论文标题
巨大的Metrewave射电望远镜Cold-Hi $ z \大约1 $调查
The Giant Metrewave Radio Telescope Cold-HI AT $z\approx1$ Survey
论文作者
论文摘要
我们描述了$ z \ of1 $（gmrt-cat $ z $ 1）调查的巨型内阁射电望远镜冷hi的设计，数据分析和基本结果，在Deep2 Survey Fields中进行了510小时升级的GMRT GMRT HI 21 cm HI 21 cm的星系调查。 GMRT-CAT $ Z $ 1的调查旨在表征在宇宙中峰值恒星形成活性时期的星系中的HI，这是星系演变的关键时期。我们在$ z = 0.74-1.45 $的11,419蓝色星系星系中获得了高质量的HI 21厘米光谱，在Deep2子场的七个点中获得了高质量的HI频谱。 We detect the stacked HI 21 cm emission signal of the 11,419 star-forming galaxies, which have an average stellar mass of $M_* \approx 10^{10} M_\odot$, at $7.1σ$ statistical significance, obtaining an average HI mass of $\langle M_{HI}\rangle=(13.7\pm1.9)\times10^{9} m_ \ odot $。这显着高于$ \ langle m_ {hi} \ rangle =（3.96 \ pm 0.17）\ times10^{9} m_ \ odot $，在$ z \ 0 $中，带有相同的恒星质量分配。我们堆叠11,419个星系的剩余框架1.4 GHz连续排放，以推断出$ 8.07 \ pm0.82 m_ \ odot yr^{ - 1} $的平均恒星形成率（SFR）。将我们的平均HI质量和平均SFR估计结合在一起，产生的HI耗竭时间尺度为$ 1.70 \ pm0.29 $ gyr，用于$ z \ 1 $，$ \ $ \ $ \ $ \ 3 $ \ 3 $乘以本地星系低约3美元。因此，我们发现，尽管$ z \ of1 $处的主要序列星系具有很高的HI质量，但在没有海外乳层培养基的快速气体积聚的情况下，它们的短时间耗尽时间尺度可能会导致其恒星形成活性的淬火。
We describe the design, data analysis, and basic results of the Giant Metrewave Radio Telescope Cold-HI AT $z\approx1$ (GMRT-CAT$z$1) survey, a 510-hour upgraded GMRT HI 21 cm emission survey of galaxies at $z=0.74-1.45$ in the DEEP2 survey fields. The GMRT-CAT$z$1 survey is aimed at characterising HI in galaxies during and just after the epoch of peak star-formation activity in the Universe, a key epoch in galaxy evolution. We obtained high-quality HI 21 cm spectra for 11,419 blue star-forming galaxies at $z=0.74-1.45$, in seven pointings on the DEEP2 subfields. We detect the stacked HI 21 cm emission signal of the 11,419 star-forming galaxies, which have an average stellar mass of $M_* \approx 10^{10} M_\odot$, at $7.1σ$ statistical significance, obtaining an average HI mass of $\langle M_{HI}\rangle=(13.7\pm1.9)\times10^{9} M_\odot$. This is significantly higher than the average HI mass of $\langle M_{HI} \rangle=(3.96 \pm 0.17)\times10^{9} M_\odot$ in star-forming galaxies at $z \approx 0$ with an identical stellar-mass distribution. We stack the rest-frame 1.4 GHz continuum emission of our 11,419 galaxies to infer an average star-formation rate (SFR) of $8.07\pm0.82 M_\odot yr^{-1}$. Combining our average HI mass and average SFR estimates yields an HI depletion timescale of $1.70\pm0.29$ Gyr, for star-forming galaxies at $z\approx1$, $\approx3$ times lower than that of local galaxies. We thus find that, although main-sequence galaxies at $z\approx1$ have a high HI mass, their short HI depletion timescale is likely to cause quenching of their star-formation activity in the absence of rapid gas accretion from the circumgalactic medium.
