Swift follow-up observations of the new gamma-ray FSRQ BZQ J0447-0322

ATel #7203; S. Vercellone, P. Romano (INAF/IASF-Pa), F. Verrecchia, C. Pittori, F. Lucarelli, (ASDC and INAF/OAR), S. Colafrancesco (INAF-OAR and Wits University), G. Piano, and M. Tavani (INAF/IAPS and Univ. Roma Tor Vergata)
on 11 Mar 2015; 10:26 UT
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Credential Certification: Stefano Vercellone (stefano@ifc.inaf.it)

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Following the recent detection of gamma-ray emission (E>100 MeV) from the FSRQ BZQ J0447-0322 region by the AGILE/GRID (Pittori et al. 2015, ATel #7193), we performed a Swift Target of Opportunity observation of BZQ J0447-0322 on 2015-03-10 with an exposure of 3ks on source. We report the preliminary results.

The XRT/PC spectrum (2984 s), fitted with an absorbed power law, yields an absorbing column density of NH=3(+8-3)E20 cm-2 (consistent with the Galactic value of 3.47E20 cm-2; Kalberla et al. 2005), a photon index Gamma=1.5+/-0.3, and a mean flux of 3E-12 erg/cm2/s (0.3-10 keV, unabsorbed).

The UVOT observed the field simultaneously with the XRT in the following optical and UV filters. The preliminary observed magnitudes in the Vega system are:

MJD Filter Magnitude

57091.5157+/-0.0005 V 16.05+/-0.07 (stat) +/-0.01 (sys)

57091.5480+/-0.0375 B 16.38+/-0.04 (stat) +/-0.02 (sys)

57091.5470+/-0.0375 U 15.47+/-0.04 (stat) +/-0.02 (sys)

57091.5456+/-0.0380 W1 15.11+/-0.03 (stat) +/-0.03 (sys)

57091.5266+/-0.0104 M2 14.92+/-0.03 (stat) +/-0.03 (sys)

57091.5491+/-0.0377 W2 15.18+/-0.03 (stat) +/-0.03 (sys)

The magnitudes are not corrected for Galactic extinction due to a reddening of E(B-V)=0.04 (Schlafly et al. 2011) in the direction of the source.

BZQ J0447-0322 was previously observed by Swift in the period 2005-04-14 - 2005-08-22. Based on the 1SXPS catalogue (Evans et al., 2014, ApJS, 210, 8) the average unabsorbed flux was 1.43E-12 erg/cm2/s (0.3-10 keV, unabsorbed, with a power-law photon index = 1.89 (+0.17,-0.12)), a factor of 2 lower than the current observation.

We also report a brightening of the source in the UV-optical bands (about 0.5 mag brighter in all bands) with respect to the average 2005 values (reported in Nesci et al., 2007, AJ, 133, 695), consistently with what reported for the V band by Nesci (ATel #7202).

We warmly thank N. Gehrels, the Science Planners, and the Observatory Duty Scientists for having scheduled these observations.