2010/05/31 by A. N. Straughn, Amber N. Straughn, H. Kuntschner +62 · 29 citations
Engineering · Physics and Astronomy · #Astronomy and Astrophysical Research #CCD and CMOS Imaging Sensors #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Grism #Infrared #Luminous infrared galaxy #Redshift #Star formation #Wide Field Camera 3 #astro-ph.CO
paper · pdf · doi:10.1088/0004-6256/141/1/14
published in The Astronomical Journal 141(1), 14 (Institute of Physics) · Accepted for publication in AJ. Updated to include referee comments. Updated sample using improved reduction contains 23 new galaxies (Table 1; Figures 2 & 3)
arxiv created 2010/10/27 · openalex publication_date 2010/12/10 · arxiv updated 2015/05/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present grism spectra of emission-line galaxies (ELGs) from 0.6 to 1.6 μm from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope . These new infrared grism data augment previous optical Advanced Camera for Surveys G800L 0.6–0.95 μm grism data in GOODS-South from the PEARS program, extending the wavelength coverage well past the G800L red cutoff. The Early Release Science (ERS) grism field was observed at a depth of two orbits per grism, yielding spectra of hundreds of faint objects, a subset of which is presented here. ELGs are studied via the Hα, [O iii ], and [O ii ] emission lines detected in the redshift ranges 0.2 ≲ z ≲ 1.4, 1.2 ≲ z ≲ 2.2, and 2.0 ≲ z ≲ 3.3, respectively, in the G102 (0.8–1.1 μm; R ≃ 210) and G141 (1.1–1.6 μm; R ≃ 130) grisms. The higher spectral resolution afforded by the WFC3 grisms also reveals emission lines not detectable with the G800L grism (e.g., [S ii ] and [S iii ] lines). From these relatively shallow observations, line luminosities, star formation rates, and grism spectroscopic redshifts are determined for a total of 48 ELGs to m AB ( F 098 M ) ≃ 25 mag. Seventeen GOODS-South galaxies that previously only had photometric redshifts now have new grism-spectroscopic redshifts, in some cases with large corrections to the photometric redshifts (Δ z ≃ 0.3–0.5). Additionally, one galaxy had no previously measured redshift but now has a secure grism-spectroscopic redshift, for a total of 18 new GOODS-South spectroscopic redshifts. The faintest source in our sample has a magnitude m AB ( F 098 M ) = 26.9 mag. The ERS grism data also reflect the expected trend of lower specific star formation rates for the highest mass galaxies in the sample as a function of redshift, consistent with downsizing and discovered previously from large surveys. These results demonstrate the remarkable efficiency and capability of the WFC3 NIR grisms for measuring galaxy properties to faint magnitudes and redshifts to z ≳ 2.