ترغب بنشر مسار تعليمي؟ اضغط هنا

Neutrino Emission and Mass Ejection in Quark Novae

49   0   0.0 ( 0 )
 نشر من قبل Rachid Ouyed
 تاريخ النشر 2004
  مجال البحث فيزياء
والبحث باللغة English
 تأليف Petteri Keranen




اسأل ChatGPT حول البحث

We explore the role of neutrinos in a Quark Nova explosion. We study production of neutrinos during this event, their propagation and their interactions with the surrounding quark matter and neutron-rich envelope. We address relevant physical issues such as the timescale for the initial core collapse, the total energy emitted in neutrinos and their effect on the low density matter surrounding the core. We find that it is feasible that the neutrino burst can lead to significant mass ejection of the nuclear envelope.



قيم البحث

اقرأ أيضاً

Classical novae are the most common astrophysical thermonuclear explosions, occurring on the surfaces of white dwarf stars accreting gas from companions in binary star systems. Novae typically expel ~10^(-4) solar masses of material at velocities exc eeding 1,000 kilometres per second. However, the mechanism of mass ejection in novae is poorly understood, and could be dominated by the impulsive flash of thermonuclear energy, prolonged optically thick winds, or binary interaction with the nova envelope. Classical novae are now routinely detected in gigaelectronvolt gamma-ray wavelengths, suggesting that relativistic particles are accelerated by strong shocks in the ejecta. Here we report high-resolution radio imaging of the gamma-ray-emitting nova V959 Mon. We find that its ejecta were shaped by the motion of the binary system: some gas was expelled rapidly along the poles as a wind from the white dwarf, while denser material drifted out along the equatorial plane, propelled by orbital motion. At the interface between the equatorial and polar regions, we observe synchrotron emission indicative of shocks and relativistic particle acceleration, thereby pinpointing the location of gamma-ray production. Binary shaping of the nova ejecta and associated internal shocks are expected to be widespread among novae, explaining why many novae are gamma-ray emitters.
47 - O. Santillan , A. Morano 2020
The axion quark nuggets introduced in cite{zhitnitsky}-cite{zhitnitsky13} are a candidate for cold dark matter which, in addition, may be relevant in baryogenesis scenarios. The present work studies their evolution till they enter in the colour super conducting phase. This evolution was already considered in cite{zhitnitsky5}, where it is concluded that a large chemical potential $mu$ is induced on the bulk of the object. The baryon number accumulated at the domain wall surrounding the object is taken as predominant in cite{zhitnitsky5}, and it is suggested that internal and external fluxes are compensated and can be neglected. In the present work, the possibility that the bulk contribution to the baryon number may be relevant at initial stages and that the object may emit a large amount of neutrinos due to quark-antiquark annihilations is taken into account. The outcome is a more violent contraction of the object and, perhaps, a more effective cooling. Therefore, the resulting objects may have a smaller size. Even taking into account these corrections, it is concluded that the cosmological applications of these objects are not spoiled. These applications are discussed along the text.
It is believed that quark matter can exist in neutron star interior if the baryon density is high enough. When there is a large isospin density, quark matter could be in a pion condensed phase. We compute neutrino emission from direct Urca processes in such a phase, particularly in the inhomogeneous Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) states. The neutrino emissivity and specific heat are obtained, from which the cooling rate is estimated.
We review infrared observations of classical and recurrent novae, at wavelengths >3microns, including both broad-band and spectroscopic observations. In recent years infrared spectroscopy in particular has revolutionised our understanding of the nova phenomenon, by revealing fine-structure and coronal lines, and the mineralogy of nova dust. Infrared spectroscopic facilities that are, or will be, becoming available in the next 10 - 20 years have the potential for a comprehensive study of nova line emission and dust mineralogy, and for an unbiassed assessment of the extragalactic nova populations.
We propose a simple model explaining two outstanding astrophysical problems related to compact objects: (1) that of stars such as G87-7 (alias EG 50) that constitute a class of relatively low-mass white dwarfs which nevertheless fall away from the C/ O composition and (2) that of GRB 110328A/Swift J164449.3+57345 which showed spectacularly long-lived strong X-ray flaring, posing a challenge to standard GRB models. We argue that both these observations may have an explanation within the unified framework of a Quark-Nova occurring in a low-mass X-ray binary (neutron star- white dwarf). For LMXBs where the binary separation is sufficiently tight, ejecta from the exploding Neutron Star triggers nuclear burning in the white dwarf on impact, possibly leading to Fe-rich composition compact white dwarfs with mass 0.43M_sun < M_WD < 0.72M_sun, reminiscent of G87-7. Our results rely on the assumption, which ultimately needs to be tested by hydrodynamic and nucleosynthesis simulations, that under certain circumstances the WD can avoid the thermonuclear runaway. For heavier white dwarfs (i.e. M_WD > 0.72M_sun) experiencing the QN shock, degeneracy will not be lifted when Carbon burning begins, and a sub-Chandrasekhar Type Ia Supernovae may result in our model. Under slightly different conditions, and for pure He white dwarfs (i.e. M_WD < 0.43M_sun), the white dwarf is ablated and its ashes raining down on the Quark star leads to accretion-driven X-ray luminosity with energetics and duration reminiscent of GRB 110328A. We predict additional flaring activity towards the end of the accretion phase if the Quark star turns into a Black Hole.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا