5,998 research outputs found
Candidate Members and Age Estimate of the Family of Kuiper Belt Object 2003 EL61
The collisional family of Kuiper belt object (KBO) 2003 EL61 opens the
possibility for many interesting new studies of processes important in the
formation and evolution of the outer solar system. As the first family in the
Kuiper belt, it can be studied using techniques developed for studying asteroid
families, although some modifications are necessary. Applying these modified
techniques allows for a dynamical study of the 2003 EL61 family. The velocity
required to change orbits is used to quantitatively identify objects near the
collision. A method for identifying family members that have potentially
diffused in resonances (like 2003 EL61) is also developed. Known family members
are among the very closest KBOs to the collision and two new likely family
members are identified: 2003 UZ117 and 1999 OY3. We also give tables of
candidate family members which require future observations to confirm
membership. We estimate that a minimum of ~1 GYr is needed for resonance
diffusion to produce the current position of 2003 EL61, implying that the
family is likely primordial. Future refinement of the age estimate is possible
once (many) more resonant objects are identified. The ancient nature of the
collision contrasts with the seemingly fresh surfaces of known family members,
suggesting that our understanding of outer solar system surfaces is incomplete.Comment: 22 pages, 5 figures, accepted to AJ, author's cv available at
http://www.gps.caltech.edu/~dari
The Stellar Population of High Redshift Galaxies
Using the VLT we have obtained high quality spectra of about 70 high redshift
(1- 4.6) galaxies within the FORS Deep Field (FDF). As expected most of them
turn out to be (bright) starburst galaxies and the observed spectra agree with
synthetic ones. The equivalent width of the CIV(1550) absorption line turns out
to be a good indicator for the galaxies metallicity. Furthermore our high-z
starburst galaxies show increasing metal content with decreasing redshift.
Compared with local starburst galaxies they tend to be overliminous for their
metallicity.Comment: 3 pages, including 4 eps-figures, Latex2e, to appear in proceedings
of MPA/ESO/MPE/USM Joint Astronomy Conference on "Lighthouses of the
Universe" (Eds.: R. Sunyaev, M. Gilfanov, E. Churazov
Gender types, self-esteem, and academic achievement in middle school students
The relationship among gender typing, self-esteem, and academic achievement was investigated in 314 middle school participants. Participants were administered the Children’s Sex Role Inventory (CSRI) and the Coopersmith Self-Esteem Inventory-School Form (CSEI). The results of the CSRI and CSEI were compared to each participant\u27s score on the California Achievement Test (CAT). Analysis of variance, chi-square, and Pearson product moment correlation\u27s were utilized to assess relationships among the variables. Results indicated that, in the current sample, self-esteem and achievement were unrelated, aschematic characteristics were correlated with high achievement, girls exhibited higher achievement than boys, both boys and girls responded most frequently to androgyny, and ethnic differences were noted. Implications of the results will be discussed
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