Enrique Perez

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James Elkins

School of the Art Institute of Chicago

Nicole Herbots

Arizona State University

Dr. Angela Amphawan

Massachusetts Institute of Technology (MIT)

Peter Hobson

Queen Mary, University of London

Prof.Dr. İbrahim USLU

Gazi University

Kiran Dasari

University of Illinois at Urbana-Champaign

Richard Gauthier

Santa Rosa Junior College

Valentina Gutierrez

Universidad de Santiago de Chile

luis medina

Universidad de Guayaquil

Franz Giessibl

University of Regensburg

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Papers by Enrique Perez

Integration, Customization and Maintenance of Heterogeneous Software with MECASP

... Integration, customization and maintenance of heterogeneous software with MECASP. 1357861 abs... more

Integration and Maintenance of Heterogeneous Applications and Data Structures

The paper introduces an XML-based solution for the conceptual representation, integration, adapta... more The paper introduces an XML-based solution for the conceptual representation, integration, adaptation and maintenance of heterogeneous applications and data structures. It first presents the architecture of the XML repository and the content of the XML (meta)models that represent applications and data structures. Then, the architecture of the repository manager is given, along with its interface (the browser) and its functions for the management and maintenance of the XML models which describe applications/ data structures.

On the Origin of the Ultraviolet Continuum in Seyfert 2 Galaxies

Astrophysical Journal - ASTROPHYS J, 1997

High-resolution Hubble Space Telescope ultraviolet images of the Seyfert 2 galaxies NGC 1667, NGC... more High-resolution Hubble Space Telescope ultraviolet images of the Seyfert 2 galaxies NGC 1667, NGC 3982, NGC 5427, and NGC 5953, previously known to have circumnuclear star-forming rings, are presented. The UV images of all four Seyfert 2 galaxies show the presence of several compact UV-bright knots at distances of ~0.7-2 kpc from the nucleus and associated to the circumnuclear star-forming ring. The optically bright Seyfert 2 nucleus is barely detected in the UV. The UV images provide the first direct empirical evidence that the UV flux emitted by galaxies having a Seyfert 2-type nucleus surrounded by a circumnuclear star-forming ring is dominated by radiation coming from clusters of young hot stars distributed along the star-forming ring. The contribution of the Seyfert 2 nucleus amounts to ~1%-10% of the observed UV flux in these four galaxies. If circumnuclear star-forming rings of 2-3 kpc in diameter, or smaller, are a common feature of Seyfert 2 galaxies, we conclude that (a) the observed UV flux in Seyfert 2 galaxies is not dominated by the radiation from the nuclear ionizing source and (b) the observed UV flux is dominated by emission from clusters of young hot stars located in circumnuclear star-forming regions. Whatever the nature of the nuclear ionizing source in these Seyfert 2 galaxies, this must be obscured. The UV and Hα luminosities associated to the Seyfert 2 nucleus in these galaxies are consistent with the scenario of the nuclear ionizing source being an obscured power-law ionizing source or a young (2-4 Myr) obscured high-metallicity (>=Zsolar) nuclear starburst.

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KINEMATICAL AND PHYSICAL PROPERTIES OF A 700 pc LARGE BUBBLE IN NGC 6946

Astrophysical Journal - ASTROPHYS J, 2009

The galaxy NGC 6946 contains a gas-star complex of 700 pc in diameter which appears populated by ... more The galaxy NGC 6946 contains a gas-star complex of 700 pc in diameter which appears populated by tens of young stellar clusters, and a Super Star Cluster (SSC) as massive as 10 6 M⊙. The ionized gas, as drawn by the Hα emission, delineates an almost circular shape which we show here to be in expansion. Previous studies have analyzed the stellar component of the complex, as well as the structure of the atomic and ionized gas; these analyses were restricted to the blueshifted component along the whole extent of the bubble or to a smaller inner region where both sides of an expanding bubble were seen. In this work we present a complete spectroscopic study of this object for two position angles crossing each other close to the young massive SSC. We have obtained new data with a spectral resolution six times better than previous spectroscopic studies, taken under atmospheric conditions better than those previously reported, allowing us to detect the approaching and receding walls of one the largest bubbles in external galaxies ever studied in detail.

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The Stellar Populations of Low‐Luminosity Active Galactic Nuclei. I. Ground‐based Observations

The Astrophysical Journal, 2004

In a recently completed survey of the stellar populations properties of LINERS and LINER/HII Tran... more In a recently completed survey of the stellar populations properties of LINERS and LINER/HII Transition Objects (TOs), we have identified a numerous class of galactic nuclei which stand out because of their conspicuous 10 8−9 yr populations, traced by high order Balmer absorption lines and other stellar indices. These objects were called "Young-TOs", since they all have TO-like emission line ratios. In this paper we extend this previous work, which concentrated on the nuclear properties, by investigating the radial variations of spectral properties in Low Luminosity Active Galactic Nuclei (LLAGN). Our analysis is based on high signal to noise long-slit spectra in the 3500-5500Å interval for a sample of 47 galaxies. The data probe distances of typically up to 850 pc from the nucleus with a resolution of ∼ 100 pc (∼ 1 ′′ ) and S/N ∼ 30. Stellar population gradients are mapped by the radial profiles of absorption line equivalent widths and continuum colours along the slit. These variations are further analyzed by means of a decomposition of each spectrum in terms of template galaxies representative of very young (≤ 10 7 yr), intermediate age (10 8−9 yr) and old (10 10 yr) stellar populations.

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On the Feedback from Super Stellar Clusters. I. The Structure of Giant H ii Regions and H ii Galaxies

The Astrophysical Journal, 2006

We review the structural properties of giant extragalactic HII regions and HII galaxies based on ... more We review the structural properties of giant extragalactic HII regions and HII galaxies based on two dimensional hydrodynamic calculations, and propose an evolutionary sequence that accounts for their observed detailed structure. The model assumes a massive and young stellar cluster surrounded by a large collection of clouds. These are thus exposed to the most important star-formation feedback mechanisms: photoionization and the cluster wind. The models show how the two feedback mechanisms compete with each other in the disruption of clouds and lead to two different hydrodynamic solutions: The storage of clouds into a long lasting ragged shell that inhibits the expansion of the thermalized wind, and the steady filtering of the shocked wind gas through channels carved within the cloud stratum that results into the creation of large-scale superbubbles. Both solutions are here claimed to be concurrently at work in giant HII regions and HII galaxies, causing their detailed inner structure. A full description of the calculations can be found in The Astrophysical Journal 643, 186. Animated version of the models presented can be found at http://www.iaa.csic.es/˜eperez/ssc/ssc.html.

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Violent star formation in NGC 2363

The Astrophysical Journal, 1994

... Printed in USA VIOLENT STAR FORMATION IN NGC 2363 ROSA M. GONZALEZ-DELGADO, PEREZ,&amp;am... more ... Printed in USA VIOLENT STAR FORMATION IN NGC 2363 ROSA M. GONZALEZ-DELGADO, PEREZ,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27; TENORIO-TAGLE, M. VILcHEz, ELENA TERLEVICH, TERLEVICH, TELLES, M. RODRIGUEZ-ESPINOSA,&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27; MIGUEL MAS-HESSE, LUISA GARCIA-VARGAS, I. DIAZ, JORDI ...