93 research outputs found

    Space, the Initial Frontier

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    It\u27s a truism among those who work in science outreach that the two aspects of science that get people really excited are space and dinosaurs. It seems reasonable to assume that at least some science and engineering students were attracted to our fields because of their interest in these topics. But concepts related to space and/or astronomy don\u27t usually make it into first-year physics textbooks, despite the relevance to the typical first-year curriculum. The students won\u27t all end up being astronomers or aerospace engineers, but can we use their interest in space to help them find fist-year physics more relevant and interesting? What would that look like? Can we extend the space hook to other subjects, like chemistry or computer science or even biology? This presentation is intended to be an exploratory discussion combined with a brainstorming session

    Testing population synthesis models with globular cluster colors

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    We have measured an extensive set of UBVRIJHK colors for M31 globular clusters [Barmby et al. 2000]. We compare the predicted simple stellar population colors of three population synthesis models to the intrinsic colors of Galactic and M31 globular clusters. The best-fitting models fit the cluster colors very well -- the weighted mean color offsets are all < 0.05 mag. The most significant offsets between model and data are in the U and B passbands; these are not unexpected and are likely due to problems with the spectral libraries used by the models. The metal-rich clusters ([Fe/H] > -0.8) are best fit by young (8 Gyr) models, while the metal-poor clusters are best fit by older (12--16 Gyr) models. If this range of globular cluster ages is correct, it implies that conditions for cluster formation must have existed for a substantial fraction of the galaxies' lifetimes.Comment: To appear in ApJ Letters; 8 pages including 3 figures and 1 tabl

    Gibbs point process model for young star clusters in M33

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    We demonstrate the power of Gibbs point process models from the spatial statistics literature when applied to studies of resolved galaxies. We conduct a rigorous analysis of the spatial distributions of objects in the star formation complexes of M33, including giant molecular clouds (GMCs) and young stellar cluster candidates (YSCCs). We choose a hierarchical model structure from GMCs to YSCCs based on the natural formation hierarchy between them. This approach circumvents the limitations of the empirical two-point correlation function analysis by naturally accounting for the inhomogeneity present in the distribution of YSCCs. We also investigate the effects of GMCs\u27 properties on their spatial distributions. We confirm that the distribution of GMCs and YSCCs are highly correlated. We found that the spatial distributions of YSCCs reaches a peak of clustering pattern at ∼250 pc scale compared to a Poisson process. This clustering mainly occurs in regions where the galactocentric distance ≳4.5 kpc. Furthermore, the galactocentric distance of GMCs and their mass have strong positive effects on the correlation strength between GMCs and YSCCs. We outline some possible implications of these findings for our understanding of the cluster formation process

    Evidence for coupling of evolved star atmospheres and spiral arms of the milky way

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    It is imperative to map the strength and distribution of feedback in galaxies to understand how feedback affects galactic ecosystems. H2O masers act as indicators of energy injection into the interstellar medium. Our goal is to measure the strength and distribution of feedback traced by water masers in the Milky Way. We identify optical counterparts to H2O masers discovered by the HOPS survey. The distribution and luminosities of H2O masers in the Milky Way are determined using parallax measurements derived from the second Gaia Data Release. We provide evidence of a correlation between evolved stars, as traced by H2O masers, and the spiral structure of the Milky Way, suggesting a link between evolved stars and the Galactic environment

    The Elliptical Galaxy formerly known as the Local Group: Merging the Globular Cluster Systems

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    Prompted by a new catalogue of M31 globular clusters, we have collected together individual metallicity values for globular clusters in the Local Group. Although we briefly describe the globular cluster systems of the individual Local Group galaxies, the main thrust of our paper is to examine the collective properties. In this way we are simulating the dissipationless merger of the Local Group, into presumably an elliptical galaxy. Such a merger is dominated by the Milky Way and M31, which appear to be fairly typical examples of globular cluster systems of spiral galaxies. The Local Group `Elliptical' has about 700 +/- 125 globular clusters, with a luminosity function resembling the `universal' one. The metallicity distribution has peaks at [Fe/H] ~ -1.55 and -0.64 with a metal-poor to metal-rich ratio of 2.5:1. The specific frequency of the Local Group Elliptical is initially about 1 but rises to about 3, when the young stellar populations fade and the galaxy resembles an old elliptical. The metallicity distribution and stellar population corrected specific frequency are similar to that of some known early type galaxies. Based on our results, we briefly speculate on the origin of globular cluster systems in galaxies.Comment: 22 pages, Latex, 4 figures, 5 tables, submitted to A &

    Citizen science projects for non-science astronomy students

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    Astronomy is a popular topic for non-science students taking a required science course; at our university, about 1500 students take such courses each year. Most of the assignments in our General Astronomy course are focused on assisting students to understand the many unfamiliar concepts introduced in the course. However, we also wanted to give students a chance to experience some astronomical research, and in doing so, encourage an interest in participating in science outside of the course context. Building on the general public interest in astronomy, the Zooniverse project aims to advance astronomical research through online citizen science projects. These typically involve sifting through a huge amount of digital data that are made available online and using the pattern-recognition abilities of the human brain to do something not easily achievable with a computer algorithm. Such projects require a minimal amount of training and no scientific background. Thousands of people all over the world have participated in these projects, and we have designed several course assignments which ask students to participate, answer some straightforward questions based on the training information, and provide proof of their participation. The poster will provide some details about the assignment implementation, quantitative information concerning student participation and some anecdotal comments from students on the experience
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