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相关论文: The composite X-ray spectrum of 3CRR Quasars

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We present the study on the X-ray emission for a sample of radio-detected quasars constructed from the cross-matches between SDSS, FIRST catalogs and XMM-Newton archives. A sample of radio-quiet SDSS quasars without FIRST radio detection is…

高能天体物理现象 · 物理学 2021-02-10 Minhua Zhou , Minfeng Gu

We performed a study of high redshift ($z>2$) quasars, looking for the main differences between Radio Loud Quasars (RLQ) and Radio Quiet Quasars (RQQ) in the X-ray band. Our sample of 472 RQQ and 81 RLQ was selected by cross-matching the…

高能天体物理现象 · 物理学 2023-01-10 F. Shaban , A. Siemiginowska , R. M. Suleiman , M. El-Nawawy , A. Ali

We present the results of an investigation into the X-ray properties of radio-intermediate and radio-loud quasars (RIQs and RLQs, respectively). We combine large, modern optical (e.g., SDSS) and radio (e.g., FIRST) surveys with archival…

宇宙学与河外天体物理 · 物理学 2015-05-20 B. P. Miller , W. N. Brandt , D. P. Schneider , R. R. Gibson , A. T. Steffen , Jianfeng Wu

We present X-ray spectral and long-term variability analyses of an unbiased sample of 361 optically selected radio-loud quasars (RLQs) utilizing sensitive serendipitous X-ray data from the Chandra and XMM-Newton archives. The spectral and…

高能天体物理现象 · 物理学 2021-05-18 Shifu Zhu , John Timlin , W. N. Brandt

We present the results of Chandra observations of six radio-loud quasars (RLQs) and one optically bright radio-quiet quasar (RQQ) at z = 4.1-4.4. These observations cover a representative sample of RLQs with moderate radio-loudness (R ~…

天体物理学 · 物理学 2009-11-10 L. C. Bassett , W. N. Brandt , D. P. Schneider , C. Vignali , G. Chartas , G. P. Garmire

Radio-loud quasars (RLQs) are more X-ray luminous than predicted by the X-ray-optical/UV relation (i.e. $L_\mathrm{x}\propto L_\mathrm{uv}^\gamma$) for radio-quiet quasars (RQQs). The excess X-ray emission depends on the radio-loudness…

高能天体物理现象 · 物理学 2020-06-25 S. F. Zhu , W. N. Brandt , B. Luo , Jianfeng Wu , Y. Q. Xue , G. Yang

We present the results of Chandra ACIS-S snapshot observations of six radio-loud quasars (RLQs) at z=3.5-4.7. These observations sample luminous RLQs with moderate-to-high radio-loudness (R=200-9600) and aim to connect the X-ray properties…

天体物理学 · 物理学 2008-11-26 L. A. Lopez , W. N. Brandt , C. Vignali , D. P. Schneider , G. Chartas , G. P. Garmire

(Abridged) We present a systematic study of the X-ray and multiwavelength properties of a sample of 17 highly radio-loud quasars (HRLQs) at z > 4 with sensitive X-ray coverage from new Chandra and archival Chandra, XMM-Newton, and Swift…

宇宙学与河外天体物理 · 物理学 2015-03-31 Jianfeng Wu , W. N. Brandt , Brendan P. Miller , Gordon P. Garmire , Donald P. Schneider , Cristian Vignali

We have investigated the jet-linked \mbox{X-ray} emission from highly radio-loud quasars (HRLQs; $\log R>2.5$) at high redshift. We studied the X-ray properties of 15 HRLQs at $z>4$, using new {\it Chandra} observations for six objects and…

高能天体物理现象 · 物理学 2018-10-31 Shifu Zhu , William N. Brandt , Jianfeng Wu , Gordon P. Garmire , Miller P. Branden

Radio-loud quasars (RLQs) are known to produce excess X-ray emission, compared to radio-quiet quasars (RQQs) of the same luminosity, commonly attributed to jet-related emission. Recently, we found that the HeII EW and $\alpha_{\rm{ox}}$ in…

高能天体物理现象 · 物理学 2021-04-30 John D. Timlin , Shifu Zhu , W. Niel Brandt , Ari Laor

We obtain a new sample of 1192 Type I quasars with the UV-optical, radio and X-ray wavebands coverage by combining \citet{Huang2022} and other matching data of SDSS-DR16 with FIRST, XMM-Newton, and Chandra Source Catalog, and a sample of…

宇宙学与河外天体物理 · 物理学 2023-10-17 L. Huang , Z. Y. Tu , N. Chang , F. F. Song , F. He , X. Y. Fu

This paper presents XMM-Newton and Chandra X-ray spectroscopy of ten flat-spectrum radio quasars (FSRQ) which are candidates to have an X-ray spectrum dominated by jet synchrotron emission. In all these FSRQ, which are less strongly…

天体物理学 · 物理学 2010-11-11 Hermine Landt , Paolo Padovani , Paolo Giommi , Matteo Perri , Chi C. Cheung

We report spectral, imaging, and variability results from four new XMM-Newton observations and two new Chandra observations of high-redshift (z > 4) radio-loud quasars (RLQs). Our targets span lower, and more representative, values of radio…

宇宙学与河外天体物理 · 物理学 2015-05-28 C. Saez , W. N. Brandt , O. Shemmer , L. Chomiuk , L. A. Lopez , H. L. Marshall , B. P. Miller , C. Vignali

The results from an X-ray spectral analysis of a large sample of quasars, observed with ASCA, are presented. Data reduction leaves 62 quasars, 35 radio-loud and 27 radio-quiet, suitable for spectral analysis. Differences are found between…

天体物理学 · 物理学 2009-10-31 James Reeves , Martin Turner

Over half the 3CRR sample of radio galaxies and quasars has been observed in X-rays with ROSAT pointed observations, and we present results from these observations, discussing many of the sources in detail. The improved spatial resolution…

天体物理学 · 物理学 2009-10-31 M. J. Hardcastle , D. M. Worrall

We present the X-ray analysis of a deep ~200 ksec Chandra observation of the compact steep spectrum radio-loud quasar 3C 186 (z=1.06) and investigate the contribution of the unresolved radio jet to the total X-ray emission. The spectral…

高能天体物理现象 · 物理学 2015-06-04 G. Migliori , A. Siemiginowska , A. Celotti

In this work, we revisit the relationship between [O III] line width $w_{\rm 90}$ (as the indicator of AGN outflow velocity) and the radio emission in RQQs by employing a large sample of Type I quasars ($\sim 37,000$) selected from the…

星系天体物理 · 物理学 2024-01-11 Mai Liao , Junxian Wang , Wenke Ren , Minhua Zhou

We analyze Chandra X-ray images of a sample of 11 quasars that are known to contain kiloparsec scale radio jets. The sample consists of five high-redshift (z >= 3.6) flat-spectrum radio quasars, and six intermediate redshift (2.1 < z < 2.9)…

The radio emission in radio-quiet quasars (RQQs) has been a long mystery and its physical origin remains unclear. In a previous work we find UV/optical more variable quasars have stronger X-ray emission, indicating a link between disc…

星系天体物理 · 物理学 2022-03-30 Mai Liao , Junxian Wang , Wenyong Kang , Minhua Zhou

Although radio-quiet quasars (RQQs), which constitute the majority of optically-identified quasar samples, are by no means radio silent the properties of their radio emission are only poorly understood. We present the results of a…

天体物理学 · 物理学 2009-10-30 Marek J. Kukula , James S. Dunlop , David H. Hughes , Steve Rawlings
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