发表机构
Manipal Academy of Higher Education; Institute of Astronomy Space and Earth Sciences; Indian Institute of Astrophysics; University of Oslo; Scuola Normale Superiore di Pisa; Indian Institute of Technology Indore（曼加洛尔高等教育局; 天体空间与地球科学研究所; 印度天体物理研究所; 奥斯陆大学; 比萨高等师范学院; 印多尔印度理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过对38个ULIRGs的射电观测，发现其能量主要来自AGN，多数源呈GPS/CSS特征，表明ULIRGs正演化为年轻射电星系，从而揭示了两者间的演化联系。
AI 中文摘要
超亮红外星系（ULIRGs）是富含气体星系重大并合的残余体。它们是尘埃系统，在红外波段极其明亮。恒星暴发和活动星系核（AGN）活动都为这些系统提供能量，但尚不清楚这两种活动如何与并合残余体的整体演化相关联。研究表明，ULIRGs与射电星系之间可能存在演化联系。对ULIRGs的射电观测是理解这一演化路径以及研究恒星暴发和AGN能量贡献的有用工具。我们利用升级后的巨米波射电望远镜（GMRT）观测数据和存档射电数据，对38个ULIRGs中的这些特征进行了系统性普查。在样本中，有30个源具有足够的频率覆盖以获得其射电频谱。其中，17个源显示出63至509 MHz之间的转折频率，以及0.009至44 Myr的光谱年龄变化。此外，8个源具有延展结构，其投影线性尺寸在0.7至11 kpc之间变化。我们的结果表明，这些系统中的主要能量来源是AGN而非恒星形成。我们样本中的大多数ULIRGs，特别是处于并合后阶段的那些，表现出千兆赫峰值谱（GPS）或致密陡谱（CSS）类特征，表明它们正在演化为年轻射电星系。我们注意到，六个具有高恒星形成活动的源显示出低频转折和较小的光谱年龄；我们确认这六个源隐藏着埋藏型AGN。这项研究使我们能够追踪ULIRGs与射电星系之间的演化联系。
英文摘要
Ultraluminous infrared galaxies (ULIRGs) are the remnants of the major mergers of gas-rich galaxies. They are dusty systems and are extremely luminous in the infrared. Both starbursts and active galactic nucleus (AGN) activity supply power in these systems, but it is not clear how these two activities are related to the overall evolution of the merger remnant. Studies suggest that there may be an evolutionary link between ULIRGs and radio galaxies. Radio observations of ULIRGs are a useful tool for understanding this evolutionary path as well as studying the energy contributions from starbursts and AGN. We perform a systematic census of these signatures in 38 ULIRGs using upgraded Giant Metrewave Radio Telescope observations and archival radio data. In the sample, 30 sources have enough frequency coverage to obtain their radio spectrum. Of these, 17 sources show a turnover frequency between 63 and 509 MHz and a spectral age variation from 0.009 to 44 Myr. Also, eight sources have extended structures with projected linear sizes varying from 0.7 to 11 kpc. Our results indicate that the primary energy source in these systems is the AGN rather than star formation. The majority of the ULIRGs in our sample, particularly those in the post-merger stage, exhibit gigahertz-peaked spectrum or compact steep spectrum-like characteristics, suggesting that they are evolving into young radio galaxies. We note that six sources with high star formation activity show a low-frequency turnover and a smaller spectral age; we confirm these six sources host buried AGN. This study enables us to trace the evolutionary link between ULIRGs and radio galaxies.
Comments28 pages, 65 figures
Journal refMonthly Notices of the Royal Astronomical Society, Volume 549, Issue 4, July 2026, stag948
