Heating by Acoustic Waves of Multiphase Media

Chelouche, Doron

doi:10.1088/0004-637x/692/1/375

Cited by 2 publications

(1 citation statement)

References 42 publications

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“…2(a), as noted many times (e.g. Rao et al 2006; Chelouche et al 2007), there are no absorbers to the bottom right‐hand panel of the figure, i.e. with large W λ2796 r and low‐H i column densities.…”

Section: Resultssupporting

confidence: 57%

Towards understanding the mass–metallicity relation of quasar absorbers: evidence for bimodality and consequences

Bouché

2008

Monthly Notices of the Royal Astronomical Society: Letters

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One way to characterize and understand H I-selected galaxies is to study their metallicity properties. In particular, we show that the metallicity of absorbers is a bivariate function of the H I column density (N H I ) and the Mg II equivalent width (W λ2796 r ). Thus, a selection upon W λ2796 r is not equivalent to a H I selection for intervening absorbers. A direct consequence for damped absorbers with log N H I > 20.3 that falls from the bivariate metallicity distribution is that any correlation between the metallicity [X/H] and velocity width (using W λ2796 r as a proxy) cannot be interpreted as a signature of the mass-metallicity relation akin to normal field galaxies. In other words, damped Lyα absorber (DLA) samples are intrinsically heterogeneous and the [X/H]-W λ2796 r or [X/H]v correlation reported in the literature arises from the H I cut. On the other hand, a sample of Mg II-selected absorbers, which are statistically dominated by lowest N H I systems (sub-DLAs) at each W λ2796 r , is found to have a more uniform metallicity distribution. We postulate that the bivariate distribution [[X/H](N H I , W λ2796 r )] can be explained by two different physical origins of absorbers, namely sight lines through the interstellar medium of small galaxies and sight lines through the out-flowing material. Several published results follow from the bivariate [X/H] distribution, namely (i) the properties of the two classes of DLAs, reported by Wolfe et al. and (ii) the constant dust-to-gas ratio for Mg II absorbers.

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Section: Resultssupporting

confidence: 57%

Towards understanding the mass–metallicity relation of quasar absorbers: evidence for bimodality and consequences

Bouché

2008

Monthly Notices of the Royal Astronomical Society: Letters

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Characterization of the emitting and absorbing media around the nucleus of the active galaxy UGC 11763 using XMM-Newton data

Cardaci

Santos-Lleó

Krongold

et al. 2009

A&A

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Aims. The detailed analysis of all data taken by the XMM-Newton satellite of UGC 11763 to characterize the different components that are emitting and absorbing radiation in the vicinity of the active nucleus. Methods. The continuum emission was studied through the EPIC spectra taking profit of the spectral range of these cameras. The high resolution RGS spectra were analyzed in order to characterize the absorbing features and the emission line features that arise in the spectra of this source. Results. A power law with a photon index Γ = 1.72−0.01 accounts for the continuum emission of this source in the hard X-rays from 10 down to 1 keV. At lower energies, a black body model with kT = 0.100 ± 0.003 keV provides a good description of the observed soft excess. The absorption signatures in the spectra of UGC 11763 are consistent with the presence of a two phase ionized material (log U = 1.65 +0.07 −0.08 ; 2.6 ± 0.1 and log N H = 21.2 ± 0.2; 21.51 ± 0.01 cm −2 , respectively) in the line of sight. The physical conditions found are consistent with the two phases being in pressure equilibrium. The low ionization component is more ionized than typically found for warm absorbers in other Seyfert 1 galaxies. There are also signatures of some emission lines: Ovii Heα(r), Ovii Heα(f), a blend of the Neix Heα triplet and Fexviii at λ 17.5 Å.

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Heating by Acoustic Waves of Multiphase Media

Cited by 2 publications

References 42 publications

Towards understanding the mass–metallicity relation of quasar absorbers: evidence for bimodality and consequences

Towards understanding the mass–metallicity relation of quasar absorbers: evidence for bimodality and consequences

Characterization of the emitting and absorbing media around the nucleus of the active galaxy UGC 11763 using XMM-Newton data

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