Delayed X-Ray Afterglows from Obscured Gamma-Ray Bursts in Star-forming Regions

2000 ◽  
Vol 543 (1) ◽  
pp. L35-L37 ◽  
Author(s):  
Peter Mészáros ◽  
Andrei Gruzinov
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
X Ray ◽  
Star Forming ◽  
Star Forming Regions

Swift observations of gamma-ray bursts

2007 ◽  
Vol 365 (1854) ◽  
pp. 1119-1128 ◽  
Author(s):  
Neil Gehrels
Keyword(s):  
Gamma Ray ◽  
High Redshift ◽  
Gamma Ray Bursts ◽  
Optical Observations ◽  
Nearby Galaxy ◽  
X Ray ◽  
Star Forming ◽  
Star Forming Regions ◽  
Other Information ◽  
Short Grbs

Since its launch on 20 November 2004, the Swift mission has been detecting approximately 100 gamma-ray bursts (GRBs) each year, and immediately (within approx. 90 s) starting simultaneous X-ray and UV/optical observations of the afterglow. It has already collected an impressive database, including prompt emission to higher sensitivities than BATSE, uniform monitoring of afterglows and a rapid follow-up by other observatories notified through the GCN. Advances in our understanding of short GRBs have been spectacular. The detection of X-ray afterglows has led to accurate localizations and the conclusion that short GRBs can occur in non-star-forming galaxies or regions, whereas long GRBs are strongly concentrated within the star-forming regions. This is consistent with the NS merger model. Swift has greatly increased the redshift range of GRB detection. The highest redshift GRBs, at z ∼5–6, are approaching the era of reionization. Ground-based deep optical spectroscopy of high redshift bursts is giving metallicity measurements and other information on the source environment to a much greater distance than other techniques. The localization of GRB 060218 to a nearby galaxy, and the association with SN 2006aj, added a valuable member to the class of GRBs with detected supernova.

scholarly journals Quark-Nova Explosion inside a Collapsar: Application to Gamma Ray Bursts

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Rachid Ouyed ◽  
Denis Leahy ◽  
Jan Staff ◽  
Brian Niebergal
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Prompt Gamma ◽  
Stellar Envelope ◽  
X Ray ◽  
Star Forming ◽  
Star Forming Regions ◽  
Long Duration ◽  
Model Features ◽  
Prompt Emission

If a quark-nova occurs inside a collapsar, the interaction between the quark-nova ejecta (relativistic iron-rich chunks) and the collapsar envelope leads to features indicative of those observed in Gamma Ray Bursts. The quark-nova ejecta collides with the stellar envelope creating an outward moving cap (Γ∼1–10) above the polar funnel. Prompt gamma-ray burst emission from internal shocks in relativistic jets (following accretion onto the quark star) becomes visible after the cap becomes optically thin. Model features include (i) precursor activity (optical, X-ray,γ-ray), (ii) promptγ-ray emission, and (iii) afterglow emission. We discuss SN-less long duration GRBs, short hard GRBs (including association and nonassociation with star forming regions), dark GRBs, the energetic X-ray flares detected in Swift GRBs, and the near-simultaneous optical andγ-ray prompt emission observed in GRBs in the context of our model.

SWIFT OBSERVATIONS OF GAMMA-RAY BURSTS

2008 ◽  
Vol 17 (09) ◽  
pp. 1311-1317
Author(s):  
NEIL GEHRELS
Keyword(s):  
Gamma Ray ◽  
High Redshift ◽  
Gamma Ray Bursts ◽  
Optical Observations ◽  
Nearby Galaxy ◽  
X Ray ◽  
Star Forming ◽  
Star Forming Regions ◽  
Other Information

The Swift mission, launched on 20 November 2004, is detecting ~ 100 gamma-ray bursts (GRBs) each year, and immediately (within ~ 90 s) starting X-ray and UV/optical observations of the afterglow. It has already collected an impressive database including prompt emission to higher sensitivities than BATSE, uniform monitoring of afterglows, and rapid follow-up by other observatories notified through the Gamma-ray bursts Coordinates Network (GCN). The X-ray afterglows have been found to have complex temporal shapes including tails emission from the prompt phase and bright flares. X-ray and optical afterglow detections from short bursts have led to accurate localizations. It is found that they can occur in non-star forming galaxies or regions, whereas long GRBs are strongly concentrated within star forming regions. This is consistent with the NS merger model. Swift has greatly increased the redshift range of GRB detection. The highest redshift GRBs, at z ~ 5-6, are approaching the era of reionization. Ground-based deep optical spectroscopy of high redshift bursts is giving metallicity measurements and other information on the source environment to much greater distance than other techniques. The localization of GRB 060218 in a nearby galaxy, and association with SN 2006aj, added a valuable member to the class of GRBs with detected supernova. The prospects for future progress are excellent given the > 10 year orbital lifetime of the Swift satellite.

scholarly journals The luminous host galaxy, faint supernova and rapid afterglow rebrightening of GRB 100418A

2018 ◽  
Vol 620 ◽  
pp. A190 ◽  
Author(s):  
A. de Ugarte Postigo ◽  
C. C. Thöne ◽  
K. Bensch ◽  
A. J. van der Horst ◽  
D. A. Kann ◽  
...  
Keyword(s):  
Light Curve ◽  
Gamma Ray ◽  
Formation Rate ◽  
Absolute Magnitude ◽  
Host Galaxy ◽  
Absorption And Emission ◽  
X Ray ◽  
Star Forming ◽  
Star Forming Regions ◽  
Central Engine

Context. Long gamma-ray bursts (GRBs) give us the chance to study both their extreme physics and the star-forming galaxies in which they form. Aims. GRB 100418A, at a redshift of z = 0.6239, had a bright optical and radio afterglow, and a luminous star-forming host galaxy. This allowed us to study the radiation of the explosion as well as the interstellar medium of the host both in absorption and emission. Methods. We collected photometric data from radio to X-ray wavelengths to study the evolution of the afterglow and the contribution of a possible supernova (SN) and three X-shooter spectra obtained during the first 60 h. Results. The light curve shows a very fast optical rebrightening, with an amplitude of ∼3 magnitudes, starting 2.4 h after the GRB onset. This cannot be explained by a standard external shock model and requires other contributions, such as late central-engine activity. Two weeks after the burst we detect an excess in the light curve consistent with a SN with peak absolute magnitude MV = −18.5 mag, among the faintest GRB-SNe detected to date. The host galaxy shows two components in emission, with velocities differing by 130 km s−1, but otherwise having similar properties. While some absorption and emission components coincide, the absorbing gas spans much higher velocities, indicating the presence of gas beyond the star-forming regions. The host has a star formation rate of SFR = 12.2 M⊙ yr−1, a metallicity of 12 + log(O/H) = 8.55, and a mass of 1.6 × 109 M⊙. Conclusions. GRB 100418A is a member of a class of afterglow light curves which show a steep rebrightening in the optical during the first day, which cannot be explained by traditional models. Its very faint associated SN shows that GRB-SNe can have a larger dispersion in luminosities than previously seen. Furthermore, we have obtained a complete view of the host of GRB 100418A owing to its spectrum, which contains a remarkable number of both emission and absorption lines.

Gamma-ray burst models

2007 ◽  
Vol 365 (1854) ◽  
pp. 1277-1280 ◽  
Author(s):  
Andrew King
Keyword(s):  
Black Hole ◽  
Star Formation ◽  
Neutron Star ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Close Binaries ◽  
Host Galaxy ◽  
Star Forming ◽  
Star Forming Regions ◽  
Long Duration

I consider various possibilities for making gamma-ray bursts, particularly from close binaries. In addition to the much-studied neutron star+neutron star and black hole+neutron star cases usually considered good candidates for short-duration bursts, there are also other possibilities. In particular, neutron star+massive white dwarf has several desirable features. These systems are likely to produce long-duration gamma-ray bursts (GRBs), in some cases definitely without an accompanying supernova, as observed recently. This class of burst would have a strong correlation with star formation and occur close to the host galaxy. However, rare members of the class need not be near star-forming regions and could have any type of host galaxy. Thus, a long-duration burst far from any star-forming region would also be a signature of this class. Estimates based on the existence of a known progenitor suggest that this type of GRB may be quite common, in agreement with the fact that the absence of a supernova can only be established in nearby bursts.

scholarly journals High-energy processes in starburst-driven winds

2020 ◽  
Vol 496 (2) ◽  
pp. 2474-2481 ◽  
Author(s):  
Ana L Müller ◽  
Gustavo E Romero ◽  
Markus Roth
Keyword(s):  
Cosmic Rays ◽  
Power Law ◽  
Large Scale ◽  
Gamma Ray ◽  
High Energy ◽  
X Ray ◽  
Star Forming ◽  
Star Forming Regions ◽  
Energy Processes ◽  
Relativistic Particles

ABSTRACT Starburst galaxies generate large-scale winds powered by the activity in the star-forming regions located in the galactic discs. Fragmentation of the disc produced by the outbreak of the wind results in the formation of clouds. Bowshocks caused by the supersonic outflow appear around such clouds. In this paper, we discuss the acceleration of relativistic particles and the production of non-thermal radiation in such scenario. Cosmic rays accelerated at the bowshocks do not reach the highest energies, although the high-energy luminosity generated is significant. We show that up to ∼10 per cent of the gamma-ray emission in starbursts might come from these sources outside the galactic discs. Discrete X-ray sources with a power-law component are also expected.

scholarly journals Are Gamma-Ray Bursts in Star-Forming Regions?

1998 ◽  
Vol 494 (1) ◽  
pp. L45-L48 ◽  
Author(s):  
Bohdan Paczyński
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Star Forming ◽  
Star Forming Regions

The X-ray luminosity function of short gamma-ray bursts

2021 ◽  
Vol 366 (4) ◽  
Author(s):  
Zhi-Ying Liu ◽  
Fu-Wen Zhang ◽  
Si-Yuan Zhu
Keyword(s):  
Luminosity Function ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
X Ray

scholarly journals Interpreting the X-ray afterglows of gamma-ray bursts with radiative losses and millisecond magnetars

2020 ◽  
Vol 499 (4) ◽  
pp. 5986-5992
Author(s):  
Nikhil Sarin ◽  
Paul D Lasky ◽  
Gregory Ashton
Keyword(s):  
Gravitational Wave ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Dipole Radiation ◽  
X Ray ◽  
Radiative Efficiency ◽  
Central Engine ◽  
Radiative Losses ◽  
Wave Emission ◽  
Prompt Emission

ABSTRACT The spin-down energy of millisecond magnetars has been invoked to explain X-ray afterglow observations of a significant fraction of short and long gamma-ray bursts. Here, we extend models previously introduced in the literature, incorporating radiative losses with the spin-down of a magnetar central engine through an arbitrary braking index. Combining this with a model for the tail of the prompt emission, we show that our model can better explain the data than millisecond-magnetar models without radiative losses or those that invoke spin-down solely through vacuum dipole radiation. We find that our model predicts a subset of X-ray flares seen in some gamma-ray bursts. We can further explain the diversity of X-ray plateaus by altering the radiative efficiency and measure the braking index of newly born millisecond magnetars. We measure the braking index of GRB061121 as $n=4.85^{+0.11}_{-0.15}$ suggesting the millisecond-magnetar born in this gamma-ray burst spins down predominantly through gravitational-wave emission.

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