2012AJ....143..145K -
Astron. J., 143, 145 (2012/June-0)
Hα dots: a catalog of faint emission-line objects discovered in narrowband images.
KELLAR J.A., SALZER J.J., WEGNER G., GRONWALL C. and WILLIAMS A.
Abstract (from CDS):
During a wide-field narrowband Hα imaging survey, we noted the presence of numerous isolated emission-line point sources in the data. These objects could represent ultra-low-luminosity galaxies at low-redshift (detection via Hα), isolated extragalactic H II regions associated with the galaxy targeted by the original observation, or background galaxies or QSOs where strong emission lines (most often [O III] λ5007) redshift into our narrowband filter. We have carried out a systematic search for these "Hα dots" in over 200 15x15 arcmin fields. To date we have cataloged 61 candidate emission-line sources in roughly 11.7 deg2. The sample has a median R magnitude of 19.5, and detects objects as faint as R = 22.6. Follow-up spectroscopy reveals that ∼85% of the candidates are bona fide emission-line objects, with roughly 60% of the real sources being lower-redshift objects (detection via Hα) and 40% being higher-redshift objects detected via [O III] emission or some other emission line. Here we present the results of our initial survey and follow-up spectroscopy. We use our sample to study the properties (including star-formation rates and metal abundances) of low-luminosity star-forming galaxies in the nearby universe and of low-metallicity star-forming galaxies at z ~ 0.33.
Abstract Copyright:
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Journal keyword(s):
galaxies: abundances - galaxies: dwarf - galaxies: starburst - surveys
VizieR on-line data:
<Available at CDS (J/AJ/143/145): table2.dat table3.dat table4.dat>
Nomenclature:
Tables 2-4: [KSW2012] NNN (Nos 1-61).
Simbad objects:
56
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