Attraction of a Senior Citizen to a Hypothetical Stranger as a Function of the Stranger\u27s Age, Sex, and Attitude Similarity

The present study was designed to examine the variables which affect attraction in a senior citizen population. In particular, variables which have been shown to affect attraction in younger persons were examined as to their relevancy to older subjects. It was predicted that a stranger’s age, sex, and proportion of similar attitudes would have a significant effect on a senior citizen\u27s attraction rating of the stranger. A stranger’s age, sex, and proportion of similar attitudes were varied according to a 3 (proportion of similar attitudes) X 3 (age of stranger) X 2 (sex of stranger) factorial design. Male and female senior-citizen subjects responded to attitude surveys representing the age, sex, and attitudes of the hypothetical stranger. The subject’s response was completion of a rating scale of his attraction toward the stranger based on the information in the attitude survey. It was found that only the proportion of similar attitudes had a significant effect on a senior citizen\u27s attraction rating of a stranger. Age and sex of the stranger had no significant effect and none of the interactions among the variables reached significance. It was also found th^t the sex of the subject had no effect on his attraction rating of the stranger. Further research was suggested to study the use of paper and pencil techniques with older subjects

A Comparison of Attitude Change in Senior Citizen and College Age Subjects

The present study was designed to examine the validity of generally held assumptions of decreased attitudinal flexibility in the aged. A preliminary study preceded the formal study and identified a target attitude, sources of varying credibility, and evaluated self-esteem as a possible confounding variable. Subsequently 40 college age and 40 senior citizen subjects\u27 attitude toward the Equal Rights Amendment were measured by a paper and pencil survey. Two weeks later an anti- E.R.A. attitude change message, attributed to sources of varying age and credibility, was presented and its impact measured by a posttest survey. Follow-up measures were taken three weeks later. An analysis of covariance yielded a significant subject age effect at the posttest with greater attitude change exhibited by the senior citizens. Neither source age nor source credibility main effects reached significance and there were no significant interactions. On the follow-up measure there were no significant main effects or interactions, though subject age approached significance. The results were interpreted as being contrary to assumptions of increased rigidity in the elderly and not supportive of the decrement model of aging. Methodological difficulties were discussed with respect to the results found and further research was recommended

Stellar Populations at the Center of IC 1613

We have observed the center of the Local Group dwarf irregular galaxy IC 1613 with WFPC2 aboard the Hubble Space Telescope in the F439W, F555W, and F814W filters. We find a dominant old stellar population (aged ~7 Gyr), identifiable by the strong red giant branch (RGB) and red clump populations. From the (V-I) color of the RGB, we estimate a mean metallicity of the intermediate-age stellar population [Fe/H] = -1.38 +/- 0.31. We confirm a distance of 715 +/- 40 kpc using the I-magnitude of the RGB tip. The main-sequence luminosity function down to I ~25 provides evidence for a roughly constant SFR of approximately 0.00035 solar masses per year across the WFPC2 field of view (0.22 square kpc) during the past 250-350 Myr. Structure in the blue loop luminosity function implies that the SFR was ~50% higher 400-900 Myr ago than today. The mean heavy element abundance of these young stars is 1/10th solar. The best explanation for a red spur on the main-sequence at I = 24.7 is the blue horizontal branch component of a very old stellar population at the center of IC 1613. We have also imaged a broader area of IC 1613 using the 3.5-meter WIYN telescope under excellent seeing conditions. The AGB-star luminosity function is consistent with a period of continuous star formation over at least the age range 2-10 Gyr. We present an approximate age-metallicity relation for IC 1613, which appears similar to that of the Small Magellanic Cloud. We compare the Hess diagram of IC 1613 to similar data for three other Local Group dwarf galaxies, and find that it most closely resembles the nearby, transition-type dwarf galaxy Pegasus (DDO 216).Comment: To appear in the September 1999 Astronomical Journal. LaTeX, uses AASTeX v4.0, emulateapj style file, 19 pages, 12 postscript figures, 2 tables. 5 of the figures available separately via the WW

Hubble Space Telescope Observations of the Draco Dwarf Spheroidal

We present an F606W-F814W color-magnitude diagram for the Draco dwarf spheroidal galaxy based on Hubble Space Telescope WFPC2 images. The luminosity function is well-sampled to 3 magnitudes below the turn-off. We see no evidence for multiple turnoffs and conclude that, at least over the field of the view of the WFPC2, star formation was primarily single-epoch. If the observed number of blue stragglers is due to extended star formation, then roughly 6% (upper limit) of the stars could be half as old as the bulk of the galaxy. The color difference between the red giant branch and the turnoff is consistent with an old population and is very similar to that observed in the old, metal-poor Galactic globular clusters M68 and M92. Despite its red horizontal branch, Draco appears to be older than M68 and M92 by 1.6 +/- 2.5 Gyrs, lending support to the argument that the ``second parameter'' which governs horizontal branch morphology must be something other than age. Draco's observed luminosity function is very similar to that of M68, and the derived initial mass function is consistent with that of the solar neighborhood.Comment: 16 pages, AASTeX, 9 postscript figures, figures 1 and 2 available at ftp://bb3.jpl.nasa.gov/pub/draco/. Accepted for publication in the Astronomical Journa

Stellar Populations in Three Outer Fields of the LMC

We present HST photometry for three fields in the outer disk of the LMC extending approximately four magnitudes below the faintest main sequence turnoff. We cannot detect any strongly significant differences in the stellar populations of the three fields based on the morphologies of the color-magnitude diagrams, the luminosity functions, and the relative numbers of stars in different evolutionary stages. Our observations therefore suggest similar star formation histories in these regions, although some variations are certainly allowed. The fields are located in two regions of the LMC: one is in the north-east field and two are located in the north-west. Under the assumption of a common star formation history, we combine the three fields with ground-based data at the same location as one of the fields to improve statistics for the brightest stars. We compare this stellar population with those predicted from several simple star formation histories suggested in the literature, using a combination of the R-method of Bertelli et al (1992) and comparisons with the observed luminosity function. The only model which we consider that is not rejected by the observations is one in which the star formation rate is roughly constant for most of the LMC's history and then increases by a factor of three about 2 Gyr ago. Such a model has roughly equal numbers of stars older and younger than 4 Gyr, and thus is not dominated by young stars. This star formation history, combined with a closed box chemical evolution model, is consistent with observations that the metallicity of the LMC has doubled in the past 2 Gyr.Comment: 30 pages, includes 10 postscript figures. Figure 1 avaiable at ftp://charon.nmsu.edu/pub/mgeha/LMC. Accepted for publication in Astronomical Journa

Visible and Far-Ultraviolet WFPC2 Imaging of the Nucleus of the Galaxy NGC 205

We have imaged the nucleus of NGC 205 through the F555W and F160BW filters of WFPC2 on the high-resolution planetary camera (PC). The nucleus consists of a resolved cluster of stars extending 7" X 6". The projected radial distribution of surface brightness can be fitted by a Hubble law with a small core of FWHM 214 x 190 mas (0.74 x 0.66 pc). We find that the nucleus of NGC 205 shares a number of characteristics with globular clusters. Absolute photometry is also presented in a half-arcsec aperture and is found to verify the amount of UV upturn observed in the spectral energy distribution of the nucleus by others (e.g., Bertola et al. 1995). Of the hypotheses available to explain the origin of the nucleus, the observations are most consistent with its being an intermediate age cluster. The most likely scenarios are that it is a either a star cluster whose orbit has decayed-therefore drawing it to rest at the galaxy center-or a cluster that has formed as the repository of the gas from generations of star formation. Together with the ground-based measurement of a low-velocity dispersion, the small core radius implies a 107 yr relaxation time, suggesting the cluster core may have collapsed. An upper limit of 9 x 10^4 M_☉ can be put on the mass of any central black hole

Hubble Space Telescope observations of the Draco dwarf spheroidal galaxy

We present an F606W-F814W color-magnitude diagram for the Draco dwarf spheroidal galaxy based on Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) images. The luminosity function is well sampled to ~3 mag below the turnoff. We see no evidence for multiple turnoffs and conclude that, at least over the field of view of the WFPC2, star formation was primarily single-epoch. If the observed number of blue stragglers is due to extended star formation, then roughly 6% (upper limit) of the stars could be half as old as the bulk of the galaxy. The color difference between the red giant branch and the turnoff is consistent with an old population and is very similar to that observed in the old, metal-poor Galactic globular clusters M68 and M92. Despite its red horizontal branch, Draco appears to be older than M68 and M92 by 1.6 ± 2.5 Gyr, lending support to the argument that the "second parameter" that governs horizontal-branch morphology must be something other than age. Draco's observed luminosity function is very similar to that of M68, and the derived initial mass function is consistent with that of the solar neighborhood

Detection of surface brightness fluctuations in NGC 4373 using the Hubble Space Telescope

Surface brightness fluctuations (SBF) have been detected for three elliptical galaxies-NGC 3379 in the Leo group, NGC 4406 in the Virgo cluster, and NGC 4373 in the Hydra-Centaurus supercluster-using marginally sampled, deep images taken with the Planetary Camera of the WFPC2 instrument on the Hubble Space Telescope (HST). The power spectrum of the fluctuations image is well fitted by an empirical model of the point-spread function constructed using point sources identified in the held. Comparison with high-quality ground-based observations of all three galaxies show excellent agreement in the measurement of the distance modulus over a substantial range in distance. This demonstrates the capability of the Planetary Camera of WFPC2 to measure distances using the SBF technique despite the marginal sampling and small spatial coverage of the images. The residual variance due to unresolved sources in all three galaxies is only 2%-5% of the detected fluctuations signal, which confirms the advantage of HST imaging in minimizing the uncertainty of this SBF correction. Extensive consistency checks, including an independent SBF analysis using an alternate software package, suggest that our internal uncertainties are <0.02 mag. The fluctuations magnitude for NGC 4373 is /_(F814W) = 31.31±0.05 mag, corresponding to a distance modulus of (m-M)_0 = 32.99±0.11. This implies a peculiar velocity for this galaxy of 415±330 km s^(-1), which is smaller than derived from the D_n-σ relation