Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Automated selection and characterization of emission-line sources in ACS
  WFC grism data   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)

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The categories of this paper are: hep-lat
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The categories of this paper are: plasm-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: econ
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The categories of this paper are: nucl-ex
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The categories of this paper are: physics
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The categories of this paper are: math
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
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The categories of this paper are: nlin
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The categories of this paper are: dg-ga
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The categories of this paper are: alg-geom
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The categories of this paper are: stat
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The categories of this paper are: adap-org
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph