Astronomy: Dawn after the dark age

  title={Astronomy: Dawn after the dark age},
  author={Richard A. McMahon},
The latest surveys provide evidence for one, maybe two, galaxies farther back in cosmic time than ever detected before. But does the fact that we don't see more mean these are the very first galaxies to be formed?The oldest known galaxyThe galaxy described on page 186 may be, for the moment, the most distant and hence oldest galaxy known. Large samples of galaxies have been found at redshifts of z∼6, but detections at earlier times tend to be uncertain and unreliable. But this 'new' old galaxy… 

Astrophysics in 2006

Abstract The fastest pulsar and the slowest nova; the oldest galaxies and the youngest stars; the weirdest life forms and the commonest dwarfs; the highest energy particles and the lowest energy



A galaxy at a redshift z = 6.96

A spectroscopic redshift of z = 6.96 is reported for a galaxy whose spectrum clearly shows Lyman-α emission at 9,682 Å, indicating active star formation at a rate of ∼10M[circdot] yr-1, which demonstrates that galaxy formation was under way when the Universe was only ∼6 per cent of its present age.

Detection of Lyman-α-emitting galaxies at redshift 4.55

STUDIESof the formation and early history of galaxies have been hampered by the difficulties inherent in detecting faint galaxy populations at high redshift. As a consequence, observations at the

Rapid evolution of the most luminous galaxies during the first 900 million years

A search for galaxies at z ≈ 7–8, about 700 Myr after the Big Bang, using the deepest near-infrared and optical images ever taken finds only one candidate galaxy and demonstrates that very luminous galaxies are quite rare.

A Probable z ~ 7 Galaxy Strongly Lensed by the Rich Cluster A2218: Exploring the Dark Ages

We discuss the observational properties of a remarkably faint triply imaged galaxy revealed in a deep z′-band Advanced Camera for Surveys observation of the lensing cluster A2218 (z = 0.175). A

Spitzer imaging of i′‐drop galaxies: old stars at z≈ 6

The presence of established systems at z≈ 6 suggests that long-lived sources at earlier epochs (z > 7) played a key role in reionizing the Universe.

DAzLE: the dark ages z (redshift) Lyman-α Explorer

DAzLE is a near infrared narrowband differential imager being built by the Institute of Astronomy, Cambridge, in collaboration with the Anglo-Australian observatory. It is a special purpose


  • Mon. Not. R. Astron. Soc. 346,
  • 2005