1,976 research outputs found
Magellan/M2FS Spectroscopy of Galaxy Clusters: Stellar Population Model and Application to Abell 267
We report the results of a pilot program to use the Magellan/M2FS
spectrograph to survey the galactic populations and internal kinematics of
galaxy clusters. For this initial study, we present spectroscopic measurements
for quiescent galaxies observed along the line of sight to the galaxy
cluster Abell 267 (). We develop a Bayesian method for modeling the
integrated light from each galaxy as a simple stellar population, with free
parameters that specify redshift () and characteristic age,
metallicity (), alpha-abundance (), and
internal velocity dispersion () for individual galaxies.
Parameter estimates derived from our 1.5-hour observation of A267 have median
random errors of ,
, $\sigma_{\mathrm{[Fe/H]}}=0.11\
\mathrm{dex}\sigma_{[\alpha/\mathrm{Fe}]}=0.07\ \mathrm{dex}\sigma_{\sigma_\mathrm{int}}=20\ \mathrm{km\ s^{-1}}$. In a companion paper,
we use these results to model the structure and internal kinematics of A267.Comment: 16 pages, 11 figures, accepted for publication in The Astronomical
Journa
Proceedings of the Ninth Annual Indiana STEM Education Conference: Resourcing STEM Education
The Proceedings of the Ninth Annual Indiana STEM Education Conference are edited by the Center for Advancing the Teaching and Learning of STEM (CATALYST, https://www.education.purdue.edu/catalyst/) at Purdue University. The theme for the 2024 conference is Resourcing STEM Education. This year’s Indiana STEM Education Conference provides opportunities to learn about effective STEM education strategies, curriculum, and resources to engage students in integrated STEM learning opportunities and address the recently updated Indiana Academic Standards for Science and Computer Science, Indiana Academic Standards for Mathematics, and Indiana Academic Standards for Integrated STEM (https://www.in.gov/doe/students/indiana-academic-standards/)
Medication adherence in patients with myotonic dystrophy and facioscapulohumeral muscular dystrophy
Myotonic dystrophy (DM) and facioscapulohumeral muscular dystrophy (FSHD) are the two most common adult muscular dystrophies and have progressive and often disabling manifestations. Higher levels of medication adherence lead to better health outcomes, especially important to patients with DM and FSHD because of their multisystem manifestations and complexity of care. However, medication adherence has not previously been studied in a large cohort of DM type 1 (DM1), DM type 2 (DM2), and FSHD patients. The purpose of our study was to survey medication adherence and disease manifestations in patients enrolled in the NIH-supported National DM and FSHD Registry. The study was completed by 110 DM1, 49 DM2, and 193 FSHD patients. Notable comorbidities were hypertension in FSHD (44 %) and DM2 (37 %), gastroesophageal reflux disease in DM1 (24 %) and DM2 (31 %) and arrhythmias (29 %) and thyroid disease (20 %) in DM1. Each group reported high levels of adherence based on regimen complexity, medication costs, health literacy, side effect profile, and their beliefs about treatment. Only dysphagia in DM1 was reported to significantly impact medication adherence. Approximately 35 % of study patients reported polypharmacy (taking 6 or more medications). Of the patients with polypharmacy, the DM1 cohort was significantly younger (mean 55.0 years) compared to DM2 (59.0 years) and FSHD (63.2 years), and had shorter disease duration (mean 26 years) compared to FSHD (26.8 years) and DM2 (34.8 years). Future research is needed to assess techniques to ease pill swallowing in DM1 and to monitor polypharmacy and potential drug interactions in DM and FSHD
Dark matter annihilation and decay profiles for the Reticulum II dwarf spheroidal galaxy
The dwarf spheroidal galaxies (dSph) of the Milky Way are among the most
attractive targets for indirect searches of dark matter. In this work, we
reconstruct the dark matter annihilation (J-factor) and decay profiles for the
newly discovered dSph Reticulum II. Using an optimized spherical Jeans analysis
of kinematic data obtained from the Michigan/Magellan Fiber System (M2FS), we
find Reticulum II's J-factor to be among the largest of any Milky Way dSph. We
have checked the robustness of this result against several ingredients of the
analysis. Unless it suffers from tidal disruption or significant inflation of
its velocity dispersion from binary stars, Reticulum II may provide a unique
window on dark matter particle properties.Comment: 5 pages, 4 figures. Match the ApJL accepted versio
The growth and erosion of cinder cones in Guatemala and El Salvador: Models and statistics
Morphologic data for 147 cinder cones in southern Guatemala andwestern El Salvador are comparedwith data from
the San Francisco volcanic field, Arizona (USA), Cima volcanic field, California (USA), Michoácan–Guanajuato
volcanic field, Mexico, and the Lamongan volcanic field, East Java. The Guatemala cones have an average height of
110+/-50 m, an average basal diameter of 660+/-230 m and an average top diameter of 180+/-150 m. The
generalmorphology of these cones can be described by their average cone angle of slope (24+/-7), average heightto-
radius ratio (0.33+/-0.09) and their flatness (0.24+/-0.18). Although the mean values for the Guatemalan
cones are similar to those for other volcanic fields (e.g., San Francisco volcanic field, Arizona; Cima volcanic field,
California; Michoácan–Guanajuato volcanic field, Mexico; and Lamongan volcanic field, East Java), the range of
morphologies encompasses almost all of those observed worldwide for cinder cones.
Three new 40Ar/39Ar age dates are combined with 19 previously published dates for cones in Guatemala and El
Salvador. There is no indication that the morphologies of these cones have changed over the last 500–1000 ka.
Furthermore, a re-analysis of published data for other volcanic fields suggests that only in the Cima volcanic field (of
those studied) is there clear evidence of degradation with age.
Preliminary results of a numerical model of cinder cone growth are used to show that the range of morphologies
observed in the Guatemalan cinder cones could all be primary, that is, due to processes occurring at the time of
eruption
The growth and erosion of cinder cones in Guatemala and El Salvador: Models and statistics
Morphologic data for 147 cinder cones in southern Guatemala andwestern El Salvador are comparedwith data from
the San Francisco volcanic field, Arizona (USA), Cima volcanic field, California (USA), Michoácan–Guanajuato
volcanic field, Mexico, and the Lamongan volcanic field, East Java. The Guatemala cones have an average height of
110+/-50 m, an average basal diameter of 660+/-230 m and an average top diameter of 180+/-150 m. The
generalmorphology of these cones can be described by their average cone angle of slope (24+/-7), average heightto-
radius ratio (0.33+/-0.09) and their flatness (0.24+/-0.18). Although the mean values for the Guatemalan
cones are similar to those for other volcanic fields (e.g., San Francisco volcanic field, Arizona; Cima volcanic field,
California; Michoácan–Guanajuato volcanic field, Mexico; and Lamongan volcanic field, East Java), the range of
morphologies encompasses almost all of those observed worldwide for cinder cones.
Three new 40Ar/39Ar age dates are combined with 19 previously published dates for cones in Guatemala and El
Salvador. There is no indication that the morphologies of these cones have changed over the last 500–1000 ka.
Furthermore, a re-analysis of published data for other volcanic fields suggests that only in the Cima volcanic field (of
those studied) is there clear evidence of degradation with age.
Preliminary results of a numerical model of cinder cone growth are used to show that the range of morphologies
observed in the Guatemalan cinder cones could all be primary, that is, due to processes occurring at the time of
eruption
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