy is viewed edge-on.