The peculiar optical-UV X-ray spectra of the X-ray weak quasar PG 0043+039

Abstract

The object PG 0043+039 has been identified as a broad absorption line (BAL) quasar based on its UV spectra. However, this optical luminous quasar has not been detected before in deep X-ray observations, making it the most extreme X-ray weak quasar known today. This study aims to detect PG 0043+039 in a deep X-ray exposure. The question is what causes the extreme X-ray weakness of PG 0043+039? Does PG 0043+039 show other spectral or continuum peculiarities? We took simultaneous deep X-ray spectra with XMM-Newton, far-ultraviolet (FUV) spectra with the Hubble Space Telescope (HST) and optical spectra of PG 0043+039 with the Hobby-Eberly Telescope (HET) and Southern African Large Telescope (SALT) in July, 2013. We have detected PG 0043+039 in our X-ray exposure taken in 2013. We presented our first results in a separate paper (Kollatschny et al. 2015). PG 0043+039 shows an extreme α_ox gradient (α_ox =-2.37). Furthermore, we were able to verify an X-ray flux of this source in a reanalysis of the X-ray data taken in 2005. At that time, it was fainter by a factor of 3.8 +- 0.9 with α_ox=-2.55. The X-ray spectrum is compatible with a normal quasar power-law spectrum (Γ=1.70_-0.45^+0.57) with moderate intrinsic absorption (N_H=5.5_-3.9^+6.9 +- 10^21cm^-2) and reflection. The UV/optical flux of PG 0043+039 has increased by a factor of 1.8 compared to spectra taken in the years 1990-1991. The FUV spectrum is highly peculiar and dominated by broad bumps besides Lyα. There is no detectable Lyman edge associated with the BAL absorbing gas seen in the CIV line. PG 0043+039 shows a maximum in the overall continuum flux at around λ 2500Å in contrast to most other AGN where the maximum is found at shorter wavelengths. All the above is compatible with an intrinsically X-ray weak quasar, rather than an absorbed X-ray emission.

18 pages, 18 figures, Astronomy & Astrophysics in press

References in corpus (14)

• An XMM-Newton survey of broad iron lines in Seyfert galaxies
• The X-ray-to-Optical Properties of Optically-Selected Active Galaxies Over Wide Luminosity and Redshift Ranges
• The XMM-Newton Serendipitous Survey. V. The Second XMM-Newton Serendipitous Source Catalogue
• A Catalog of Broad Absorption Line Quasars in Sloan Digital Sky Survey Data Release 5
• On the origin of radio emission in radio quiet quasars
• Emergence of a Broad-Absorption-Line Outflow in the Narrow-line Seyfert 1 Galaxy WPVS 007
• Weak Hard X-ray Emission from Broad Absorption Line Quasars: Evidence for Intrinsic X-ray Weakness
• A strong magnetic field in the jet base of a supermassive black hole
• Evidence for AGN Feedback in the Broad Absorption Lines and Reddening of Mrk 231
• X-ray spectral variability in PG1535+547: the changing-look of a 'soft X-ray weak' AGN
• Broad-line region structure and kinematics in the radio galaxy 3C 120
• The nature of the intranight variability of radio-quiet quasars
• XMM-Newton observation of the deep minimum state of PG 2112+059: A spectrum dominated by reflection from the accretion disk?
• Proving strong magnetic fields near to the central black hole in the quasar PG0043+039 via cyclotron lines

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• Swift, NuStar and XMM-Newton observations of the NLS1 galaxy RX J2317.8-4422 in an extreme X-ray low flux state