Search Publications
Phase-Space Correlations among Systems of Satellite Galaxies
Pawlowski, Marcel S.
Driven by the increasingly complete observational knowledge of systems of satellite galaxies, mutual spatial alignments and relations in velocities among satellites belonging to a common host have become a productive field of research. Numerous studies have investigated different types of such phase-space correlations and were met with varying deg…
Discovery of 178 Giant Radio Galaxies in 1059 deg2 of the Rapid ASKAP Continuum Survey at 888 MHz
Andernach, Heinz; Jiménez-Andrade, Eric F.; Willis, Anthony G.
We report the results of a visual inspection of images of the Rapid ASKAP Continuum Survey (RACS) in search of extended radio galaxies (ERG) that reach or exceed linear sizes on the order of one Megaparsec. We searched a contiguous area of 1059 deg2 from RAJ = 20h20m to 06h20m, and ‑50∘<DecJ<‑40∘, which is covered by deep multi-band optical …
The Cusp–Core Problem in Gas-Poor Dwarf Spheroidal Galaxies
Boldrini, Pierre
This review deals with the inconsistency of inner dark matter density profiles in dwarf galaxies, known as the cusp–core problem. In particular, we aim to focus on gas-poor dwarf galaxies. One of the most promising solutions to this cold dark matter small-scale issue is the stellar feedback, but it seems to be only designed for gas-rich dwarfs. Ho…
Gamma-ray and Neutrino Signals from Accretion Disk Coronae of Active Galactic Nuclei
Inoue, Yoshiyuki; Doi, Akihiro; Khangulyan, Dmitry
To explain the X-ray spectra of active galactic nuclei (AGN), non-thermal activity in AGN coronae such as pair cascade models has been extensively discussed in the past literature. Although X-ray and gamma-ray observations in the 1990s disfavored such pair cascade models, recent millimeter-wave observations of nearby Seyferts have established the …
One Source, Two Source(s): Ribs and Tethers
Knowles, Kenda; Rudnick, Lawrence; Kolokythas, Konstantinos +1 more
We present the unique and challenging case of a radio galaxy in Abell 3266 observed as part of the MeerKAT Galaxy Cluster Legacy Survey. It has quasi-periodic bright patches along the tail which connect to never-before-seen thin transverse extensions, which we call "ribs", reaching up to ∼50 kpc from the central axis of the tail. At a distance of …
Are Disks of Satellites Comprised of Tidal Dwarf Galaxies?
Famaey, Benoit; Kroupa, Pavel; Thies, Ingo +1 more
It was found that satellites of nearby galaxies can form flattened co-rotating structures called disks of satellites or planes of satellites. Their existence is not expected by the current galaxy formation simulations in the standard dark matter-based cosmology. On the contrary, modified gravity offers a promising alternative: the objects in the d…
Exploring New Redshift Indicators for Radio-Powerful AGN
Carvajal, Rodrigo; Matute, Israel; Afonso, José +4 more
Active Galactic Nuclei (AGN) are relevant sources of radiation that might have helped reionising the Universe during its early epochs. The super-massive black holes (SMBHs) they host helped accreting material and emitting large amounts of energy into the medium. Recent studies have shown that, for epochs earlier than z∼5, the number density of SMB…
Modeling of Spiral Structure in a Multi-Component Milky Way-Like Galaxy
Korchagin, Vladimir; Khrapov, Sergey; Khoperskov, Alexander
Using recent observational data, we construct a set of multi-component equilibrium models of the disk of a Milky Way-like galaxy. The disk dynamics are studied using collisionless-gaseous numerical simulations, based on the joined integration of the equations of motion for the collision-less particles using direct integration of gravitational inte…
A Multiwavelength Dynamical State Analysis of ACT-CL J0019.6+0336
Hilton, Matt; Moodley, Kavilan; Wollack, Edward J. +8 more
In our study, we show a multiwavelength view of ACT-CL J0019.6+0336 (which hosts a radio halo), to investigate the cluster dynamics, morphology, and ICM. We use a combination of XMM-Newton images, Dark Energy Survey (DES) imaging and photometry, SDSS spectroscopic information, and 1.16 GHz MeerKAT data to study the cluster properties. Various X-ra…
A Stringent Test of Magnetic Models of Stellar Evolution
Torres, Guillermo; Vanderburg, Andrew; Curtis, Jason L. +1 more
Main-sequence stars with convective envelopes often appear larger and cooler than predicted by standard models of stellar evolution for their measured masses. This is believed to be caused by stellar activity. In a recent study, accurate measurements were published for the K-type components of the 1.62-day detached eclipsing binary EPIC 219511354,…