High Redshift Galaxies


High Redshift Galaxies

Active Projects

SPLASH: Spitzer Large Area Survey with Hyper-SuprimeCam

Main Collaborators: The Hyper-Suprime-Cam, COSMOS, and SXDS teams

SPLASH is a 1251h survey with Spitzer which will build the foundation for comprehensive investigations of the earliest stages of galaxy, AGN and large-scale structure formation on cosmologically important scales, providing deep mid-IR imaging for a 1.8 square degree region in the COSMOS field. This field has been the target of, and is scheduled for, unparalleled deep imaging in the optical, sub-mm and radio. The major science enabled by the Spitzer observations includes: the co-evolution of cosmic large scale structure and the assembly and growth of galaxies and AGN; understanding the relative importance of smooth gas accretion vs. mergers for galaxy growth in the early universe; probing re-ionization through Infrared Background Fluctuations; constraining the Initial Mass Function at high redshift, AGN activity in the early universe, and the physics of supernova through transient studies. None of these are possible with existing Spitzer surveys, which are limited by both insufficient contiguous area, insufficient depth of ancillary data and/or temporal cadence. The COSMOS field will have unique, Hyper-Suprime-Cam (HSC) imaging (to ~27-28 magAB for broad bands across the 0.4-1.0um wavelength range) and science will be immediately enabled by Spitzer using pre-existing deep X-ray to radio multi-wavelength data, including: UV (Galex), X-ray (Chandra/XMM), optical (HST), near-infrared, mid-Infrared (Spitzer/Herschel), sub-mm, and radio. The COSMOS field is the primary deep field for the Nu-Star mission, has been ranked as a high priority deep-field target for Euclid, and has extensive spectroscopy with Keck (>50nt), Subaru-FMOS (>30nt), VLT (>1000h), and will be a primary target for the future Subaru Prime Focus Spectrograph (PFS) surveys. The legacy impact of these data will be enormous, and will provide a treasure trove of targets for JWST.


Deep Spectroscopy Of 4<z<6 Galaxies

Main Collaborators: B. Mobasher, N. Scoville, Y. Kakazu, D. Masters, O. LeFevre, D. Sanders, M. Urry, C. Scarlata, W. Wang

I am leading a large project on Keck divided between Caltech, UC, Hawaii, and Yale that obtain deep spectroscopy of ~500 objects at 3.5<z<6 brighter than z'<25 over 1 square degree in the COSMOS and GOODS fields. In addition I am collaborating with O. LeFevre and the VVDS team to obtain a large, faint sample of galaxies at 2<z<6 using VMOS on the VLT. 

These surveys compliment the existing zCOSMOS and VVDS surveys which probes comparable mass galaxies at 0.2<z<3.5 and will allow us to trace massive galaxy formation from 400Myr after the big bang to the present.  The spectra should be deep enough to probe feedback mechanisms, the metal content, the ISM, and large scale structure at high redshift along with confirming redshifts at 3.5<z<6.

Based on the results of this survey I recently obtained ALMA Cycle-1 time to characterize the far-infrared emission and dynamics (via the C[II] line) for ten normal galaxies at 5<z<6 to better understand the process of early galaxy assembly.

Publications:
Ilbert...Capak et al. 2013
Mallery...Capak et al. 2012
Smolcic...Capak et al. 2012
Masters, Capak et al. 2012
Donley...Capak et al. 2012
Salvato...Capak et al. 2011
Civano...Capak et al. 2011
Smolcic, Capak et al. 2011
Capak et al. 2011b
Capak et al. 2011a


Z>4 Sub-mm Galaxies

Main Collaborators: K. Sheth, E. Schinnerer, V. Smolcic, D. Sanders

I discovered one of the highest redshift extreme starburst (sub-mm galaxy) known in a massive proto-cluster at z=5.3 (Capak et al. 2011), and have shown it contains significant amounts of CO gas (Reichers et al. 2010).   I now have a sample of 7 z>4 Sub-mm systems and are characterizing their properties. 

It appears the global star formation rate density in these objects is comparable that measured with Ultraviolet surveys and that these objects are preferentially found in large scale structures.  This is in broad agreement with theoretical expectations.

Publications:
Smolcic...Capak et al. 2012
Smolcic, Capak et al. 2011
Capak et al. 2011a
Riechers, Capak et al. 2010
Aravena...Capak et al. 2010
Capak et al. 2008

 


z>7 Galaxies

Main Collaborators: M. Carollo, A. Faisst, N. Hathi, O. Ilbert, B. Mobasher, N. Scoville, W. Wang

I recently published a paper detailing deep spectroscopy of a z~12 candidate in the UDF that was thought to be a strong emission line object with the new Keck-MOSFIRE instrument. We found the line flux in this object must be fainter than previously reported or the source must be at z~12.

Previously I wrote a paper on three objects brighter than K<23 (AB) which meet all criteria for z>7 galaxies. However, one is clearly at z~2 and three nights of Keck spectroscopy from 0.6 to 1.8um failed to confirm or reject the remaining two as z>7 objects.  Its likely these are a population on poorly understood objects that contaminate z>7 galaxy searches.  We have since analyzed the much deeper Ultra-Vista Y,J,H,K photometry and are following up these sources with Keck-MOSFIRE.

Publications:
Capak et al. 2013
Hathi...Capak et al. 2012
Krug...Capak et al. 2012
Capak et al. 2011b

 


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Capak Research Areas:
High Redshift Galaxies
Galaxy Evolution
Active Galaxies
Gravitational Lensing
Photometric Redshifts
Astrophysics Software
Links:
Home
Observing
Astronomy Links
Other Links

Relavent Publications:
Capak et al. 2013
Capak et al. 2011a
Capak et al. 2011b
Ilbert...Capak et al. 2013
Mallery...Capak et al. 2012
Smolcic...Capak et al. 2012
Masters, Capak et al. 2012
Krug...Capak et al. 2012
Capak et al. 2008
Hathi...Capak et al. 2012
Smolcic...Capak et al. 2012
Civano...Capak et al. 2011
Dwek...Capak et al. 2011
Smolcic, Capak et al. 2011
Riechers, Capak et al. 2010
Aravena...Capak et al. 2010
Hu...Capak et al. 2010

 

 

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last update: 09/15/2013   ©2011 Peter L. Capak. All Rights Reserved. image