11 papers
How massive and clumpy must a quasar wind be to create emission line blueshifts?
James H. Matthews
Blue asymmetries (``Blueshifts'') in the C IV 1550A emission line are common in luminous quasars. If they are formed in winds, how much energy, momentum and mass do those winds tra…
TBD LBD: The nature of `little blue dots'
Albert Sneppen, Darach Watson, James H. Matthews +1
Previous Sirocco radiative-transfer models of gas-cocooned AGN predicted lower-column counterparts to little red dots (LRDs): compact, X-ray-weak sources with bluer continuum slope…
Quenching of X-ray emission in little red dots by both Compton-thick gas and high accretion rates
Albert Sneppen, Darach Watson, James H. Matthews +1
Little red dots (LRDs) are candidate high-redshift supermassive black holes accreting in dense gas. They remain undetected in X-rays. In previous work, we provided the first quanti…
Paschen Jumps in Little Red Dots: Evidence for Nebular Continua
Albert Sneppen, James H. Matthews, Darach Watson +6
''Little Red Dots'' (LRDs) are broad-line sources at high redshift, initially identified by their compact morphologies, red colours and prominent Balmer breaks. The origin of their…
Radiation-ionization hydrodynamic simulations of AGN line-driven winds lead to transient shielding and BAL/UFO signatures
Nicolas Scepi, Christian Knigge, Amin Mosallanezhad +4
Disc winds from active galactic nuclei (AGN) can be launched by radiation pressure acting on spectral lines. However, launching a line-driven wind in the X-ray rich environment of…
Optical outburst evolution of the transient black hole X-ray binary Swift J1727.8-1613: Disc response to jet ejections and late-outburst emergence of powerful disc winds
N. Castro Segura, K. Solomons, J. M. Corral-Santana +22
Swift J1727.81613 is a newly discovered transient low-mass X-ray binary harbouring a stellar-mass () black hole. We present state-resolved VLT/X-Shooter optical…