1,032 research outputs found

    “I Am Undocumented and a New Yorker”: Affirmative City Citizenship and New York City’s IDNYC Program

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    The power to confer legal citizenship status is possessed solely by the federal government. Yet the courts and legal theorists have demonstrated that citizenship encompasses factors beyond legal status, including rights, inclusion, and political participation. As a result, even legal citizens can face barriers to citizenship, broadly understood, due to factors including their race, class, gender, or disability. Given this multidimensionality, the city, as the place where residents carry out the tasks of their daily lives, is a critical space for promoting elements of citizenship. This Note argues that recent city municipal identification-card programs have created a new form of citizenship for their residents. This citizenship, which this Note terms “Affirmative City Citizenship,” is significant for both marginalized populations generally, as well as undocumented immigrant city residents who, because of their noncitizen legal status, face additional hurdles to city life. Utilizing “IDNYC”—New York City’s municipal identification-card program—as a case study, this Note examines the strengths and limitations of Affirmative City Citizenship as a means for supporting undocumented immigrant city residents. It concludes that while Affirmative City Citizenship is a powerful tool for confronting barriers to citizenship, its success with the immigrant population relies in part on the city’s adoption of other proimmigrant policies that more directly conflict with federal law. Accordingly, it recommends that cities seeking to protect their undocumented immigrant city residents adopt both types of policies

    VLBA Determination of the Distance to Nearby Star-forming Regions. IV. A Preliminary Distance to the Proto-Herbig AeBe Star EC 95 in the Serpens Core

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    Using the Very Long Base Array, we observed the young stellar object EC 95 in the Serpens cloud core at eight epochs from 2007 December to 2009 December. Two sources are detected in our field and are shown to form a tight binary system. The primary (EC 95a) is a 4-5 M_⊙ proto-Herbig AeBe object (arguably the youngest such object known), whereas the secondary (EC 95b) is most likely a low-mass T Tauri star. Interestingly, both sources are non-thermal emitters. While T Tauri stars are expected to power a corona because they are convective while they go down the Hayashi track, intermediate-mass stars approach the main sequence on radiative tracks. Thus, they are not expected to have strong superficial magnetic fields, and should not be magnetically active. We review several mechanisms that could produce the non-thermal emission of EC 95a and argue that the observed properties of EC 95a might be most readily interpreted if it possessed a corona powered by a rotation-driven convective layer. Using our observations, we show that the trigonometric parallax of EC 95 is π = 2.41 ± 0.02 mas, corresponding to a distance of 414.9^(+4.4)_ (–4.3) pc. We argue that this implies a distance to the Serpens core of 415 ± 5 pc and a mean distance to the Serpens cloud of 415 ± 25 pc. This value is significantly larger than previous estimates (d ~ 260 pc) based on measurements of the extinction suffered by stars in the direction of Serpens. A possible explanation for this discrepancy is that these previous observations picked out foreground dust clouds associated with the Aquila Rift system rather than Serpens itself

    VLBA determination of the distance to nearby star-forming regions II. Hubble 4 and HDE 283572 in Taurus

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    The non-thermal 3.6 cm radio continuum emission from the naked T Tauri stars Hubble 4 and HDE 283572 in Taurus has been observed with the Very Long Baseline Array (VLBA) at 6 epochs between September 2004 and December 2005 with a typical separation between successive observations of 3 months. Thanks to the remarkably accurate astrometry delivered by the VLBA, the trajectory described by both stars on the plane of the sky could be traced very precisely, and modeled as the superposition of their trigonometric parallax and uniform proper motion. The best fits yield distances to Hubble 4 and HDE 283572 of 132.8 +/- 0.5 and 128.5 +/- 0.6 pc, respectively. Combining these results with the other two existing VLBI distance determinations in Taurus, we estimate the mean distance to the Taurus association to be 137 pc with a dispersion (most probably reflecting the depth of the complex) of about 20 pc.Comment: 21 pages, 4 figues, accepted in ApJ (Dec 20, 2007 issue

    Fault Injection and Monitoring Capability for a Fault-Tolerant Distributed Computation System

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    The Configurable Fault-Injection and Monitoring System (CFIMS) is intended for the experimental characterization of effects caused by a variety of adverse conditions on a distributed computation system running flight control applications. A product of research collaboration between NASA Langley Research Center and Old Dominion University, the CFIMS is the main research tool for generating actual fault response data with which to develop and validate analytical performance models and design methodologies for the mitigation of fault effects in distributed flight control systems. Rather than a fixed design solution, the CFIMS is a flexible system that enables the systematic exploration of the problem space and can be adapted to meet the evolving needs of the research. The CFIMS has the capabilities of system-under-test (SUT) functional stimulus generation, fault injection and state monitoring, all of which are supported by a configuration capability for setting up the system as desired for a particular experiment. This report summarizes the work accomplished so far in the development of the CFIMS concept and documents the first design realization

    Mid-Infrared Spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 2. Determination of the Mean Composition of the Upper Troposphere and Stratosphere

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    Mid-infrared spectral observations Uranus acquired with the Infrared Spectrometer (IRS) on the Spitzer Space Telescope are used to determine the abundances of C2H2, C2H6, CH3C2H, C4H2, CO2, and tentatively CH3 on Uranus at the time of the 2007 equinox. For vertically uniform eddy diffusion coefficients in the range 2200-2600 cm2 s-1, photochemical models that reproduce the observed methane emission also predict C2H6 profiles that compare well with emission in the 11.6-12.5 micron wavelength region, where the nu9 band of C2H6 is prominent. Our nominal model with a uniform eddy diffusion coefficient Kzz = 2430 cm2 sec-1 and a CH4 tropopause mole fraction of 1.6x10-5 provides a good fit to other hydrocarbon emission features, such as those of C2H2 and C4H2, but the model profile for CH3C2H must be scaled by a factor of 0.43, suggesting that improvements are needed in the chemical reaction mechanism for C3Hx species. The nominal model is consistent with a CH3D/CH4 ratio of 3.0+-0.2x10-4. From the best-fit scaling of these photochemical-model profiles, we derive column abundances above the 10-mbar level of 4.5+01.1/-0.8 x 10+19 molecule-cm-2 for CH4, 6.2 +- 1.0 x 10+16 molecule-cm-2 for C2H2 (with a value 24% higher from a different longitudinal sampling), 3.1 +- 0.3 x 10+16 molecule-cm-2 for C2H6, 8.6 +- 2.6 x 10+13 molecule-cm-2 for CH3C2H, 1.8 +- 0.3 x 10+13 molecule-cm-2 for C4H2, and 1.7 +- 0.4 x 10+13 molecule-cm-2 for CO2 on Uranus. Our results have implications with respect to the influx rate of exogenic oxygen species and the production rate of stratospheric hazes on Uranus, as well as the C4H2 vapor pressure over C4H2 ice at low temperatures

    An astrometric planetary companion candidate to the M9 Dwarf TVLM 513-46546

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    Astrometric observations of the M9 dwarf TVLM 513-46546 taken with the VLBA reveal an astrometric signature consistent with a period of 221 ±\pm 5 days. The orbital fit implies that the companion has a mass mp_{p} = 0.35-0.42 MJM_{J}, a circular orbit (e0e \simeq 0), a semi-major axis a = 0.28-0.31 AU and an inclination angle i = 71-88^\circ. The detected companion, TVLM~513bb, is one of the few giant-mass planets found associated to UCDs. The presence of a Saturn-like planet on a circular orbit, 0.3 AU from a 0.06-0.08 MM_\odot star, represents a challenge to planet formation theory. This is the first astrometric detection of a planet at radio wavelengths.Comment: 12 pages, 6 figures, AJ, in pres
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