Observing the High Redshift Universe with SITELLE

Observing the High Redshift
Universe with SITELLE
Luc Simard (NRC Herzberg)
SITELLE Science Workshop, Québec City, May 11-14, 2013
SITELLE Science Workshop
Québec City, May 11-14, 2013
Outline
•  Formation and evolution of galaxies
•  Cosmic Star Formation
•  Impact of AGN activity
•  Limitations of current surveys
•  Ideas for SITELLE surveys
•  Summary
SITELLE Science Workshop
Québec City, May 11-14, 2013
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Re-Ionization and Early Galaxies
Nature of re-­‐ionizing sources is s1ll unknown Studying Lyman-­‐alpha emi<ers can provide clues, and large samples are needed if many sub-­‐popula1ons of sources are at work SITELLE Science Workshop
Québec City, May 11-14, 2013
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Evolution of Galaxies
``Spheroid’’
``Early+
Disks’’
``Elliptical’’
High L
+ Low L
SITELLE Science Workshop
Québec City, May 11-14, 2013
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Evolution of Galaxies
``Spheroid’’
``Early+
Disks’’
What happens to star
formation through all this?
``Elliptical’’
High L
+ Low L
SITELLE Science Workshop
Québec City, May 11-14, 2013
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Cosmic Star Formation
Hopkins & Beacom 2006 SITELLE Science Workshop
Québec City, May 11-14, 2013
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Cosmic Star Formation
Juneau et al. 2005 Cosmic SFR Density depends on galaxy stellar mass – What happens at very low Masses? SITELLE Science Workshop
Québec City, May 11-14, 2013
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Impact of AGN Activity
Models cannot reproduce the bimodality of galaxy colors without invoking AGN feedback SITELLE Science Workshop
Québec City, May 11-14, 2013
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Impact of AGN Activity
Ueda et al. 2003 Luminous AGN ac1vity peaks around z = 2-­‐3 This is also the epoch of peak galaxy merger rate SITELLE Science Workshop
Québec City, May 11-14, 2013
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Limitations of Slit Surveys
•  Pre-selection from images required
-  Biased target selection
•  Density of slits on sky limits slit length
-  Sky subtraction harder
•  Slit losses
-  Flux falling outside of slits makes total flux measurements difficult
because aperture corrections are then needed
•  Slit spectrographs are not as efficient as FTS (for
emission)
SITELLE Science Workshop
Québec City, May 11-14, 2013
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Cosmic Star Formation
Glazebrook et al. 2004 20 arcmin2 1.7-­‐2.4x10-­‐17 ergs s-­‐1 cm-­‐2 Differences between datasets is due to cosmic variance SITELLE Science Workshop
Québec City, May 11-14, 2013
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HETDEX [OII] Pilot Survey
•  Hobby-Eberly Telescope Dark Energy Experiment
(HETDEX)
•  Pilot survey with VIRUS-P on 2.7-m telescope
-  246-fiber array with 4’’.2 fiber diameter and 1/3 fill factor
-  360 – 580 nm with 0.5 nm resolution
•  169 arcmin2 total in COSMOS, GOODS-N, MUNICS-S2
and XMM-LSS
•  6-pointing dither pattern for each field with 1-hour per
dither position
•  5.5σ flux limit of 6.7x10-17 ergs s-1 cm-2
•  Detected 284 z < 0.56 [OII]-emitting galaxies
SITELLE Science Workshop
Québec City, May 11-14, 2013
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HETDEX [OII] Galaxy SFR
Ciardullo et al. 2013 SITELLE Science Workshop
Québec City, May 11-14, 2013
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Luminosity Function of LymanAlpha Emitters
Dawson et al. 2007 More recent studies have pushed up in redshi] but not in volume … SITELLE Science Workshop
Québec City, May 11-14, 2013
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SITELLE as a Survey Instrument
•  Large field of view (11’ x 11’, 121 arcmin2)
-  Effect of cosmic variance is lessened
•  Lines can be identified via a peak in flux without reference
to a broadband image
-  Unbiased observations
•  Higher resolution (Δλ ~ 10Å) can be achieved
-  Better match to typical line widths with corresponding gains in S/N
•  Precise removal of background from line profile
-  Total line fluxes without aperture corrections
SITELLE Science Workshop
Québec City, May 11-14, 2013
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SITELLE Survey I: Star Formation
•  0.6 < z < 1 (6000 – 7500 Å for [OII]3727)
•  5.5σ flux limit of 4.3x10-17 ergs s-1 cm-2
-  Line luminosity of 2.3x1041 ergs s-1 at z = 1
•  6,500 arcmin2
•  Total cosmological volume of 4.5x106 Mpc3
-  1000 times larger than Glazebrook et al.
•  Star formation density measurements good to ~0.05 dex
•  Dependence on galaxy stellar mass in greater details
•  55 pointings with exposure time of four hours per pointing
for a total of 40 nights
SITELLE Science Workshop
Québec City, May 11-14, 2013
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SITELLE Survey II: Ly-α Emitters
•  1000 Lyman-alpha emitters with L > 6.5x1042 ergs s-1
•  4 < z < 5 (6000 – 7500 Å)
•  5.5σ flux limit of 4.3x10-17 ergs s-1 cm-2
-  Sensitive to SFRs down to 5 solar masses per year
•  6,500 square arcmin2
•  Total cosmological volume of 2x107 Mpc3
•  55 pointings with exposure time of four hours per pointing
for a total of 40 nights
Parameters overlap with
Survey I
SITELLE Science Workshop
Québec City, May 11-14, 2013
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SITELLE Synergy: X-Ray Surveys
•  Larger volumes is not only about better statistics
•  Cross-correlating SITELLE sources with catalogs at other
wavelengths offers powerful synergies
•  AGN feedback:
-  [OII] luminosity function versus X-ray point source
luminosities at redshifts 2-3 where AGN activity is highest
•  X-ray structures and [OII] emitter over-densities:
-  Detection of low mass galaxy groups via clustered [OII]
emission
-  X-ray gives mass estimates and amount of hot gas which
may impact star formation
-  Add weak lensing maps to put [OII] emitters in the full context
of large scale structures
SITELLE Science Workshop
Québec City, May 11-14, 2013
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SITELLE Survey III: CFHTLS D1
•  36 pointings with 2 hours per pointing to reach a flux limit
of 4x10-17 ergs s-1 cm-2
-  Total observing time of 80-90 hours
•  Wavelength range of 420-500 nm with R = 1000
•  Science goals:
-  [OII] mapping in z = 0.3 clusters and groups
-  SFR-environment relations
-  SF at large radii
-  Timescale of environmental quenching
-  Dynamical and X-ray masses
-  X-ray structures versus [OII] over-densities
SITELLE Science Workshop
Québec City, May 11-14, 2013
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Summary
•  SITELLE will be a powerful survey instrument for the high
redshift Universe
•  Will provide factors of 1000x in survey volume and
sample size
-  With un-biased object detection!
•  Interesting areas include cosmic star formation, early
galaxy formation and AGN feedback
•  Let’s get on sky!
SITELLE Science Workshop
Québec City, May 11-14, 2013
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