Creativity in Illustration

Creativity in Illustrationhttps://source.sheridancollege.ca/fhass_infographics_creativity/1005/thumbnail.jp

Radial Trends in IMF-Sensitive Absorption Features in Two Early-Type Galaxies: Evidence for Abundance-Driven Gradients

Samples of early-type galaxies show a correlation between stellar velocity dispersion and the stellar initial mass function (IMF) as inferred from gravity-sensitive absorption lines in the galaxies' central regions. To search for spatial variations in the IMF, we have observed two early-type galaxies with Keck/LRIS and measured radial gradients in the strengths of absorption features from 4000-5500 \AA $\,$ and 8000-10,000 \AA. We present spatially resolved measurements of the dwarf-sensitive spectral indices NaI (8190 \AA) and Wing-Ford FeH (9915 \AA), as well as indices for species of H, C$_2$, CN, Mg, Ca, TiO, and Fe. Our measurements show a metallicity gradient in both objects, and Mg/Fe consistent with a shallow gradient in \alpha-enhancement, matching widely observed trends for massive early-type galaxies. The NaI index and the CN$_1$ index at 4160 \AA $\,$ exhibit significantly steeper gradients, with a break at $r \sim 0.1 r_{\rm eff}$ ($r \sim 300$ pc). Inside this radius NaI strength increases sharply toward the galaxy center, consistent with a rapid central rise in [Na/Fe]. In contrast, the ratio of FeH to Fe index strength decreases toward the galaxy center. This behavior cannot be reproduced by a steepening IMF inside $0.1 r_{\rm eff}$ if the IMF is a single power law. While gradients in the mass function above $\sim 0.4 M_\odot$ may occur, exceptional care is required to disentangle these IMF variations from the extreme variations in individual element abundances near the galaxies' centers.Comment: Accepted for publication in ApJ. Updates from v1 include an expanded comparison of measured index strengths to SPS models. 20 page body + 7 page appendix + references. Includes 25 figure

World Regional Geography

This Grants Collection for World Regional Geography was created under a Round Twelve ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/geo-collections/1007/thumbnail.jp

Resources, Society, and the Environment (VSU)

This Grants Collection for Resources, Society, and the Environment was created under a Round Nine ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/geo-collections/1004/thumbnail.jp

Practicing Ignatian Pedagogy: A Digital Collection of Resources

In the Spring 2015 issue of Jesuit Higher Education: A Journal, Kimberly Connor described building an Ignatian Pedagogy Faculty Learning Community at the University of San Francisco. One outcome of the FLC was to gather and make easily available a collection of resources on Jesuit education and the IPP (Ignatian Pedagogical Paradigm). In this issue, two USF Gleeson Library/Geschke Center librarians, Zheng (Jessica) Lu, Digital Collections Librarian, and Vicki Rosen, Distance Learning Services Librarian, describe creating Practicing Ignatian Pedagogy: A Digital Collection of Resources, an openly accessible database available through the USF Library website, using the FLC resources and digital technolog

Practicing Ignatian Pedagogy: A Digital Collection of Resources

In the Spring 2015 issue of Jesuit Higher Education: A Journal, Kimberly Connor described building an Ignatian Pedagogy Faculty Learning Community at the University of San Francisco. One outcome of the FLC was to gather and make easily available a collection of resources on Jesuit education and the IPP (Ignatian Pedagogical Paradigm). In this issue, two USF Gleeson Library/Geschke Center librarians, Zheng (Jessica) Lu, Digital Collections Librarian, and Vicki Rosen, Distance Learning Services Librarian, describe creating Practicing Ignatian Pedagogy: A Digital Collection of Resources, an openly accessible database available through the USF Library website, using the FLC resources and digital technolog

The orbital motion of the Arches cluster — clues on cluster formation near the galactic center

The Arches cluster is one of the most massive, young clusters in the Milky Way. Located inside the central molecular zone in the inner 200 pc of the Galactic center, it formed in one of the most extreme star-forming environments in the present-day Galaxy. Its young age of only 2.5 Myr allows us to observe the cluster despite the strong tidal shear forces in the inner Galaxy. The orbit of the cluster determines its dynamical evolution, tidal stripping, and hence its fate. We have measured the proper motion of the Arches cluster relative to the ambient field from Keck/NIRC2 LGS-AO and VLT/NAOS-CONICA NGS-AO observations taken 4.3 years earlier. When combined with the radial velocity, we derive a 3D space motion of 232 ± 30 km/s for the Arches. This motion is exceptionally large when compared to molecular cloud orbits in the GC, and places stringent constraints on the formation scenarios for starburst clusters in dense, nuclear environments