English
Related papers

Related papers: CLASS: Coronal Line Activity Spectroscopic Survey

200 papers

[Abridged and Edited] We investigate nuclear light profiles in 135 ATLAS3D galaxies for which the Hubble Space Telescope (HST) imaging is available and compare them to the large scale kinematics obtained with the SAURON integral-field…

We are conducting a search for supermassive black holes (SMBHs) with masses below 10^7 M_sun by looking for signs of extremely low-level nuclear activity in nearby galaxies that are not known to be AGNs. Our survey has the following…

Astrophysics · Physics 2009-11-13 Himel Ghosh , Smita Mathur , Fabrizio Fiore , Laura Ferrarese

The infrared solar spectrum contains a wealth of physical data about the Sun and is being explored using modern detectors and technology with new ground-based solar telescopes. One such instrument will be the ground-based Cryogenic Near-IR…

Solar and Stellar Astrophysics · Physics 2022-06-22 Aatiya Ali , Alin Paraschiv , Kevin Reardon , Philip Judge

To improve our knowledge of nuclear emission in luminous QSOs at Cosmic Noon, we studied the X-ray emission of the WISE/SDSS-selected hyper-luminous (WISSH) QSO sample: 85 broad-line AGN with $L_{bol}>few\times 10^{47}\,erg\,s^{-1}$ at…

The corona is an integral component of Active Galactic Nuclei (AGN) which produces the bulk of the X-ray emission above 1--2 keV. However, many of its physical properties and the mechanisms powering this emission remain a mystery. In…

Coronal cavities, often associated with prominences, are crucial structures in understanding coronal heating and the eruption mechanism of Coronal Mass Ejections (CMEs). Previous studies have identified their lower density, higher…

Solar and Stellar Astrophysics · Physics 2025-12-23 Chenxi Huangfu , Hui Fu , Bo Li , ZhengHua Huang , MingZhe Sun , WeiXin Liu , XiaoYu Yu , LiDong Xia

We report systematic HCN J=1-0 (and CO) observations of a sample of 53 infrared (IR) and/or CO-bright and/or luminous galaxies, including seven ultraluminous infrared galaxies, nearly 20 luminous infrared galaxies, and more than a dozen of…

Astrophysics · Physics 2009-11-10 Yu Gao , Philip M. Solomon

Recently a distinctive class of hard X ray (HXR) sources located in the corona was found, which implies that the collisionally thick target model (CTTM) applies even to the corona. We investigated whether this idea can independently be…

Solar and Stellar Astrophysics · Physics 2015-06-15 Jeongwoo Lee , Daye Lim , G. S. Choe , Kap-Sung Kim , Minhwan Jang

Understanding the nature of high-$z$ dusty galaxies requires a comprehensive view of their ISM and molecular complexity. However, the molecular ISM at high-$z$ is commonly studied using only a few species beyond CO, limiting our…

The redshifted spectral line radiation emitted from both atomic fine-structure and molecular rotational transitions in the interstellar medium (ISM) of high-redshift galaxies can be detected in the centimetre, millimetre and submillimetre…

Astrophysics · Physics 2009-10-31 Andrew W. Blain , D. T. Frayer , J. J. Bock , N. Z. Scoville

We present X-ray observations of nine Weak-Line Radio Galaxies (WLRGs), optically classified as confirmed or possible Low Ionization Nuclear Emission-line Regions (LINERs). The data were taken from the Chandra, XMM, and BeppoSax archives.…

Astrophysics · Physics 2009-11-10 Alexander S. Rinn , Rita M. Sambruna , Mario Gliozzi

The high energy X-ray and ultraviolet (UV) radiation fields of exoplanet host stars play a crucial role in controlling the atmospheric conditions and the potential habitability of exoplanets. Major surveys of the X-ray/UV emissions from…

It is generally accepted that densities of quiet sun and active region plasma are sufficiently low to justify the optically thin approximation, and it is commonly used in the analysis of line emissions from plasma in the solar corona.…

Solar and Stellar Astrophysics · Physics 2018-02-14 Edward Thiemann , Phillip Chamberlin , Francis Eparvier , Luke Epp

Extreme coronal line emitters (ECLEs) are a rare class of galaxy that exhibit strong, high-ionization iron coronal emission lines in their spectra. In some cases, these lines are transient and may be the result of tidal disruption event…

Under the unified model for active galactic nuclei (AGNs), narrow-line (Type 2) AGNs are, in fact, broad-line (Type 1) AGNs but each with a heavily obscured accretion disk. We would therefore expect the optical continuum emission from Type…

We present a sample of 930 intermediate-mass black hole (IMBH) active galactic nuclei (AGNs) with black hole masses of $M_\mathrm{BH} \leqslant 2 \times 10^{6}$ M$_{\odot}$, uniformly selected from the Seventeenth Data Release of the Sloan…

Astrophysics of Galaxies · Physics 2026-05-12 Wen-Juan Liu , Luis C. Ho , Xiao-Bo Dong , Su Yao , Paulina Lira , Yicheng Guo

Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are characterized by strong, high-ionization lines, which are in contrast to what is found in typical AGNs. Here, we carry out an infrared analysis aimed at understanding the spectral…

Astrophysics of Galaxies · Physics 2023-07-05 F. C. Cerqueira-Campos , A. Rodríguez-Ardila , S. Panda , R. Riffel , L. G. Dahmer-Hahn , M. Marinello

Extreme coronal line emitters (ECLEs) are objects showing transient high-ionization lines in the centers of galaxies. They have been attributed to echoes of high-energy flares of ionizing radiation, such as those produced by tidal…

The nature of the interaction between low-excitation gas filaments at ~10^4 K, seen in optical line emission, and diffuse X-ray emitting coronal gas at ~10^7 K in the centers of galaxy clusters remains a puzzle. The presence of a strong,…

Aims: Massive stars in low-metallicity environments may produce exotic explosions such as long-duration gamma-ray bursts and pair-instability supernovae when they die as core-collapse supernovae (CCSNe). Here we determine the feasibility of…