%0 Generic %1 knudsen2016merger %A Knudsen, Kirsten K. %A Watson, Darach %A Frayer, David %A Christensen, Lise %A Gallazzi, Anna %A Michalowski, Michal J. %A Richard, Johan %A Zavala, Jesus %D 2016 %K dusty galaxy high-z %T A merger in the dusty, $z=7.5$ galaxy A1689-zD1? %U http://arxiv.org/abs/1603.03222 %X The gravitationally-lensed galaxy A1689-zD1 is one of the most distant spectroscopically confirmed sources ($z=7.5$). It is the earliest known galaxy where the interstellar medium (ISM) has been detected; dust emission was detected with the Atacama Large Millimetre Array (ALMA). A1689-zD1 is also unusual among high-redshift dust emitters as it is a sub-L* galaxy and is therefore a good prospect for the detection of gaseous ISM in a more typical galaxy at this redshift. We observed A1689-zD1 with ALMA in bands 6 and 7 and with the Green Bank Telescope (GBT) in band Q. We map the mm thermal dust emission, confirming the large dust emission found before, and finding two spatial components with sizes about 0.4-1.7 kpc (lensing-corrected). The rough spatial morphology is similar to what is observed in the near-infrared with HST and points to a perturbed dynamical state, perhaps indicative of a major merger or a disc in early formation. The ALMA photometry is used to constrain the far-infrared spectral energy distribution, yielding a moderate dust temperature ($T_dust 35$ K for $= 1.65$). We do not detect the CO(3-2) line in the GBT data with a 95% upper limit of 0.3mJy observed. We find a slight excess emission in ALMA band 6 at 220.9 GHz. If this excess is real, it is likely due to emission from the CII 158.8 $\mu$m line at $z_CII = 7.603$. The stringent upper limits on the CII and CO(3-2) line luminosities suggest a high ISM gas density in A1689-zD1.

@misc{knudsen2016merger, abstract = {The gravitationally-lensed galaxy A1689-zD1 is one of the most distant spectroscopically confirmed sources ($z=7.5$). It is the earliest known galaxy where the interstellar medium (ISM) has been detected; dust emission was detected with the Atacama Large Millimetre Array (ALMA). A1689-zD1 is also unusual among high-redshift dust emitters as it is a sub-L* galaxy and is therefore a good prospect for the detection of gaseous ISM in a more typical galaxy at this redshift. We observed A1689-zD1 with ALMA in bands 6 and 7 and with the Green Bank Telescope (GBT) in band Q. We map the mm thermal dust emission, confirming the large dust emission found before, and finding two spatial components with sizes about 0.4-1.7 kpc (lensing-corrected). The rough spatial morphology is similar to what is observed in the near-infrared with HST and points to a perturbed dynamical state, perhaps indicative of a major merger or a disc in early formation. The ALMA photometry is used to constrain the far-infrared spectral energy distribution, yielding a moderate dust temperature ($T_{\rm dust} \sim 35$ K for $\beta = 1.65$). We do not detect the CO(3-2) line in the GBT data with a 95% upper limit of 0.3mJy observed. We find a slight excess emission in ALMA band 6 at 220.9 GHz. If this excess is real, it is likely due to emission from the [CII] 158.8 $\mu$m line at $z_{\rm [CII]} = 7.603$. The stringent upper limits on the [CII] and CO(3-2) line luminosities suggest a high ISM gas density in A1689-zD1.}, added-at = {2016-03-11T07:27:01.000+0100}, author = {Knudsen, Kirsten K. and Watson, Darach and Frayer, David and Christensen, Lise and Gallazzi, Anna and Michalowski, Michal J. and Richard, Johan and Zavala, Jesus}, biburl = {https://www.bibsonomy.org/bibtex/2857c97ebdee441691f7cc792e48ca9e4/miki}, description = {[1603.03222] A merger in the dusty, $z=7.5$ galaxy A1689-zD1?}, interhash = {218b981bcd5b50d804dcaac1c237afa7}, intrahash = {857c97ebdee441691f7cc792e48ca9e4}, keywords = {dusty galaxy high-z}, note = {cite arxiv:1603.03222Comment: 10 pages, submitted to MNRAS}, timestamp = {2016-03-11T07:27:01.000+0100}, title = {A merger in the dusty, $z=7.5$ galaxy A1689-zD1?}, url = {http://arxiv.org/abs/1603.03222}, year = 2016 }