Search Publications
Constraints on Upper Cutoffs in the Mass Functions of Young Star Clusters
Fall, S. Michael; Chandar, Rupali; Mok, Angus
We test claims that the power-law mass functions of young star clusters (ages ≲ few × 108 yr) have physical upper cutoffs at {M}* ∼ {10}5 {M}⊙ . Specifically, we perform maximum likelihood fits of the Schechter function, \psi (M)={dN}/{dM}\propto {M}β \exp (-M/{M}* ), to the observe…
M I C R O S C O P E limits on the strength of a new force with comparisons to gravity and electromagnetism
Fayet, Pierre
Extremely weak new forces could lead to apparent violations of the equivalence principle. The MICROSCOPE experiment implies that the relative strength of a new long-range force, compared with gravity, is constrained to |α¯ g|<3.2 ×10-11 , 2.3 ×10-13 , 2.2 ×10-13 , 6.7 ×10-13 , and 1.5 ×10
Abundances of disk and bulge giants from high-resolution optical spectra. IV. Zr, La, Ce, Eu
Ryde, N.; Jönsson, H.; Matteucci, F. +1 more
Context. Observations of the Galactic bulge suggest that the disk formed through secular evolution rather than gas dissipation and/or mergers, as previously believed. This would imply very similar chemistry in the disk and bulge. Some elements, such as the α-elements, are well studied in the bulge, but others like the neutron-capture elements are …
Cloud Atlas: Hubble Space Telescope Near-infrared Spectral Library of Brown Dwarfs, Planetary-mass Companions, and Hot Jupiters
Schneider, Glenn; Apai, Dániel; Burgasser, Adam J. +12 more
Bayesian atmospheric retrieval tools can place constraints on the properties of brown dwarfs' and hot Jupiters' atmospheres. To fully exploit these methods, high signal-to-noise spectral libraries with well-understood uncertainties are essential. We present a high signal-to-noise spectral library (1.10-1.69 µm) of the thermal emission of 76 …
Modelling depletion by re-accretion of gas from a dusty disc in post-AGB stars
Van Winckel, Hans; Nelemans, Gijs; Pols, Onno +1 more
Many disc-type post-asymptotic giant branch (post-AGB) stars are chemically peculiar, showing underabundances of refractory elements in their photospheres that correlate with condensation temperature. The aim of this paper is to investigate how accretion from a circumbinary disc can cause this phenomenon of depletion and how this impacts the evolu…
Properties of Radial Velocities Measurement Based on LAMOST-II Medium-resolution Spectroscopic Observations
Wu, H.; Chen, L.; Wang, R. +28 more
The radial velocity (RV) is a basic physical quantity that can be determined through the Doppler shift of the spectrum of a star. The precision of the RV measurement depends on the resolution of the spectrum we used and the accuracy of wavelength calibration. In this work, radial velocities of the Large Sky Area Multi-Object Fibre Spectroscopic Te…
Quiescent Discrete Auroral Arcs: A Review of Magnetospheric Generator Mechanisms
Echim, Marius M.; Borovsky, Joseph E.; Otto, Antonius +7 more
One of the longstanding questions of space science is: How does the Earth's magnetosphere generate auroral arcs? A related question is: What form of energy is extracted from the magnetosphere to drive auroral arcs? Not knowing the answers to these questions hinders our ability to determine the impact of auroral arcs on the magnetospheric system. M…
Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4
Molina, D.; Bretton, M.; Jones, H. R. A. +34 more
We homogeneously analyse ∼3.2 × 105 photometric measurements for ∼1100 transit light curves belonging to 17 exoplanet hosts. The photometric data cover 16 years (2004-2019) and include amateur and professional observations. Old archival light curves were reprocessed using up-to-date exoplanetary parameters and empirically debiased limb-…
Multifractal and Chaotic Properties of Solar Wind at MHD and Kinetic Domains: An Empirical Mode Decomposition Approach
Marcucci, Maria Federica; Consolini, Giuseppe; Alberti, Tommaso +3 more
Turbulence, intermittency, and self-organized structures in space plasmas can be investigated by using a multifractal formalism mostly based on the canonical structure function analysis with fixed constraints about stationarity, linearity, and scales. Here, the Empirical Mode Decomposition (EMD) method is firstly used to investigate timescale fluc…
Constraining the evolution of stellar rotation using solar twins
Bedell, Megan; Meléndez, Jorge; Bean, Jacob L. +7 more
The stellar rotation versus age relation is commonly considered a useful tool to derive reliable ages for Sun-like stars. However, in the light of Kepler data, the presence of apparently old and fast rotators that do not obey the usual gyrochronology relations led to the hypothesis of weakened magnetic breaking in some stars. In this letter, we co…