A Ly alpha GALAXY AT REDSHIFT z=6.944 IN THE COSMOS FIELD

作者：Rhoads James E^*; Hibon Pascale; Malhotra Sangeeta; Cooper Michael; Weiner Benjamin

来源：Astrophysical Journal Letters, 2012, 752(2): L28.

DOI：10.1088/2041-8205/752/2/L28

• dark ages, reionization, first stars
• galaxies: high-redshift

Ly alpha emitting galaxies can be used to study cosmological reionization, because a neutral intergalactic medium (IGM) scatters Ly alpha photons into diffuse halos whose surface brightness falls below typical survey detection limits. Here, we present the Ly alpha emitting galaxy LAE J095950.99+021219.1, identified at redshift z = 6.944 in the COSMOS field using narrowband imaging and follow-up spectroscopy with the IMACS instrument on the Magellan I Baade telescope. With a single object spectroscopically confirmed so far, our survey remains consistent with a wide range of IGM neutral fraction at z approximate to 7, but further observations are planned and will help clarify the situation. Meantime, the object we present here is only the third Ly alpha-selected galaxy to be spectroscopically confirmed at z greater than or similar to 7, and is similar to 2-3 times fainter than the previously confirmed z approximate to 7 Ly alpha galaxies.

• 出版日期2012-6-20