5 papers · 1 filter
HALO II: Constraining Hubble constant through continuum delay fitting of Fairall 9
Amit Kumar Mandal, Francisco Pozo Nuñez, Vikram Kumar Jaiswal +28
The Hubble tension remains one of the most significant unresolved problems in modern cosmology. A key question is whether it may arise from underestimated systematic uncertainties…
Observations of a Possible Transient Magnetically Arrested Accretion State in a Nearby Quasar: OQ208
Brian Punsly, Cormac Reynolds, Paola Marziani +12
OQ208 is a nearby, partially obscured quasar (z=0.077) that is a young, bright, parsec scale radio source. We assemble archival and new high frequency VLBA and VLA observations and…
Super-Eddington Accretion in Quasars
P. Marziani, K. Garnica Luna, A. Floris +5
This review provides an observational perspective on the fundamental properties of super-Eddington accretion onto supermassive black holes in quasars. It begins by outlining the se…
Dark and bright sides of the Broad Line Region clouds as seen in the FeII emission of SDSS RM 102
Alberto Floris, Ashwani Pandey, Bozena Czerny +4
Contamination from singly ionized iron emission is one of the greatest obstacles to determining the intensity of emission lines in the UV and optical wavelength ranges. This study…
Chemical abundances along the quasar main sequence
A. Floris, P. Marziani, S. Panda +5
The 4D eigenvector 1 (E1) sequence has emerged as a powerful tool for organizing the observational and physical characteristics of type-1 active galactic nuclei (AGNs). In this stu…