Oxford SWIFT integral field spectrograph and multiwavelength observations of the Eagle galaxy at z= 0.77


E-mail: susan.kassin@nasa.gov

Present address: Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771, USA.

Hubble Fellow.


The ‘Eagle’ galaxy at a redshift of 0.77 is studied with the Oxford Short Wavelength Integral Field Spectrograph (SWIFT) and multiwavelength data from the All-wavelength Extended Groth strip International Survey (AEGIS). It was chosen from AEGIS because of the bright and extended emission in its slit spectrum. 3D kinematic maps of the Eagle reveal a gradient in velocity dispersion which spans 35–75 ± 10 km s−1 and a rotation velocity of 25 ± 5 km s−1 uncorrected for inclination. Hubble Space Telescope images suggest it is close to face-on. In comparison with galaxies from AEGIS at similar redshifts, the Eagle is extremely bright and blue in the rest-frame optical, highly star forming, dominated by unobscured star formation and has a low metallicity for its size. This is consistent with its selection. The Eagle is likely undergoing a major merger and is caught in the early stage of a starburst when it has not yet experienced metal enrichment or formed the mass of dust typically found in star-forming galaxies.