Hubble’s Slitless Spectroscopy

Patrick McCarthy – Carnegie Observatories

HST III Venice, October 2010 1

Hubble’s Slitless Spectroscopy

HST III Venice, October 2010 2

• Slitless Spectra

• Stars & Planets

• Super Novae

• Faint Galaxies in the VisibleStar forming & Passive systems

• Distant Galaxies in the Near-IR

See poster by H. Atek & talk by A. Straughn

• Slitless Spectra

• Stars & Planets

• Super Novae

• Faint Galaxies in the VisibleStar forming & Passive systems

• Distant Galaxies in the Near-IR

See poster by H. Atek & talk by A. Straughn

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!

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!

SN 1987A

Hα[NII][NII] [SII]

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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

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

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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

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

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Two-Day Workshop on Slitless Grism Spectroscopy with Hubble

STScI - November, 15-16 See STScI website for details

Grisms for Slitless Modes on HST

R is 2-pixel resolution for point source

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Water Ice in the outer Solar System

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Pluto Charon

NICMOS G141 & G206 Spectra

Exoplanet Atmospheres

NICMOS G141 & G206 Spectra of Exoplanet eclipse

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Swain, Tinetti et al. Nature

High Redshift SNe Spectroscopy

ACS G800L spectra of

type Ia SNe to z ~ 1

Blakeslee et al. 2003

ACS G800L spectra of

type Ia SNe to z ~ 1

Blakeslee et al. 2003

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ACS Grism Spectroscopy

ACS G800L spectra of

Faintest Lyman Break

galaxies at z ~ 5

Rhoads et al. 2009

“GRAPES”

ACS G800L spectra of

Faintest Lyman Break

galaxies at z ~ 5

Rhoads et al. 2009

“GRAPES”

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ACS Grism Spectroscopy

ACS G800L spectra of

Passive Galaxies in the UDF

Daddi et al. 2005

ACS G800L spectra of

Passive Galaxies in the UDF

Daddi et al. 2005

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NICMOS Grism Spectra

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NICMOS G141 spectra of Hα emitters

1 – 3 orbits per frame

NICMOS G141 spectra of Hα emitters

1 – 3 orbits per frame

McCarthy et al. ‘99

1 emission line in every 3rd frame

1 line per object, max!

1 emission line in every 3rd frame

1 line per object, max!

Hα Luminosity Functions

Yan et al. 99, Hopkins et al. 2000, Shim et al. 2009

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Hα Luminosity Density

Shim et al. 2009HST III Venice, October 2010 14

Cycle 17 WFC3 Grism Programs

ERS Amber Straughn Pathfinder1 Field in both G102 & G141 GOODS-S2 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 orbitsG102 & G141 ~60 pointings 150 sq.

arcminutes1-5 orbits each grism

To Date: 40 pointings over 100 square arcminutes

ERS Amber Straughn Pathfinder1 Field in both G102 & G141 GOODS-S2 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 orbitsG102 & G141 ~60 pointings 150 sq.

arcminutes1-5 orbits each grism

To Date: 40 pointings over 100 square arcminutes

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Zero-Order 1st-Order 2nd-Order

Emission-lines

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WFC3: 30 – 40 emission-line galaxies per field

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Star Forming Galaxies

[HeI]10830

[SIII]

WFC3 G102 + G141

2 orbits each

Atek et al. 2010

Same telescope,

same ruling (G141)!

z ~ 1

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Star Forming Galaxies

[OIII]5007 is the strongest line, [OII]3727 is unimpressive

Atek et al. 2010

1.5 < z <2

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Star Forming GalaxiesNote numerous Hβ detections –

essential to E(B-V) and [Fe/H] determinations

Atek et al. 2010

High Equivalent Widths

[OIII] Hα

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See Atek et al. poster

High Equivalent Widths

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Rest-frame Wλ([OIII]) > 500A!

Keck/Deimos spectra of

z = 0.7 High EW

[OIII] emitter from G141

Keck/Deimos spectra of

z = 0.7 High EW

[OIII] emitter from G141

Redshifted “Green Peas”

“Red Beans”?

High Equivalent Widths

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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

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 23

Quenched Galaxies at z = 1.5-2

Van Dokkum & Bremer 2010 Atek, Malkan, McC et al. 2010

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1 magnitude fainter!

500 Myrs after quenching of star formation

Quenched Galaxies at z > 2

Scarlatta, PMcC et al. 2010

Contamination

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Another magnitude fainter!

Passive Galaxies at z = 1 - 3

Scarlatta, PMcC et al. 2010HST III Venice, October 2010 26

G102 Search for Lyα Emission

Lyα at z = 6.8?

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Lyα?

Decrement?

H ~ 25AB

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!

“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 28

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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*

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!

So Long, and Thanks for All the FishSpect

ra!

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