The Normal Bladder

Macalpine, Jas.B.

doi:10.1016/b978-1-4831-9650-3.50008-x

Cited by 3 publications

(3 citation statements)

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“…It is very high, but the covering factor is an old problem of the BLR, and various ways has been postulated to solve it (see e.g. MacAlpine et al 2003). However, if we assume that the source has significant soft X-ray excess and instead of using a photon index Γ = 2.0 in the X-ray band we simply interpolate between the last UV point and X-ray point (this gives Γ = 2.65) the covering factor reduced to 0.24 -0.39.…”

Section: Covering Factormentioning

confidence: 99%

SALT long-slit spectroscopy of CTS C30.10: two-component Mg II line

Modzelewska

Czerny

Hryniewicz

et al. 2014

A&A

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Context. Quasars can be used as a complementary tool to SN Ia to probe the distribution of dark energy in the Universe by measuring the time delay of the emission line with respect to the continuum. The understanding of the Mg II emission line structure is important for cosmological application and for the black hole mass measurements of intermediate redshift quasars. Aims. Knowing the shape of Mg II line and its variability allows for identifying which part of the line should be used to measure the time delay and the black hole mass. We thus aim at determining the structure and the variability of the Mg II line, as well as the underlying Fe II pseudo-continuum. Methods. We performed five spectroscopic observations of a quasar CTS C30.10 (z = 0.9000) with the SALT telescope between December 2012 and March 2014, and we studied the variations in the spectral shape in the 2700 Å−2900 Å rest frame. Results. We show that the Mg II line in this source consists of two kinematic components, which makes the source representative of type B quasars. Both components were modeled well with a Lorentzian shape, and they vary in a similar way. The Fe II contribution seems to be related only to the first (blue) Mg II component. Broad band spectral fitting instead favor the use of the whole line profile. The contribution of the narrow line region to Mg II is very low, below 2%. The Mg II variability is lower than the variability of the continuum, which is consistent with the simple reprocessing scenario. The variability level of CTS C30.10 and the measurement accuracy of the line and continuum is high enough to expect that further monitoring will allow the time delay between the Mg II line and continuum to be measured.

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Section: Covering Factormentioning

confidence: 99%

SALT long-slit spectroscopy of CTS C30.10: two-component Mg II line

Modzelewska

Czerny

Hryniewicz

et al. 2014

A&A

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“…As of now there remain some outstanding difficulties in the current standard models to account for the observed broad hydrogen lines and some low-ionization lines in quasars, such as the steep Balmer decrement(e.g., Osterbrock 1984;Kwan & Krolik 1979, 1981Drake & Ulrich 1980;Korista & Goad 2004), the different redshift values among some broad lines, the excess line emission (i.e., the energy-budget discrepancy of Fe II, Mg II, He II lines in UV and optical wavebands, Netzer 1985;Collin-Souffrin 1986;MacAlpine 2003;Baldwin et al 2004;Joly et al 2008). The quasi-line emission could provide a solution for these long standing puzzles, for which the energy is extracted from the kinetic energy of the fast electrons, rather than from the continuum photons.…”

Section: Blend Modelmentioning

confidence: 99%

One possible explanation for the Balmer and Lyman line shifts in quasars

Liu,

Shi,

You

2015

Preprint

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Internal line shifts in quasars spectra have played a more prominent role in our understanding of quasar structure and dynamics. The observed different redshift among broad hydrogen lines is still an amazing puzzle in the study of quasars. We have argued that the broad hydrogen lines, as well as the low-ionization lines in quasars, are significantly contributed by the Cerenkov quasi-line emission of the fast electrons in the dense clouds/filaments/sheets (N H ≥ 10 14 cm −3 ); whereas this line-like radiation mechanism is invalid for producing the high ionization lines. In order to account for redshift difference, the Cerenkov line-like radiation mechanism could provide a plausible resolution: it is the 'Cerenkov line redshift', which is different from line to line, causes the peculiar redshift-differences among Lyα, Hα and Hβ lines. The different redshifts among different broad hydrogen lines could stand for an evidence to quantitatively support that the observed broad hydrogen lines should be blended by both the real line emission and the Cerenkov quasi-line emission. The good fitting to the observed redshifts of quasars confirms the existence of Cerenkov component in the broad hydrogen lines, which indicates that, in the blended Lyα line, the line-intensity of the Cerenkov component approximately equals that of the accompanying 'normal line' (an approximate equipartition of intensity between the two components in the broad Lyα line). This result illustrates the importance of the Cerenkov component in the broad lines of quasars, which can be further confirmed by future observations.

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“…Excess line emission. The greatest difficulty in the classical photoionization models should be the excess emission of some broad lines (e.g., the Fe ii and He ii lines in UV and optical wavebands, Netzer 1985;Collin-Souffrin 1986;MacAlpine 2003;Baldwin et al 2004;Joly et al 2008). …”

Section: Introductionmentioning

confidence: 99%

Significant Contribution of the Cerenkov Line-Like Radiation to the Broad Emission Lines of Quasars

Liu

Chen

You

et al. 2013

ApJ

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The Cerenkov line-like radiation in a dense gas (N H > 10 13 cm −3 ) is potentially important in the exploration of the optical broad emission lines of quasars and Seyfert 1 galaxies. With this quasi-line emission mechanism, some long standing puzzles in the study of quasars could be resolved. In this paper, we calculate the power of the Cerenkov line-like radiation in dense gas and compare with the powers of other radiation mechanisms by a fast electron to confirm its importance. From the observed gamma-ray luminosity of 3C 279, we show that the total number of fast electrons is sufficiently high to allow effective operation of the quasi-line emission. We present a model calculation for the luminosity of the Cerenkov Lyα line of 3C 279, which is high enough to compare with observations. We therefore conclude that the broad line of quasars may be a blend of the Cerenkov emission line with the real line produced by the bound-bound transition. A new approach to the absorption of the Cerenkov line is presented with the method of escape probability, which markedly simplifies the computation in the optically thick case. The revised set of formulae for the Cerenkov line-like radiation is more convenient in applications.

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The Normal Bladder

Cited by 3 publications

References 0 publications

SALT long-slit spectroscopy of CTS C30.10: two-component Mg II line

SALT long-slit spectroscopy of CTS C30.10: two-component Mg II line

One possible explanation for the Balmer and Lyman line shifts in quasars

Significant Contribution of the Cerenkov Line-Like Radiation to the Broad Emission Lines of Quasars

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