Discovery of the X-ray transient Narrow-Line Seyfert 1 Galaxy WPVS 007 in a very low optical/UV flux state detected by Swift.

ATel #7622; Dirk Grupe (Morehead State University), S. Komossa (Max-Planck-Institut fuer Radioastronomie), Karen Leighly (University of Oklahoma), and Don Terndrup (The Ohio State University)
on 12 Jun 2015; 02:33 UT
Credential Certification: Dirk Grupe (dgrupe007@gmail.com)

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We report on the lowest flux state in the optical/UV of the Narrow Line Seyfert 1 galaxy WPVS 007 (RA-2000: 00 39 15.8, Dec-2000: -51 17 01, z=0.02861) since we started monitoring this AGN in the optical and UV in October 2005. WPVS 007 has been known to be a highly variable AGN in X-rays. It was discovered as a bright X-ray AGN during the ROSAT All Sky Survey in 1990, but when it was re-observed years later it appeared to have almost vanished from the X-ray sky (Grupe et al. 1995, A&A, 300, L21). Although our Swift monitoring displayed periods of re-brightening in 2010 and 2011 (Grupe et al., 2013, AJ, 146, 78), over the last few years its activity has declined, overall. The cause for this strong variability is most likely absorption. FUSE observations in 2003 revealed extremely strong broad absorption lines which are usually only known from high-luminosity quasars (Leighly et al. 2009, ApJ, 701, 78). When Swift observed WPVS 007 on 2015 February 21 it found it at the lowest state in the uvm2 filter with an apparent magnitude of 15.23+/-0.06 mag. We then requested an additional observation with Swift which was performed on 2015 February 28, which showed WPVS 007 even fainter at 15.38+/-0.08 in uvm2. Our most recent Swift observation on 2015 June 02 and 09 show that WPVS has returned into an intermediate state again. Chandra and HST director's discretionary time observations were requested by us and executed on March 28th and 30th, respectively. The Chandra observation reveals that WPVS 007 is in one of the lowest observed state so far, with an absorbed flux of 2 x 10^-18 W m^-2. HST spectroscopy shows that the broad absorption line feature previously detected is now almost gone (Leighly et al, ApJL submitted). We plan to continue monitoring WPVS 007 with a 7 day cadence with Swift. We thank Neil Gehrels for approving our various Swift ToO requests, and Belinda Wilkes and the HST team for approving the Chandra and HST DDT observations, respectively.