We have carried out a systematic search with Spitzer Warm Mission and archival data for infrared emission from the hotspots in radio lobes that have been described by Hardcastle et al. (2004). These hotspots have been detected with both radio and X-ray observations, but an observation at an intermediate frequency in the infrared can be critical to distinguish between competing models for particle acceleration and radiation processes in these objects. Between the archival and warm mission data, we report detections of 18 hotspots; the archival data generally include detections at all four IRAC bands, the Warm Mission data only at 3.6 microns.
Using a theoretical formalism adopted from Godfrey et al. (2009), we fit both archival and warm mission spectral energy distributions [SEDs] - including radio, X-ray, and optical data from Hardcastle as well as the Spitzer data - with a synchrotron self-Compton [SSC] model, in which the X-rays are produced by Compton scattering of the radio frequency photons by the energetic electrons which radiate them. With one exception, a SSC model requires that the magnetic field be less or much less than the equipartition value which minimizes total energy and has comparable amounts of energy in the magnetic field and in the energetic particles. This conclusion agrees with those of comparable recent studies of hotspots, and with the analysis presented by Hardcastle et al. (2004). We also show that the infrared data rule out the simplest synchrotron only models for the SEDs. We briefly discuss the implications of these results and of alternate interpretations of the data.
A Polarization Study of 3 Blazars using the uGMRT at ~600 MHz
我们目前的结果，从我们的无线电偏振研究与升级的巨型米波射电望远镜（uGMRT）在波段4（550-850 MHz）的3个耀变体：射电大声类星体3C390.3，4C71.07和BL Lac对象1 ES 2344+514。本研究的目的是（一）进行可行性研究波段4偏振与uGMRT，（二）比较和对比的kpc尺度的blazar子类之间的偏振特性。我们在所有三个源中都检测到了线性偏振。两个类星体核心的线偏振度高于BL Lac天体，这与在耀变体秒差距尺度上观察到的类似差异一致。在3C390.3的热点区域观察到15%的最高分数极化，这也显示出扩展的极化瓣结构。1 ES 2344+514显示了核-晕结构，而4C71.07仍然未被解析。沿3C390.3的北部热点和1 ES 2344+514的核心的极化电矢量的旋转，建议射流弯曲。与北叶相比，3C390.3南叶的去极化更大，表明存在“Laing-Garrington效应”。多频率uGMRT极化数据正在进行中，以研究这些源的kpc尺度旋转测量，以寻找周围介质的差异。
From compact jets to extended lobes: radio morphologies of distant quasars at z > 4
Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences（孔科利天文台，HUN-REN 地球与天文学研究中心）；ELTE Eötvös Loránd University（布达佩斯罗兰大学）；Institute of Astronomy, Faculty of Physics, Astronomy and Informatics, NCU（托伦大学物理、天文与信息学院天体物理研究所）；Joint Institute for VLBI ERIC（甚长基线干涉测量联合研究所）；Shangqiu Normal University（商丘师范学院）；University of Science and Technology of China（中国科学技术大学）
Euclid: Quick Data Release (Q1) -- Optical hotspots in powerful radio galaxies
University of Hertfordshire（赫特福德大学）；INAF-Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；INAF, Istituto di Radioastronomia（意大利国家天体物理研究所射电天文研究所）；INAF-Istituto di Astrofisica e Planetologia Spaziali（意大利国家天体物理研究所天体物理学与行星科学研究所）；Durham University（杜伦大学）；Leiden University（莱顿大学）；Roma Tre University（罗马三大）；INAF-Osservatorio Astronomico di Roma（意大利国家天体物理研究所罗马天文台）；University of Oslo（奥斯陆大学）
Galactic-scale evolution of classical and complex radio galaxies. Impact of ambient morphology and jet geometry
Istituto Nazionale di Astrofisica (INAF) – Istituto di Radioastronomia (IRA)（意大利国家天体物理研究所（INAF）- 射电天文研究所）；Indian Institute of Astrophysics（印度天体物理研究所）；Núcleo de Astrofísica, Universidade Cidade de São Paulo（圣保罗城市大学天体物理中心）；INAF/Osservatorio Astrofisico di Torino（意大利国家天体物理研究所/都灵天文台）；Department of Physics, University of Bath（巴斯大学物理系）；Department of Physics, University of Pretoria（比勒陀利亚大学物理系）；Centre for Radio Astronomy Techniques and Technologies, Department of Physics and Electronics, Rhodes University（罗德斯大学物理与电子学院射电天文技术与方法中心）；Istituto Nazionale di Astrofisica (INAF) - Istituto di Astrofisica e Planetologia Spaziali (IAPS)（意大利国家天体物理研究所（INAF）- 天体物理学与行星科学研究所）
The high-redshift radio galaxy 3C 294 at low frequencies: radio detection of the X-ray Ghost
Cavendish Laboratory, University of Cambridge（剑桥大学卡文迪许实验室）；Kavli Institute for Cosmology, University of Cambridge（剑桥大学卡弗里宇宙学研究所）；Centre for Extragalactic Astronomy, Department of Physics, Durham University（杜伦大学物理系河外天文中心）；Institute for Computational Cosmology, Department of Physics, Durham University（杜伦大学物理系计算宇宙学研究所）；Institute of Astronomy, University of Cambridge（剑桥大学天文学研究所）
