Redshifts of southern radio sources. VI

Jauncey, D. L.; Batty, M; Wright, A. E.; Peterson, Bruce A.; Savage, A.

doi:10.1086/162624

Cited by 35 publications

(20 citation statements)

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“…There are only minor variations at high frequencies, in good agreement with the properties observed by Wilkinson et al (1991). B1936-155: this blazar has a redshift of 1.657 (Jauncey et al 1984). It is classified as a high-peaking GPS source (Tornikoski et al 2001).…”

Section: B0743−006: Is a Gps Quasar Identified Bysupporting

confidence: 82%

Long term variability of gigahertz-peaked spectrum sources and candidates

Torniainen¹,

Tornikoski²,

Teräsranta³

et al. 2005

A&A

102

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Abstract.We have combined new data from our observing campaigns and data from the literature to construct the radio continuum spectra for a sample of mostly quasar-type high peaking gigahertz-peaked spectrum (GPS) source candidates. We have also studied the spectra and variability of so called "bona fide" GPS sources and other inverted-spectrum sources from the literature. For many of our sample sources we now have data spanning over two decades, enabling us to study their long term behaviour. Based on our earlier results we expected to find several new high peaking GPS sources. Instead we found out that even most of the "bona fide" GPS sources cease to adhere to the generic GPS source properties when using these well-sampled long term data sets. In our sample of 35 inverted-spectrum sources from the literature only five seem to be consistent with the GPS properties, and even out of these sources two are too sparsely sampled to firmly make conclusions about their variability. Thirteen of the "bona fide" GPS sources exhibit pronounced activity, which diverges from the low variability expected from these sources. None of our new candidates turned out to have both a convex spectrum and little to no variability, but there is one variable source with a consistently convex spectrum. All the rest have flat spectra, but the upper envelope of the spectrum is clearly convex for four extremely variable sources. Similar continuum spectra with a flat lower envelope and a convex upper envelope are observed for eight previously identified inverted-spectrum sources. According to this study the genuine quasar-type GPS sources are rare but there is a large number of highly variable sources that can have a convex spectrum peaking at high radio frequencies (up to ca. 100 GHz) during flares. Many of the GPS sources from the literature have too easily been classified as GPS sources based on too sparse data, and studying the long term variability is essential for identifying the sources with consistently convex continuum spectra.

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Section: B0743−006: Is a Gps Quasar Identified Bysupporting

confidence: 82%

Long term variability of gigahertz-peaked spectrum sources and candidates

Torniainen¹,

Tornikoski²,

Teräsranta³

et al. 2005

A&A

102

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“…An isotropic, monochoromatic radiation field is a good representation for a more complicated dust torus geometry as long as the emitting region is closer to the black hole than the dust torus radius (e.g., Finke 2016). PKS 2326−502 has an uncertain redshift of z=0.518 based on a weak detection of a single emission line identified with Mg II l2798 (Jauncey et al 1984). We use this redshift for our modeling, but one should keep its uncertainty in mind.…”

Section: Resultsmentioning

confidence: 99%

“…A detailed explanation of the model parameters can be found in Dermer et al (2009); there is a short description of them given in Table 3. We chose a relatively weak multi-color accretion disk (Shakura & Sunyaev 1973) to model the optical portion of the SED in the quiescent state, which is consistent with the lack of features in the source's optical spectrum (Jauncey et al 1984). The black hole's mass is not known, but we chose a standard value of  M 10 9…”

Section: Resultsmentioning

confidence: 99%

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Multiband Observations of the Quasar PKS 2326–502 during Active and Quiescent Gamma-Ray States in 2010–2012

Dutka

Carpenter

Ojha

et al. 2017

ApJ

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Quasi-simultaneous observations of the Flat Spectrum Radio Quasar PKS 2326−502 were carried out in the γ-ray, X-ray, UV, optical, near-infrared, and radio bands. Using these observations, we are able to characterize the spectral energy distribution (SED) of the source during two flaring and one quiescent γ-ray states. These data were used to constrain one-zone leptonic models of the SEDs of each flare and investigate the physical conditions giving rise to them. While modeling one flare required only changes in the electron spectrum compared to the quiescent state, modeling the other flare required changes in both the electron spectrum and the size of the emitting region. These results are consistent with an emerging pattern of two broad classes of flaring states seen in blazars. Type 1 flares are explained by changes solely in the electron distribution, whereas type 2 flares require a change in an additional parameter. This suggests that different flares, even in the same source, may result from different physical conditions or different regions in the jet.

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“…Despite uncertainties in the BLR physical structures, the same virial product that is used 8), measured manually in a double-blind manner. The line width for PKS 0938+18 was measured by Jauncey et al (1984); PKS 0440À00 was measured by Jackson & Browne (1991); 4C 45.51 was measured by Stickel & Kühr (1993); and 3C 422 was measured by Aldcroft et al (1994). Col. (10) to estimate black hole masses in AGNs using H is found to have analogs in the UV with C iv or Mg ii lines, over the luminosity range present in our AGN sample (Vestergaard 2002;McLure & Jarvis 2002;Kaspi et al 2005).…”

Section: Virial M Bh Measurementmentioning

confidence: 99%

Probing the Coevolution of Supermassive Black Holes and Quasar Host Galaxies

Peng¹,

Impey²,

Ho³

et al. 2006

ApJ

161

159

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At low redshift, there are fundamental correlations between the mass of supermassive black holes (M BH ) and the mass (M bulge ) and luminosity of the host galaxy bulge. We investigate the same relation at z k 1. Using virial mass estimates for 11 quasars at z k 2 to measure their black hole mass, we find that black holes at high z fall nearly on the same M BH versus R-band magnitude (M R ) relation (to $0.3 mag) as low-redshift active and inactive galaxies, without making any correction for luminosity evolution. Using a set of conservative assumptions about the host galaxy stellar population, we show that at z k 2 (10 Gyr ago), the ratio of M BH /M bulge was 3-6 times larger than today. Barring unknown systematic errors on the measurement of M BH , we also rule out scenarios in which moderately luminous quasar hosts at z k 2 were fully formed bulges that passively faded to the present epoch. On the other hand, five quasar hosts at z % 1 are consistent with the current-day M BH -M R relationship after taking into account evolution that is appropriate for E/S0 galaxies. Therefore, z % 1 host galaxies appear to fit the hypothesis that they are fully formed early-type galaxies. We also find that most quasar hosts with absolute magnitudes brighter than M R ¼ À23 cannot fade below L Ã galaxies today, regardless of their stellar population makeup, because their black hole masses are too high and they must arrive at the local M BH -M R relationship by z ¼ 0.

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Redshifts of southern radio sources. VI

Cited by 35 publications

References 0 publications

Long term variability of gigahertz-peaked spectrum sources and candidates

Long term variability of gigahertz-peaked spectrum sources and candidates

Multiband Observations of the Quasar PKS 2326–502 during Active and Quiescent Gamma-Ray States in 2010–2012

Probing the Coevolution of Supermassive Black Holes and Quasar Host Galaxies

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