منابع مشابه
The Highest Redshift Relativistic Jets
It is now well established that X-ray emission is a common feature of kiloparsecscale radio jets (see Harris & Krawczynski 2006, for a recent review and the associated website, http://hea-www.harvard.edu/XJET/). The spectral energy distributions (SEDs) of the powerful quasar jets are predominantly characterized as “optically faint”, with the spectra rising between the optical and X-ray bands. C...
متن کاملOn the Origin of the Highest Redshift Gamma-ray Bursts
GRB 080913 and GRB 090423 are the most distant gamma-ray bursts (GRBs) known to-date, with spectroscopically determined redshifts of z = 6.7 and z = 8.1, respectively. The detection of bursts at this early epoch of the Universe significantly constrains the nature of GRBs and their progenitors. We perform population synthesis studies of the formation and evolution of early stars, and calculate t...
متن کاملThe Highest Redshift Radio Galaxy Known in the Southern Hemisphere
We present the discovery of a z = 4.13 galaxy TN J1338-1942, the most distant radio galaxy in the southern hemisphere known to date. The source was selected from a sample of Ultra Steep Spectrum (USS; α < −1.3; S ∝ ν) radio sources using the Texas and NVSS catalogs. The discovery spectrum, obtained with the ESO 3.6m telescope, shows bright extended Ly-α emission. The radio source has a very asy...
متن کاملWhat Is the Highest Plausible Redshift of Luminous Quasars?
The recent discoveries of luminous quasars at high redshifts imply that black holes more massive than a few billion solar masses have been assembled already when the universe was less than a billion years old. We show that the existence of these black holes is not surprising in popular hierarchical models of structure formation. For example, the black hole needed to power the quasar SDSS 1044-0...
متن کاملDiscovery of strong CIV absorption in the highest redshift quasar⋆
We report the near-IR detection of a prominent CIV absorption in the rest-frame UV spectrum of the most distant known QSO, SDSS J104433.04−012502.2, at z = 5.80. This QSO was recently observed with XMM-Newton and it was found to be notably X-ray weak. The equivalent width of the CIV absorption feature (∼10Å) strongly supports the idea that the X-ray faintness of this QSO is due to heavy absorpt...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1980
ISSN: 0074-1809
DOI: 10.1017/s0074180900068686