Galaxy Stellar Mass Assembly between 0.2<z<2 from the S-COSMOS survey
O. Ilbert, M. Salvato, E. Le Floc'h, H. Aussel, P. Capak, H. J. McCracken, B. Mobasher, J. Kartaltepe, N. Scoville, D. B. Sanders, S. Arnouts, K. Bundy, P. Cass… 展开作者
O. Ilbert, M. Salvato, E. Le Floc'h, H. Aussel, P. Capak, H. J. McCracken, B. Mobasher, J. Kartaltepe, N. Scoville, D. B. Sanders, S. Arnouts, K. Bundy, P. Cassata, J. -P. Kneib, A. Koekemoer, O. Le Fevre, S. Lilly, J. Surace, Y. Taniguchi, L. Tasca, D. Thompson, L. Tresse, M. Zamojski, G. Zamorani, E. Zucca
备注：
37 pages, 29 figures, accepted for publication in ApJ
我们在COSMOS 2度^[2]场中，通过形态学和光谱类型来跟踪星系恒星质量集合。我们选取了196，000个F（3.6 μ m）> 1 μ Jy的星系，用精确的光度红移（sigma_（（zp-zs）/（1+zs））=0.008（i<22.5））计算了z=2 ~ z=0.2的恒星质量函数和质量密度。利用光谱分类，我们发现z~1是静止星系恒星质量集合的一个跃迁时期。它们的恒星质量密度在z=1.5-2和z=0.8-1之间增加1.1 dex（Δ t ~2.5 Gyr），但在z=0.8-1和z~0.1之间仅增加0.3 dex（Δ t ~ 6 Gyr）。然后，我们添加形态信息，发现80-90%的大质量静止星系（log（M）~11）在z<0.8时具有椭圆形态。因此，一个占主导地位的机制链接关闭的恒星形成和收购的椭圆形态在大质量星系。尽管如此，仍有相当一部分静止星系在低质量时呈现Spi/Irr形态（log（M）~9.5时为40-60%），但这一比例小于使用“晕淬灭”配方的半分析模型的预测。我们还分析了恒星形成星系的演化，并将它们分为“中等活动”和“高活动”星系。我们发现，质量最大的“高活动”星系首先结束了它们的高恒星形成率阶段。最后，在z<1时，大质量恒星形成星系的空间密度变得低于大质量椭圆星系的空间密度。因此，在z<1时，大质量椭圆星系形成过程中的“湿合并”速率必须非常迅速地下降，这可以解释在这些静止和大质量源的组装中观察到的减速。
英文摘要：
We follow the galaxy stellar mass assembly by morphological and spectral type in the COSMOS 2-deg^2 field. We derive the stellar mass functions and stellar mass densities from z=2 to z=0.2 using 196,000 galaxies selected at F(3.6 micron) > 1 microJy with accurate photometric redshifts (sigma_((zp-zs)/(1+zs))=0.008 at i<22.5). Using a spectral classification, we find that z~1 is an epoch of transition in the stellar mass assembly of quiescent galaxies. Their stellar mass density increases by 1.1 dex between z=1.5-2 and z=0.8-1 (Delta t ~2.5 Gyr), but only by 0.3 dex between z=0.8-1 and z~0.1 (Delta t ~ 6 Gyr). Then, we add the morphological information and find that 80-90% of the massive quiescent galaxies (log(M)~11) have an elliptical morphology at z<0.8. Therefore, a dominant mechanism links the shutdown of star formation and the acquisition of an elliptical morphology in massive galaxies. Still, a significant fraction of quiescent galaxies present a Spi/Irr morphology at low mass (40-60% at log(M)~9.5), but this fraction is smaller than predicted by semi-analytical models using a ``halo quenching'' recipe. We also analyze the evolution of star-forming galaxies and split them into ``intermediate activity'' and ``high activity'' galaxies. We find that the most massive ``high activity'' galaxies end their high star formation rate phase first. Finally, the space density of massive star-forming galaxies becomes lower than the space density of massive elliptical galaxies at z<1. As a consequence, the rate of ``wet mergers'' involved in the formation of the most massive ellipticals must decline very rapidly at z<1, which could explain the observed slow down in the assembly of these quiescent and massive sources.
One of the main predictions of excursion set theory is that the clustering of dark matter haloes only depends on halo mass. However, it has been long established that the clustering of haloes also depends on other properties, including formation time, concentration, and spin; this effect is commonly known as halo assembly bias. We use a suite of gravity-only simulations to study the dependence of halo assembly bias on cosmology; these simulations cover cosmological parameters spanning 10$σ$ around state-of-the-art best-fitting values, including standard extensions of the $Λ$CDM paradigm such a…
Constraining the star formation and the assembly histories of normal and compact early-type galaxies at 1<z<2
[摘要]我们提出了一项基于62个早型星系（ETG）样本的研究，其样本为0.9<z_spec<2，旨在限制它们过去的恒星形成和质量组装历史。该样品是由正常的ETG的有效半径相当于当地的平均半径和紧凑的ETG的有效半径从2到6倍小。我们没有发现证据的ETG的紧凑性依赖于他们的恒星质量。我们发现正常ETG的恒星质量形成于z_form<3，而致密ETG的恒星含量形成于2<z_form <10 with a large fraction of them characterized by z_form>5。在z_form>5时形成的早期恒星聚集在致密且质量更大（M_*>10^11 M_sun）的ETG中，而在z_form<3时形成的晚期恒星或在随后的恒星形成阶段形成的恒星聚集在致密和正常ETG中。因此，恒星星族越老，宿主星系的质量就越大，但反之则不然。这表明形成时代可能在大规模ETG的形成中发挥作用，而不是质量本身。正常<z>~1.5 ETG可能是高z致密球体通过随后的干合并扩大的后代的一般方案是不兼容的，目前的模型预测的干合并的数量比所需的数量级低两个数量级。此外，我们没有发现证据支持依赖于它们的组装红移星系的紧凑性。最后，我们提出了一个简单的基于耗散富气合并的ETG恒星质量的形成和组装方案，该方案可以定性地解释在~1.5观测到的正常ETG和致密ETG的共存<z…
The combination of galaxy-galaxy lensing (GGL) and galaxy clustering is a promising route to measuring the amplitude of matter clustering and testing modified gravity theories of cosmic acceleration. Halo occupation distribution (HOD) modeling can extend the approach down to nonlinear scales, but galaxy assembly bias could introduce systematic errors by causing the HOD to vary with large scale environment at fixed halo mass. We investigate this problem using the mock galaxy catalogs created by Hearin & Watson (2013, HW13), which exhibit significant assembly bias because galaxy luminosity is ti…
We investigate the use of the halo mass-gap statistic --- defined as the logarithmic difference in mass between the host halo and its most massive satellite subhalo --- as a probe of halo age and concentration. A cosmological N-body simulation is used to study N ~25, 000 group/cluster sized halos in the mass range 10^12.5 < M_halo/M_sol < 10^14.5. In agreement with previous work, we find that halo mass-gap is related to halo formation time and concentration. On average, older and more highly concentrated halos have larger halo mass-gaps, and this trend is stronger than the mass-concentration r…
We employ the Delphi semi-analytical model to study the impact of black hole growth on high-redshift galaxies, both in terms of the observed UV luminosity and of the star formation rate. To do this, firstly, we assess the contribution of AGN to the total galaxy UV luminosity as a function of stellar mass and redshift. We find that for $M_{UV} < -24$ mag and $z \approx 5 - 6$ the galaxies for which the black hole UV luminosity outshines the stellar UV emission become the majority, and we estimate their duty cycle. Secondly, we study the evolution of the AGN and stellar luminosity functions (LFs…
Characterizing the assembly of dark matter halos with protohalo size histories: I. Redshift evolution, relation to descendant halos, and halo assembly bias
Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；University of Massachusetts Amherst（马萨诸塞大学阿默斯特分校）；University of Science and Technology of China（中国科学技术大学）；Shanghai Jiao Tong University（上海交通大学）
Roman CCS White Paper: Tracing stellar mass assembly and emerging quiescence at cosmic noon -- the case for deep imaging with all of Roman's wide filters in the HLTDS
本文论证了在 Roman 望远镜 HLTDS 中使用除 F146 外所有宽滤光片进行深度成像的必要性，以推动河外深场科学并改进 SN Ia 宇宙学系统学。
Disentangling the assembly of the central and diffuse stellar components in galaxy clusters through dynamical friction and tidal stripping
University of Nottingham（诺丁汉大学）；École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院）；Universidad de La Laguna（拉帕尔马大学）；Instituto de Astrofísica de Canarias（加那利天体物理研究所）；Universidad Autónoma de Madrid（马德里自治大学）
