@miki

CII emission in z ~ 6 strongly lensed, star-forming galaxies

, , , , , , , and . (2016)cite arxiv:1603.02277Comment: 5 pages, submitted to MNRAS.

Abstract

The far-infrared fine-structure line CII at 1900.5GHz is known to be one of the brightest cooling lines in local galaxies, and therefore it has been suggested to be an efficient tracer for star-formation in very high-redshift galaxies. However, recent results for galaxies at $z>6$ have yielded numerous non-detections in star-forming galaxies, except for quasars and submillimeter galaxies. We report the results of ALMA observations of two lensed, star-forming galaxies at $z = 6.029$ and $z=6.703$. The galaxy A383-5.1 (star formation rate SFR of 3.2 M$_ødot$yr$^-1$ and magnification of $= 11.4$) shows a line detection with $L_CII = 8.3\times10^6$ L$_ødot$, making it the so far lowest $L_CII$ ever detected at $z>6$. For MS0451-H (SFR = 0.4M$_ødot$yr$^-1$ and $= 100\pm20$) we provide an upper limit of $L_CII < 3\times10^5$ L$_ødot$, which is 1\,dex below the local SFR-$L_CII$ relations. The results are consistent with predictions for low-metallicity galaxies at $z>6$, however, other effects could also play a role in terms of decreasing $L_CII$. The detection of A383-5.1 is encouraging and suggests that detections are possible, but much fainter than initially predicted.

Description

[1603.02277] [CII] emission in z ~ 6 strongly lensed, star-forming galaxies

Links and resources

Tags