Discovery of a Classic FR II Broad Absorption Line Quasar from the FIRST Survey

Gregg, Michael D.; Becker, R. H.; Brotherton, Michael S.; Laurent-Muehleisen, S. A.; Lacy, Mark; White, R. L.

doi:10.1086/317194

Cited by 55 publications

(87 citation statements)

References 42 publications

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“…Gregg et al (2000) suggest that this quasar rather happens to be seen in a rare and short-lived state, showing both, BAL features and developed radio lobes at the same time, and postulate that it is a rejuvenated quasar, possibly through merger. Contrary to this conclusion we claim that these observations actually support the orientation model.…”

mentioning

confidence: 86%

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Binary black holes and tori in AGN

Zier

Biermann

2002

A&A

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Abstract. In this second paper, in a series of two, we determine the properties of the stellar torus that we showed in the first paper to result as a product of two merging black holes. If the surrounding stellar cluster is as massive as the binary black hole, the torque acting on the stars ejects a fraction which extracts the binary's angular momentum. After the black holes coalesced on scales of ∼10 7 yr, a geometrically thick torus remained. In the present article we show that a certain fraction of the stars has winds, shaped into elongated tails by the central radiation pressure, which are optically thick for line of sights aligned with them. These stars are sufficiently numerous to achieve a covering factor of 1, so that the complete torus is optically thick. This patchy structured torus is then compared with observations. We find the parameters of such a torus to be just in the right range in order to explain the observed large column densities in AGN and their temporal variations on time scales of about a decade. Within this model the broad absorption line quasars can be interpreted as quasars seen at intermediate inclination angles, with the line of sight grazing the edge of the torus. The half-opening angle of the torus is wider for major mergers and thus correlates with the central luminosity, as has been suggested previously. In this picture the spin of the merged black hole is possibly dominated by the orbital angular momentum of the binary. Thus the spin of the merged black hole points into a new direction, and consequently the jet experiences a spin-flip according to the spin-paradigm. This re-orientation could be an explanation for the X-shaped radio galaxies, and the advancing of a new jet through the ambient medium for Compact Symmetric Objects.

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mentioning

confidence: 86%

“…In the special case of the quasar FIRST J101614.3+520916 Gregg et al (2000) find BAL features in the optical and radio loud emission from lobes of classic FR II type at the same time. According to the authors this quasar has some properties in common with low-ionization BAL QSOs, as for example higher reddening.…”

mentioning

confidence: 91%

Binary black holes and tori in AGN

Zier

Biermann

2002

A&A

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“…The last column shows the notes on individual sources, i.e., details about the calculation of the BI or the reference from which we gathered information about the object. (6): X-ray analysis used in this work: a − spectral analysis, HR − hardness ratio analysis; Col. (7): number of individual XMM-Newton observations; Col. (8): notes on individual objects: "Mg II" denotes LoBAL, which BALnicity index were computed from Mg II absorption troughs; "Cr" -the optical spectrum was retrieved from Croom et al (2004); "C" -optical spectra courtesly provided by Cocchia et al (2007); "Br" -optical spectra from AXIS survey courtesly provided by Barcons et al (2002); "W" -BALnicity index value was taken from Weymann et al (1991); "H" -reconstructed spectrum from Hines & Wills (1995); "St" -reconstructed spectrum from Stern et al (2002); "P" -optical spectra courtesly provided by Prescott et al (2006); "Wi" -BALnicity index value was taken from Wills et al (1999); "Gr" -BALnicity index value was taken from Gregg et al (2000); "G" -BALnicity index value was taken from Goodrich et al (2001); "LH" -spectra were taken and reconstructed from Lehmann et al (2001); "Hu" -BALnicity index value was taken from Hutsemékers & Lamy (2000); "F" -reconstructed spectrum from Foltz et al (1987); "J" -reconstructed spectrum from Junkkarinen et al (1987); "Mor" -reconstructed spectrum from Morris et al (1991). The spectra for rest of the objects were retrieved from the SDSS archive and correspond to the following catalogues: Trump et al (2006); Shen et al (2008) and Gibson et al (2009).…”

Section: The Samplementioning

confidence: 99%

A revision of the X-ray absorption nature of BALQSOs

Streblyanska

Barcons

Carrera

et al. 2010

A&A

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Aims. Broad absorption-line quasars (BALQSOs) are key objects for studying the structure and emission/absorption properties of AGN. However, despite their fundamental importance, the properties of BALQSOs remain poorly understood. To investigate the X-ray nature of these sources, as well as the correlations between X-ray and rest-frame UV properties, we compile a large sample of BALQSOs observed by XMM-Newton. Methods. We collect information for 88 sources from the literature and existing catalogues, creating the largest BALQSO sample analysed optically and in X-ray to date. We performed a full X-ray spectral analysis (using unabsorbed and both neutral and ionized absorption models) on a sample of 39 sources with higher X-ray spectral quality, and an approximate hardness-ratio analysis on the remaining sources. Using available optical spectra, we calculate the BALnicity index and investigate the dependence of this optical parameter on different X-ray properties. Results. Using the neutral absorption model, we find that 36% of our BALQSOs have N n H < 5 × 10 21 cm −2 , lower than the expected X-ray absorption for these objects. However, when we used a physically-motivated model for the X-ray absorption in BALQSOs, i.e., ionized absorption, ∼90% of the objects are absorbed. The observed difference in ionized properties of sources with the BALnicity index (BI) = 0 and BI > 0 might be explained by different physical conditions of the outflow and/or inclination effects. The absorption properties also suggest that LoBALs may be physically different objects from HiBALs. In addition, we report on a correlation between the ionized absorption column density and BAL parameters. There is evidence (at the 98% level) that the amount of X-ray absorption is correlated with the strength of high-ionization UV absorption. Not previously reported, this correlation can be naturally understood in virtually all BALQSO models, as being driven by the total amount of gas mass flowing towards the observer. We also find a hint of a correlation between the BI and the ionization level detected in X-rays.

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“…In general, the radio-loud BALQs tend to be compact in the radio, similar to gigahertz-peaked spectrum (GPS) and compact steep spectrum (CSS) sources, which are thought to the progenitors of large-scale radio sources Montenegro-Montes et al 2009). It has been proposed that the BALs are not closely related with the inclinations, and may be associated with a relatively short-lived evolutionary phase with a large BAL-wind covering-fraction (e.g., Briggs et al 1984;Gregg et al 2000). We found that the two radio-loud steep spectrum BALQs in this current paper have different radio structures.…”

Section: Balqsmentioning

confidence: 48%

The optical variability of steep-spectrum radio quasars in the SDSS stripe 82 region

Gu¹,

2011

A&A

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Context. There have been many investigations of the optical variability of flat-spectrum radio quasars (FSRQs), but the optical variability of steep-spectrum radio quasars (SSRQs) has been poorly studied. Aims. We investigate the optical variability of SSRQs, comparing this with the optical variability of FSRQs. Methods. We measure the optical variability of 18 SSRQs and 15 FSRQs in the SDSS Stripe 82 region using SDSS DR7 released multi-epoch data covering about nine years. We determine the spectral index by fitting a power law to SDSS ugriz photometric data, and explore the relationship between this spectral index and source brightness. Results. For all SSRQs studied, we detect variations in r band flux of overall amplitude between 0.22 mag and 0.92 mag in different sources. Eight of 18 SSRQs display a bluer-when-brighter (BWB) trend. In contrast, the variability amplitude of 15 FSRQs in r band ranges from 0.18 to 0.97 mag, and 11 of 15 sources follow a BWB trend. For all SSRQs studied, we found an anti-correlation between the Eddington ratio and the variability amplitude in r band, which is similar to that in radio-quiet AGNs. This implies that the thermal emission from the accretion disk may be responsible for the variability in SSRQs, although the jet nonthermal emission cannot be excluded. In contrast, there is no correlation found for FSRQs, which implies that the mechanisms of variability in FSRQs may be different from that in SSRQs. The optical continuum variability of radio-loud broad absorption-line quasars (BALQs) are investigated for the first time here for two sources with steep radio spectra. Both radio-loud BALQs display variations with amplitudes of about 0.3 mag at r band. Their spectral variability all follow a BWB trend. In our previous analysis of a combined sample of 18 SSRQs and 44 FSRQs, we found that the line width of the broad Mg II emission line is broader for steeper radio spectral indices. It implies a disk-like broad line region (BLR) geometry may present in these quasars. In these 62 quasars, we found a ∼57% source percentage showing BWB trend in FSRQs, whereas it is ∼44% in SSRQs.

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Discovery of a Classic FR II Broad Absorption Line Quasar from the FIRST Survey

Cited by 55 publications

References 42 publications

Binary black holes and tori in AGN

Binary black holes and tori in AGN

A revision of the X-ray absorption nature of BALQSOs

The optical variability of steep-spectrum radio quasars in the SDSS stripe 82 region

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