تقرير
Proof of CMB-driven X-ray brightening of high-z radio galaxies
| العنوان: | Proof of CMB-driven X-ray brightening of high-z radio galaxies |
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| المؤلفون: | Edmund Hodges-Kluck, Elena Gallo, Gabriele Ghisellini, Francesco Haardt, Jianfeng Wu, Benedetta Ciardi |
| المصدر: | Monthly Notices of the Royal Astronomical Society. 505(1) |
| بيانات النشر: | United States: NASA Center for Aerospace Information (CASI), 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | Astronomy, Astrophysics |
| الوصف: | We present a definitive assessment of the role of inverse Compton scattering of cosmic microwave background photons (IC/CMB) in the context of radio galaxies. Owing to the steep increase of the CMB radiation energy density, IC/CMB is supposed to become progressively more important with respect to radio synchrotron cooling as the redshift increases. For typical energies at play, this process will up-scatter the CMB photons into the X-ray band, and is thus expected to yield a redshift-dependent, concurrent X-ray brightening and radio dimming of the jet-powered structures. Here, we show how a conclusive proof of this effect hinges on high-resolution imaging data in which the extended lobes can be distinguished from the compact hotspots where synchrotron self-Compton dominates the X-ray emission regardless of redshift. We analyse Chandra and Very Large Array data of 11 radio galaxies between 1.3 ≲ z8 ≲ 4.3, and demonstrate that the emission from their lobes is fully consistent with the expectations from IC/CMB in equipartition. Once the dependence on size and radio luminosity are properly accounted for, the measured lobe X-ray luminosities bear the characteristic ∝(1 + z)4 proportionality expected of a CMB seed radiation field. Whereas this effect can effectively quench the (rest-frame) GHz radio emission from z ≳ 3 radio galaxies below ≲ 1 mJy, IC/CMB alone cannot be responsible for a deficit in high-z, radio-loud active galactic nuclei (AGNs) if – as we argue – such AGNs typically have bright, compact hotspots. |
| نوع الوثيقة: | Report |
| اللغة: | English |
| تدمد: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stab1314 |
| URL الوصول: | https://ntrs.nasa.gov/citations/20210015301 |
| ملاحظات: | 888692 NAS8- 03060 |
| رقم الأكسشن: | edsnas.20210015301 |
| قاعدة البيانات: | NASA Technical Reports |
Full Text Finder | تدمد: | 13652966 00358711 |
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| DOI: | 10.1093/mnras/stab1314 |