X-ray Halos around Massive Galaxies: Data and Theory

Kavli Affiliate: Mark Vogelsberger | First 5 Authors: Akos Bogdan, Mark Vogelsberger, , , | Summary: The presence of gaseous X-ray halos around massive galaxies is a basic prediction of all past and modern structure formation simulations. The importance of these X-ray halos is further emphasized by the fact that they retain signatures of the […]


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Chandra, HST/STIS, NICER, Swift, and TESS Detail the Flare Evolution of the Repeating Nuclear Transient ASASSN-14ko

Kavli Affiliate: Michael M. Fausnaugh | First 5 Authors: Anna V. Payne, Katie Auchettl, Benjamin J. Shappee, Christopher S. Kochanek, Patricia T. Boyd | Summary: ASASSN-14ko is a nuclear transient at the center of the AGN ESO 253-G003 that undergoes periodic flares. Optical flares were first observed in 2014 by the All-Sky Automated Survey for […]


Continue.. Chandra, HST/STIS, NICER, Swift, and TESS Detail the Flare Evolution of the Repeating Nuclear Transient ASASSN-14ko

Polarized X-rays Constrain The Disk-Jet Geometry in a Black Hole X-ray Binary

Kavli Affiliate: Herman L. Marshall | First 5 Authors: Henric Krawczynski, Fabio Muleri, Michal Dovčiak, Alexandra Veledina, Nicole Rodriguez Cavero | Summary: In a black hole X-ray binary (XRB) system, gas accreted from a normal star onto a black hole glows brightly in X-rays. We report on an observation of the XRB Cygnus X-1 (Cyg […]


Continue.. Polarized X-rays Constrain The Disk-Jet Geometry in a Black Hole X-ray Binary

X-ray performance of critical-angle transmission grating prototypes for the Arcus mission

Kavli Affiliate: Moritz Guenther | First 5 Authors: Ralf K. Heilmann, Alexander R. Bruccoleri, Vadim Burwitz, Casey deRoo, Alan Garner | Summary: Arcus is a proposed soft x-ray grating spectrometer Explorer. It aims to explore cosmic feedback by mapping hot gases within and between galaxies and galaxy clusters and characterizing jets and winds from supermassive […]


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The formation of low surface brightness galaxies in the IllustrisTNG simulation

Kavli Affiliate: Mark Vogelsberger | First 5 Authors: Luis Enrique Pérez-Montaño, Vicente Rodriguez-Gomez, Bernardo Cervantes Sodi, Qirong Zhu, Annalisa Pillepich | Summary: We explore the nature of low surface brightness galaxies (LSBGs) in the hydrodynamic cosmological simulation TNG100 of the IllustrisTNG project, selecting a sample of LSBGs ($r$-band effective surface brightness $mu_r > 22.0$ mag […]


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The Atari Disk, a Metal-Poor Stellar Population in the Disk System of the Milky Way

Kavli Affiliate: Anna Frebel | First 5 Authors: Mohammad K. Mardini, Anna Frebel, Anirudh Chiti, Yohai Meiron, Kaley V. Brauer | Summary: We have developed a chemo-dynamical approach to assign 36,010 metal-poor SkyMapper stars to various Galactic stellar populations. Using two independent techniques (velocity and action space behavior), $Gaia$ EDR3 astrometry, and photometric metallicities, we […]


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Transit Hunt for Young and Maturing Exoplanets (THYME) VIII: a Pleiades-age association harboring two transiting planetary systems from Kepler

Kavli Affiliate: Andrew Vanderburg | First 5 Authors: Madyson G. Barber, Andrew W. Mann, Jonathan L. Bush, Benjamin M. Tofflemire, Adam L. Kraus | Summary: Young planets provide a window into the early stages and evolution of planetary systems. Ideal planets for such research are in coeval associations, where the parent population can precisely determine […]


Continue.. Transit Hunt for Young and Maturing Exoplanets (THYME) VIII: a Pleiades-age association harboring two transiting planetary systems from Kepler

Angling for x-ray pulsar geometry with polarimetry

Kavli Affiliate: Herman L. Marshall | First 5 Authors: Victor Doroshenko, Juri Poutanen, Sergey Tsygankov, Valery Suleimanov, Matteo Bachetti | Summary: Using observations of X-ray pulsar Her X-1 by the Imaging X-ray Polarimetry Explorer, we report on a highly significant detection of the polarization signal from an accreting neutron star. The observed degree of the […]


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Possibilities and Limitations of Kinematically Identifying Stars from Accreted Ultra-Faint Dwarf Galaxies

Kavli Affiliate: Anna Frebel | First 5 Authors: Kaley Brauer, Hillary D. Andales, Alexander P. Ji, Anna Frebel, Mohammad K. Mardini | Summary: The Milky Way has accreted many ultra-faint dwarf galaxies (UFDs), and stars from these galaxies can be found throughout our Galaxy today. Studying these stars provides insight into galaxy formation and early […]


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TESS Hunt for Young and Maturing Exoplanets (THYME) VII : Membership, rotation, and lithium in the young cluster Group-X and a new young exoplanet

Kavli Affiliate: Sara Seager | First 5 Authors: Elisabeth R. Newton, Rayna Rampalli, Adam L. Kraus, Andrew W. Mann, Jason L. Curtis | Summary: The public, all-sky surveys Gaia and TESS provide the ability to identify new young associations and determine their ages. These associations enable study of planetary evolution by providing new opportunities to […]


Continue.. TESS Hunt for Young and Maturing Exoplanets (THYME) VII : Membership, rotation, and lithium in the young cluster Group-X and a new young exoplanet