Stellar Mass-Radius Relation

Mass-radius Relation for Magnetic White Dwarfs

Recently, several white dwarfs with very strong surface magnetic fields have been observed. In this paper we explore the possibility that such stars could have sufficiently strong internal fields to alter their structure. We obtain a revised white dwarf mass-radius relation in the presence of strong internal magnetic fields. We first derive the equation of state for a fully degenerate ideal ele...

The Universal Stellar Mass–stellar Metallicity Relation for Dwarf Galaxies

We present spectroscopic metallicities of individual stars in seven gas-rich dwarf irregular galaxies (dIrrs), and we show that dIrrs obey the same mass–metallicity relation as the dwarf spheroidal (dSph) satellites of both the Milky Way and M31: Z∗ ∝ M 0.30±0.02 ∗ . The uniformity of the relation is in contradiction to previous estimates of metallicity based on photometry. This relationship is...

The galaxy stellar mass–star formation rate relation: Evidence for an evolving stellar initial mass function?

The evolution of the galaxy stellar mass–star formation rate relationship (M∗−SFR) provides key constraints on the stellar mass assembly histories of galaxies. For star-forming galaxies, M∗−SFR is observed to be fairly tight with a slope close to unity from z ∼ 0 → 2, and it evolves downwards roughly independently of M∗. Simulations of galaxy formation reproduce these trends, broadly independen...

Radius Mass Position of Radius

Bump Cepheids and the Stellar Mass-Luminosity Relation

We present the results of non-linear pulsation modeling of bump Cepheids in the LMC and SMC. By obtaining an optimal fit to the observed MACHO V and R lightcurves we can determine the fundamental parameters of each Cepheid, namely mass, luminosity, effective temperature, distance modulus and reddening. We are able to describe the mass-luminosity relation for core-He burning intermediate mass st...