Search Publications
Revealing the tidal scars of the Small Magellanic Cloud
Erkal, Denis; Gallart, Carme; De Leo, Michele +3 more
Due to their close proximity, the Large and Small Magellanic Clouds (LMC/SMC) provide natural laboratories for understanding how galaxies form and evolve. With the goal of determining the structure and dynamical state of the SMC, we present new spectroscopic data for ∼3000 SMC red giant branch stars observed using the AAOmega spectrograph at the A…
Star-Gas Surface Density Correlations in 12 Nearby Molecular Clouds. I. Data Collection and Star-sampled Analysis
Henning, Thomas; Myers, Philip C.; Gutermuth, Robert A. +15 more
We explore the relation between the stellar mass surface density and the mass surface density of molecular hydrogen gas in 12 nearby molecular clouds that are located at <1.5 kpc distance. The sample clouds span an order-of-magnitude range in mass, size, and star formation rates. We use thermal dust emission from Herschel maps to probe the gas …
The 2020 April-June super-outburst of OJ 287 and its long-term multiwavelength light curve with Swift: binary supermassive black hole and jet activity
Komossa, S.; Grupe, D.; Parker, M. L. +4 more
We report detection of a very bright X-ray-UV-optical outburst of OJ 287 in 2020 April-June, the second brightest since the beginning of our Swift multiyear monitoring in late 2015. It is shown that the outburst is predominantly powered by jet emission. Optical-UV-X-rays are closely correlated, and the low-energy part of the XMM-Newton spectrum di…
Into the UV: A Precise Transmission Spectrum of HAT-P-41b Using Hubble's WFC3/UVIS G280 Grism
Wakeford, H. R.; Sing, D. K.; Nikolov, N. +8 more
The ultraviolet-visible wavelength range holds critical spectral diagnostics for the chemistry and physics at work in planetary atmospheres. To date, time-series studies of exoplanets to characterize their atmospheres have relied on several combinations of modes on the Hubble Space Telescope's STIS/COS instruments to access this wavelength regime.…
Galaxy Sizes Since z = 2 from the Perspective of Stellar Mass Distribution within Galaxies
Tacchella, Sandro; Mosleh, Moein; Hosseinnejad, Shiva +1 more
How stellar mass assembles within galaxies is still an open question. We present measurements of the stellar mass distribution on kiloparsec-scales for ∼5500 galaxies with stellar masses above $\mathrm{log}({M}_{* }/{M}_{\odot })\geqslant 9.8$ up to redshift 2.0. We create stellar mass maps from Hubble Space Telescope observations by means of the …
Prediction of the In Situ Coronal Mass Ejection Rate for Solar Cycle 25: Implications for Parker Solar Probe In Situ Observations
Lugaz, Noé; Möstl, Christian; McIntosh, Scott W. +7 more
The Parker Solar Probe (PSP) and Solar Orbiter missions are designed to make groundbreaking observations of the Sun and interplanetary space within this decade. We show that a particularly interesting in situ observation of an interplanetary coronal mass ejection (ICME) by PSP may arise during close solar flybys (<0.1 au). During these times, t…
Metal-poor nuclear star clusters in two dwarf galaxies near Centaurus A suggesting formation from the in-spiraling of globular clusters
Fahrion, Katja; Müller, Oliver; Jerjen, Helmut +7 more
Studies of nucleated dwarf galaxies can constrain the scenarios for the formation and evolution of nuclear star clusters (NSC) in low-mass galaxies and give us insights on the origin of ultra compact dwarf galaxies (UCDs). We report the discovery of a NSC in the dwarf galaxy KKs58 and investigate its properties together with those of another NSC i…
Weak lensing reveals a tight connection between dark matter halo mass and the distribution of stellar mass in massive galaxies
Sifón, Cristóbal; Leauthaud, Alexie; Behroozi, Peter +9 more
Using deep images from the Hyper Suprime-Cam (HSC) survey and taking advantage of its unprecedented weak lensing capabilities, we reveal a remarkably tight connection between the stellar mass distribution of massive central galaxies and their host dark matter halo mass. Massive galaxies with more extended stellar mass distributions tend to live in…
The Young Suns Exoplanet Survey: Detection of a wide-orbit planetary-mass companion to a solar-type Sco-Cen member
Todorov, K. O.; Ginski, C.; Manara, C. F. +9 more
The Young Suns Exoplanet Survey consists of a homogeneous sample of 70 young, solar-mass stars located in the Lower Centaurus-Crux subgroup of the Scorpius-Centaurus association with an average age of 15 ± 3 Myr. We report the detection of a co-moving companion around the K3IV star TYC 8998-760-1 (2MASSJ13251211-6456207) that is located at a dista…
On testing CDM and geometry-driven Milky Way rotation curve models with Gaia DR2
Lattanzi, Mario G.; Crosta, Mariateresa; Giammaria, Marco +1 more
Flat rotation curves (RCs) in disc galaxies provide the main observational support to the hypothesis of surrounding dark matter (DM). Despite of the difficulty in identifying the DM contribution to the total mass density in our Galaxy, stellar kinematics, as tracer of gravitational potential, is the most reliable observable for gauging different m…