Related papers: ChronoFlow: A Data-Driven Model for Gyrochronology
We develop a new method for simulating stellar streams generated by globular clusters using angle-action coordinates. This method reproduces the variable mass-loss and variable frequency of the stripped stars caused by the changing tidal…
I explore the current ability of both white dwarf cooling theory and main sequence stellar evolution theory to accurately determine stellar population ages by comparing ages derived using both techniques for open clusters ranging from 0.1…
Main sequence turnoff magnitudes from the recent set of Yale isochrones (Chaboyer \ea 1995) have been combined with a variety of relations for the absolute magnitude of RR Lyr stars (\mvrr) to calibrate age as a function of the difference…
The origin of young star clusters represents a major challenge for modern stellar astrophysics. While stellar rotation partially explains the colour spread observed along main-sequence turn-offs, i.e. where stars leave the main-sequence…
Extended main-sequence turn-offs (eMSTO) are a commonly observed property of young clusters. A global theoretical interpretation for the eMSTOs is still lacking, but stellar rotation is considered a necessary ingredient to explain the…
Cosmological simulations still lack numerical resolution or physical processes to simulate dwarf galaxies in sufficient details. Accurate numerical simulations of individual dwarf galaxies are thus still in demand. We aim at (i) studying in…
We present accurate relative ages for a sample of 55 Galactic globular clusters. The ages have been obtained by measuring the difference between the horizontal branch and the turnoff in two, internally photometrically homogeneous databases.…
Ages of extragalactic globular clusters can provide valuable insights into the formation and evolution of galaxies. In this contribution the photometric methods of age dating old globular cluster systems are summarised. The spectroscopic…
Galactic archaeology largely relies on precise ages of distant evolved stars in the Milky Way. Nowadays, asteroseismology can deliver ages for many red giants observed with high-cadence, high-precision photometric space missions. Our aim is…
Most of the dynamical mass loss from star clusters is thought to be caused by the time-variability of the tidal field (``tidal shocks''). Systematic studies of tidal shocks have been hampered by the fact that each tidal history is unique,…
Cosmic Flows is a program to determine galaxy distances for 30,000 galaxies with systematic errors below 2%, almost ten times the number currently known and a five-fold improvement in systematics. The resultant velocity field will provide…
In this invited talk I show how the reddest and rarest galaxies at high redshift ($z \simeq 1.5$) can be used to set the stellar evolution clock. I argue that one can confidently compute the collapse redshift of these objects. This yields…
Rotational speed is an important physical parameter of stars and knowing the distribution of stellar rotational velocities is essential for the understanding stellar evolution. However, it cannot be measured directly but the convolution of…
We forward-model mass-weighted stellar ages (MWAs) and quiescent fractions in projected phase space (PPS), using data from the Sloan Digital Sky Survey, to jointly constrain an infall quenching model for galaxies in…
Integrated spectra have been obtained of 31 star clusters in the Magellanic Clouds (MC) and of 4 Galactic globular clusters. The spectra cover the wavelength range 3500 -- 4700 Angstroms at a resolution of 3.2 Angstroms FWHM. The MC…
This overview summarizes the age dating methods available for young sub-solar mass stars. Pre-main sequence age diagnostics include the Hertzsprung-Russell (HR) diagram, spectroscopic surface gravity indicators, and lithium depletion;…
Over the past 40 years, observational surveys have established the existence of a tight relationship between a star's age, rotation period, and magnetic activity. This age-rotation-activity relation documents the interplay between a star's…
The rotational evolution of a young stellar population can give informations about the rotation pattern of more evolved clusters. Combined with rotational period values of thousands of young stars and theoretical propositions about the…
In the Large Magellanic Cloud (LMC), there have been very few clusters observed with ages between 4 and 11 Gyr. This phenomenon is sometimes referred to as the `LMC age gap'. We constructed a model of the cluster age distribution aimed at…
We review the current state of our knowledge concerning the rotation and angular momentum evolution of young stellar objects and brown dwarfs from a primarily observational view point. Periods are typically accurate to 1% and available for…