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Hubble’s Slitless Spectroscopy. Patrick McCarthy – Carnegie Observatories. Hubble’s Slitless Spectroscopy. Slitless Spectra Stars & Planets Super Novae Faint Galaxies in the Visible Star forming & Passive systems Distant Galaxies in the Near-IR
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Hubble’s Slitless Spectroscopy Patrick McCarthy – Carnegie Observatories HST III Venice, October 2010
Hubble’s Slitless Spectroscopy • Slitless Spectra • Stars & Planets • Super Novae • Faint Galaxies in the Visible • Star forming & Passive systems • Distant Galaxies in the Near-IR • See poster by H. Atek & talk by A. Straughn HST III Venice, October 2010
Slitless Spectroscopy No entrance aperture - Disperser, PSF & Object shape set resolution - Focal plane image is a stack of monochromatic images of all objects - No unique mapping between x,y and λ - Good software is essential! Hα [SII] [NII] [NII] SN 1987A HST III Venice, October 2010
Slitless Spectroscopy Backgrounds & Foregrounds – - All pixels see the full background - Wider band-pass more background - Background is dispersed and reintegrated, so higher dispersion less contrast - Low dispersion is preferred Best Targets: Compact objects with strong features Cool stars, Planets, SNe, Distant Galaxies, AGN HST III Venice, October 2010
Slitless Spectroscopy Good software is essential “AxE” package developed by ECF in Garching - Background removal - Image plane – Spectral plane mapping - Spectral extraction, wavelength calibration and flat-fields ECF Archive - NICMOS slitless grism spectra - 48,000 calibrated ACS slitless spectra Two-Day Workshop on SlitlessGrism Spectroscopy with Hubble STScI - November, 15-16 See STScI website for details HST III Venice, October 2010
Grisms for Slitless Modes on HST R is 2-pixel resolution for point source HST III Venice, October 2010
Water Ice in the outer Solar System NICMOS G141 & G206 Spectra Pluto Charon HST III Venice, October 2010
Exoplanet Atmospheres NICMOS G141 & G206 Spectra of Exoplanet eclipse Swain, Tinetti et al. Nature HST III Venice, October 2010
High Redshift SNe Spectroscopy ACS G800L spectra of type IaSNe to z ~ 1 Blakeslee et al. 2003 HST III Venice, October 2010
ACS Grism Spectroscopy ACS G800L spectra of Faintest Lyman Break galaxies at z ~ 5 Rhoads et al. 2009 “GRAPES” HST III Venice, October 2010
ACS Grism Spectroscopy ACS G800L spectra of Passive Galaxies in the UDF Daddi et al. 2005 HST III Venice, October 2010
NICMOS Grism Spectra NICMOS G141 spectra of Hα emitters 1 – 3 orbits per frame 1 emission line in every 3rd frame 1 line per object, max! McCarthy et al. ‘99 HST III Venice, October 2010
Hα Luminosity Functions Yan et al. 99, Hopkins et al. 2000, Shim et al. 2009 HST III Venice, October 2010
Hα Luminosity Density Shim et al. 2009 HST III Venice, October 2010
Cycle 17 WFC3 Grism Programs ERS Amber Straughn Pathfinder 1 Field in both G102 & G141 GOODS-S 2 orbits each GO1161 Ben Weiner 56 orbits G141 in GOODS North 25 pointings, 2-orbits each WISPS Matt Malkan “Wide-Field Infrared Spectroscopic Parallel Survey” 250 pure parallel orbits G102 & G141 ~60 pointings 150 sq. arcminutes 1-5 orbits each grism To Date: 40 pointings over 100 square arcminutes HST III Venice, October 2010
WFC3: 30 – 40 emission-line galaxies per field Emission-lines 2nd-Order 1st-Order Zero-Order HST III Venice, October 2010
Star Forming Galaxies WFC3 G102 + G141 2 orbits each [SIII] [HeI]10830 Same telescope, same ruling (G141)! Atek et al. 2010 HST III Venice, October 2010
Star Forming Galaxies [OIII]5007 is the strongest line, [OII]3727 is unimpressive z ~ 1 Atek et al. 2010 HST III Venice, October 2010
Star Forming Galaxies Note numerous Hβ detections – essential to E(B-V) and [Fe/H] determinations 1.5 < z <2 Atek et al. 2010 HST III Venice, October 2010
High Equivalent Widths [OIII] Hα See Atek et al. poster HST III Venice, October 2010
High Equivalent Widths Keck/Deimos spectra of z = 0.7 High EW [OIII] emitter from G141 Redshifted “Green Peas” “Red Beans”? Rest-frame Wλ([OIII]) > 500A! HST III Venice, October 2010
High Equivalent Widths HST III Venice, October 2010
Sampling the Galaxy Mass Function The WFC3 Grisms have the sensitivity to sample 0.1L* and fainter galaxies to z > 2 Emission-line corrections push continuum 1-2 mag fainter in some cases HST III Venice, October 2010
Quenched Galaxies at z = 1.5-2 500 Myrs after quenching of star formation 1 magnitude fainter! Van Dokkum & Bremer 2010 Atek, Malkan, McC et al. 2010 HST III Venice, October 2010
Quenched Galaxies at z > 2 Contamination Another magnitude fainter! Scarlatta, PMcC et al. 2010 HST III Venice, October 2010
Passive Galaxies at z = 1 - 3 Scarlatta, PMcC et al. 2010 HST III Venice, October 2010
G102 Search for Lyα Emission Lyα at z = 6.8? Lyα? H ~ 25AB Decrement? HST III Venice, October 2010
Cycle 18 & Beyond “WISPS” Malkan et al. 280 pure parallel orbits “3DHST” van Dokkum et al. 248 prime orbits - G141 over full CANDELS area 2-orbit depth - Built on deep imaging fields “CANDLES” & “CLASH” SNe grism spectroscopy A slitless Deep or Ultra-Deep Field? JWST 2-5μm slitless mode Hα to z = 6.5 Dedicated Slitless Missions – Euclid! HST III Venice, October 2010
So Long, and Thanks for All the Fish Spectra! Special Thanks to the ECF team for their dedicated effort to support slitless spectroscopy! Richard Hook Jeremy Walsh Jonas Haase Harald Kuntschner Piero Rosati Martin Kornmesser Martin Kummel Marco Lombardi Kim Nilsson Brit Sjoberg Felix Stoehr Michael Rosa Colleen Sharkey Nor Pirzkal* And…… Bob Fosbury! HST III Venice, October 2010