Search Publications
A Large and Pristine Sample of Standard Candles across the Milky Way: ∼100,000 Red Clump Stars with 3% Contamination
Ting, Yuan-Sen; Rix, Hans-Walter; Hawkins, Keith
Core helium-burning red clump (RC) stars are excellent standard candles in the Milky Way. These stars may have more precise distance estimates from spectrophotometry than from Gaia parallaxes beyond 3 kpc. However, RC stars have values of T eff and {log}g that are very similar to some red giant branch (RGB) stars. Especially for low-res…
Testing gravity with wide binary stars like α Centauri
Banik, Indranil; Zhao, Hongsheng
We consider the feasibility of testing Newtonian gravity at low accelerations using wide binary (WB) stars separated by ≳ 3 kAU. These systems probe the accelerations at which galaxy rotation curves unexpectedly flatline, possibly due to modified Newtonian dynamics (MOND). We conduct Newtonian and MOND simulations of WBs covering a grid of model p…
The search for multiple populations in Magellanic Cloud clusters - IV. Coeval multiple stellar populations in the young star cluster NGC 1978
Martocchia, S.; Dalessandro, E.; Salaris, M. +15 more
We have recently shown that the ∼2 Gyr old Large Magellanic Cloud star cluster NGC 1978 hosts multiple populations in terms of star-to-star abundance variations in [N/Fe]. These can be seen as a splitting or spread in the subgiant and red giant branches (SGB and RGB) when certain photometric filter combinations are used. Because of its relative yo…
Reconciling Observed and Simulated Stellar Halo Masses
Faucher-Giguère, Claude-André; Hopkins, Philip F.; Wetzel, Andrew +6 more
We use cosmological hydrodynamical simulations of Milky Way-mass galaxies from the FIRE project to evaluate various strategies for estimating the mass of a galaxy’s stellar halo from deep, integrated-light images. We find good agreement with integrated-light observations if we mimic observational methods to measure the mass of the stellar halo by …
The 4:1 outer Lindblad resonance of a long-slow bar as an explanation for the Hercules stream
Bovy, Jo; Hunt, Jason A. S.
There are multiple groups of comoving stars in the Solar neighbourhood, which are possible signatures of one of the fundamental resonances of non-axisymmetric structure such as the Galactic bar or spiral arms. One such stream, Hercules, has been proposed to result from the outer Lindblad resonance of a short-fast rotating bar as shown analytically…
Shock location and CME 3D reconstruction of a solar type II radio burst with LOFAR
Eislöffel, J.; Mann, G.; Anderson, J. +62 more
Context. Type II radio bursts are evidence of shocks in the solar atmosphere and inner heliosphere that emit radio waves ranging from sub-meter to kilometer lengths. These shocks may be associated with coronal mass ejections (CMEs) and reach speeds higher than the local magnetosonic speed. Radio imaging of decameter wavelengths (20-90 MHz) is now …
Lithium abundance patterns of late-F stars: an in-depth analysis of the lithium desert
Aguilera-Gómez, Claudia; Chanamé, Julio; Ramírez, Iván
Aims: We address the existence and origin of the lithium (Li) desert, a region in the Li-Teff plane sparsely populated by stars. Here we analyze some of the explanations that have been suggested for this region, including mixing in the late main sequence, a Li dip origin for stars with low Li abundances in the region, and a possibl…
Testing the disk instability model of cataclysmic variables
Lasota, Jean-Pierre; Dubus, Guillaume; Otulakowska-Hypka, Magdalena
Context. The disk instability model (DIM) attributes the outbursts of dwarf novae to a thermal-viscous instability of their accretion disk, an instability to which nova-like stars are not subject.
Aims: We aim to test the fundamental prediction of the DIM: the separation of cataclysmic variables (CVs) into nova-likes and dwarf novae depending…
Synthetic Stellar Photometry - II. Testing the bolometric flux scale and tables of bolometric corrections for the Hipparcos/Tycho, Pan-STARRS1, SkyMapper, and JWST systems
Casagrande, L.; VandenBerg, Don A.
We use MARCS model atmosphere fluxes to compute synthetic colours, bolometric corrections and reddening coefficients for the Hipparcos/Tycho, Pan-STARRS1, SkyMapper, and JWST systems. Tables and interpolation subroutines are provided to transform isochrones from the theoretical to various observational planes, to derive bolometric corrections, syn…
The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2016 follow-up campaign - I. Overview and classification of candidates selected by two techniques
Smith, M.; D'Andrea, C. B.; Abbott, T. M. C. +79 more
The primary goals of the STRong lensing Insights into the Dark Energy Survey (STRIDES) collaboration are to measure the dark energy equation of state parameter and the free streaming length of dark matter. To this aim, STRIDES is discovering strongly lensed quasars in the imaging data of the Dark Energy Survey and following them up to measure time…