The WFC3 Infrared Spectroscopic Parallel (WISP) Survey

November 2010 • 2010ApJ...723..104A

Authors • Atek, H. • Malkan, M. • McCarthy, P. • Teplitz, H. I. • Scarlata, C. • Siana, B. • Henry, A. • Colbert, J. W. • Ross, N. R. • Bridge, C. • Bunker, A. J. • Dressler, A. • Fosbury, R. A. E. • Martin, C. • Shim, H.

Abstract • We present the WFC3 Infrared Spectroscopic Parallel (WISP) Survey. WISP is obtaining slitless, near-infrared grism spectroscopy of ~90 independent, high-latitude fields by observing in the pure-parallel mode with the Wide Field Camera Three on the Hubble Space Telescope for a total of ~250 orbits. Spectra are obtained with the G ₁₀₂ (λ = 0.8-1.17 μm, R ~210) and G ₁₄₁ grisms (λ = 1.11-1.67 μm, R ~130), together with direct imaging in the J and H bands (F110W and F140W, respectively). In the present paper, we present the first results from 19 WISP fields, covering approximately 63 arcmin². For typical exposure times (~6400 s in G ₁₀₂ and ~2700 s in G ₁₄₁), we reach 5σ detection limits for emission lines of f ~ 5 × 10^-17 erg s^-1 cm^-2 for compact objects. Typical direct imaging 5σ limits are 26.3 and 26.1 mag. (AB) in F110W and F140W, respectively. Restricting ourselves to the lines measured with the highest confidence, we present a list of 328 emission lines, in 229 objects, in a redshift range 0.3 < z < 3. The single-line emitters are likely to be a mix of Hα and [O III]5007,4959 Å, with Hα predominating. The overall surface density of high-confidence emission-line objects in our sample is approximately 4 per arcmin². These first fields show high equivalent width sources, active galactic nucleus, and post-starburst galaxies. The median observed star formation rate (SFR) of our Hα-selected sample is 4 M _sun yr^-1. At intermediate redshifts, we detect emission lines in galaxies as faint as H ₁₄₀ ~ 25, or M_R < -19, and are sensitive to SFRs down to less than 1 M _sun yr^-1. The slitless grisms on WFC3 provide a unique opportunity to study the spectral properties of galaxies much fainter than L* at the peak of the galaxy assembly epoch.

Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program 11696.

Links

• PDF https://iopscience.iop.org/article/10.1088/0004-637X/723/1/104/pdf
• PDF https://stacks.iop.org/0004-637X/723/104/pdf
• PREPRINT http://arxiv.org/abs/1005.4068
• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2010ApJ...723..104A
• DATA https://hst.esac.esa.int/ehst/#/pages/search;bibcode=2010ApJ...723..104A
• ELECTR https://doi.org/10.1088%2F0004-637X%2F723%2F1%2F104