2008/02/20 by Amber N. Straughn, G. R. Meurer, Gerhardt R. Meurer +17 · 1 citation
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Grism #Hubble Deep Field #Hubble Ultra-Deep Field #Physics #Radio galaxy #Redshift #Reionization #Star formation #astro-ph
paper · pdf · doi:10.1088/0004-6256/135/4/1624
13 pages, accepted for publication in AJ
arxiv created 2008/02/20 · openalex publication_date 2008/03/13 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
The Hubble Space Telescope Advanced Camera for Surveys grism Probing Evolution And Reionization Spectroscopically (PEARS) survey provides a large dataset of low-resolution spectra from thousands of galaxies in the GOODS north and south fields. One important subset of objects in these data is emission-line galaxies (ELGs), and we have investigated several different methods aimed at systematically selecting these galaxies. Here, we present a new methodology and results of a search for these ELGs in the PEARS observations of the Hubble Ultra Deep Field (HUDF) using a 2D detection method that utilizes the observation that many emission lines originate from clumpy knots within galaxies. This 2D line-finding method proves to be useful in detecting emission lines from compact knots within galaxies that might not otherwise be detected using more traditional 1D line-finding techniques. We find in total 96 emission lines in the HUDF, originating from 81 distinct "knots" within 63 individual galaxies. We find in general that [O iii ] emitters are the most common, comprising 44% of the sample, and on average have high equivalent widths (70% of [O iii ] emitters having rest-frame EW>100 Å). There are 12 galaxies with multiple emitting knots—with different knots exhibiting varying flux values, suggesting that the differing star-formation properties across a single galaxy can in general be probed at redshifts ≳0.2–0.4. The most prevalent morphologies are large face-on spirals and clumpy interacting systems, many being unique detections owing to the 2D method described here, thus highlighting the strength of this technique.