我们提出了一种形式主义来推断合并的存在，通过比较所观察到的星系恒星质量函数（MF）的时间导数的MF预期从星系中的恒星形成率（SFR）作为质量和时间的函数的变化。我们给出了在9<logM<12和0<z =3范围内SFR作为恒星质量和时间的函数<5. We show that at z>，平均SFR是恒星质量的幂律（SFR~M^0.6）。在这个红移的最大质量天体的平均SFR是100-500 Msun/yr。在z~3处，SFR在高质量端开始下降。随着z进一步减小，SFR在质量逐渐降低（缩小）时下降，在高质量（logM>11）星系中下降最快。SFR开始偏离幂律形式时的质量（断裂质量）从z~5时的logM~13平滑地进展到z~0.5时的logM~10.9。突变质量随红移的变化为M（z）=2.7x10^10（1+z）^2.1。我们直接观察SFH和质量之间的关系。更大质量的星系有更陡和更早的SF，它们的SFR峰值更早和更高，并且接下来的衰变有更短的e折叠时间。在z~4的高质量星系中观测到的SFR足以解释它们数密度的快速增加。在很大的不确定性，在最多0.8主要合并每陀螺仪是一致的高Z数据，但足以将大多数高质量的对象到椭圆形的同期与他们的主要恒星形成插曲。相比之下，在z为11时<1.5 and at logM>，合并对数密度的相对增加贡献了0.1-0.2 Gyr^-1（在1.5>z>0时，每个大质量天体约有1次大合并）。在10<logM<11时，星系在高z的合并中最好被摧毁，而在稍后的时间里，它们的数量变化变成正值。这显示了其他观测所建议的红色序列的自上而下的积累。
英文摘要：
We present a formalism to infer the presence of merging by comparing the time derivative of the observed galaxy stellar mass function (MF) to the change of the MF expected from the star formation rate (SFR) in galaxies as a function of mass and time. We present the SFR in as a function of stellar mass and time spanning 9<logM<12 and 0<z<5. We show that at z>=3 the average SFR, is a power law of stellar mass (SFR~M^0.6). The average SFR in the most massive objects at this redshift is 100-500 Msun/yr. At z~3, the SFR starts to drop at the high mass end. As z decreases further, the SFR drops at progressively lower masses (downsizing), dropping most rapidly for high mass (logM>11) galaxies. The mass at which the SFR starts to deviate from the power-law form (break mass) progresses smoothly from logM~13 at z~5 to logM~10.9 at z~0.5. The break mass evolves with redshift as M(z)=2.7x10^10 (1+z)^2.1. We directly observe a relationship between SFH and mass. More massive galaxies have steeper and earlier onsets of SF, their SFR peaks earlier and higher, and the following decay has a shorter e-folding time. The SFR observed in high mass galaxies at z~4 is sufficient to explain their rapid increase in number density. Within large uncertainties, at most 0.8 major mergers per Gyr are consistent with the high-z data, yet enough to transform most high mass objects into ellipticals contemporaneously with their major star formation episode. In contrast, at z<1.5 and at logM>11, mergers contribute 0.1-0.2 Gyr^-1 to the relative increase in number density (~1 major merger per massive object at 1.5>z>0). At 10<logM<11, galaxies are being preferably destroyed in mergers at high z, while at later times the change in their numbers turns positive. This shows the top-down buildup of the red sequence suggested by other observations.
CK Vul (Nova Vul 1670) is one of the most mysterious objects among erupting stellar objects. Past studies have suggested that CK Vul is a final helium-flash object resembling V605 Aql and V4334 Sgr (Sakurai's object). The peculiar outburst light curve of CK Vul, however, had no similar counterpart among the known eruptive objects. Furthermore, the presence of hydrogen in the proposed remnant seems to contradict with the final helium-flash scenario. We propose that the peculiarities of CK Vul can be naturally understood if we consider a merging of main-sequence stars, following a new interpreta…
基于双星恒星演化的演化方案，研究了相对论双星（NS+NS，NS+BH，BH+BH）在不同BH形成假设下的合并速率。我们发现银河型星系的BH+BH合并率在每20万-50万年一次之间，而NS+NS合并率$R_{ns}$大约是它的10倍，这意味着，即使对于高达400 km/s的NS的高平均反冲速度，预期的事件发生率也至少为30-每年有50个来自200 Mpc距离内的二进制NS合并。由于典型的BH形成的质量是NS质量的3-10倍（假设1.4 M $_\odot$），所获得的速率意味着LIGO型引力波探测器对BH的预期探测速率比NS合并速率高10-100倍。
Merging Massive Star Clusters as Building Blocks of Dwarf Galaxies ?
最近对天炉座星系团中星系的光谱观测揭示了几乎无法分辨的“类星”天体，其红移与天炉座星系团相适应。这些天体的内禀大小约为100 pc，B波段绝对星等范围为-14 < M_B < -11.5 mag and lower limits for the central surface brightness mu_B >= 23 mag/arcsec ^[2]（Phillips等，2001; Hilker等，1999），因此似乎构成了一个新的超致密矮星系（UCD）群体。P. Kroupa（1998）预测这种致密的矮星是由恒星超星团（=星团的星团;不要与超级星团（SSC）混淆）合并而成的，它们是年轻的大质量星团（YMC）的丰富聚集体，可以在富含气体的星系之间的碰撞中形成。在这里，我们提出的超星系团在潮汐场的演变。YMC在几个超级星团交叉时刻合并。最初像相互作用的星系中的纽结S那样集中和巨大的超星系团（Whitmore et al. 1999）演变成合并物体，这些物体寿命长，并显示出与新发现的UCD相当的性质。
