Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-03-12
Astron.J.134:77-95,2007
Astronomy and Astrophysics
Astrophysics
AJ accepted. 27 pages, 4 tables, 11 figures. Uses emulateapj.cls
Scientific paper
10.1086/518228
We present complimentary techniques to find emission-line targets and measure their properties in a semi-automated fashion from grism observations obtained with the Advanced Camera for Surveys aboard the Hubble Space Telescope. The first technique is to find all likely sources in a direct image, extract their spectra and search them for emission lines. The second method is to look for emission-line sources as compact structures in an unsharp masked version of the grism image. Using these methods we identify 46 emission-line targets in the Hubble Deep Field North using a modest (3 orbit) expenditure of HST observing time. Grism spectroscopy is a powerful tool for efficiently identifying interesting low luminosity, moderate redshift emission-line field galaxies. The sources found here have a median i band flux 1.5 mag fainter than the spectroscopic redshift catalog of Cohen et al. They have redshift z <= 1.42, high equivalent widths (typically EW > 100{\AA}), and are usually less luminous than the characteristic luminosity at the same redshift. The chief obstacle in interpreting the results is line identification, since the majority of sources have a single emission line and the spectral resolution is low. Photometric redshifts are useful for providing a first guess redshift. However, even at the depth of the state-of-the-art data used here, photometric errors can result in uncertainties in line identifications, especially for sources with i > ~24.5 ABmag. Reliable line identification for the faintest emission-line galaxies requires additional ground-based spectroscopy for confirmation. Of particular concern are the faint high EW [OII] emitters which could represent a strongly evolving galaxy population if the possibility that they are mis-identified lower redshift interlopers can be ruled out. (Slightly abridged)
Benítez Narciso
Blakeslee John P.
Bouwens Rychard J.
Bradley Larry Daniel
Capak Peter
No associations
LandOfFree
Automated selection and characterization of emission-line sources in ACS WFC grism data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Automated selection and characterization of emission-line sources in ACS WFC grism data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automated selection and characterization of emission-line sources in ACS WFC grism data will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-438151