Related papers: The Binary Black Hole Model for Mrk 231 Bites the …
The nature of Little Red Dots (LRDs) has largely been investigated through their continuum emission, with lines assumed to arise from a broad-line region. In this paper, we instead use recombination lines to infer the intrinsic properties…
Accretion onto supermassive black hole (SMBH) can release energy via radiation, jets or winds, providing feedback effects on the circumnuclear gas environment. However, not all active galactic nuclei (AGNs) exhibit clear signature of such…
We present a dynamical study of the narrow-line regions in two nearby QSO2s. We construct dynamical models based on detailed photoionization models of the emission-line gas, including the effects of internal dust, to apply to observations…
The AGN Space Telescope and Optical Reverberation Mapping 2 (STORM 2) campaign targeted Mrk 817 with intensive multi-wavelength monitoring and found its soft X-ray emission to be strongly absorbed. We present results from 157 near-IR…
Planetary nebulae (PNe) are an important tool for studying the dynamics and chemical evolution of galaxies in the Local Universe, given their characteristic, bright emission line spectra. The Andromeda Galaxy (M31) provides a unique…
The X-ray spectra of Anomalous X-ray Pulsars have long been fit by smooth, empirical models such as the sum of a black-body plus a power law. These reproduce the ~0.5 to 10 keV range well, but fail at lower and higher energies, grossly…
We perform a systematic search for sub-parsec binary supermassive black holes (BHs) in normal broad line quasars at z<0.8, using multi-epoch SDSS spectroscopy of the broad Hbeta line. Our working model is that: only one of the two BHs in…
Massive stars typically undergo short-lived post-main sequence evolutionary phases with strong mass loss and occasional mass eruptions. Many of such massive stars in transition phases have been identified based on their dusty envelopes. The…
Published interpretations of the relative intensity variations of the Unidentified Infrared Bands (UIBs) and their underlying continuum are discussed. An alternative model is proposed, in which a single carrier for both emits a) mostly a…
The co-evolution between black holes and galaxies suggests that feedback of active galactic nuclei influence host galaxies through ejecting radiative and kinetic energies to surroundings. Larger scale outflow in local universe are…
We present deep optical spectropolarimety of SMM J02399-0136 (z=2.8) done with the VLT Antu 8.2 m telescope equipped with FORS1. Moderate continuum and emission line polarization are measured (P~5%). We do not detect broad lines in…
Thermal mid-infrared emission of quasars requires an obscuring structure that can be modeled as a magneto-hydrodynamic wind in which radiation pressure on dust shapes the outflow. We have taken the dusty wind models presented by Keating and…
Theoretically, bound binaries of massive black holes are expected as the natural outcome of mergers of massive galaxies. From the observational side, however, massive black hole binaries remain elusive. Velocity shifts between narrow and…
This paper focuses on the dynamical implications of close supermassive black hole binaries both as an example of resonant phase mixing and as a potential explanation of inversions and other anomalous features observed in the luminosity…
The radio properties of 11 obscured `radio-intermediate' quasars at redshifts z>~2 have been investigated using the European Very-Long-Baseline-Interferometry Network (EVN) at 1.66 GHz. A sensitivity of ~25 micro Jy per 14x17 mas2 beam was…
Multiwavelength variability of blazars offers indirect insight into their powerful engines and on the mechanisms through which energy is propagated from the centre down the jet. The BL Lac object Mkn 421 is a TeV emitter, a bright blazar at…
We calculate the flux received from a binary system obscured by a circumbinary disc. The disc is modelled using two dimensional hydrodynamical simulations, and the vertical structure is derived by assuming it is isothermal. The…
We use direct-summation N-body integrations to follow the evolution of binary black holes at the centers of galaxy models with large, constant-density cores. Particle numbers as large as 400K are considered. The results are compared with…
Recent theoretical and observational studies have shown that ashes from thermonuclear burning may be ejected during radius-expansion bursts, giving rise to photoionisation edges in the X-ray spectra. We report a search for such features in…
Large-scale dust heating and cooling in the diffuse medium of M31 is studied using the HiRes IRAS maps in conjunction with UV, optical (UBV) and the HI maps. A dust heating/cooling model is developed based on a radiative transfer model…