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Search Results: 1 - 10 of 498384 matches for " Michael A. Fanelli "
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UIT Astro-2 Observations of NGC 4449
Robert S. Hill,Michael N. Fanelli,Denise A. Smith,Theodore P. Stecher,the UIT Team
Physics , 1996, DOI: 10.1063/1.52826
Abstract: The bright Magellanic irregular galaxy NGC 4449 was observed by the Ultraviolet Imaging Telescope (UIT) during the Astro-2 Spacelab mission in March, 1995. Far ultraviolet (FUV) images at a spatial resolution of ~3 arcsec show bright star-forming knots that are consistent with the general optical morphology of the galaxy and are often coincident with bright H II regions. Comparison of FUV with H-alpha shows that in a few regions, sequential star formation may have occurred over the last few Myr. The bright star forming complexes in NGC 4449 are superposed on a smooth, diffuse FUV background that may be associated with the H-alpha "froth."
Ultraviolet Imaging of the Irregular Galaxy NGC 4449 with UIT: Photometry and Recent Star-Formation History
Robert S. Hill,Michael N. Fanelli,Denise A. Smith,Ralph C. Bohlin,Susan G. Neff,Robert W. O'Connell,Morton S. Roberts,Andrew M. Smith,Theodore P. Stecher
Physics , 1998, DOI: 10.1086/306302
Abstract: The bright Magellanic irregular galaxy NGC 4449 was observed during the Astro-2 Space Shuttle mission by the Ultraviolet Imaging Telescope (UIT), which obtained images of a ~40 arcmin field centered on the galaxy in two broad far-ultraviolet (FUV) bands centered at 1520 A and 1620 A, with 3 arcsec - 5 arcsec spatial resolution. Together with H-alpha and H-beta fluxes from ground-based Fabry-Perot images, these data are analyzed in order to explore the recent star formation history of NGC 4449. Maps of the flux ratios H-alpha/FUV and FUV/blue continuum are presented and interpreted using evolutionary synthesis models. Photometry is presented both for 22 apertures containing large OB complexes and for 57 small apertures containing compact FUV-emitting knots. The OB complexes along the northern edge of the visible system have high H-alpha/FUV ratios, and thus appear to be more dominated by the current generation of stars than are other parts of the galaxy. However, young sources do exist elsewhere and are particularly conspicuous along the bar. The small aperture analysis shows three candidate regions for sequential star formation. Surface brightness profiles are consistent with an exponential disk in both the FUV and the optical continuum.
Políticas públicas frente a la "fuga de cerebros": Reflexiones a partir del caso argentino
García de Fanelli, Ana;
Revista de la educación superior , 2008,
Abstract: we analyze public policies implemented to prevent the "brain drain" (repatriation strategies and virtual networks). then, we examine other public policies that do not share this main objective but whose indirect impact could determine its effectiveness (the institutional strength of science and technology institutions and of the phd and postdoctoral programs, the improvement of the incentive structure for faculty and researchers, and transnational education). we conclude by opening the debate on the relative importance that direct and indirect policies could ultimately have in resolving the loss of human capital as a consequence of the brain drain.
La reforma universitaria impulsada vía el financiamiento: Alcances y limitaciones de las políticas de asignación
Ana García de Fanelli
Espacio Abierto , 2007,
Abstract: Desde los a os 90, los gobiernos de varios países latinoamericanos, entre ellos Argentina, imitando modelos desarrollados en los países industrializados, han comenzado a experimentar con el empleo de instrumentos de financiamiento a fin de inducir la reforma de la educación superior. En este artículo se analizan los principales instrumentos utilizados y se reflexiona respecto del alcance de los mismos para inducir transformaciones en las universidades públicas. Se concluye se alando que para que estos mecanismos sean eficaces, deben tomar en consideración la complejidad de las organizaciones universitarias y de su estructura de governance. Deben además configurar una batería de instrumentos consistente, sobre una base de financiamiento suficiente para proveer educación de calidad, y que atienda a esta complejidad a la par que conduzcan a generar acuerdos entre las universidades y los gobiernos
Far Ultraviolet Imagery of the Edge-On Spiral Galaxy NGC 4631
Andrew M. Smith,Nicholas R. Collins,William H. Waller,Morton S. Roberts,Denise A. Smith,Ralph C. Bohlin,K. P. Cheng,Michael N. Fanelli,Susan G. Neff,Robert W. O'Connell,Ronald A. Parise,Eric P. Smith,Theodore P. Stecher
Physics , 2000, DOI: 10.1086/318273
Abstract: Far ultraviolet FUV imagery of the edge-on, Sc/SBd galaxy, NGC 4631 reveals very strong FUV emission, resulting from active star formation, uniformly distributed along the galactic mid- plane. Multi-band imagery, HI and HII position-velocity curves and extinction considerations all imply that the emission is from the outer edges of the visible galaxy. The overall FUV morphology of this edge-on disk system is remarkably similar to those of the so-called "chain galaxies" evident at high redshift, thus suggesting a similar interpretation for at least some of those distant objects. FUV, U, B and V magnitudes, measured for 48 star forming regions, along with corresponding H-alpha and H-beta measurements are used to construct diagnostic color-color diagrams. Although there are significant exceptions, most of the star forming regions are less massive and older than 30 Doradus. Comparison with the expectations from two star formation models yields ages of 2.7 to 10 Myr for the instantaneous burst (IB) model and star formation cut-off ages of 0 to 9 Myr for the continuous star formation (CSF) model. Interpreted in terms of the IB model the photometry implies a total created mass in the 48 star forming regions of 25 million solar-masses. When viewed as resulting from constant star formation the photometry implies a star formation rate of 0.33 solar-masses/yr. These results are compared to those derived from FIR and radio observations. Corrections for FUV emission reprocessed by interstellar grains are estimated.
Ultraviolet Imaging of the z=0.23 Cluster Abell 2246
Robert H. Cornett,Ben Dorman,Eric P. Smith,Michael A. Fanelli,William R. Oegerle,Ralph C. Bohlin,Susan G. Neff,Robert W. O'Connell,Morton S. Roberts,Andrew M. Smith,Theodore P. Stecher
Physics , 1998, DOI: 10.1086/300430
Abstract: We present deep ultraviolet observations of a field containing the cluster Abell 2246 (z=0.225) which provide far-ultraviolet (FUV) images of some of the faintest galaxies yet observed in that bandpass. Abell 2246 lies within the field of view of Ultraviolet Imaging Telescope (UIT) observations of the quasar HS1700+64, which accumulated over 7100 seconds of UIT FUV exposure time during the Astro-2 mission in March 1995. For objects found on both the FUV and ground-based V-band images, we obtain FUV (l ~ 1520 A) photometry and V-band photometry, as well as mid-UV (l ~ 2490 A) photometry from UIT Astro-1 observations and ground-based I-band photometry. We find five objects in the images which are probably galaxies at the distance of Abell 2246, with FUV magnitudes (m(FUV)) between 18.6 and 19.6, and V magnitudes between 18.4 and 19.6. We find that their absolute FUV fluxes and colors imply strongly that they are luminous galaxies with significant current star formation, as well as some relatively recent, but not current, (> 400 Myr ago) star formation. We interpret the colors of these five objects by comparing them with local objects, redshift-corrected template spectra and stellar population models, finding that they are plausibly matched by 10-Gyr-old population models with decaying star formation, with decay time constants in the range 3 Gyr < t < 5 Gyr, with an additional color component from a single burst of moderate ( ~ 400-500 Myr) age. From derived FUV luminosities we compute current star formation rates. We compare the UV properties of Abell 2246 with those of the Coma cluster, finding that Abell 2246 has significantly more recent star formation, consistent with the Butcher-Oemler phenomenon.
Los contratos-programa en las universidades: Lecciones de la comparación internacional. The Contract-Programs in Universities: Lessons from the International Comparison
Ana M. García de Fanelli
Education Policy Analysis Archives , 2006,
Abstract: En el a o 2005 el Ministerio de Educación de la Argentina incorporó una nueva política para asignar recursos públicos a las universidades nacionales: los contratos-programa. Su propósito ha sido brindar fondos para el mejoramiento de la calidad a partir de planes institucionales de mejora elaborados por las propias universidades. Se espera además que estos planes sean respuestas a las debilidades detectadas durante los procedimientos de evaluación externa llevados a cabo por la Comisión Nacional de Evaluación y Acreditación Universitaria (CONEAU). En este trabajo se exponen los resultados de una investigación comparativa sobre los casos de Francia y la Comunidad de Catalu a destinada a contribuir con el dise o de esta política de contractualización. La metodología de investigación incluyó el análisis de documentos, la observación de instancias de negociación y entrevistas con actores clave del gobierno y de las universidades. Se concluye se alando las principales lecciones que se desprenden de este análisis comparativo y subrayando las claras ventajas que presenta esta mecanismo en pos de alinear los objetivos estratégicos del gobierno y de las universidades, tras el fin común de mejorar la calidad. In 2005, the Ministry of Education of Argentina launched a new policy to allocate public funds to national universities: the contractualization policy. Its purpose is to allocate funds to improve teaching quality based on an institutional plan defined by each university. It is expected that this plan addresses the main weaknesses detected during the external assessment coordinated by the National Committee of University Assessment and Accrediting (CONEAU). This paper presents the main findings of a research project carried out to help in the design of this contractualization policy. The two most important antecedents, the French and the Catalonian cases, are examined through the study of official documents, on-site observation of the French negotiation processes, and interviews with government and university key officials. The study concludes with the main lessons learned from these experiences and shows that this mechanism has clear advantages when aligning the strategic objectives that the government and universities have, in order to improve university quality.
On the lack of dispersion for a class of magnetic Dirac flows
Naiara Arrizabalaga,Luca Fanelli,Andoni García
Mathematics , 2011,
Abstract: We show that global Strichartz estimates for magnetic Dirac operators generally fails, if the potentials do not decay fast enough at in?nity. In order to prove this, we construct some explicit examples of homogeneous magnetic potentials with less than Coulomb decay, i. e. with homogeneity-degree more than -1, such that the magnetic ?field points to a ?fixed direction, which does not depend on $x\in \mathbb{R}^3$.
Luminosities and Star Formation Rates Of Galaxies Observed With the Ultraviolet Imaging Telescope: A Comparison of Far-UV, H-alpha, and Far-IR Diagnostics
Michael N. Fanelli,Theodore P. Stecher,the UIT Science Team
Physics , 1996, DOI: 10.1063/1.52770
Abstract: During the UIT/Astro Spacelab missions, the Ultraviolet Imaging Telescope obtained spatially resolved far-UV (lambda 1500 A) imagery of ~35 galaxies exhibiting recent massive star formation. The sample includes disk systems, irregular, dwarf, and blue compact galaxies. The objects span an observed FUV luminosity range from -17 to -22 magnitudes. We estimate global star formation rates by comparing the observed FUV fluxes to the predictions of stellar population models, and compare the FUV-derived astration rates to those derived from H-alpha and far-IR photometry.
UV Signposts of Resonant Dynamics in Disk Galaxies
William H. Waller,Christine Winslow,Michael Fanelli,Theodore B. Stecher
Physics , 1998,
Abstract: Imaging in the restframe ultraviolet has proven to be an effective and vital means of tracing dynamical patterns of star formation in galaxies out to high redshifts. Using images from the Ultraviolet Imaging Telescope (UIT), Hubble Space Telescope (HST) and complementary groundbased telescopes, we have investigated the starburst activity and associated dynamics in nearby early-type disk galaxies. Concentrating on the starburst-ring (R)SA(r)ab galaxy M94 (NGC 4736), we find compelling evidence for bar-mediated resonances as the primary drivers of evolution at the present epoch. Similar ring-bar dynamics may prevail in the centers of early-type disk galaxies at high redshift. The gravitationally-lensed "Pretzel Galaxy" (0024+1654) at a redshift of ~1.5 provides an important precedent in this regard.
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