一个接近的类星体对在磁盘-磁盘星系的合并 z = 2.17
Yu-Ching Chen1,2, Xin Liu3,4, Adi Foord5
1Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Nature
|April 5, 2023
概括
天文学家在宇宙中午发现了第一个KPC级双类星系, SDSS J0749+2255,由星系合并主办. 这一发现为超大质量黑洞在宇宙活动高峰期的演变提供了关键的见解.
科学领域:
- * 天文学与天体物理学
- * 银河系进化
- * 宇宙学
背景情况:
- * 已知星系的合并会产生一对超大质量黑洞 (SMBH).
- * 这些SMBH对可以作为双类星体观察到,当它们都在积极增长时,特别是在千帕秒 (kpc) 尺度的分离时.
- * 虽然在低红移合并中发现了kpc尺度的双活跃星系核,但在宇宙中午没有明确的双类星体 (z ≈ 2).
研究的目的:
- 在宇宙中午发现和描述KPC尺度的双类星系统.
- 调查宿主星系的属性,并为这个系统提供结合证据.
- 了解超大质量黑洞的形成和进化.
主要方法:
- 斯隆数字天空调查 (SDSS) 的多波长观测 J0749+2255.
- * 对扩展宿主星系和低表面亮度的潮特征的分析.
- * 对类星核分离和宿主星系形态的研究.
主要成果:
- * SDSS J0749+2255被确定为一个Kpc尺度 (3.8Kpc分离) 双类星系统,红移z=2.17.
- *发现了扩展的主星系和潮特征,证实了星系的合并.
- * 观测到宿主星系是巨大的,紧的,并且以圆盘为主,缺乏突出的恒星凸起.
结论:
- 这是第一个在宇宙中午发现的无模糊的KPC级双类星系统.
- *宿主星系的特性表明,SMBH可能会在宿主恒星膨胀之前形成.
- * 该系统在轨道上可能在0.22Gyr内形成一个重力束的双星SMBH.
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