Constraints on the Small‐Scale Power Spectrum of Density Fluctuations from High‐Redshift Gamma‐Ray Bursts

2005 ◽  
Vol 623 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Andrei Mesinger ◽  
Rosalba Perna ◽  
Zoltan Haiman
Keyword(s):  
Power Spectrum ◽  
Gamma Ray ◽  
High Redshift ◽  
Density Fluctuations ◽  
Gamma Ray Bursts ◽  
Small Scale

scholarly journals Gamma‐Ray Bursts as a Probe of the Very High Redshift Universe

2000 ◽  
Vol 536 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Donald Q. Lamb ◽  
Daniel E. Reichart
Keyword(s):  
Gamma Ray ◽  
High Redshift ◽  
Gamma Ray Bursts ◽  
High Redshift Universe ◽  
Very High

scholarly journals Gamma-ray bursts from stellar remnants: probing the Universe at high redshift

1998 ◽  
Vol 294 (1) ◽  
pp. L13-L17 ◽  
Author(s):  
R. A. M. J. Wijers ◽  
J. S. Bloom ◽  
J. S. Bagla ◽  
P. Natarajan
Keyword(s):  
Gamma Ray ◽  
High Redshift ◽  
Gamma Ray Bursts ◽  
The Universe

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 Small-scale Substructure in Dark Matter Haloes: Where Does Galaxy Formation Come to an End?

2004 ◽  
Vol 220 ◽  
pp. 91-98 ◽  
Author(s):  
J. E. Taylor ◽  
J. Silk ◽  
A. Babul
Keyword(s):  
Dark Matter ◽  
Power Spectrum ◽  
Structure Formation ◽  
Galaxy Formation ◽  
Cold Dark Matter ◽  
High Redshift ◽  
Small Scale ◽  
Analytic Model ◽  
Model Predictions ◽  
Low Mass

Models of structure formation based on cold dark matter predict that most of the small dark matter haloes that first formed at high redshift would have merged into larger systems by the present epoch. Substructure in present-day haloes preserves the remains of these ancient systems, providing the only direct information we may ever have about the low-mass end of the power spectrum. We describe some recent attempts to model halo substructure down to very small masses, using a semi-analytic model of halo formation. We make a preliminary comparison between the model predictions, observations of substructure in lensed systems, and the properties of local satellite galaxies.

scholarly journals The case for a high-redshift origin of GRB 100205A

2019 ◽  
Vol 488 (1) ◽  
pp. 902-909
Author(s):  
A A Chrimes ◽  
A J Levan ◽  
E R Stanway ◽  
E Berger ◽  
J S Bloom ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Near Infrared ◽  
Gamma Ray ◽  
Hubble Space Telescope ◽  
High Redshift ◽  
Gamma Ray Bursts ◽  
Host Galaxy ◽  
Late Time ◽  
Time Limits

Abstract The number of long gamma-ray bursts (GRBs) known to have occurred in the distant Universe (z > 5) is small (∼15); however, these events provide a powerful way of probing star formation at the onset of galaxy evolution. In this paper, we present the case for GRB 100205A being a largely overlooked high-redshift event. While initially noted as a high-z candidate, this event and its host galaxy have not been explored in detail. By combining optical and near-infrared Gemini afterglow imaging (at t < 1.3 d since burst) with deep late-time limits on host emission from the Hubble Space Telescope, we show that the most likely scenario is that GRB 100205A arose in the range 4 < z < 8. GRB 100205A is an example of a burst whose afterglow, even at ∼1 h post burst, could only be identified by 8-m class IR observations, and suggests that such observations of all optically dark bursts may be necessary to significantly enhance the number of high-redshift GRBs known.

scholarly journals PARTICLE ACCELERATION, MAGNETIC FIELD GENERATION, AND ASSOCIATED EMISSION IN COLLISIONLESS RELATIVISTIC JETS

2008 ◽  
Vol 17 (10) ◽  
pp. 1761-1767 ◽  
Author(s):  
K.-I. NISHIKAWA ◽  
Y. MIZUNO ◽  
G. J. FISHMAN ◽  
P. HARDEE
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Small Scale ◽  
Spectral Structure ◽  
Relativistic Jets ◽  
Weibel Instability ◽  
Electron Positron ◽  
Jitter Radiation

Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., active galactic nuclei (AGNs), gamma-ray bursts (GRBs), and galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations using injected relativistic electron-ion (electron-positron) jets show that acceleration occurs within the downstream jet. Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electrons' transverse deflection behind the jet head. The "jitter" radiation from deflected electrons has different properties to synchrotron radiation which assumes a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.

scholarly journals Accessing the population of high-redshift Gamma Ray Bursts

2015 ◽  
Vol 448 (3) ◽  
pp. 2514-2524 ◽  
Author(s):  
G. Ghirlanda ◽  
R. Salvaterra ◽  
G. Ghisellini ◽  
S. Mereghetti ◽  
G. Tagliaferri ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Redshift ◽  
Gamma Ray Bursts

Gamma-ray bursts and cosmology

2007 ◽  
Vol 365 (1854) ◽  
pp. 1363-1376 ◽  
Author(s):  
D.Q Lamb
Keyword(s):  
Dark Energy ◽  
Early Universe ◽  
Gamma Ray ◽  
High Redshift ◽  
Gamma Ray Bursts ◽  
Current Status ◽  
Scientific Results ◽  
Short Grbs ◽  
Very High

I review the current status of the use of gamma-ray bursts (GRBs) as probes of the early Universe and cosmology. I describe the promise of long GRBs as probes of the high redshift ( z >4) and very high redshift ( z >5) Universe, and several key scientific results that have come from observations made possible by accurate, rapid localizations of these bursts by Swift. I then estimate the fraction of long GRBs that lie at very high redshifts and discuss ways in which it may be possible to rapidly identify—and therefore study—a larger number of these bursts. Finally, I discuss the ways in which both long and short GRBs can be made ‘standard candles’ and used to constrain the properties of dark energy.

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