Search Publications
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,…
Analysis of the Open Cluster NGC 2281
Terrell, Dirk; Gross, John; Cooney, Walter R., Jr.
B V observations of an approximately 68 ' × 48 ' field centered on the open cluster NGC 2281 and covering more than 400 nights from 2013 to 2018 are presented. The photometric observations were transformed to the standard system using standards from the American Association of Variable Star Observers Photometric All-sky Survey (APASS) DR10 and ana…
Frequency of Planets in Binaries
Bonavita, Mariangela; Desidera, Silvano
The frequency of planets in binaries is an important issue in the field of extrasolar planet studies because of its relevance in the estimation of the global planet population of our galaxy and the clues it can give to our understanding of planet formation and evolution. Multiple stars have often been excluded from exoplanet searches, especially t…
The UV Perspective of Low-Mass Star Formation
France, Kevin; Schneider, P. Christian; Günther, H. Moritz
The formation of low-mass (M★≲2M⊙) stars in molecular clouds involves accretion disks and jets, which are of broad astrophysical interest. Accreting stars represent the closest examples of these phenomena. Star and planet formation are also intimately connected, setting the starting point for planetary systems like our own. The ultraviolet (UV) sp…
Massive Star Formation in the Ultraviolet Observed with the Hubble Space Telescope
Leitherer, Claus
Spectroscopic observations of a massive star formation in the ultraviolet and their interpretation are reviewed. After a brief historical retrospective, two well-studied resolved star clusters and the surrounding H II regions are introduced: NGC 2070 in the Large Magellanic Cloud and NGC 604 in M33. These regions serve as a training set for studie…
Unraveling the Physics of Quasar Jets: Optical Polarimetry and Implications for the X-ray Emission Process
Perlman, Eric S.; Clautice, Devon; Avachat, Sayali +4 more
Since the launch of Chandra twenty years ago, one of the greatest mysteries surrounding Quasar Jets is the production mechanism for their extremely high X-ray luminosity. Two mechanisms have been proposed. In the first view, the X-ray emission is inverse-Comptonized CMB photons. This view requires a jet that is highly relativistic (bulk Lorentz fa…