Now showing items 1-20 of 44

  • A common origin of magnetism from planets to white dwarfs 

    Isern Vilaboy, Jordi; García-Berro Montilla, Enrique; Kulebi, Baybar; Lorén Aguilar, Pablo (2017-02-20)
    Article
    Open Access
    Isolated magnetic white dwarfs have field strengths ranging from kilogauss to gigagauss. However, the origin of the magnetic field has not been hitherto elucidated. Whether these fields are fossil, hence the remnants of ...
  • An asteroseismic constraint on the mass of the axion from the period drift of the pulsating da white dwarf star L19-2 

    Córsico, Alejandro H.; Romero, Alejandra Daniela; Althaus, Leandro G.; García-Berro Montilla, Enrique; Isern Vilaboy, Jordi; Kepler, S.O.; Miller Bartolami, Marcelo M.; Sullivan, Denis J. (2016-07-01)
    Article
    Open Access
    We employ an asteroseismic model of L19-2, a relatively massive (Msstarf ~ 0.75 M¿) and hot (Teff ~ 12 100 K) pulsating DA (H-rich atmosphere) white dwarf star (DAV or ZZ Ceti variable), and use the observed values of the ...
  • A new kind of type I supernovae? 

    Isern Vilaboy, Jordi; Bravo Guil, Eduardo; Domínguez, Inmaculada (Istituto Nazionale di Astrofisica, 2000-12)
    Article
    Open Access
    In this paper we examine the consequences of the propagation of a slow deflagration front through a C-0 white dwarf that leads to the formation of a marginally bound remnant. This situation corresponds to the transition ...
  • Axions and the luminosity function of white dwarfs : the thin and thick discs, and the halo 

    Isern Vilaboy, Jordi; García-Berro Montilla, Enrique; Torres Gil, Santiago; Cojocaru, Elena Ruxandra; Catalán, S (Oxford University Press, 2018-08-01)
    Article
    Open Access
    The evolution of white dwarfs is a simple gravothermal process of cooling. Since the shape of their luminosity function is sensitive to the characteristic cooling time, it is possible to use its slope to test the existence ...
  • Binary systems and their nuclear explosions 

    Isern Vilaboy, Jordi; Hernanz Carbó, Margarita; José Pont, Jordi (2011-01)
    Part of book or chapter of book
    Restricted access - publisher's policy
  • Binary systems and their nuclear explosions 

    Isern Vilaboy, Jordi; Hernanz Carbó, Margarita; José Pont, Jordi (Springer, 2018-08-01)
    Part of book or chapter of book
    Open Access
  • Bounds on the possible evolution of the gravitational constant from cosmological type-Ia supernovae 

    Gaztañaga, E.; García-Berro Montilla, Enrique; Isern Vilaboy, Jordi; Bravo Guil, Eduardo; Domínguez, Inmaculada (2002-01)
    Article
    Open Access
    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 distant supernovae is different, ...
  • Clues to type ia supernovae progenitors from degenerate carbon ignition models 

    Bravo Guil, Eduardo; Tornambé, A; Domínguez, Inmaculada; Isern Vilaboy, Jordi (1996-04)
    Article
    Open Access
  • Cobalt-56 gamma-ray emission lines from the type Ia supernova 2014J 

    Churazov, Eugene; Sunyaev, Rashid; Isern Vilaboy, Jordi; Knodlseder, Jurgen; Jean, Pierre; Lebrun, François; Chugai, Nikolai; Grebenev, Sergei; Bravo Guil, Eduardo; Sazonov, Sergei; Renaud, Matthieu (2014-08-28)
    Article
    Restricted access - publisher's policy
    A type Ia supernova is thought to be a thermonuclear explosion of either a single carbon–oxygen white dwarf or a pair of merging white dwarfs. The explosion fuses a large amount of radioactive 56Ni. After the explosion, ...
  • Detection and interpretation of gamma-ray emission from SNIa 

    Isern Vilaboy, Jordi; Bravo Guil, Eduardo; Hirschmann, Alina (2008-10)
    Article
    Restricted access - publisher's policy
    The explosion mechanism associated with thermonuclear supernovae (SNIa) is still a matter of debate. Nevertheless, there is a wide agreement that large amounts of radioactive nuclei are produced during these events, which ...
  • Detonations in white dwarf dynamical interactions 

    Aznar Siguan, Gabriela; García-Berro Montilla, Enrique; Lorén Aguilar, Pablo; José Pont, Jordi; Isern Vilaboy, Jordi (2013)
    Article
    Open Access
    n old, dense stellar systems collisions of white dwarfs are a rather frequent phenomenon. Here we present the results of a comprehensive set of Smoothed Particle Hydrodynamics simulations of close encounters of white ...
  • Double degenerate mergers as progenitors of high-field magnetic white dwarfs 

    García-Berro Montilla, Enrique; Lorén Aguilar, Pablo; Aznar Siguan, Gabriela; Torres Gil, Santiago; Camacho Díaz, Judit; Althaus, Leandro Gabriel; Córsico, Alejando Hugo; Kulebi, Baybar; Isern Vilaboy, Jordi (2011-04-10)
    Article
    Open Access
    High-field magnetic white dwarfs have been long suspected to be the result of stellar mergers. However, the nature of the coalescing stars and the precise mech anism that produces the magnetic field are still unknown. ...
  • Exploding stars: the gamma-ray signature of type Ia supernovae 

    Isern Vilaboy, Jordi; Gomez, J.; Bravo Guil, Eduardo (Istituto Nazionale di Astrofisica, 1996-12)
    Article
    Open Access
    Type Ia supenovae are commonly thought to be the outcome of the thermonuclear explosion of a white dwarf in a binary system. Nevertheless, there is no agreement on the scenarios (double degenerates, symbiotics stars ...) ...
  • Gamma-ray emission from SN2014J near maximum optical light 

    Isern Vilaboy, Jordi; Jean, Pierre; Bravo Guil, Eduardo; Knodlseder, Jurgen; Lebrun, François; Churazov, Eugene; Sunyaev, Rashid; Domingo, Alberto; Badenes, Carles; Hartmann, Dieter, H; Hoeflich, Peter; Renaud, Matthieu; Soldi, Simona; Elias Rosa, Nancy; Hernanz Carbó, Margarita; Domínguez Aguilera, Inmaculada; García Senz, Domingo; Lichti, G.G.; Vedrenne, G.; Von Ballmoos, Peter (EDP Sciences, 2016-04)
    Article
    Open Access
    Context. The optical light curve of Type Ia supernovae (SNIa) is powered by thermalized gamma-rays produced by the decay of 56Ni and 56Co, the main radioactive isotopes synthesized by the thermonuclear explosion of a C/O ...
  • Gamma-ray emission from type Ia supernovae 

    Isern Vilaboy, Jordi; Bravo Guil, Eduardo; Hirschmann, Alina; García Senz, Domingo (2004-02)
    Article
    Restricted access - publisher's policy
    The explosion mechanism associated with thermonuclear supernovae is still a matter of debate. Since huge amounts of radioactive elements are synthesized during such explosions, it is possible to use the associated γ-ray ...
  • Gamma rays from Type Ia supernova SN 2014j 

    Churazov, Eugene; Sunyaev, Rashid; Isern Vilaboy, Jordi; Bikmaev, I; Bravo Guil, Eduardo; Chugai, Nikolai; Grebenev, Sergei; Jean, Pierre; Knodlseder, Jurgen; Lebrun, François; Kuulkers, Eric (2015-10-08)
    Article
    Open Access
    The whole set of INTEGRAL observations of Type Ia supernova SN 2014J, covering the period 19–162 days after the explosion, has been analyzed. For spectral fitting the data are split into early and late periods covering ...
  • Gamma-ray spectrum of type Ia supernovae 

    Isern Vilaboy, Jordi; Bravo Guil, Eduardo; Gómez, J.; García Senz, Domingo; Jean, Pierre (1999-12)
    Article
    Restricted access - publisher's policy
    The explosion mechanism associated with thermonuclear supernovae (SNia) is still a matter of debate. In this paper we examine the 'f-ray emission of the radioactive debris predicted by the different theoretícal models ...
  • High-proper-motion white dwarfs and halo dark matter 

    Torres Gil, Santiago; García-Berro Montilla, Enrique; Burkert, Andreas; Isern Vilaboy, Jordi (Blackwell, 2002-11)
    Article
    Open Access
    The interpretation of the old, cool white dwarfs recently found by Oppenheimer et al. is still controversial. Whereas these authors claim that they have finally found the elusive ancienthalo white dwarf population that ...
  • High-resolution smoothed particle hydrodynamics simulations of the merger of binary white dwarfs 

    Lorén Aguilar, Pablo; Isern Vilaboy, Jordi; García-Berro Montilla, Enrique (2009-06)
    Article
    Open Access
    Context. The coalescence of two white dwarfs is the final outcome of a sizeable fraction of binary stellar systems. Moreover, this process has been proposed to explain several interesting astrophysical phenomena. Aims. ...
  • Nucleosynthesis during the merger of white dwarfs and the origin of R Coronae Borealis stars 

    Longland, Richard Leigh; Lorén Aguilar, Pablo; José Pont, Jordi; García-Berro Montilla, Enrique; Althaus, Leandro Gabriel; Isern Vilaboy, Jordi (2011-08-20)
    Article
    Restricted access - publisher's policy
    Many hydrogen-deficient stars are characterized by surface abundance patterns that are hard to reconcile with conventional stellar evolution. Instead, it has been suggested that they may represent the result of a merger ...