Submillimeter Galaxies at<i>z</i>∼ 2: Evidence for Major Mergers and Constraints on Lifetimes, IMF, and CO‐H<sub>2</sub>Conversion Factor

Tacconi, L. J.; Genzel, R.; Smail, Ian; Neri, R.; Chapman, Stephen; Ivison, R. J.; Blain, A. W.; Cox, P.; Omont, A.; Bertoldi, F.; Greve, T. R.; Schreiber, N. M. Foerster; Genel, Shy; Lutz, D.; Swinbank, A. M.; Shapley, Alice E.; Erb, Dawn K.; Cimatti, A.; Daddi, E.; Baker, A. J.

doi:10.1086/587168

Cited by 691 publications

(1,032 citation statements)

References 145 publications

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“…At higher redshifts, the best measurements of DSFG timescales come from 850µm-selected SMGs with CO measurements Greve et al, 2005;Tacconi et al, 2006Tacconi et al, , 2008Coppin et al, 2008b;Bothwell et al, 2010;Casey et al, 2011a;Bothwell et al, 2013a). Bothwell et al (2013a) provides a summary of all CO surveys directed at 850µm-selected sources, and more recently summarizes molecular gas surveys at high-z.…”

Section: Star Formation History and Dynamical Timementioning

confidence: 99%

“…For example, CO dynamical mass measurements (e.g. Greve et al, 2005;Tacconi et al, 2008;Bothwell et al, 2013a) in combination with an assumed dark halo profile can provide a constraint on the remaining stellar mass. This neglects any contribution to the mass by HI, and comes with the uncertainty of an assumed dynamical state of SMGs.…”

Section: Stellar Massesmentioning

confidence: 99%

“…Tacconi et al (2008) simultaneously modeled the CO-H 2 conversion factor, stellar masses and IMFs of z ∼ 2 SMGs, and found that the IMF may have an excess of high-mass stars, with a best fit mass to light (M/L) ratio roughly half that off a standard Kroupa IMF. This however assumes that high-J CO transitions trace the same region as low-J CO lines, however this often cannot be the case as the integrated SMG star formation history would exceed the local baryon density .…”

Section: Stellar Imfmentioning

confidence: 99%

“…When molecular gas CO observations are taken at high-resolution (e.g. Tacconi et al, 2008;Bothwell et al, 2010;Engel et al, 2010, for SMGs), a consequence of obtaining kinematics is also obtaining the simple size measurement of the cold gas reservoir. While the morphologies of the sources themselves might be disturbed, these works reached a consensus that SMGs have effective radii of r e = 2 ± 1 kpc 15 , on average twice the physical size of local ULIRGs which are very compact with r e < ∼ 1 kpc.…”

Section: Physical Size and Morphologymentioning

confidence: 99%

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Dusty star-forming galaxies at high redshift

2014

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Far-infrared and submillimeter wavelength surveys have now established the important role of dusty, star-forming galaxies (DSFGs) in the assembly of stellar mass and the evolution of massive galaxies in the Universe. The brightest of these galaxies have infrared luminosities in excess of 10 13 L with implied star-formation rates of thousands of solar masses per year. They represent the most intense starbursts in the Universe, yet many are completely optically obscured. Their easy detection at submm wavelengths is due to dust heated by ultraviolet radiation of newly forming stars. When summed up, all of the dusty, star-forming galaxies in the Universe produce an infrared radiation field that has an equal energy density as the direct starlight emission from all galaxies visible at ultraviolet and optical wavelengths. The bulk of this infrared extragalactic background light emanates from galaxies as diverse as gas-rich disks to mergers of intense starbursting galaxies. Major advances in far-infrared instrumentation in recent years, both spacebased and ground-based, has led to the detection of nearly a million DSFGs, yet our understanding of the underlying astrophysics that govern the start and end of the dusty starburst phase is still in nascent stage. This review is aimed at summarizing the current status of DSFG studies, focusing especially on the detailed characterization of the bestunderstood subset (submillimeter galaxies, who were summarized in the last review of this field over a decade ago, Blain et al. 2002), but also the selection and characterization of more recently discovered DSFG populations. We review DSFG population statistics, their physical properties including dust, gas and stellar contents, their environments, and current theoretical models related to the formation and evolution of these galaxies.

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Section: Star Formation History and Dynamical Timementioning

confidence: 99%

Section: Stellar Massesmentioning

confidence: 99%

Section: Stellar Imfmentioning

confidence: 99%

Section: Physical Size and Morphologymentioning

confidence: 99%

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Dusty star-forming galaxies at high redshift

2014

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“…The predicted CO(1-0) line luminosity is 4.3 x 10 10 K km s -1 pc 2 , close to the measured value for CO(2-1). Depending on the choice of α, the CO-to-H 2 conversion factor, this line luminosity implies a molecular gas mass of M H2 = 3.5 x (α/0.8) x 10 10 M sun ; here α=0.8, in units of M sun (K km s -1 pc 2 ) -1 , is the conversion factor adopted for ultra-luminous infrared galaxies (ULIRGs) 13 and thought to be applicable to sub-millimeter bright objects 14 . The implied molecular gas mass fraction is M H2 /M dyn ~ 0.25±0.08 (α/0.8); i.e.…”

mentioning

confidence: 99%

The intense starburst HDF 850.1 in a galaxy overdensity at z ≈ 5.2 in the Hubble Deep Field

Walter

Decarli

Carilli

et al. 2012

Nature

282

348

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The Hubble Deep Field (HDF) is a region in the sky that provides one of the deepest multi-wavelength views of the distant universe and has led to the detection of thousands of galaxies seen throughout cosmic time 1 . An early map of the HDF at a wavelength of 850 microns that is sensitive to dust emission powered by star formation revealed the brightest source in the field, dubbed HDF850.1 2 . For more than a decade, this source remained elusive and, despite significant efforts, no counterpart at shorter wavelengths, and thus no redshift, size or mass, could be identified 3-7 . Here we report, using a millimeter wave molecular line scan, an unambiguous redshift determination for HDF850.1 of z=5.183. This places HDF850.1 in a galaxy overdensity at z~5.2 in the HDF, corresponding to a cosmic age of only 1.1 Gyr after the Big Bang. This redshift is significantly higher than earlier estimates 3,4,6,8 and higher than most of the >100 sub-millimeter bright galaxies identified to date. The source has a star formation rate of 850 M sun yr -1 and is spatially resolved on scales of 5 kpc, with an implied dynamical mass of ~1.3x10 11 M sun , a significant fraction of which is present in the form of molecular gas. Despite our accurate redshift and position, a counterpart arising from starlight remains elusive.We have obtained a full frequency scan of the 3 mm band towards the HDF using the IRAM Plateau de Bure Interferometer (PdBI). The observations covered the frequency range from 80-115 GHz in 10 frequency settings at uniform sensitivity and at a resolution (~2.3") that is a good match to galaxy sizes at high redshift. They resulted in the detection of two lines of Carbon Monoxide (CO), the most common tracer for molecular gas at high redshift 9 , at 93.20 GHz and 111.84 GHz at the position of HDF850.1. Identifying these lines with the J=5 and J=6 rotational transitions of CO gives a redshift for HDF850.1 of z=5.183. This redshift was then unambiguously confirmed by the PdBI detection of the 158 μm line of ionized carbon ([CII], redshifted to 307.38 GHz), one of the main cooling lines of the star-forming interstellar medium. Stacking of other molecules covered by our frequency scan that trace higher volume densities did not lead to a detection (see Supplementary Information). Subsequently, the J=2 line of CO has also been detected using the NRAO Jansky Very Large Array (Jansky VLA) at 37.29 GHz. The observed [CII] and CO spectra towards HDF850.1 are shown in Fig. 1.The beamsize of our CO observations (~2.3", 15 kpc at z=5.183) is too large to spatially resolve the molecular gas emission in HDF850.1. However the [CII] and underlying continuum observations (~1.2" x 0.8") show that the source is extended (hitherto, the interstellar medium has been spatially resolved only in extremely rare quasar host galaxies at such high redshift 10 ). A single Gaussian fit yields a deconvolved size of 0.9±0.3", or 5.7±1.9 kpc at the redshift of the source. Fig. 2 shows the maps of total [CII] emission (left) as well as the red-and blue-...

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Molecular Gas at High Redshift

Walter

Carilli

Daddi

2010

Reviews in Modern Astronomy

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Submillimeter Galaxies atz∼ 2: Evidence for Major Mergers and Constraints on Lifetimes, IMF, and CO‐H₂Conversion Factor

Cited by 691 publications

References 145 publications

Dusty star-forming galaxies at high redshift

Dusty star-forming galaxies at high redshift

The intense starburst HDF 850.1 in a galaxy overdensity at z ≈ 5.2 in the Hubble Deep Field

Molecular Gas at High Redshift

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Submillimeter Galaxies atz∼ 2: Evidence for Major Mergers and Constraints on Lifetimes, IMF, and CO‐H2Conversion Factor

Cited by 691 publications

References 145 publications

Dusty star-forming galaxies at high redshift

Dusty star-forming galaxies at high redshift

The intense starburst HDF 850.1 in a galaxy overdensity at z ≈ 5.2 in the Hubble Deep Field

Molecular Gas at High Redshift

Contact Info

Product

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Submillimeter Galaxies atz∼ 2: Evidence for Major Mergers and Constraints on Lifetimes, IMF, and CO‐H₂Conversion Factor