• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The Astrophysical journal >Star Formation Rates In Lyman Break Galaxies: Radio Stacking Of Lbgs In The Cosmos Field And The Sub-μjy Radio Source Population
【24h】

Star Formation Rates In Lyman Break Galaxies: Radio Stacking Of Lbgs In The Cosmos Field And The Sub-μjy Radio Source Population

机译：莱曼断裂星系中的恒星形成速率：宇宙场和次μjy无线电源种群中的Lbgs的无线电堆积

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We present an analysis of the radio properties of large samples of Lyman break galaxies (LBGs) at z～3,4, and 5 from the COSMOS field. The median stacking analysis yields a statistical detection of the z～3 LBGs (U-band dropouts), with a 1.4 GHz flux density of 0.90 ± 0.21 μJy. The stacked emission is unresolved, with a size < 1, or a physical size <8 kpc. The total star formation rate implied by this radio luminosity is 31 ± 7 M_☉ yr~(-1), based on the radio-FIR correlation in low-redshift star-forming galaxies. The star formation rate derived from a similar analysis of the UV luminosities is 17 M_☉ yr~(-1), without any correction for UV dust attenuation. The simplest conclusion is that the dust attenuation factor is 1.8 at UV wavelengths. However, this factor is considerably smaller than the standard attenuation factor of～5, normally assumed for LBGs. We discuss potential reasons for this discrepancy, including the possibility that the dust attenuation factor at z > 3 is smaller than at lower redshifts. Conversely, the radio luminosity for a given star formation rate may be systematically lower at very high redshift. Two possible causes for a suppressed radio luminosity are (1) increased inverse Compton cooling of the relativistic electron population due to scattering off the increasing CMB at high redshift or (2) cosmic-ray diffusion from systematically smaller galaxies. The radio detections of individual sources are consistent with a radio-loud AGN fraction of 0.3%. One source is identified as a very dusty, extreme starburst galaxy (a "submillimeter galaxy").
机译：我们对来自COSMOS场的z〜3,4和5的莱曼断裂星系（LBG）的大样本的无线电特性进行了分析。中值叠加分析得出z〜3个LBG（U波段丢失）的统计检测结果，其1.4 GHz通量密度为0.90±0.21μJy。尺寸小于1或物理尺寸小于8 kpc的堆叠发射尚未解析。基于低红移星系星系的射电-FIR相关性，这种射电光度所隐含的总恒星形成速率为31±7M_☉yr〜（-1）。由类似的紫外光度分析得出的恒星形成率为17M_☉yr〜（-1），未对紫外尘埃衰减进行任何校正。最简单的结论是，在紫外线波长下，粉尘衰减系数为1.8。但是，该因子比LBG通常假定的标准衰减因子〜5小得多。我们讨论了造成这种差异的潜在原因，包括z> 3处的粉尘衰减系数小于较低的红移的可能性。相反，在非常高的红移下，给定恒星形成速率的射电发光度可能会系统降低。抑制无线电发光度的两个可能原因是：（1）由于在高红移条件下逐渐增加的CMB被散射而导致相对论电子群的逆康普顿冷却增加，或者（2）来自系统较小星系的宇宙射线扩散。单个源的无线电检测与0.3％的无线电响AGN分数一致。一种来源被认为是尘土飞扬，极端爆炸的星系（“亚毫米星系”）。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号