Comparing The Impact Of An Astronomy Course And A Science And Society Seminar On Undergraduate Students' Attitudes Toward Science

A common challenge among university professors is how to best design undergraduate courses to successfully enhance students' attitudes. To compare which curriculum was more efficient at fostering a positive attitude towards science in general, I studied the impact of two different general education science courses on the attitudes of college students. The first course was an arithmetic-based Introductory Astronomy course for non-science majoring undergraduates that used interactive and inquiry-based teaching techniques. The comparison course was a Science, Technology, & Society (STS) seminar with context-based science contents, discussions, and intensive reading and writing. The post-semester results showed that neither curriculum on its own significantly changed the overall attitude of students towards science as far the assessment could measure, but that each curriculum did successfully enhance specific aspects of the students’ attitude in differing categories. The STS students had scores showing a gain in believing that scientists are honest. The astronomy students had scores showing a gain in understanding that scientific theories can change in the light of new evidence. However, the most significant change was a loss in the astronomy students’ confidence that the general public can and should understand science. Thus, the results suggest that professors who strongly desire to enhance the broad nature of students' attitudes need to use more purposeful instructional experiences rather than rely only on students' deepening understanding of the specific scientific content

The Central Engines of 19 LINERs as Viewed by Chandra

Using archival Chandra observations of 19 LINERs we explore the X-ray properties of their inner kiloparsec to determine the origin of their nuclear X-ray emission, to investigate the presence of an AGN, and to identify the power source of the optical emission lines. The relative numbers of LINER types in our sample are similar to those in optical spectroscopic surveys. We find that diffuse, thermal emission is very common and is concentrated within the central few hundred parsec. The average spectra of the hot gas in spirals and ellipticals are very similar to those of normal galaxies. They can be fitted with a thermal plasma (kT~0.5 keV) plus a power law (photon index of 1.3-1.5) model. There are on average 3 detected point sources in their inner kiloparsec with L(0.5-10 keV)~10^37-10^40 erg/s. The average cumulative luminosity functions for sources in spirals and ellipticals are identical to those of normal galaxies. In the innermost circle of 2.5" radius in each galaxy we find an AGN in 12 of the 19 galaxies. The AGNs contribute a median of 60% of the 0.5-10 keV luminosity of the central 2.5" region, they have luminosities of 10^37-10^39 erg/s (Eddington ratios 10^-8 to 10^-5). The ionizing luminosity of the AGNs is not enough to power the observed optical emission lines in this particular sample. Thus, we suggest that the lines are powered either by the mechanical interaction of an AGN jet (or wind) with the circumnuclear gas, or by stellar processes, e.g. photoionization by post-AGB stars or young stars.Comment: Accepted by Ap.J. 23 pages, 8 figures, emulatepj format, images of fig 1 not included, for complete PDF preprint see http://www.astro.psu.edu/users/mce/preprints