2004/03/19 by Kim‐Vy Tran, Kim-Vy H. Tran, Marijn Franx +6 · 3 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Bulge #Galaxies: Formation, Evolution, Phenomena #Galaxy #Physics #Population #RADIUS #Redshift #Star formation #Stellar, planetary, and galactic studies #Velocity dispersion #astro-ph
paper · pdf · doi:10.1086/421237
Accepted by ApJ
arxiv created 2004/03/19 · openalex publication_date 2004/07/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We select E+A candidates from a spectroscopic data set of ~800 field galaxies and measure the E+A fraction at 0.3 < z < 1 to be 2.7% ± 1.1%, a value lower than that in galaxy clusters at comparable redshifts (11% ± 3%). HST WFPC2 imaging for five of our six E+A's shows that they have a heterogeneous parent population: these E+A's span a range in half-light radius (0.8 h -1 kpc < r 1/2 < 8 h -1 kpc) and estimated internal velocity dispersion (50 km s -1 ≲ σ est ≲ 220 km s -1 ), and they include luminous systems (-21.6 ≤ M - 5 log h ≤ -19.2). Despite their diversity in some aspects, the E+A's share several common characteristics that indicate that the E+A phase is an important link in the evolution of star-forming galaxies into passive systems: the E+A's are uniformly redder than the blue, star-forming galaxies that make up the majority of the field, they are more likely to be bulge-dominated than the average field galaxy, and they tend to be morphologically irregular. We find that E+A's make up ~9% of the absorption-line systems in this redshift range and estimate that ≳25% of passive galaxies in the local field had an E+A phase at z ≲ 1.