{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/alma-reveals-metals-yet-no-dust-within","title":"ALMA reveals metals yet no dust within multiple components in CR7","arxiv_id":"1709.06569","date":"2017-09-19","proceeding":null,"authors":["J. Matthee","D. Sobral","F. Boone","H. Röttgering","D. Schaerer","M. Girard","A. Pallottini","L. Vallini","A. Ferrara","B. Darvish","B. Mobasher"],"abstract":"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$_{\\rm IR} (T_d = 35 \\rm \\, K) < 3.1\\times10^{10}$ L$_{\\odot}$. This allows us to mitigate uncertainties in the dust-corrected SFR and derive SFRs for the three UV clumps A, B and C of 28, 5 and 7 M$_{\\odot}$ yr$^{-1}$. All clumps have [CII] luminosities consistent within the scatter observed in the local relation between SFR and L$_{\\rm [CII]}$, implying that strong Ly$\\alpha$ emission does not necessarily anti-correlate with [CII] luminosity. Combining our measurements with the literature, we show that galaxies with blue UV slopes have weaker [CII] emission at fixed SFR, potentially due to their lower metallicities and/or higher photoionisation. Comparison with hydrodynamical simulations suggests that CR7's 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.","url_abs":"http://arxiv.org/abs/1709.06569v2","url_pdf":"http://arxiv.org/pdf/1709.06569v2.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"alma-reveals-metals-yet-no-dust-within","repo_url":"https://github.com/laurence231/Astronomy","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}