Search Publications
On the Mass Function, Multiplicity, and Origins of Wide-orbit Giant Planets
Wagner, Kevin; Apai, Dániel; Kratter, Kaitlin M.
A major outstanding question regarding the formation of planetary systems is whether wide-orbit giant planets form differently than close-in giant planets. We aim to establish constraints on two key parameters that are relevant for understanding the formation of wide-orbit planets: (1) the relative mass function and (2) the fraction of systems hos…
Multiphase circumgalactic medium probed with MUSE and ALMA
Pettini, Max; York, Donald G.; Hamanowicz, Aleksandra +9 more
Galaxy haloes appear to be missing a large fraction of their baryons, most probably hiding in the circumgalactic medium (CGM), a diffuse component within the dark matter halo that extends far from the inner regions of the galaxies. A powerful tool to study the CGM gas is offered by absorption lines in the spectra of background quasars. Here, we pr…
The Close AGN Reference Survey (CARS). A massive multi-phase outflow impacting the edge-on galaxy HE 1353-1917
Gaspari, M.; Combes, F.; Scharwächter, J. +15 more
Context. Galaxy-wide outflows driven by star formation and/or an active galactic nucleus (AGN) are thought to play a crucial rule in the evolution of galaxies and the metal enrichment of the inter-galactic medium. Direct measurements of these processes are still scarce and new observations are needed to reveal the nature of outflows in the majorit…
Testing the Radius Scaling Relation with Gaia DR2 in the Kepler Field
Huber, Daniel; Stello, Dennis; Serenelli, Aldo +3 more
We compare radii based on Gaia parallaxes to radii based on asteroseismic scaling relations for ∼300 dwarfs and subgiants and ∼3600 first-ascent giants from the Kepler mission. Systematics due to temperature, bolometric correction, extinction, asteroseismic radius, and the spatially correlated Gaia parallax zero-point contribute to a 2% systematic…
Spectacular Hubble Space Telescope Observations of the Coma Galaxy D100 and Star Formation in Its Ram Pressure-stripped Tail
Sun, M.; Yagi, M.; Roediger, E. +5 more
We present new HST F275W, F475W, and F814W imaging of the region of the Coma cluster around D100, a spiral galaxy with a remarkably long and narrow (60 × 1.5 kpc) ram pressure-stripped gas tail. We find blue sources coincident with the Hα tail, which we identify as young stars formed in the tail. We also determine they are likely to be unbound ste…
Structure formation and exotic compact objects in a dissipative dark sector
Chang, Jae Hyeok; Egana-Ugrinovic, Daniel; Essig, Rouven +1 more
We present the complete history of structure formation in a simple dissipative dark-sector model. The model has only two particles: a dark electron, which is a subdominant component of dark matter, and a dark photon. Dark-electron perturbations grow from primordial overdensities, become non-linear, and form dense dark galaxies. Bremsstrahlung cool…
Lifetimes and Emergence/Decay Rates of Star Spots on Solar-type Stars Estimated by Kepler Data in Comparison with Those of Sunspots
Notsu, Yuta; Maehara, Hiroyuki; Namekata, Kosuke +7 more
Active solar-type stars show large quasi-periodic brightness variations caused by stellar rotation with star spots, and the amplitude changes as the spots emerge and decay. The Kepler data are suitable for investigations of the emergence and decay processes of star spots, which are important to understand the underlying stellar dynamo and stellar …
Distinguishing Mergers and Disks in High-redshift Observations of Galaxy Kinematics
Pacifici, Camilla; de la Vega, Alexander; Hayward, Christopher C. +9 more
The majority of massive star-forming galaxies at z ∼ 2 have velocity gradients suggestive of rotation, in addition to large amounts of disordered motions. In this paper, we demonstrate that it is challenging to distinguish the regular rotation of a disk galaxy from the orbital motions of merging galaxies with seeing-limited data. However, the merg…
Common origin for Hercules-Aquila and Virgo Clouds in Gaia DR2
Belokurov, Vasily; Koposov, Sergey E.; Simion, Iulia T.
We use a sample of ∼350 RR Lyrae stars with radial velocities and Gaia Data Release 2 proper motions to study orbital properties of the Hercules-Aquila Cloud (HAC) and Virgo Over-density (VOD). We demonstrate that both structures are dominated by stars on highly eccentric orbits, with pericentres around ∼1 kpc and apocentres at 15-25 kpc from the …
Massive Dead Galaxies at z ∼ 2 with HST Grism Spectroscopy. I. Star Formation Histories and Metallicity Enrichment
Vulcani, B.; Treu, T.; Jones, T. +7 more
Observations have revealed massive ({log}{M}* /{M}⊙ ≳ 11) galaxies that were already dead when the universe was only ∼2 Gyr. Given the short time before these galaxies were quenched, their past histories and quenching mechanism(s) are of particular interest. In this paper, we study star formation histories (SFHs) of 24 massiv…