112 citations · 331 across the 16 of their papers we have counts for
16 papers
X-ray properties of massive compact relic galaxies
Orsolya E. Kovacs, Norbert Werner, Akos Bogdan +1
We present the X-ray analysis of seven local compact elliptical galaxies (cEGs), selected for their morphological resemblance to high-redshift red nuggets. As likely descendants of…
A candidate supermassive black hole in a gravitationally-lensed galaxy at
Orsolya E. Kovacs, Akos Bogdan, Priyamvada Natarajan +8
While supermassive black holes (BHs) are widely observed in the nearby and distant universe, their origin remains debated with two viable formation scenarios with light and heavy s…
Circumgalactic Medium on the Largest Scales: Detecting X-ray Absorption Lines with Large-Area Microcalorimeters
Akos Bogdan, Ildar Khabibullin, Orsolya Kovacs +22
The circumgalactic medium (CGM) plays a crucial role in galaxy evolution as it fuels star formation, retains metals ejected from the galaxies, and hosts gas flows in and out of gal…
Evidence for heavy seed origin of early supermassive black holes from a z~10 X-ray quasar
Akos Bogdan, Andy Goulding, Priyamvada Natarajan +9
Observations of quasars reveal that many supermassive black holes (BHs) were in place less than 700 million years after the Big Bang. However, the origin of the first BHs remains a…
X-ray Absorption Lines in the Warm-Hot Intergalactic Medium: Probing Chandra observations with the CAMEL simulations
Amanda Butler Contreras, Erwin T. Lau, Benjamin D. Oppenheimer +5
Known as the "Missing Baryon Problem", about one-third of baryons in the local universe remain unaccounted for. The missing baryons are thought to reside in the warm-hot intergalac…
Line Emission Mapper (LEM): Probing the physics of cosmic ecosystems
Ralph Kraft, Maxim Markevitch, Caroline Kilbourne +107
The Line Emission Mapper (LEM) is an X-ray Probe for the 2030s that will answer the outstanding questions of the Universe's structure formation. It will also provide transformative…
Detection of a Superluminous Spiral Galaxy in the Heart of a Massive Galaxy Cluster
Akos Bogdan, Lorenzo Lovisari, Patrick Ogle +5
It is well established that brightest cluster galaxies (BCGs), residing in the center of galaxy clusters, are typically massive and quenched galaxies with cD or elliptical morpholo…
Exploring Gravitationally-Lensed X-ray AGN Behind the RELICS clusters
Akos Bogdan, Orsolya E. Kovacs, Christine Jones +5
Although observations of high-redshift quasars demonstrate that many supermassive black holes (BHs) reached large masses within one billion years after the Big Bang, the origin of…
Ultra-diffuse galaxies in the Coma cluster: Probing their origin and AGN occupation fraction
Orsolya E. Kovacs, Akos Bogdan, Rebecca E. A. Canning
Ultra-diffuse galaxies (UDGs) exhibit low surface brightness, but their optical extent is comparable to Milky Way-type galaxies. Due to their peculiar properties, it remains ambigu…
Constraining the dark matter halo mass of isolated low-surface-brightness galaxies
Orsolya E. Kovacs, Akos Bogdan, Rebecca E. A. Canning
Recent advancements in the imaging of low-surface-brightness objects revealed numerous ultra-diffuse galaxies in the local Universe. These peculiar objects are unusually extended a…
Expanding the Sample: The Relationship Between the Black Hole Mass of BCGs and the Total Mass of Galaxy Clusters
Frederika Phipps, Akos Bogdan, Lorenzo Lovisari +3
Supermassive Black Holes (BHs) residing in brightest cluster galaxies (BCGs) are overly massive when considering the local relationships between the BH mass and stellar bulge mass…
The quest for stellar coronal mass ejections in late-type stars: I. Investigating Balmer-line asymmetries of single stars in Virtual Observatory data
Krisztián Vida, Martin Leitzinger, Levente Kriskovics +5
Flares and CMEs can have deleterious effects on their surroundings: they can erode atmospheres of orbiting planets over time and also have high importance in stellar evolution. Mos…
Detection of the Missing Baryons toward the Sightline of H1821+643
Orsolya E. Kovacs, Akos Bogdan, Randall K. Smith +2
Based on constraints from Big Bang nucleosynthesis and the cosmic microwave background, the baryon content of the high-redshift Universe can be precisely determined. However, at lo…
Detection of a Star Forming Galaxy in the Center of a Low-Mass Galaxy Cluster
Akos Bogdan, Lorenzo Lovisari, Orsolya E. Kovacs +4
Brightest Cluster Galaxies (BCGs) residing in the centers of galaxy clusters are typically quenched giant ellipticals. A recent study hinted that star-forming galaxies with large d…
Antisolar differential rotation with surface lithium enrichment on the single K-giant V1192 Orionis
Zs. Kővári, K. G. Strassmeier, T. A. Carroll +7
Context: Stars with about 12 solar masses at the red giant branch (RGB) represent an intriguing period of stellar evolution, i.e. when the convective envelope interacts with the…
Hunting for Stellar Coronal Mass Ejections
Heidi Korhonen, Krisztian Vida, Martin Leitzinger +2
Coronal mass ejections (CMEs) are explosive events that occur basically daily on the Sun. It is thought that these events play a crucial role in the angular momentum and mass loss…