9 papers
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…
Finding the elusive RR Lyrae companions via speckle imaging
R. Salinas, V. Kalari, G. Hajdu +25
Despite their key role in astrophysics, the binary properties of RR Lyrae stars (RRL) remain almost completely unknown since only a single RRL is confirmed as belonging to a binary…
Period-Luminosity Relations, projection factor and radii of Anomalous Cepheids
Piotr Wielgórski, Grzegorz PietrzyÅski, Wolfgang Gieren +24
Anomalous Cepheids are radially pulsating stars observed in dwarf galaxies, the Galactic bulge and halo, and globular clusters. Similarly to other radially pulsating stars, they ca…
HALO I: Photometric continuum reverberation mapping of Fairall 9
Amit Kumar Mandal, Francisco Pozo Nuñez, Vikram Kumar Jaiswal +23
We investigate the origin of inter-band continuum time delays in active galactic nuclei (AGNs) to study the structure and properties of their accretion disks. We aim to measure the…
Distance to the Globular Cluster M 3 from the Infrared Surface Brightness Technique applied to RR Lyrae stars
BartÅomiej Zgirski, Wolfgang Gieren, Grzegorz PietrzyÅski +10
The Infrared Surface Brightness (IRSB) technique is a specific application of the Baade-Wesselink method. Given a proper calibration, well covered optical and near-infrared photome…
Secondary standards in the UKIRT faint standard fields
Marek Górski, Grzegorz PietrzyÅski, Paulina Karczmarek +8
We present precise J- and K-band photometric measurements for 128 near-infrared secondary standard stars, located in the 19 UKIRT/MKO primary faint standard fields. The data were c…