@article{sobral_nature_2017,
	title = {On the nature of the luminous {Lya} emitter {CR7} and its {UV} components: physical conditions and {JWST} predictions},
	volume = {1710},
	shorttitle = {On the nature of the luminous {Lya} emitter {CR7} and its {UV} components},
	url = {http://adsabs.harvard.edu/abs/2017arXiv171008422S},
	abstract = {We present new HST/WFC3 grism observations and re-analyse VLT data to 
unveil the continuum, variability and rest-frame UV lines of the three
UV components of the most luminous Ly-alpha (Lya) emitter at z=6.6,
COSMOS Redshift 7 (CR7). Our re-reduced, flux calibrated X-SHOOTER
spectra of CR7 reveal a tentative detection of HeII with
F(HeII)=\$(1.8{\textbackslash}pm0.7){\textbackslash}times10{\textasciicircum}\{-17\}\$erg s\${\textasciicircum}\{-1\}\$cm\${\textasciicircum}\{-2\}\$ and we identify
the signal ({\textasciitilde}2.6\${\textbackslash}sigma\$) as coming only from observations obtained
along the major axis of Lya emission. There is a change of +0.2-0.5mag
in UltraVISTA J band data for CR7 from DR2 to DR3, which virtually
eliminates the strong J-band excess previously interpreted as being
caused by HeII. Our WFC3 grism spectra provide a significant detection
of the UV continuum of CR7's clump A, yielding an excellent fit to a
power law with \${\textbackslash}beta=-2.4{\textbackslash}pm0.4\$ and \$M\_\{UV\}=-21.7{\textbackslash}pm0.3\$, consistent
with no variability. HST grism data fail to detect any rest-frame UV
line in clump A above 3\${\textbackslash}sigma\$, yielding
F(HeII){\textless}\$0.5{\textbackslash}times10{\textasciicircum}\{-17\}\$erg s\${\textasciicircum}\{-1\}\$cm\${\textasciicircum}\{-2\}\$ (EW\$\_0\${\textless}10A) at a
95\% confidence level. Clump C is tentatively identified as a potential
variable and high ionisation source with
F(HeII)=\$(1.0{\textbackslash}pm0.4){\textbackslash}times10{\textasciicircum}\{-17\}\$erg s\${\textasciicircum}\{-1\}\$cm\${\textasciicircum}\{-2\}\$. We perform
CLOUDY modelling to constrain the metallicity and the ionising nature of
CR7, and also make emission-line predictions for JWST/NIRSpec. CR7 seems
to be actively forming stars without any clear AGN activity in clumps A
and B, consistent with a metallicity of {\textasciitilde}0.05-0.2 Z\$\_\{{\textbackslash}odot\}\$ and with
component A experiencing the most massive starburst. Component C may
host a high ionisation source/AGN. Our results highlight the need for
spatially resolved information to study the complex formation and
assembly of early galaxies within the epoch of re-ionisation.},
	journal = {ArXiv e-prints},
	author = {Sobral, David and Matthee, Jorryt and Brammer, Gabriel and Ferrara, Andrea and Alegre, Lara and Rottgering, Huub and Schaerer, Daniel and Mobasher, Bahram and Darvish, Behnam},
	month = oct,
	year = {2017},
	keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
	pages = {arXiv:1710.08422},
}

{"_id":"aRGaLS6oswmYzuKpp","bibbaseid":"sobral-matthee-brammer-ferrara-alegre-rottgering-schaerer-mobasher-etal-onthenatureoftheluminouslyaemittercr7anditsuvcomponentsphysicalconditionsandjwstpredictions-2017","author_short":["Sobral, D.","Matthee, J.","Brammer, G.","Ferrara, A.","Alegre, L.","Rottgering, H.","Schaerer, D.","Mobasher, B.","Darvish, B."],"bibdata":{"bibtype":"article","type":"article","title":"On the nature of the luminous Lya emitter CR7 and its UV components: physical conditions and JWST predictions","volume":"1710","shorttitle":"On the nature of the luminous Lya emitter CR7 and its UV components","url":"http://adsabs.harvard.edu/abs/2017arXiv171008422S","abstract":"We present new HST/WFC3 grism observations and re-analyse VLT data to unveil the continuum, variability and rest-frame UV lines of the three UV components of the most luminous Ly-alpha (Lya) emitter at z=6.6, COSMOS Redshift 7 (CR7). Our re-reduced, flux calibrated X-SHOOTER spectra of CR7 reveal a tentative detection of HeII with F(HeII)=\\$(1.8{\\textbackslash}pm0.7){\\textbackslash}times10{\\textasciicircum}\\{-17\\}\\$erg s\\${\\textasciicircum}\\{-1\\}\\$cm\\${\\textasciicircum}\\{-2\\}\\$ and we identify the signal (\\textasciitilde2.6\\${\\textbackslash}sigma\\$) as coming only from observations obtained along the major axis of Lya emission. There is a change of +0.2-0.5mag in UltraVISTA J band data for CR7 from DR2 to DR3, which virtually eliminates the strong J-band excess previously interpreted as being caused by HeII. Our WFC3 grism spectra provide a significant detection of the UV continuum of CR7's clump A, yielding an excellent fit to a power law with \\${\\textbackslash}beta=-2.4{\\textbackslash}pm0.4\\$ and \\$M_\\{UV\\}=-21.7{\\textbackslash}pm0.3\\$, consistent with no variability. HST grism data fail to detect any rest-frame UV line in clump A above 3\\${\\textbackslash}sigma\\$, yielding F(HeII)\\textless\\$0.5{\\textbackslash}times10{\\textasciicircum}\\{-17\\}\\$erg s\\${\\textasciicircum}\\{-1\\}\\$cm\\${\\textasciicircum}\\{-2\\}\\$ (EW\\$_0\\$\\textless10A) at a 95% confidence level. Clump C is tentatively identified as a potential variable and high ionisation source with F(HeII)=\\$(1.0{\\textbackslash}pm0.4){\\textbackslash}times10{\\textasciicircum}\\{-17\\}\\$erg s\\${\\textasciicircum}\\{-1\\}\\$cm\\${\\textasciicircum}\\{-2\\}\\$. We perform CLOUDY modelling to constrain the metallicity and the ionising nature of CR7, and also make emission-line predictions for JWST/NIRSpec. CR7 seems to be actively forming stars without any clear AGN activity in clumps A and B, consistent with a metallicity of \\textasciitilde0.05-0.2 Z\\$_\\{{\\textbackslash}odot\\}\\$ and with component A experiencing the most massive starburst. Component C may host a high ionisation source/AGN. Our results highlight the need for spatially resolved information to study the complex formation and assembly of early galaxies within the epoch of re-ionisation.","journal":"ArXiv e-prints","author":[{"propositions":[],"lastnames":["Sobral"],"firstnames":["David"],"suffixes":[]},{"propositions":[],"lastnames":["Matthee"],"firstnames":["Jorryt"],"suffixes":[]},{"propositions":[],"lastnames":["Brammer"],"firstnames":["Gabriel"],"suffixes":[]},{"propositions":[],"lastnames":["Ferrara"],"firstnames":["Andrea"],"suffixes":[]},{"propositions":[],"lastnames":["Alegre"],"firstnames":["Lara"],"suffixes":[]},{"propositions":[],"lastnames":["Rottgering"],"firstnames":["Huub"],"suffixes":[]},{"propositions":[],"lastnames":["Schaerer"],"firstnames":["Daniel"],"suffixes":[]},{"propositions":[],"lastnames":["Mobasher"],"firstnames":["Bahram"],"suffixes":[]},{"propositions":[],"lastnames":["Darvish"],"firstnames":["Behnam"],"suffixes":[]}],"month":"October","year":"2017","keywords":"Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics","pages":"arXiv:1710.08422","bibtex":"@article{sobral_nature_2017,\n\ttitle = {On the nature of the luminous {Lya} emitter {CR7} and its {UV} components: physical conditions and {JWST} predictions},\n\tvolume = {1710},\n\tshorttitle = {On the nature of the luminous {Lya} emitter {CR7} and its {UV} components},\n\turl = {http://adsabs.harvard.edu/abs/2017arXiv171008422S},\n\tabstract = {We present new HST/WFC3 grism observations and re-analyse VLT data to \nunveil the continuum, variability and rest-frame UV lines of the three\nUV components of the most luminous Ly-alpha (Lya) emitter at z=6.6,\nCOSMOS Redshift 7 (CR7). Our re-reduced, flux calibrated X-SHOOTER\nspectra of CR7 reveal a tentative detection of HeII with\nF(HeII)=\\$(1.8{\\textbackslash}pm0.7){\\textbackslash}times10{\\textasciicircum}\\{-17\\}\\$erg s\\${\\textasciicircum}\\{-1\\}\\$cm\\${\\textasciicircum}\\{-2\\}\\$ and we identify\nthe signal ({\\textasciitilde}2.6\\${\\textbackslash}sigma\\$) as coming only from observations obtained\nalong the major axis of Lya emission. There is a change of +0.2-0.5mag\nin UltraVISTA J band data for CR7 from DR2 to DR3, which virtually\neliminates the strong J-band excess previously interpreted as being\ncaused by HeII. Our WFC3 grism spectra provide a significant detection\nof the UV continuum of CR7's clump A, yielding an excellent fit to a\npower law with \\${\\textbackslash}beta=-2.4{\\textbackslash}pm0.4\\$ and \\$M\\_\\{UV\\}=-21.7{\\textbackslash}pm0.3\\$, consistent\nwith no variability. HST grism data fail to detect any rest-frame UV\nline in clump A above 3\\${\\textbackslash}sigma\\$, yielding\nF(HeII){\\textless}\\$0.5{\\textbackslash}times10{\\textasciicircum}\\{-17\\}\\$erg s\\${\\textasciicircum}\\{-1\\}\\$cm\\${\\textasciicircum}\\{-2\\}\\$ (EW\\$\\_0\\${\\textless}10A) at a\n95\\% confidence level. Clump C is tentatively identified as a potential\nvariable and high ionisation source with\nF(HeII)=\\$(1.0{\\textbackslash}pm0.4){\\textbackslash}times10{\\textasciicircum}\\{-17\\}\\$erg s\\${\\textasciicircum}\\{-1\\}\\$cm\\${\\textasciicircum}\\{-2\\}\\$. We perform\nCLOUDY modelling to constrain the metallicity and the ionising nature of\nCR7, and also make emission-line predictions for JWST/NIRSpec. CR7 seems\nto be actively forming stars without any clear AGN activity in clumps A\nand B, consistent with a metallicity of {\\textasciitilde}0.05-0.2 Z\\$\\_\\{{\\textbackslash}odot\\}\\$ and with\ncomponent A experiencing the most massive starburst. Component C may\nhost a high ionisation source/AGN. Our results highlight the need for\nspatially resolved information to study the complex formation and\nassembly of early galaxies within the epoch of re-ionisation.},\n\tjournal = {ArXiv e-prints},\n\tauthor = {Sobral, David and Matthee, Jorryt and Brammer, Gabriel and Ferrara, Andrea and Alegre, Lara and Rottgering, Huub and Schaerer, Daniel and Mobasher, Bahram and Darvish, Behnam},\n\tmonth = oct,\n\tyear = {2017},\n\tkeywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},\n\tpages = {arXiv:1710.08422},\n}\n\n","author_short":["Sobral, D.","Matthee, J.","Brammer, G.","Ferrara, A.","Alegre, L.","Rottgering, H.","Schaerer, D.","Mobasher, B.","Darvish, B."],"key":"sobral_nature_2017","id":"sobral_nature_2017","bibbaseid":"sobral-matthee-brammer-ferrara-alegre-rottgering-schaerer-mobasher-etal-onthenatureoftheluminouslyaemittercr7anditsuvcomponentsphysicalconditionsandjwstpredictions-2017","role":"author","urls":{"Paper":"http://adsabs.harvard.edu/abs/2017arXiv171008422S"},"keyword":["Astrophysics - Astrophysics of Galaxies","Astrophysics - Cosmology and Nongalactic Astrophysics"],"metadata":{"authorlinks":{}}},"bibtype":"article","biburl":"https://bibbase.org/zotero/polyphant","dataSources":["7gvjSdWrEu7z5vjjj"],"keywords":["astrophysics - astrophysics of galaxies","astrophysics - cosmology and nongalactic astrophysics"],"search_terms":["nature","luminous","lya","emitter","cr7","components","physical","conditions","jwst","predictions","sobral","matthee","brammer","ferrara","alegre","rottgering","schaerer","mobasher","darvish"],"title":"On the nature of the luminous Lya emitter CR7 and its UV components: physical conditions and JWST predictions","year":2017}