XMM-Newton first X-ray detection of the low-ionization broad absorption line quasar PG 1700+518

Ballo, L.; Piconcelli, E.; Vignali, C.; Schartel, N.

doi:10.1111/j.1365-2966.2011.18883.x

Cited by 15 publications

(23 citation statements)

References 63 publications

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“…LoBAL quasars are a subset (≈ 10%) of BAL quasars that have BALs from ions at lower ionization states such as Mg II or Al III (e.g., Weymann et al 1991;Sprayberry & Foltz 1992). They often show signs of dust reddening and are X-ray weaker than HiBAL quasars (e.g., Green et al 2001;Gallagher et al 2006;Gibson et al 2009). an absorbed power-law model (Ballo et al 2011). After correction for this strong absorption, PG 1700+518 is still ≈ 12 times X-ray weaker than expected.…”

Section: The Two Targeted Broad Absorption Line Quasarsmentioning

confidence: 99%

“…The small Γ eff value (although with a large uncertainty) for PG 1700+518 suggests that significant absorption ( 5 × 10 23 cm −2 ) and likely also Compton reflection is present. Note that a column density of ≈ 2 × 10 23 cm −2 was derived from the XMM-Newton data with an absorbed power-law model (Ballo et al 2011). The X-ray luminosities in the 4-20 keV band (listed in Table 2) for the two objects are 5.3 × 10 43 erg s −1 and 2.3 × 10 43 erg s −1 , smaller than expectations for typical quasars (> 10 44 erg s −1 ).…”

Section: Nustar Observations and Photometric Propertiesmentioning

confidence: 99%

“…For PG 1700+518, the dust reddening was not corrected; reddening correction would increase the 2500 Å flux density by ≈ 50% (i.e., more negative α OX ). The rest-frame 2 keV flux density was derived from the bestfit spectral model (see Section 2.2 above) for PG 1004+130, and it was adopted from the weighted-average value of Chandra and XMM-Newton observations in Ballo et al (2011) 31 The < 2 keV X-ray emission of PG 1700+518 likely has a small contribution from its star-forming activity (< 25%; Ballo et al 2011), which does not affect our analyses here. 32 For radio-quiet quasars, the Elvis et al (1994) sample is biased toward X-ray bright quasars, and the Elvis et al (2012) XMM-COSMOS sample consists mainly of less-luminous AGNs, and thus these composite SEDs were not adopted here; using these composite SEDs would make the X-ray emission of PG 1700+518 even weaker compared to the quasar samples.…”

Section: Spectral Energy Distributionsmentioning

confidence: 99%

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WEAK HARD X-RAY EMISSION FROM TWO BROAD ABSORPTION LINE QUASARS OBSERVED WITHNuSTAR: COMPTON-THICK ABSORPTION OR INTRINSIC X-RAY WEAKNESS?

Luo

Brandt

Alexander

et al. 2013

ApJ

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We present NuSTAR hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are among the optically brightest BAL quasars, yet they are known to be significantly X-ray weak at restframe 2-10 keV (16-120 times fainter than typical quasars). We would expect to obtain ≈ 400-600 hard X-ray ( 10 keV) photons with NuSTAR, provided that these photons are not significantly absorbed (N H 10 24 cm −2 ). However, both BAL quasars are only detected in the softer NuSTAR bands (e.g., 4-20 keV) but not in its harder bands (e.g., 20-30 keV), suggesting that either the shielding gas is highly Compton-thick or the two targets are intrinsically X-ray weak. We constrain the column densities for both to be N H ≈ 7 × 10 24 cm −2 if the weak hard X-ray emission is caused by obscuration from the shielding gas. We discuss a few possibilities for how PG 1004+130 could have Compton-thick shielding gas without strong Fe Kα line emission; dilution from jetlinked X-ray emission is one likely explanation. We also discuss the intrinsic X-ray weakness scenario based on a coronal-quenching model relevant to the shielding gas and disk wind of BAL quasars. Motivated by our NuSTAR results, we perform a Chandra stacking analysis with the Large Bright Quasar Survey BAL quasar sample and place statistical constraints upon the fraction of intrinsically X-ray weak BAL quasars; this fraction is likely 17-40%.

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Section: The Two Targeted Broad Absorption Line Quasarsmentioning

confidence: 99%

Section: Nustar Observations and Photometric Propertiesmentioning

confidence: 99%

Section: Spectral Energy Distributionsmentioning

confidence: 99%

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WEAK HARD X-RAY EMISSION FROM TWO BROAD ABSORPTION LINE QUASARS OBSERVED WITHNuSTAR: COMPTON-THICK ABSORPTION OR INTRINSIC X-RAY WEAKNESS?

Luo

Brandt

Alexander

et al. 2013

ApJ

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“…Further measurements of extreme X-ray weak quasars (Saez et al 2012) are incorporated by cyan circles. Additional observations are given for the quasars PG 2112+059 (blue open triangle; Schartel et al 2010Schartel et al , 2007, PG 1535+547 (green star; Ballo et al 2008), and PG 1700+518 (yellow open circle; Ballo et al 2011). Among all galaxies PG 0043+039 shows the most extreme α ox gradient (α ox = −2.55) based on the data taken in 2005.…”

Section: Opt/uv/x-ray Slopementioning

confidence: 99%

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

Kollatschny

Schartel

Zetzl

et al. 2015

A&A

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Context. 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. Aims. 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? Methods. 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. Results. 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 +0.57 −0.45 ) with moderate intrinsic absorption (N H = 5.5 +6.9 −3.9 × 10 21 cm −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 ≈ 2500 Å 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. Besides strong FeII multiplets and broad Balmer and HeI lines in the optical band we only detect a narrow [O ii]λ3727 emission line and a BAL system in the CaH λ3968, CaK λ3934 lines (blueshifted by 4900 km s −1 ) and in the He i λ3889 line (blueshifted by 5600 km s −1 ).

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“…Gallagher et al 1999;Wang et al 1999;Gallagher et al 2002;Chartas et al 2002;Grupe, Mathur & Elvis al. 2003;Gallagher et al 2004;Shemmer et al 2005;Miller et al 2006;Schartel et al 2007;Ballo et al 2008;Schartel et al 2010;Giustini et al 2011;Ballo et al 2011;Scott et al 2015). Saez et al (2012) started to unite the two strategies by spectroscopically studying a sample of 11 BAL QSOs with available multiple X-ray observations in order to search for spectral variability.…”

Section: Sample and Observationsmentioning

confidence: 99%

Unveiing the X‐ray/UV properties of disk winds in active galactic nuclei using broad and mini‐broad absorption line quasars

Giustini

2016

Astron Nachr

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We present the results of the uniform analysis of 46 XMM-Newton observations of six BAL and seven mini-BAL QSOs belonging to the Palomar-Green Quasar catalogue. Moderate-quality X-ray spectroscopy was performed with the EPICpn, and allowed to characterise the general source spectral shape to be complex, significantly deviating from a power law emission. A simple power law analysis in different energy bands strongly suggests absorption to be more significant than reflection in shaping the spectra. If allowing for the absorbing gas to be either partially covering the continuum emission source or to be ionised, large column densities of the order of 10 22−24 cm −2 are inferred. When the statistics was high enough, virtually every source was found to vary in spectral shape on various time scales, from years to hours. All in all these observational results are compatible with radiation driven accretion disk winds shaping the spectra of these intriguing cosmic sources.

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XMM-Newton first X-ray detection of the low-ionization broad absorption line quasar PG 1700+518

Cited by 15 publications

References 63 publications

WEAK HARD X-RAY EMISSION FROM TWO BROAD ABSORPTION LINE QUASARS OBSERVED WITHNuSTAR: COMPTON-THICK ABSORPTION OR INTRINSIC X-RAY WEAKNESS?

WEAK HARD X-RAY EMISSION FROM TWO BROAD ABSORPTION LINE QUASARS OBSERVED WITHNuSTAR: COMPTON-THICK ABSORPTION OR INTRINSIC X-RAY WEAKNESS?

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

Unveiing the X‐ray/UV properties of disk winds in active galactic nuclei using broad and mini‐broad absorption line quasars

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