arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1206.1827astro-ph.CO
收藏

LoBAL类星体的性质:I. SED和中红外光谱特性

The Nature of LoBAL QSOs: I. SEDs and mid-infrared spectral properties

Mariana S. Lazarova, Gabriela Canalizo, Mark Lacy, Anna Sajina

摘要:

我们已经获得了斯皮策IRS光谱和MIPS 24,70,和160微米测光的体积有限的样品22 SDSS选择的低电离宽吸收线类星体(LoBALs)在0.5 < z < 0.6。通过比较它们的中红外光谱特性和远红外SED与M_i中匹配的35个非LoBALs的对照样本,我们研究了这两个群体在红外发射和恒星形成活动方面的差异。25%的LoBALs显示PAH特征,45%具有弱的9.7微米硅酸盐粉尘排放。我们模拟的SED和解耦的活动星系核和星爆的贡献,远红外光度在LoBALs和非LoBALs。它们的中值总光度、星爆光度和活动星系核的红外光度相当。20%(但不超过60%)的LoBALs和26%的非LoBALs是超亮红外星系(ULIRGs; L_IR>10^12*L_sun)。我们估计恒星形成率(SFR)校正的活动星系核贡献的FIR通量,并发现LoBALs有可比水平的恒星形成活动的非LoBALs时,考虑到整个样本。然而,IR发光LoBALs的SFR比对照样品中的对应物高80%。在LoBALs和非LoBALs中,恒星形成对总远红外通量的贡献的中位数估计为40- 50%,与以前PG类星体的结果一致。总体而言,我们的研究结果表明,没有强有力的证据表明,从中红外和远红外特性,LoBALs是从不同的父人群比非LoBALs。

英文摘要:

We have obtained Spitzer IRS spectra and MIPS 24, 70, and 160 micron photometry for a volume-limited sample of 22 SDSS-selected Low-ionization Broad Absorption Line QSOs (LoBALs) at 0.5 < z < 0.6. By comparing their mid-IR spectral properties and far-IR SEDs with those of a control sample of 35 non-LoBALs matched in M_i, we investigate the differences between the two populations in terms of their infrared emission and star formation activity. Twenty five percent of the LoBALs show PAH features and 45% have weak 9.7 micron silicate dust emission. We model the SEDs and decouple the AGN and starburst contributions to the far-infrared luminosity in LoBALs and in non-LoBALs. Their median total, starburst, and AGN infrared luminosities are comparable. Twenty percent (but no more than 60%) of the LoBALs and 26% of the non-LoBALs are ultra-luminous infrared galaxies (ULIRGs; L_IR>10^12*L_sun). We estimate star formation rates (SFRs) corrected for the AGN contribution to the FIR flux and find that LoBALs have comparable levels of star formation activity to non-LoBALs when considering the entire samples. However, the SFRs of the IR-luminous LoBALs are 80% higher than those of their counterparts in the control sample. The median contribution of star formation to the total far-infrared flux in LoBALs and in non-LoBALs is estimated to be 40-50%, in agreement with previous results for PG QSOs. Overall, our results show that there is no strong evidence from the mid- and far-IR properties that LoBALs are drawn from a different parent population than non-LoBALs.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑