1,474 research outputs found
An empirical calibration to estimate cool dwarf fundamental parameters from H-band spectra
Interferometric radius measurements provide a direct probe of the fundamental
parameters of M dwarfs, but is within reach for only a limited sample of
nearby, bright stars. We use interferometrically-measured radii, bolometric
luminosities, and effective temperatures to develop new empirical calibrations
based on low-resolution, near-infrared spectra. We use H-band Mg and Al
features to derive calibrations for effective temperature, radius and log
luminosity; the standard deviations in the residuals of our best fits are,
respectively, 73K, 0.027Rsun, and 0.049 dex (11% error on luminosity). These
relationships are valid for mid K to mid M dwarf stars, roughly corresponding
to temperatures between 3100 and 4800K. We apply our calibrations to M dwarfs
targeted by the MEarth transiting planet survey and to the cool Kepler Objects
of Interest (KOIs). We independently validate our calibrations by demonstrating
a clear relationship between our inferred parameters and the absolute K
magnitudes of the MEarth stars, and we identify objects with magnitudes too
bright for their estimated luminosities as candidate multiple systems. We also
use our inferred luminosities to address the applicability of near-infrared
metallicity calibrations to mid and late M dwarfs. The temperatures we infer
for the KOIs agree remarkably well with those from the literature; however, our
stellar radii are systematically larger than those presented in previous works
that derive radii from model isochrones. This results in a mean planet radius
that is 15% larger than one would infer using the stellar properties from
recent catalogs. Our results confirm those of previous in-depth studies of
Kepler-42, Kepler-45, and Kepler-186.Comment: Accepted to ApJ. Tables 4 and 5, and machine readable versions of
Tables 5 and 7 are available in the ApJ journal articl
A VLA Survey For Faint Compact Radio Sources in the Orion Nebula Cluster
We present Karl G. Janksy Very Large Array (VLA) 1.3 cm, 3.6 cm, and 6 cm
continuum maps of compact radio sources in the Orion Nebular Cluster. We
mosaicked 34 square arcminutes at 1.3 cm, 70 square arcminutes at 3.6 cm and
109 square arcminutes at 6 cm, containing 778 near-infrared detected YSOs and
190 HST-identified proplyds (with significant overlap between those
characterizations). We detected radio emission from 175 compact radio sources
in the ONC, including 26 sources that were detected for the first time at these
wavelengths. For each detected source we fit a simple free-free and dust
emission model to characterize the radio emission. We extrapolate the free-free
emission spectrum model for each source to ALMA bands to illustrate how these
measurements could be used to correctly measure protoplanetary disk dust masses
from sub-millimeter flux measurements. Finally, we compare the fluxes measured
in this survey with previously measured fluxes for our targets, as well as four
separate epochs of 1.3 cm data, to search for and quantify variability of our
sources.Comment: 13 pages, 6 figures, 4 tables, ApJ, in pres
Making the Internal Revenue Service Work
This is an Article about how to redesign the federal tax system so that the Internal Revenue Service (IRS) can administer it more effectively given that Congress is only willing to let the IRS have around 82,000 employees and a $12 billion budget. As the IRS Oversight Board and the National Taxpayer Advocate have frequently emphasized, the United States underinvests in the IRS. Underinvesting means that taxpayer services are suffering and that tax enforcement has been significantly weakened. With budget deficits for “as far as the eye can see” and the recent IRS troubles with tax-exempt political organizations, the prospects for increased funding for the IRS are remote. In this Article, we consider a variety of approaches that would make it easier for the IRS to raise and collect revenue, and we offer a number of recommendations for legislative and administrative changes. For example, we recommend simplifying the tax system, enhancing third-party reporting, and streamlining the tax-filing and dispute-resolution procedures. In short, this Article discusses how the tax system should be designed so that it can work with a modestly-funded tax administrator. Part II of this Article provides an overview of the federal tax system, and Part III of this Article provides an overview of tax administration. Part IV of this Article discusses the key problems with current tax administration. Finally, Part V of this Article offers a number of recommendations for change, including some that would require legislation and some that could be achieved administratively
Borrowing from Millennials to Pay Boomers: Can Tax Policy Create Sustainable Intergenerational Equity?
At the outset, Part I of the Article provides an overview of sustainable intergenerational justice and tax policy. Part II then provides an overview of the U.S. tax system, deficits, and public debt. Part III then considers how taxes can influence the level of resources that are available to future generations, and Part IV considers how taxes can influence the mix of resources that are available to future generations
From Lower Town to St. Cloud State: Geophysical Survey of an Evolving Urban Landscape 1869-2019
In 2019 a team of graduate students from the Cultural Resource Management Masters program, led by Rob Mann, PhD., Professor of Anthropology, under took a ground penetrating radar survey of critical sites on the St. Cloud State University campus. These were sites that had played a role in shaping the development of the University. The project was funded by a graduate student research grant from St. Cloud State University
West Virginia Story: Achievement Gains from a Statewide Comprehensive Instructional Technology Program
This report describes West Virginia\u27s Basic Skills/Computer Education (BS/CE) program and connects its features to gains in student test scores that are practically and statistically significant. The program consists of three components: (1) software that focuses on the state\u27s basic skills goals in reading, language arts, and mathematics; (2) enough computers in the schools so that all students will be able to have easy and regular access to the basic skills software; and (3) professional development for teachers in the use of the software and the use of computers in general. Data were collected from all fifth graders (n=950) in 18 elementary schools selected to represent the range of variables that might influence technology use and student achievement. Survey data were also collected from 290 teachers. Results were analyzed using a model that includes access to software and computers, attitudes toward technology, and teacher training and involvement. The relationship of BS/CE to student achievement, as measured by the Stanford-9 achievement test, is examined. Findings suggest that the BS/CE program had a powerfully positive effect, especially in those schools that used it most intensively. Ten figures and tables illustrate findings. (AEF
Intertextual poetics: the modernist poetry of Anthony Burgess
This dissertation offers a series of exegetical readings of short and long poems by
Anthony Burgess, with the aim of establishing the extent to which this poetry
participates in Modernist and Postmodernist traditions. Beginning with Burgess's
poems of the 1930s, the thesis discusses all of his major poetic works until 1993.
Making extensive use of unpublished manuscript material, this is the first thesis to
treat poetry and verse drama (including translations) as a discrete area of Burgess's
literary production. As such, the thesis significantly extends the critical enquiries of
previous scholars.
Having identified specific poetic influences, the thesis addresses the poetic effects of
the intertextual techniques used by Burgess. His poetry and writing about poetry are
accounted for chronologically, and a selection of longer texts are discussed in detail.
Influential Modernist poets are found to practice a range of techniques which Burgess
parodies and pastiches with serious intent. Burgess is found to use Modernist
techniques throughout his literary career, and to apprehend tradition through a
conservative version of Modernism.
Burgess's later poetry is shown to be self-reflexive and formalist in ways which are
identifiably Postmodern. In texts such as Byrne, St. Winefred's Well and The End of
Things, Burgess reassesses his relationship with Modernism, and intertextuality itself
becomes a key preoccupation.
Arguing the case for Burgess as a transitional late Modernist poet, the thesis charts the
development of Burgess's engagement with Modernism and Postmodernism, and
proposes that the two are interdependent rather than antithetical
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