تقرير
Effect of extinction on quasar luminosity distances determined from UV and X-ray flux measurements
| العنوان: | Effect of extinction on quasar luminosity distances determined from UV and X-ray flux measurements |
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| المؤلفون: | Zajaček, Michal, Czerny, Bożena, Khadka, Narayan, Martínez-Aldama, Mary Loli, Prince, Raj, Panda, Swayamtrupta, Ratra, Bharat |
| المصدر: | The Astrophysical Journal, 961:229 (18pp), 2024 February 1 |
| سنة النشر: | 2023 |
| المجموعة: | Astrophysics General Relativity and Quantum Cosmology High Energy Physics - Phenomenology High Energy Physics - Theory |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, General Relativity and Quantum Cosmology, High Energy Physics - Phenomenology, High Energy Physics - Theory |
| الوصف: | In Khadka et al. (2023), a sample of X-ray-detected reverberation-mapped quasars was presented and applied for the comparison of cosmological constraints inferred using two well-established relations in AGN -- the X-ray/UV luminosity ($L_{X}-L_{UV}$) relation and the broad-line region radius-luminosity ($R-L$) relation. $L_{X}-L_{UV}$ and $R-L$ luminosity distances to the same quasars exhibit a distribution of their differences that is generally asymmetric and positively shifted for the six cosmological models we consider. We demonstrate that this behaviour can be interpreted qualitatively to arise as a result of the dust extinction of UV/X-ray quasar emission. We show that the extinction always contributes to the non-zero difference between $L_{X}-L_{UV}$-based and $R-L$-based luminosity distances and we derive a linear relationship between the X-ray/UV colour index $E_{X-UV}$ and the luminosity-distance difference, which also depends on the value of the $L_{X}-L_{UV}$ relation slope. Taking into account the median and the peak values of the luminosity-distance difference distributions, the average X-ray/UV colour index falls in the range of $\overline{E}_{X-UV}=0.03-0.28$ mag for the current sample of 58 sources. This amount of extinction is typical for the majority of quasars and it can be attributed to the circumnuclear and interstellar media of host galaxies. After applying the standard hard X-ray and far-UV extinction cuts, heavily extincted sources are removed but overall the shift towards positive values persists. The effect of extinction on luminosity distances is more pronounced for the $L_{X}-L_{UV}$ relation since the extinction of UV and X-ray emissions both contribute. Comment: 22 pages, 11 figures, 4 tables; accepted by AAS journals |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.3847/1538-4357/ad11dc |
| URL الوصول: | http://arxiv.org/abs/2305.08179 |
| رقم الأكسشن: | edsarx.2305.08179 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.3847/1538-4357/ad11dc |
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