Lorén-Aguilar, P., Isern, J., García-Berro, E.
We present the results of a set of high-resolution simulations of the merging process of two white dwarfs. In order to do so, we use an up-to-date Smoothed Particle Hydrodynamics code which...
Axions and the white dwarf luminosity function (2008)
Isern, J., Catalan, S., Garcia-Berro, E., Torres, S.
The evolution of white dwarfs can be described as a simple cooling process. Recently, it has been possible to determine with an unprecedented precision their luminosity function, that is, the number...
Axions and the cooling of white dwarf stars (2008)
Isern, J., Garcia-Berro, E., Torres, S., Catalan, S.
White dwarfs are the end-product of the lifes of intermediate- and low-mass stars and their evolution is described as a simple cooling process. Recently, it has been possible to determine with an...
Catalan, S., Isern, J., Garcia-Berro, E., Ribas, I.
The initial-final mass relationship connects the mass of a white dwarf with the mass of its progenitor in the main-sequence. Although this function is of fundamental importance to several fields in...
The contribution of red dwarfs and white dwarfs to the halo dark matter (2008)
Torres, S., Camacho, J., Isern, J., Garcia-Berro, E.
The nature of the several microlensing events observed by the MACHO team towards the LMC still remains controversial. Low-mass substellar objects and stars with masses larger than ~1 M_{sun} have...
Edi cio de Informatica y Matematicas (2008)
M. Hern, J. Cabrera, M. Castrillon, A. Dom Nguez, C. Guerra, D. Hern, ...
Abstract. In this paper, a basic conceptual architecture aimed at the design of Computer Vision System is qualitatively described. The proposed architecture addresses the design of vision systems in...
Gravitational settling of 22Ne and white dwarf evolution (2007)
Althaus, L. G., Córsico, A. H., Isern, J.
We study the effects of the sedimentation of the trace element 22Ne in the cooling of white dwarfs. In contrast with previous studies, which adopted a simplified treatment of the effects of 22Ne...
Edificio de Informatica y Matematicas (2007)
M. Hern, J. Cabrera, C. Guerra, D. Hern, J. Isern
Abstract. In this paper, a basic conceptual architecture aimed at the design of Computer Vision System is qualitatively described. The proposed architecture addresses the design of vision systems in...
Experiences with A Museum Robot (2007)
J. Cabrera, D. Hern, A. C. Domnguez, J. Lorenzo, J. Isern, C. Guerra, ...
Centro de Tecnologa de los Sistemas y de la Inteligencia Articial (CeTSIA)
Monte Carlo Simulations Of The White Dwarf Population And Luminosity Function (2007)
Matt A. Wood, J. Isern, M. Hernanz
. The white dwarf luminosity function has been used in recent years as an independent probe of the age and evolution of the local Galactic disk. A long-standing uncertainty of the technique is that...
WD0433+270: an old Hyades stream member or an Fe-core white dwarf? (2007)
Catalan, S., Ribas, I., Isern, J., Garcia-Berro, E.
G39-27/289 is a common proper motion pair formed by a white dwarf (WD0433+270) and a main-sequence star (BD+26 730) that apparently has been classified as a member of the Hyades open cluster....
The initial-final mass relationship from white dwarfs in common proper motion pairs (2007)
Catalan, S., Isern, J., Garcia-Berro, E., Ribas, I., Prieto, C. Allende, Bonanos, A. Z.
The initial-final mass relationship of white dwarfs, which is poorly constrained, is of paramount importance for different aspects in modern astrophysics. From an observational perspective, most of...
The contribution of Oxygen-Neon white dwarfs to the MACHO content of the Galactic Halo (2007)
Camacho, J., Torres, S., Isern, J., Althaus, L. G., Garcia-Berro, E.
The interpretation of microlensing results towards the Large Magellanic Cloud (LMC) still remains controversial. White dwarfs have been proposed to explain these results and, hence, to contribute...
Torres, S., Garcia-Berro, E., Isern, J.
Only the 1/V_max method has been employed so far for observationally determining the white dwarf luminosity function, whereas for other kind of luminosity functions several other methods have been...
Evidence for a merger of binary white dwarfs: the case of GD 362 (2007)
Garcia-Berro, E., Loren-Aguilar, P., Pedemonte, A. G., Isern, J., Bergeron, P., Dufour, P., ...
GD 362 is a massive white dwarf with a spectrum suggesting a H-rich atmosphere which also shows very high abundances of Ca, Mg, Fe and other metals. However, for pure H-atmospheres the diffusion...
The age and colors of massive white dwarf stars (2007)
Althaus, L. G., García-Berro, E., Isern, J., Córsico, A. H., Rohrmann, R. D.
We present evolutionary calculations and colors for massive white dwarfs with oxygen-neon cores for masses between 1.06 and 1.28 Mo. The evolutionary stages computed cover the luminosity range from...
The white dwarf luminosity function. I. Statistical errors and alternatives (2006)
Geijo, E. M., Torres, S., Isern, J., Garcia-Berro, E.
Over the years, several methods have been proposed to compute galaxy luminosity functions, from the most simple ones -counting sample objects inside a given volume- to very sophisticated ones -like...
MAX: Development of a Laue diffraction lens for nuclear astrophysics (2006)
Barriere, N., Von Ballmoos, P., Skinner, G., Smither, B., Bastie, P., Hinglais, E., ...
The next generation of instrumentation for nuclear astrophysics will have to achieve an improvement in sensitivity by a factor of 10100 over present technologies. With the focusing gamma-ray...
L'observatori astronòmic del Montsec (2006)
Torra Roca, Jordi, Colomé, J., Isern, J., Ribas-Marqués, I., Fernández, D., Palau, X.
MAX: Development of a Laue diffraction lens for nuclear astrophysics (2006)
Barriere, N., Von Ballmoos, P., Skinner, G., Smither, B., Bastie, P., Hinglais, E., ...
The next generation of instrumentation for nuclear astrophysics will have to achieve an improvement in sensitivity by a factor of 10100 over present technologies. With the focusing gamma-ray...
MAX: Development of a Laue diffraction lens for nuclear astrophysics (2006)
Barriere, N., Von Ballmoos, P., Skinner, G., Smither, B., Bastie, P., Hinglais, E., ...
The next generation of instrumentation for nuclear astrophysics will have to achieve an improvement in sensitivity by a factor of 10100 over present technologies. With the focusing gamma-ray...
Garcia-Berro, E., Kubyshin, Yu. A., Loren-Aguilar, P., Isern, J.
We consider a cosmological model with a variable gravitational constant, G, based on a scalar-tensor theory. Using the recent observational data for the Hubble diagram of type Ia supernovae (SNeIa)...
Garcia-Berro, E., Loren-Aguilar, P., Corsico, A. H., Althaus, L. G., Lobo, J. A., Isern, J.
We compute the emission of gravitational radiation from pulsating white dwarfs. This is done by using an up-to-date stellar evolutionary code coupled with a state-of-the-art pulsational code. The...
Mass-radius relations for massive white dwarf stars (2005)
Althaus, L. G., Isern, J., Córsico, A. H.
We present detailed theoretical mass-radius relations for massive white dwarf stars with oxygen-neon cores. This work is motivated by recent observational evidence about the existence of white dwarf...
Simulating Gaia performances on white dwarfs (2005)
Torres, S., Garcia-Berro, E., Isern, J., Figueras, F.
One of the most promising space missions of ESA is the astrometric satellite Gaia, which will provide very precise astrometry and multicolour photometry, for all 1.3 billion objects to V~20, and...
Gravitational wave radiation from the coalescence of white dwarfs (2004)
Loren-Aguilar, P., Guerrero, J., Isern, J., Lobo, J. A., Garcia-Berro, E.
We compute the emission of gravitational radiation from the merging of a close white dwarf binary system. This is done for a wide range of masses and compositions of the white dwarfs, ranging from...
Corsico, A. H., Althaus, L. G., Montgomery, M. H., Garcia-Berro, E., Isern, J.
We present in this work new pulsational calculations for improved carbon-oxygen DA white dwarf models suitable for the study of massive ZZ Ceti stars. The background models employed in this study,...
Pulsations of massive ZZ Ceti stars with carbon/oxygen and oxygen/neon cores (2004)
Corsico, A. H., Garcia-Berro, E., Althaus, L. G., Isern, J.
We explore the adiabatic pulsational properties of massive white dwarf stars with hydrogen-rich envelopes and oxygen/neon and carbon/oxygen cores. To this end, we compute the cooling of massive white...
Unified 1-D Simulations of Gamma-Ray Line Emission from Type Ia Supernovae (2004)
Milne, P. A., Hungerford, A. L., Fryer, C. L., Evans, T. M., Urbatsch, T. J., Boggs, S. E., ...
The light curves of Type Ia Supernovae (SN Ia) are powered by gamma-rays emitted by the decay of radioactive elements such as $^{56}$Ni and its decay products. These gamma-rays are...
Monte Carlo simulations of the halo white dwarf population (2004)
Garcia-Berro, E., Torres, S., Isern, J., Burkert, A.
The interpretation of microlensing results towards the Large Magellanic Cloud (LMC) still remains controversial. Whereas white dwarfs have been proposed to explain these results and, hence, to...
Monte Carlo simulations of the halo white dwarf population (2004)
García-Berro, E., Torres, S., Isern, J., Burkert, A.
The interpretation of microlensing results towards the Large Magellanic Cloud (LMC) still remains controversial. While white dwarfs have been proposed to explain these results and, hence, to...
Time variation of G and \alpha within models with extra dimensions (2003)
Loren-Aguilar, P., Garcia-Berro, E., Isern, J., Kubyshin, Yu. A.
We derive the formulae for the time variation of the gravitational "constant" G and of the fine structure "constant" \alpha in various models with extra dimensions and analyze their consistency with...
s-Process Nucleosynthesis in Carbon Stars (2002)
Abia, C., Dominguez, I., Gallino, R., Busso, M., Masera, S., Straniero, O., ...
We present the first detailed and homogeneous analysis of the s-element content in Galactic carbon stars of N-type. Abundances of Sr,Y, Zr (low-mass s-elements, or ls) and of Ba, La, Nd, Sm and Ce...
Future INTEGRAL observations of classical novae (2002)
Hernanz, M., Jean, P., Jose, J., Coc, A., Starrfield, S., Truran, J., ...
Future INTEGRAL observations of classical novae (2002)
Hernanz, M., Jean, P., Jose, J., Coc, A., Starrfield, S., Truran, J., ...
Gaztanaga, E., Garcia-Berro, E., Isern, J., Bravo, E., Dominguez, I.
Recent high-redshift Type Ia supernovae results can be used to set new bounds on a possible variation of the gravitational constant $G$. If the local value of $G$ at the space-time location of...
The Kr85 s-process Branching and the Mass of Carbon Stars (2001)
Abia, C., Busso, M., Gallino, R., Dominguez, I., Straniero, O., Isern, J.
We present new spectroscopic observations for a sample of C(N)-type red giants. These objects belong to the class of Asymptotic Giant Branch stars, experiencing thermal instabilities in the...
Abia, C., Dominguez, I., Straniero, O., Limongi, M., Chieffi, A., Isern, J.
Motivated by the recent detection of metals in different components of the high redshift universe and by the abundance ratios measured in the extremely metal-poor stars of our Galaxy, we study the...
The potential of the variable DA white dwarf G117-B15A as a tool for Fundamental Physics (2001)
Corsico, A. H., Benvenuto, O. G., Althaus, L. G., Isern, J., Garcia-Berro, E.
White dwarfs are well studied objects. The relative simplicity of their physics allows to obtain very detailed models which can be ultimately compared with their observed properties. Among white...
On the White Dwarf distances to Galactic Globular Clusters (2001)
Salaris, M., Cassisi, S., Garcia-Berro, E., Isern, J., Torres, S.
We analyze in detail various possible sources of systematic errors on the distances of globular clusters derived by fitting a local template DA white dwarf sequence to the cluster counterpart (the...
The ages of very cool hydrogen-rich white dwarfs (2000)
Salaris, M., Garcia-Berro, E., Hernanz, M., Isern, J., Saumon, D.
The evolution of white dwarfs is essentially a cooling process that depends primarily on the energy stored in their degenerate cores and on the transparency of their envelopes. In this paper we...
Hernanz, M., Jose, J., Coc, A., Gomez-Gomar, J., Isern, J.
Classical novae emit gamma-ray radiation at 511 keV and below, with a cut-off at around (20-30) keV, related to positron annihilation and its Comptonization in the expanding envelope. This emission...
On the Evolution of Cosmological Type Ia Supernovae and the Gravitational Constant (1999)
Garcia-Berro, E., Gaztanaga, E., Isern, J., Benvenuto, O., Althaus, L.
There are at least three ways in which a varying gravitational constant $G$ could affect the interpretation of the recent high-redhisft Type Ia supernovae results. If the local value of $G$ at the...
The energetics of crystallizing white dwarfs revisited again (1999)
Isern, J., Garcia-Berro, E., Hernanz, M., Chabrier, G.
The evolution of white dwarfs is a cooling process that depends on the energy stored in the core and on the way in which it is transferred through the envelope. In this paper we show that despite...
Jean, P., Gomez-Gomar, J., Hernanz, M., Jose, J., Isern, J., Vedrenne, G., ...
The shield of the INTEGRAL spectrometer provides a large detection area with a wide field-of-view. Calculations have been performed to check whether the temporal analysis of the counting rate of the...
Gamma-ray emission of classical novae and its detectability by INTEGRAL (1998)
Hernanz, M., Gomez-Gomar, J., Jose, J., Coc, A., Isern, J.
A lot of information concerning the mechanism of nova explosions will be extracted from the possible future observations with INTEGRAL. In order to be prepared for this task, we are performing...
Monte Carlo simulations of the disk white dwarf population (1998)
Garcia-Berro, E., Torres, S., Isern, J., Burkert, A.
In order to understand the dynamical and chemical evolution of our Galaxy it is of fundamental importance to study the local neighborhood. White dwarf stars are ideal candidates to probe the history...
The role of gravitational supernovae on the galactic evolution of the LiBeB isotopes (1998)
Abia, C., Isern, J., Lisenfeld, U.
The observed Be and B relationships with metallicity clearly support the idea that both elements have a primary origin and that are produced by the same class of objects. Spallation by particles...
The halo white dwarf population (1998)
Isern, J., Garcia-Berro, E., Hernanz, M., Mochkovitch, R., Torres, S.
Halo white dwarfs can provide important information about the properties and evolution of the galactic halo. In this paper we compute, assuming a standard IMF and updated models of white dwarf...
Gamma--ray emission from individual classical novae (1997)
Gómez-Gomar, J., Hernanz, M., José, J., Isern, J.
Classical novae are important producers of radioactive nuclei, such as be7, n13, f18, na22 and al26. The disintegration of these nuclei produces positrons (except for be7) that through annihilation...
Further constraints on white dwarf galactic halos (1997)
Canal, R., Isern, J., Ruiz-Lapuente, P.
The suggestion that roughly half the mass of the galactic halo might be in the form of white dwarfs, together with the limits on the infrared background light and on the initial metallicity of the...
Predictions of gamma-ray emission from classical novae and their detectability by CGRO (1997)
Hernanz, M., Gomez-Gomar, J., Jose, J., Isern, J.
An implicit hydrodynamic code following the explosion of classical novae, from the accretion phase up to the final ejection of the envelope, has been coupled to a MonteCarlo code able to simulate...
The cooling of CO white dwarfs: influence of the internal chemical distribution (1997)
Salaris, M., Dominguez, I., Garcia-Berro, E., Hernanz, M., Isern, J., Mochkovitch, R.
In this paper we compute detailed evolutionary models providing chemical profiles for white dwarfs having progenitors in the mass range from 1.0 to $7 M_{\sun}$ and we examine the influence of such...
The Physics of crystallizing white dwarfs (1997)
Isern, J., Mochkovitch, R., Hernanz, Margarita
White dwarfs can be used as galactic chronometers and, therefore, provide important information about galactic evolution if good theoretical models of their cooling are available. Consequently, it is...
Nucleosynthesis in novae: production of $^{26}$Al, $^{22}$Na and $^7$Be (1997)
Coc, A., Hernanz, M., Isern, J., Jose, J., Mochkovitch, R., Oberto, Y., ...
Nucleosynthesis in novae: production of $^{26}$Al, $^{22}$Na and $^7$Be (1997)
Coc, A., Hernanz, M., Isern, J., Jose, J., Mochkovitch, R., Oberto, Y., ...
Simplified treatment of the radiative transfer problem in expanding envelopes (1996)
In this paper we study the application of a simplified method to solve the dynamic radiative transfer problem in expanding envelopes. The method, which requires a computational effort similar to that...
On the ^7 Li and ^7 Be synthesis in novae (1996)
Hernanz, M., Jose, J., Coc, A., Isern, J.
The production of ^7 Li and ^7 Be during the explosive hydrogen-burning that occurs in nova explosions is computed by means of a hydrodynamic code able to treat both the accretion and the explosion...
Lopez-Ferrer, A, De Bolos, C, Barranco, C, Garrido, M, Isern, J, Carlstedt, I, ...
BACKGROUND—In normal gastric epithelium, MUC5AC is detected in superficial epithelium associated with Lewis type 1 antigens and MUC6 is detected in antral glands with Lewis type 2. Therefore, the...