요약본 (Summary):
This paper discusses the X-ray properties of the cores of high redshift FRII radio galaxies, which are matched in isotropic radio power. The sample consists of 19 sources, including 10 radio galaxies and 9 quasars. The authors perform a comprehensive spectral analysis and compare their results to unification models that attribute the differences between radio galaxies and quasars to viewing angle, beaming, and the presence of a dust and gas torus.
The study reveals that the spectrum of all quasars can be fitted with a single power law, and the spectral index flattens with decreasing angle to the line of sight, indicating an increasing dominance of inverse Compton X-ray emission from the jet. For up to 70% of radio galaxies, intrinsic absorption is detected, and their core spectra are best fitted with either unabsorbed steep power laws or absorbed power laws with flatter spectral indices compared to observed radio-quiet quasars.
The authors conclude that the presence of a jet affects the spectral properties of nuclear X-ray emission in AGN, such that any steep-spectrum component must be masked by the jet or related emission. This supports the idea that lobe-dominated quasars are viewed at an angle to the line of sight, and suggests that the observed correlation between nuclear soft X-ray emission and core radio emission is due to the relativistically beamed origin of the emission at the base of the jet.
이 논문은 등방성 무선 전력과 일치하는 고 레드 시프트 FRII 라디오 은하의 코어의 X- 레이 특성에 대해 논의합니다. 이 샘플은 10 개의 라디오 은하와 9 개의 Quasar를 포함하여 19 개의 소스로 구성됩니다. 저자는 포괄적 인 스펙트럼 분석을 수행하고 무선 은하와 퀘이사의 차이점을 볼 각도, 빛나는 곳 및 먼지 및 가스 토러스의 존재에 기인하는 Unification 모델과 결과를 비교합니다.
이 연구는 모든 퀘이사의 스펙트럼에 단일 전력 법칙이 장착 될 수 있으며, 스펙트럼 지수는 시야로의 각도가 감소하여 제트로부터 역수 X- 선 방출의 지배력이 증가 함을 나타냅니다. 무선 은하의 최대 70%의 경우 고유 흡수가 감지되고, 핵심 스펙트럼에는 관찰 된 무선 쿼트 퀘이사에 비해 더 평평한 스펙트럼 지수가있는 흡수되지 않은 가파른 전력 법칙 또는 흡수 전력 법칙이 가장 잘 맞습니다.
저자는 제트의 존재가 AGN에서 핵 X- 선 방출의 스펙트럼 특성에 영향을 미치며, 따라서 가파른 스펙트럼 성분은 제트 또는 관련 방출에 의해 마스크되어야한다고 결론 지었다. 이것은 로브가 지배적 인 퀘이사가 시야에 각도로 볼 수 있다는 생각을 뒷받침하며, 핵 소프트 X- 선 방출과 코어 무선 방출 사이의 관찰 된 상관 관계는 제트기의 기저에서의 방출의 상대적으로 빔 기원에 기인한다는 것을 시사한다.
Excerpt from PDF:
arXiv:astro-ph/0511606v1 21 Nov 2005 Mon. Not. R. Astron. Soc. 000, 000–000 (0000) Printed 13 July 2018 (MN LATEX style file v2.2) High redshift FRII radio galaxies: X-ray properties of the cores E. Belsole1⋆, D. M. Worrall1 and M.J. Hardcastle2 1 Department of Physics, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK 2 School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield, Hertfordshire AL10 9AB Accepted . Received ; in original form ABSTRACT We present an extensive X-ray spectral analysis of the cores of 19 FRII sources in the redshift range 0.5 < z < 1.0 which were selected to be matched in isotropic radio power. The sample consists of 10 radio galaxies and 9 quasars. We compare our results with the expectations from a unification model that ascribes the difference between these two types of sources to the viewing angle to the line of sight, beaming and the presence of a dust and gas torus. We find that the spectrum of all the quasars can be fitted with a single power law, and that the spectral index flattens with decreasing angle to the line of sight. We interpret this as the effect of increasingly dominant inverse Compton X-ray emission, beamed such that the jet emission outshines other core components. For up to 70 per cent of the radio galaxies we detect intrinsic absorption; their core spectra are best fitted with an unabsorbed steep power law of average spectral index Γ = 2.1 and an absorbed power law of spectral index Γ = 1.6, which is flatter than that observed for radio-quiet quasars. We further conclude that the presence of a jet affects the spectral properties of absorbed nuclear emission in AGN. In radio galaxies, any steep-spectrum component of nuclear X-ray emission, similar to that seen in radio-quiet quasars, must be masked by a jet or by jet-related emission. Key words: galaxies: active: high redshift: nuclei; quasars: general; radio continuum: galax- ies; X-ray: galaxies 1 INTRODUCTION Active Galactic Nuclei (AGN) are observed across the whole elec- tromagnetic spectrum, but X-ray observations probe the process of converting gravitational energy into radiation most directly, as spectral and variability studies have shown that at least some of the X-ray emission comes from regions very close to the central en- gine. The most luminous AGN are found at high redshift and thus their study probes accretion processes and AGN environment early in the Universe. AGN comprise a large variety of objects, for which both sim- ple and more complicated classification schemes have been pro- posed. Unification Models explain the observed differences among AGN as the result of orientation with respect to the line of sight (e.g. Barthel 1989; Urry & Padovani 1995). In particular, it is pro- posed that powerful radio galaxies and radio-loud quasars are the same objects, and an obscuring torus is invoked to hide the nucleus of objects (namely radio galaxies) viewed at large angles to the jet axis (e.g. Barthel 1989). Large orientation-unbiased samples of AGN are ...더보기
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번역 (Translation):
ARXIV : Astro-PH/0511606V1 21 Nov 2005 Mon. 아니다. R. Astron. 사회 000, 000–000 (0000) 2018 년 7 월 13 일 인쇄 (MN 라텍스 스타일 파일 v2.2) 높은 레드 시프트 FRII 라디오 은하의 X- 레이 특성 : X- 레이 특성 : D. M. Worrall1 및 M.J. Hardcastle2 1 Bristol, Tyndall Avenue, Bristol Bs8 1ttl, School of School, Anndy, Annderty, and and and and and ancocation. Hertfordshire, College Lane, Hat Field, Hertfordshire AL10 9AB의 허용. 받았다 ; 원래 형태의 초록에서 우리는 등방성 무선 전력에서 일치하도록 선택된 레드 시프트 범위 0.5 이 논문은 arXiv에서 제공되는 자료를 바탕으로 업로드되었습니다.
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