Zobrazeno 1 - 10
of 99
pro vyhledávání: '"Hesser, J. E."'
Autor:
Smith, V. V., Hinkle, K. H., Cunha, K., Plez, B., Lambert, D. L., Pilachowski, C. A., Barbuy, B., Melendez, J., Balachandran, S., Bessell, M. S., Geisler, D. P., Hesser, J. E., Winge, C.
High-resolution infrared spectra (R=50,000) have been obtained for twelve red-giant members of the LMC with the Gemini South 8.3-meter telescope plus Phoenix spectrometer. Quantitative chemical abundances of carbon-12, carbon-13, nitrogen-14, and oxy
Externí odkaz:
http://arxiv.org/abs/astro-ph/0208417
Deep HST/WFPC2 (V,I) photometry is used to investigate the globular cluster system (GCS) in NGC 4874, the central cD galaxy of the Coma cluster. The luminosity function of the clusters displays its normal Gaussian-like shape and turnover level. Other
Externí odkaz:
http://arxiv.org/abs/astro-ph/9912095
We have used deep HST/WFPC2 images in V (F606W) and I (F814W) to measure the luminosity distribution of the globular clusters in NGC 4874, the central cD galaxy of the Coma cluster. We find the ``turnover'' point of the globular cluster luminosity fu
Externí odkaz:
http://arxiv.org/abs/astro-ph/9911206
We present V, V-I color-magnitude diagrams (CMDs) for three old star clusters in the Large Magellanic Cloud (LMC): NGC 1466, NGC 2257 and Hodge 11. Our data extend about 3 magnitudes below the main-sequence turnoff, allowing us to determine accurate
Externí odkaz:
http://arxiv.org/abs/astro-ph/9911187
Autor:
Carlberg, R. G., Yee, H. K. C., Ellingson, E., Morris, S. L., Lin, H., Sawicki, M., Patton, D., Wirth, G., Abraham, R., Gravel, P., Pritchet, C. J., Smecker-Hane, T., Schade, D., Hartwick, F. D. A., Hesser, J. E., Hutchings, J. B., Oke, J. B.
The CNOC redshift survey of galaxy clusters measures Omega_M from Omega_e(z)= M/L x j/\rho_c which can be applied on a cluster-by-cluster basis. The mass-to-light ratios, M/L, are estimated from rich galaxy clusters, corrected to the field population
Externí odkaz:
http://arxiv.org/abs/astro-ph/9804312
Autor:
Carlberg, R. G., Yee, H. K. C., Lin, H., Sawicki, M., Shepherd, C. W., Ellingson, E., Morris, S. L., Schade, D., Hesser, J. E., Hutchings, J. B., Oke, J. B., Patton, D., Wirth, G., Balogh, M., Hartwick, F. D. A., Pritchet, C. J., Abraham, R., Smecker-Hane, T.
The CNOC1 cluster survey measures Omega_M via Oort's method, Omega_M= M/L x j/rho_c, where M/L is the field mass-to-light ratio, j is the field luminosity density and rho_c is the closure density. A wide range of potential systematic effects are expl
Externí odkaz:
http://arxiv.org/abs/astro-ph/9711272
Publikováno v:
Publ.Astron.Soc.Pac.109:907-919,1997
We compare our compilation of the W' calcium index for 71 Galactic globular clusters to the widely used Zinn and West (1984 ApJS, 55, 45) [Fe/H] scale and to Carretta and Gratton's (1997 A&A Supplement 121, 95) scale from high-dispersion spectra anal
Externí odkaz:
http://arxiv.org/abs/astro-ph/9707068
Autor:
Rutledge, G. A., Hesser, J. E., Stetson, P. B., Mateo, M., Simard, L., Bolte, M., Friel, E. D., Copin, Y.
We have obtained 2640 CCD spectra with resolution ~4 Angstrom in the region 7250-9000 Angstroms for 976 stars lying near the red giant branches in color-magnitude diagrams of 52 Galactic globular clusters. Radial velocities of ~16 km/second accuracy
Externí odkaz:
http://arxiv.org/abs/astro-ph/9707067
Autor:
Harris, W. E., Bell, R. A., VandenBerg, D. A., Bolte, M., Stetson, P. B., Hesser, J. E., vandenBergh, S., Bond, H. E., Fahlman, G. G., Richer, H. B.
The WFPC2 camera on HST has been used to obtain deep main sequence photometry of the low-metallicity ([Fe/H]=-2.14), outer-halo globular cluster NGC 2419. A differential fit of the NGC 2419 CMD to that of the similarly metal-poor \ standard cluster M
Externí odkaz:
http://arxiv.org/abs/astro-ph/9707048
Autor:
Carlberg, R. G., Morris, S. L., Yee, H. K. C., Ellingson, E., Abraham, R., Lin, H., Schade, D., Gravel, P., Pritchet, C. J., Smecker-Hane, T., Hartwick, F. D. A., Hesser, J. E., Hutchings, J. B., Oke, J. B.
The baryon density of the universe is equal to the product of the baryon-to-light ratio, M_b/L, and the luminosity density, j. We estimate M_b/L as the sum of the masses of the X-ray gas and the visible stars in a rich cluster of galaxies divided by
Externí odkaz:
http://arxiv.org/abs/astro-ph/9706115