论文标题

研究星系相互作用对0.5 <z <3.0恒星形成的影响

Investigating the Effect of Galaxy Interactions on Star Formation at 0.5<z<3.0

论文作者

Shah, Ekta A., Kartaltepe, Jeyhan S., Magagnoli, Christina T., Cox, Isabella G., Wetherell, Caleb T., Vanderhoof, Brittany N., Cooke, Kevin C., Calabro, Antonello, Chartab, Nima, Conselice, Christopher J., Croton, Darren J., de la Vega, Alexander, Hathi, Nimish P., Ilbert, Olivier, Inami, Hanae, Kocevski, Dale D., Koekemoer, Anton M., Lemaux, Brian C., Lubin, Lori, Mantha, Kameswara Bharadwaj, Marchesi, Stefano, Martig, Marie, Moreno, Jorge, Pampliega, Belen Alcalde, Patton, David R., Salvato, Mara, Treister, Ezequiel

论文摘要

当地宇宙中相互作用星系和合并的观测和模拟表明,相互作用可以显着提高恒星形成速率(SFR)和活性银河核(AGN)的加油。但是,在较高的红移下,一些模拟表明,由于气体级数较高,并且在这些星系中已经增加了SFR,因此相互作用引起的恒星形成水平较低。为了进行测试,我们在总共2351(1327)中测量SFR增强量($ M _*> 10^{10} {10} M_ \ ODOT $)主要($ 1 <M_1/M_2 <4 $)光谱谱系Galaxy Pairs at 0.5 <Z <z <3.0,带有$ΔV<5000 $ km km km km km s $ km s $ km s $^m。 S $^{ - 1} $)和预计的分离<150 kpc从宇宙和烛台中的广泛的光谱覆盖范围中选择。我们发现,相对于恒星质量,红移 - 和环境匹配的对照样品,SFR增强的最高水平是1.23 $^{+0.08} _ { - 0.09} $。我们发现,在0.5 <z <1时,SFR增强的水平比在最接近的投影分离箱中比1 <z <3高。在视觉上识别的合并样本中,我们发现共同系统的1.86 $^{+0.29} _ { - 0.18} $的增强倍。对于此视觉上识别的样本,我们看到SFR增强的明显趋势随着预计分离的减少(2.40 $^{+0.62} _ { - 0.37} $ vs. \ 1.58 $^{+0.29} _ { - 0.29} _ { - 0.20} $ 0.5 <z <z <z <z <z <z <z <z <z <z <z <z <z <3.0,在我们的相互作用和合并中看到的SFR增强均低于相同分离中局部样品中看到的水平,这表明相互作用诱导的恒星形成水平在这段时间内显着发展。

Observations and simulations of interacting galaxies and mergers in the local universe have shown that interactions can significantly enhance the star formation rates (SFR) and fueling of Active Galactic Nuclei (AGN). However, at higher redshift, some simulations suggest that the level of star formation enhancement induced by interactions is lower due to the higher gas fractions and already increased SFRs in these galaxies. To test this, we measure the SFR enhancement in a total of 2351 (1327) massive ($M_*>10^{10}M_\odot$) major ($1<M_1/M_2<4$) spectroscopic galaxy pairs at 0.5<z<3.0 with $ΔV <5000$ km s$^{-1}$ (1000 km s$^{-1}$) and projected separation <150 kpc selected from the extensive spectroscopic coverage in the COSMOS and CANDELS fields. We find that the highest level of SFR enhancement is a factor of 1.23$^{+0.08}_{-0.09}$ in the closest projected separation bin (<25 kpc) relative to a stellar mass-, redshift-, and environment-matched control sample of isolated galaxies. We find that the level of SFR enhancement is a factor of $\sim1.5$ higher at 0.5<z<1 than at 1<z<3 in the closest projected separation bin. Among a sample of visually identified mergers, we find an enhancement of a factor of 1.86$^{+0.29}_{-0.18}$ for coalesced systems. For this visually identified sample, we see a clear trend of increased SFR enhancement with decreasing projected separation (2.40$^{+0.62}_{-0.37}$ vs.\ 1.58$^{+0.29}_{-0.20}$ for 0.5<z<1.6 and 1.6<z<3.0, respectively). The SFR enhancement seen in our interactions and mergers are all lower than the level seen in local samples at the same separation, suggesting that the level of interaction-induced star formation evolves significantly over this time period.

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