Rights statement: This is an author-created, un-copyedited version of an article accepted for publication/published in The Astrophysical Journal. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi: 10.3847/1538-4357/aa9931
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - ALMA reveals metals yet no dust within multiple components in CR7
AU - Matthee, J.
AU - Sobral, D.
AU - Boone, F.
AU - Röttgering, H.
AU - Schaerer, D.
AU - Girard, M.
AU - Pallottini, A.
AU - Vallini, L.
AU - Ferrara, A.
AU - Darvish, B.
AU - Mobasher, B.
N1 - This is an author-created, un-copyedited version of an article accepted for publication/published in The Astrophysical Journal. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi: 10.3847/1538-4357/aa9931
PY - 2017/12/20
Y1 - 2017/12/20
N2 - We present spectroscopic follow-up observations of CR7 with ALMA, targeted at constraining the infrared (IR) continuum and [CII]$_{158 \mu \rm m}$ line-emission at high spatial resolution matched to the HST/WFC3 imaging. CR7 is a luminous Ly$\alpha$ emitting galaxy at $z=6.6$ that consists of three separated UV-continuum components. Our observations reveal several well-separated components of [CII] emission. The two most luminous components in [CII] coincide with the brightest UV components (A and B), blue-shifted by $\approx 150$ km s$^{-1}$ with respect to the peak of Ly$\alpha$ emission. Other [CII] components are observed close to UV clumps B and C and are blue-shifted by $\approx300$ and $\approx80$ km s$^{-1}$ with respect to the systemic redshift. We do not detect FIR continuum emission due to dust with a 3$\sigma$ limiting luminosity L$_{\rm IR} (T_d = 35 \rm \, K) CR7s clumps have metallicities of $0.1\rm Z/Z_{\odot}0.2$. The observed ISM structure of CR7 indicates that we are likely witnessing the build up of a central galaxy in the early Universe through complex accretion of satellites.
AB - We present spectroscopic follow-up observations of CR7 with ALMA, targeted at constraining the infrared (IR) continuum and [CII]$_{158 \mu \rm m}$ line-emission at high spatial resolution matched to the HST/WFC3 imaging. CR7 is a luminous Ly$\alpha$ emitting galaxy at $z=6.6$ that consists of three separated UV-continuum components. Our observations reveal several well-separated components of [CII] emission. The two most luminous components in [CII] coincide with the brightest UV components (A and B), blue-shifted by $\approx 150$ km s$^{-1}$ with respect to the peak of Ly$\alpha$ emission. Other [CII] components are observed close to UV clumps B and C and are blue-shifted by $\approx300$ and $\approx80$ km s$^{-1}$ with respect to the systemic redshift. We do not detect FIR continuum emission due to dust with a 3$\sigma$ limiting luminosity L$_{\rm IR} (T_d = 35 \rm \, K) CR7s clumps have metallicities of $0.1\rm Z/Z_{\odot}0.2$. The observed ISM structure of CR7 indicates that we are likely witnessing the build up of a central galaxy in the early Universe through complex accretion of satellites.
KW - Dark ages, reionization, first stars
KW - galaxies: formation
KW - galaxies: high-redshift
KW - galaxies: ISM
KW - galaxies: kinematics and dynamics
KW - STAR-FORMING GALAXIES
KW - COLLAPSE BLACK-HOLE
KW - ALPHA EMITTER CR7
KW - INFRARED LINE EMISSION
KW - HIGH-REDSHIFT GALAXIES
KW - ULTRA DEEP FIELD
KW - CII EMISSION
KW - LY-ALPHA
KW - LUMINOSITY FUNCTION
U2 - 10.3847/1538-4357/aa9931
DO - 10.3847/1538-4357/aa9931
M3 - Journal article
VL - 851
JO - The Astrophysical Journal
JF - The Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 145
ER -