%0 Generic %1 pentericci2016tracing %A Pentericci, L. %A Carniani, S. %A Castellano, M. %A Fontana, A. %A Maiolino, R. %A Guaita, L. %A Vanzella, E. %A Grazian, A. %A Santini, P. %A Yan, H. %A Cristiani, S. %A Conselice, C. %A Giavalisco, M. %A Hathi, N. %A Koekemoer, A. %D 2016 %K [CII] detection high-z %T Tracing the reionization epoch with ALMA: CII emission in z~7 galaxies %U http://arxiv.org/abs/1608.08837 %X We present new results on CII158$\mu$ m emission from four galaxies in the reionization epoch. These galaxies were previously confirmed to be at redshifts between 6.6 and 7.15 from the presence of the Ly$\alpha$ emission line in their spectra. The Ly$\alpha$ emission line is redshifted by 100-200 km/s compared to the systemic redshift given by the CII line. These velocity offsets are smaller than what is observed in z~3 Lyman break galaxies with similar UV luminosities and emission line properties. Smaller velocity shifts reduce the visibility of Ly$\alpha$ and hence somewhat alleviate the need for a very neutral IGM at z~7 to explain the drop in the fraction of Ly$\alpha$ emitters observed at this epoch. The galaxies show CII emission with LCII=0.6-1.6 x10$^8 L_ødot$: these luminosities place them consistently below the SFR-LCII relation observed for low redshift star forming and metal poor galaxies and also below z =5.5 Lyman break galaxies with similar star formation rates. We argue that previous undetections of CII in z~7 galaxies with similar or smaller star formation rates are due to selection effects: previous targets were mostly strong Ly$\alpha$ emitters and therefore probably metal poor systems, while our galaxies are more representative of the general high redshift star forming population .

@misc{pentericci2016tracing, abstract = {We present new results on [CII]158$\mu$ m emission from four galaxies in the reionization epoch. These galaxies were previously confirmed to be at redshifts between 6.6 and 7.15 from the presence of the Ly$\alpha$ emission line in their spectra. The Ly$\alpha$ emission line is redshifted by 100-200 km/s compared to the systemic redshift given by the [CII] line. These velocity offsets are smaller than what is observed in z~3 Lyman break galaxies with similar UV luminosities and emission line properties. Smaller velocity shifts reduce the visibility of Ly$\alpha$ and hence somewhat alleviate the need for a very neutral IGM at z~7 to explain the drop in the fraction of Ly$\alpha$ emitters observed at this epoch. The galaxies show [CII] emission with L[CII]=0.6-1.6 x10$^8 L_\odot$: these luminosities place them consistently below the SFR-L[CII] relation observed for low redshift star forming and metal poor galaxies and also below z =5.5 Lyman break galaxies with similar star formation rates. We argue that previous undetections of [CII] in z~7 galaxies with similar or smaller star formation rates are due to selection effects: previous targets were mostly strong Ly$\alpha$ emitters and therefore probably metal poor systems, while our galaxies are more representative of the general high redshift star forming population .}, added-at = {2016-09-01T10:08:14.000+0200}, author = {Pentericci, L. and Carniani, S. and Castellano, M. and Fontana, A. and Maiolino, R. and Guaita, L. and Vanzella, E. and Grazian, A. and Santini, P. and Yan, H. and Cristiani, S. and Conselice, C. and Giavalisco, M. and Hathi, N. and Koekemoer, A.}, biburl = {https://www.bibsonomy.org/bibtex/223df1c17080a24e722fe5753b563e64a/miki}, description = {[1608.08837] Tracing the reionization epoch with ALMA: [CII] emission in z~7 galaxies}, interhash = {905eb8706a5acd2dd23f99eae4a088c8}, intrahash = {23df1c17080a24e722fe5753b563e64a}, keywords = {[CII] detection high-z}, note = {cite arxiv:1608.08837Comment: To appear in ApJL}, timestamp = {2016-09-01T10:08:14.000+0200}, title = {Tracing the reionization epoch with ALMA: [CII] emission in z~7 galaxies}, url = {http://arxiv.org/abs/1608.08837}, year = 2016 }