Zobrazeno 1 - 10
of 70
pro vyhledávání: '"Dorman, Ben"'
Publikováno v:
Astrophys.J. 591 (2003) 878-890
The restframe mid-ultraviolet spectral region (2000-3200 A) is important in analyzing the stellar populations of the "red envelope" systems observed at high redshifts. Here, we explore the usefulness of the mid-UV for determining ages and abundances
Externí odkaz:
http://arxiv.org/abs/astro-ph/0303477
Autor:
Peterson, Ruth C., Carney, Bruce W., Dorman, Ben, Green, Elizabeth M., Landsman, Wayne, Liebert, James, O'Connell, Robert W., Rood, Robert T.
Publikováno v:
Astrophys.J. 588 (2003) 299-310
Twenty years ago, Burstein et al. (1984)suggested that strong CN and Hbeta absorption meant younger ages among globular clusters in the Andromeda galaxy (M31), unless blue stars above the main-sequence turnoff or on the horizontal branch were uncommo
Externí odkaz:
http://arxiv.org/abs/astro-ph/0301412
Determining the properties of old stellar systems using evolutionary population synthesis requires a library of reliable model stellar fluxes. Empirical libraries are limited to spectra of stars in the solar neighborhood, with nearly solar abundances
Externí odkaz:
http://arxiv.org/abs/astro-ph/0009208
Autor:
D'Cruz, Noella L., O'Connell, Robert W., Rood, Robert T., Whitney, Jonathan H., Dorman, Ben, Landsman, Wayne B., Hill, Robert S., Stecher, Theodore P., Bohlin, Ralph C.
The globular cluster omega Centauri contains the largest known population of very hot horizontal branch (HB) stars. We have used the Hubble Space Telescope to obtain a far-UV/optical color-magnitude diagram of three fields in omega Cen. We find that
Externí odkaz:
http://arxiv.org/abs/astro-ph/9909371
Using HST-WFPC2 observations in two ultraviolet (UV) filters (F225W and F336W) of the central region of the high density Galactic Globular cluster (GGC) M80 we have identified 305 Blue Straggler Stars (BSS) which represents the largest and most conce
Externí odkaz:
http://arxiv.org/abs/astro-ph/9904196
Autor:
Cornett, Robert H., Dorman, Ben, Smith, Eric P., Fanelli, Michael A., Oegerle, William R., Bohlin, Ralph C., Neff, Susan G., O'Connell, Robert W., Roberts, Morton S., Smith, Andrew M., Stecher, Theodore P.
We present deep ultraviolet observations of a field containing the cluster Abell 2246 (z=0.225) which provide far-ultraviolet (FUV) images of some of the faintest galaxies yet observed in that bandpass. Abell 2246 lies within the field of view of Ult
Externí odkaz:
http://arxiv.org/abs/astro-ph/9805111
Autor:
Ferraro, Francesco R., Paltrinieri, Barbara, Pecci, Flavio Fusi, Dorman, Ben, Rood, Robert T.
We report on HST/WFPC2 U,V and far-ultraviolet observations of two Galactic Globular Clusters (GGCs), NGC 6205 = M13 and NGC 6093 = M80. Both of these clusters have horizontal-branch (HB) tails that extend to the helium-burning main sequence, with th
Externí odkaz:
http://arxiv.org/abs/astro-ph/9708210
Autor:
Ferraro, Francesco R., Paltrinieri, Barbara, Pecci, Flavio Fusi, Rood, Robert T., Dorman, Ben
The core of the galactic globular cluster M13 (NGC 6205) has been observed with WFPC2 on the Hubble Space Telescope through visual, blue and mid- and far-UV filters in a programme devoted to study the UV population in a sample of Galactic globular cl
Externí odkaz:
http://arxiv.org/abs/astro-ph/9707046
Autor:
Dorman, Ben, O'Connell, Robert W.
We consider the extent to which broadband mid-UV (2000 - 3000 Angstrom) colors can give superior constraints on the ages and abundances of old stellar populations than can their optical counterparts. The ultraviolet colors directly measure the turnof
Externí odkaz:
http://arxiv.org/abs/astro-ph/9706193
Autor:
Ferraro, Francesco R., Paltrinieri, Barbara, Pecci, Flavio Fusi, Cacciari, Carla, Dorman, Ben, Rood, Robert T.
We present preliminary results from HST/WFPC2 observations of the central regions of the of the Galactic globular clusters M13 and M3. The clusters are almost identical in most respects including chemical composition, but there are dramatic differenc
Externí odkaz:
http://arxiv.org/abs/astro-ph/9705159