13,635 research outputs found
Grids of stellar models including second harmonic and colours: Solar composition
Grids of stellar evolution are required in many fields of
astronomy/astrophysics, such as planet hosting stars, binaries, clusters,
chemically peculiar stars, etc. In this study, a grid of stellar evolution
models with updated ingredients and {recently determined solar abundaces} is
presented. The solar values for the initial abundances of hydrogen, heavy
elements and mixing-length parameter are 0.0172, 0.7024 and 1.98, respectively.
The mass step is small enough (0.01 M) that interpolation for a given
star mass is not required. The range of stellar mass is 0.74 to 10.00
M. We present results in different forms of tables for easy and general
application. The second stellar harmonic, required for analysis of apsidal
motion of eclipsing binaries, is also listed. We also construct rotating models
to determine effect of rotation on stellar structure and derive fitting formula
for luminosity, radius and the second stellar harmonic as a function of
rotational parameter. We also compute and list colours and bolometric
corrections of models required for transformation between theoretical and
observational results. The results are tested for the Sun, the Hyades cluster,
the slowly rotating chemically peculiar Am stars and the eclipsing binaries
with apsidal motion. The theoretical and observational results along isochrones
are in good agreement. The grids are also applicable to rotating stars provided
that equatorial velocity is given.Comment: 13 Figures 21 pages. Accepted by RA
Intergenerational Mobility of Immigrants in Germany: Moving with Natives or Stuck in their Neighborhoods?
In this paper, I analyze intergenerational mobility of immigrants and natives in Germany. Using the German Socioeconomic Panel (GSOEP), I find intergenerational elasticities that range from 0.19 to 0.26 for natives and from 0.37 to 0.40 for immigrants. These elasticity estimates are lower than typically found for the U.S. and imply higher mobility in Germany than in the U.S. However, as in the U.S., I find greater mobility among German natives than among immigrants. Moreover, I investigate to what extent the lower mobility among immigrants in Germany is due to “ethnic capital” as suggested by Borjas (1992). I find that the impact of father’s earnings on son’s earnings remains virtually unchanged when including a measure of ethnic capital, suggesting that the higher father-son correlation found among immigrants is not due to omitting ethnic capital. However, I do find a large independent effect of ethnic capital on sons’ earnings (the coefficient is 0.81 as opposed to 0.25 found by Borjas (1992)). These results are consistent with estimates from Microcensus data, where the combined effect of parents’ and ethnic capital is close to unity. Thus, contrary to the U.S. results which suggest convergence of immigrants’ earnings towards natives’ earnings, the German results suggest divergence of immigrant earnings.immigration, intergenerational mobility, natives, ethnic capital
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