Accretion states, which are universally observed in stellar-mass black holes in X-ray binaries, are also anticipated in active galactic nuclei (AGN). This is the case at low luminosities, when the jet-corona coupling dominates the energy output in both populations. Previous attempts to extend this framework to a wider AGN population have been extremely challenging due to heavy hydrogen absorption of the accretion disc continuum and starlight contamination from the host galaxies. We present the luminosity-excitation diagram (LED), based on the [OIV]$_{25.9μm}$ and [NeII]$_{12.8μm}$ mid-infrared nebular line fluxes. This tool enables to probe the accretion disc contribution to the ionising continuum. When applied to a sample of 167 nearby AGN, the LED recovers the characteristic q-shaped morphology outlined by individual X-ray binaries during a typical accretion episode, allowing us to tentatively identify the main accretion states. The soft state would include broad-line Seyferts and about half of the Seyfert 2 population, showing highly excited gas and radio-quiet cores consistent with disc-dominated nuclei. The hard state mostly includes low-luminosity AGN ($\leq 10^{-3}\, \rm{L_{Edd}}$) characterised by low-excitation radio-loud nuclei and a negligible disc contribution. The remaining half of Seyfert 2 nuclei and the bright LINERs show low excitation at high accretion luminosities, and could be identified with the bright-hard and intermediate states. Their hosts show ongoing star formation in the central kiloparsecs. We discuss the above scenario, its potential links with the galaxy evolution picture and the possible presence of accretion state transitions in AGN, as suggested by the growing population of changing-look quasars.
SN2023ixf: ultraviolet-to-infrared radiative-transfer modeling of the nebular-phase evolution until 1000 days
Institut d’Astrophysique de Paris, CNRS-Sorbonne Université（巴黎天体物理研究所，法国国家科学研究中心-索邦大学）；French-Chilean Laboratory for Astronomy, IRL 3386, CNRS and Instituto de Astrofísica, Pontificia Universidad Católica de Chile（中法天文实验室，法国国家科学研究中心和智利天主教Pontificia大学天体物理研究所）；Cahill Center for Astrophysics, California Institute of Technology（加州理工学院卡希尔天体物理学中心）；Steward Observatory, University of Arizona（亚利桑那大学斯图尔德天文台）；Department of Astronomy, University of California, Berkeley（加州大学伯克利分校天文学系）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所（CSIC））；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚空间研究研究所）；Department of Physics and Astronomy, University of California, Davis（加州大学戴维斯分校物理与天文学系）
X-ray Simulations of Polar Gas in Accreting Supermassive Black Holes
最近的观测表明，活动星系核（AGN）的中红外（MIR）光谱有很大一部分来自极区。在本文中，我们研究了这种极性气体对活动星系核的X射线谱的影响，使用射线追踪模拟。考虑极性气体的两种几何形状，（1）对应于最佳拟合MIR模型的中空圆锥和（2）填充圆锥，两者都具有不同的柱密度（范围从$10^{21}-10^{22.5}$ cm $^{-2}$）以及围绕中心X射线源的环面。我们发现，极性气体导致低于$5$ keV的几条荧光线的等效宽度增加（例如，O、Ne、Mg、Si）。充满的几何结构对于极区成分来说是不可能的，因为许多1型活动星系核的X射线光谱会显示出遮蔽的特征。我们还考虑了额外的发射从窄线区域，如散射的幂律与许多光电离线从模糊AGN，和不同的开口角和物质组成的空心锥。这些模拟将为当前和未来的高光谱分辨率X射线仪器（如XRISM和Athena上的仪器）提供基本基准。
JWST Nebular Spectroscopy of SN 2023qov: Circumstellar Dust Emission in a Normal Type Ia Supernova
Purdue University（普渡大学）；Rutgers, the State University of New Jersey（新泽西州立罗格斯大学）；Space Telescope Science Institute（太空望远镜科学研究所）；Northwestern University（西北大学）；University of Pittsburgh（匹兹堡大学）；Stockholm University（斯德哥尔摩大学）；European Southern Observatory（欧洲南方天文台）
WTP19aalnxx: Discovery of a bright mid-infrared transient in the emerging class of low luminosity supernovae revealed by delayed circumstellar interaction
Radiation and Magnetic Pressure Support in Accretion Disks around Supermassive Black Holes and The Physical Origin of the Extreme Ultraviolet to Soft X-ray Spectrum
