22 Result(s)

Article

Maximal Mass Neutron Star as a Key to Superdense Matter Physics

We propose a universal approximation of the equation of state of superdense matter in neutron star (NS) interiors. It contains only two parameters, the pressure and the density at the center of the maximally m...

D. D. Ofengeim, P. S. Shternin, T. Piran in Astronomy Letters (2023)

Article

A mildly relativistic wide-angle outflow in the neutron-star merger event GW170817

The observed electromagnetic emission from GW170817 suggests that a ‘cocoon’ of mildly relativistic material was released as a jet transferred its energy to the neutron-rich dynamical ejecta from the merger.

K. P. Mooley, E. Nakar, K. Hotokezaka, G. Hallinan, A. Corsi, D. A. Frail… in Nature (2018)

Article

Spectroscopic identification of r-process nucleosynthesis in a double neutron-star merger

Observations of the transient associated with the gravitational-wave event GW170817 and γ-ray burst GRB 170817A reveal a bright kilonova with fast-moving ejecta, including lanthanides synthesized by rapid neut...

E. Pian, P. D’Avanzo, S. Benetti, M. Branchesi, E. Brocato, S. Campana… in Nature (2017)

Article

Broadband observations of the naked-eye γ-ray burst GRB 080319B

Long-duration γ-ray bursts (GRBs) release copious amounts of energy across the entire electromagnetic spectrum, and so provide a window into the process of black hole formation from the collapse of massive sta...

J. L. Racusin, S. V. Karpov, M. Sokolowski, J. Granot, X. F. Wu, V. Pal’shin… in Nature (2008)

Article

A novel explosive process is required for the γ-ray burst GRB 060614

The tidy classification system that divided γ-ray bursts (GRBs) into long-duration busts (lasting more than two seconds) and short may have had its day. The final nail in its coffin may be GRB 060614. Discover...

A. Gal-Yam, D. B. Fox, P. A. Price, E. O. Ofek, M. R. Davis, D. C. Leonard… in Nature (2006)

Article

Relativistic ejecta from X-ray flash XRF 060218 and the rate of cosmic explosions

A link between long γ-ray bursts (GRBs) and supernovae has been established, but whether there is a similar relationship between the weaker and softer X-ray flashes and supernovae is unclear. GRB/XRF 060218, s...

A. M. Soderberg, S. R. Kulkarni, E. Nakar, E. Berger, P. B. Cameron, D. B. Fox… in Nature (2006)

Article

The afterglow and elliptical host galaxy of the short γ-ray burst GRB 050724

Gamma-ray bursts (GRBs) are either ‘long and soft’, or ‘short and hard’. It is now clear that the long-duration type are caused by explosions of massive stars in distant star-forming galaxies. Only in recent m...

E. Berger, P. A. Price, S. B. Cenko, A. Gal-Yam, A. M. Soderberg, M. Kasliwal… in Nature (2005)

Article

The afterglow of GRB 050709 and the nature of the short-hard γ-ray bursts

The final chapter in the long-standing mystery of the γ-ray bursts (GRBs) centres on the origin of the short-hard class of bursts, which are suspected on theoretical grounds to result from the coalescence of n...

D. B. Fox, D. A. Frail, P. A. Price, S. R. Kulkarni, E. Berger, T. Piran… in Nature (2005)

Chapter

Gamma-Ray Bursts as Probes for Quantum Gravity

Gamma ray bursts (GRBs) are short and intense pulses of γ-rays arriving from random directions in the sky. Several years ago Amelino-Camelia et al. [1] (see also [2]) pointed out that a comparison of time of a...

T. Piran in Planck Scale Effects in Astrophysics and Cosmology (2005)

Chapter and Conference Paper

Theory of GRB Afterglow

The most interesting current open question in the theory of GRB afterglow is the propagation of jetted afterglows during the sideway expansion phase. Recent numerical simulations show hydrodynamic behavior tha...

T. Piran, J. Granot in Gamma-Ray Bursts in the Afterglow Era (2001)

Chapter and Conference Paper

Light Curves from an Expanding Relativistic Jet

We perform fully relativistic hydrodynamic simulations of the deceleration and lateral expansion of a relativistic jet as it expands into an ambient medium. The hydrodynamic calculations use a 2D adaptive mesh...

J. Granot, M. Miller, T. Piran, W. M. Suen… in Gamma-Ray Bursts in the Afterglow Era (2001)

Chapter and Conference Paper

New Results on the Temporal Structure of GRBs

We analyze the temporal structure of long ( T ₉₀ > 2sec) and short ( T ₉₀ < 2sec) BATSE bursts. We find that: (i) In many shor...

E. Nakar, T. Piran in Gamma-Ray Bursts in the Afterglow Era (2001)

Article

The afterglow, redshift and extreme energetics of the γ-ray burst of 23 January 1999

Long-lived emission, known as afterglow, has now been detected from about a dozen γ-ray bursts. Distance determinations place the bursts at cosmological distances, with redshifts, z, ranging from ∼1 to 3. The ene...

S. R. Kulkarni, S. G. Djorgovski, S. C. Odewahn, J. S. Bloom, R. R. Gal… in Nature (1999)

Article

Book review

P. Spindel, T. Piran, Helmut Rumpf in General Relativity and Gravitation (1990)

Article

Neutrino temperatures and fluxes from the LMC supernova

The observation^1,2of neutrinos from the LMC supernova makes possible direct tests of the theory of supernova explosions and of properties of weakly interacting particles. Here we describe a combined analysis of t...

J. N. Bahcall, T. Piran, W. H. Press, D. N. Spergel in Nature (1987)

Article

Neutrinos from the recent LMC supernova

In 1987, a supernova exploded in the nearby Large Magellanic Cloud. Bahcall, Dar and Piran were quick to point out in Nature that a neutrino burst from the collapsing star should have reached Earth and that, if d...

J. N. BAHCALL, A. DAR, T. PIRAN in Nature (1987)

Article

A processing ring model for SS433

THE wavelengths of the shifted optical lines in SS433 seem to show a periodic variability at a period of 160 ± 3 d (or a multiple integer thereof)^1,2. We have suggested that such periodicity could arise if the li...

A. AMITAI-MILCHGRUB, T. PIRAN, J. SHAHAM in Nature (1979)