Dwarf novae in the Hamburg quasar survey: rarer than expected
Dwarf novae in the Hamburg quasar survey: rarer than expected
复制标题
DOI：
10.1051/0004-6361:20065049
复制
发表时间：
2006-05
影响因子：
6.5
通讯作者：
A. Aungwerojwit;B. Gänsicke;P. Rodríguez-Gil;P. Rodríguez-Gil;H. Hagen;S. Araujo-Betancor;O. Baernbantner;D. Engels;Robert E. Fried;E. Harlaftis;D. Mislis;D. Nogami;P. Schmeer;R. Schwarz;A. Staude;M. A. Torres
中科院分区：
文献类型：
--
作者：
A. Aungwerojwit;B. Gänsicke;P. Rodríguez-Gil;P. Rodríguez-Gil;H. Hagen;S. Araujo-Betancor;O. Baernbantner;D. Engels;Robert E. Fried;E. Harlaftis;D. Mislis;D. Nogami;P. Schmeer;R. Schwarz;A. Staude;M. A. Torres
目标。我们报道了在汉堡类星体观测(HQS)中发现的五颗新的矮新星，并讨论了来自HQS的新的矮新星样本的性质。方法：研究方法。获得了后续的时间分辨光谱和光度学来表征新的体系。结果。由径向速度变化和/或轨道光度变化分析确定的轨道周期：HS0417+7445的PORB=105.1min或PORB 109.9min，HS1016+3412的PORB=114.3±2.7min，HS1340+1524的PORB=92.66±0.17min，HS1857+7127的PORB=272.317±0.001分钟，HS2214+2845的PORB=258.02±0.56min。HS1857+7127出现偏食现象。在HS2214+2845中，清晰地探测到光谱类型为M3±1的次星，我们估计到该系统的距离为d=390±40pC。我们记录了一次HS0417+7445的超强爆发，确认该系统是一颗超大马特型矮新星。HS 1016+3412和HS 1340+1524具有罕见的突发性，其亚型尚未确定。HS 1857+7127的亮度变化频繁，可能是一颗ZCam类型的矮新星。HS 2214+2845是一颗UGem型矮新星，最有可能的周期为71d。到目前为止，在总部已经发现了14颗新的矮新星。这个样本的短周期(3h)系统的比率为1.3，与所有已知的矮新星的比率2.7相比要小得多。HQS矮新星表现出典型的罕见或低幅度爆发活动，突显了光谱选择在识别新的CV方面的力量，而不是依赖于它们的变异性。新发现的和以前已知的HQ中短周期CV的光谱性质表明，它们中的大多数或可能全部仍在向最小周期演化。它们的总数与人口模型的预测在一个数量级内一致。然而，据预测，所有简历中的大部分都已经超过了最低期限，这些系统仍未确定。这表明，与已知的平均短周期CV相比，这些反弹后系统的Hβ发射线明显较弱，并且没有或非常罕见地发生爆发。
Aims. We report the discovery of five new dwarf novae that were spectroscopically identified in the Hamburg Quasar Survey (HQS),and discuss the properties of the sample of new dwarf novae from the HQS. Methods. Follow-up time-resolved spectroscopy and photometry have been obtained to characterise the new systems. Results. The orbital periods determined from analyses of the radial velocity variations and/or orbital photometric variability are Porb 105.1min or Porb 109.9min for HS 0417+7445, Porb = 114.3 ± 2.7min for HS 1016+3412, Porb = 92.66 ± 0.17 min for HS 1340+1524, Porb = 272.317 ± 0.001 min for HS 1857+7127, and Porb = 258.02 ± 0.56 min for HS 2214+2845. HS 1857+7127 is found to be partially eclipsing. In HS 2214+2845 the secondary star of spectral type M3 ± 1 is clearly detected, and we estimate the distance to the system to be d = 390 ± 40 pc. We recorded one superoutburst of HS 0417+7445, identifying the system as a SUUMatype dwarf nova. HS 1016+3412 and HS 1340+1524 have rare outbursts, and their subtype is yet undetermined. HS 1857+7127 frequently varies in brightness and may be a ZCam-type dwarf nova. HS 2214+2845 is a UGem-type dwarf nova with a most likely cycle length of 71 d. Conclusions. To date, 14 new dwarf novae have been identified in the HQS. The ratio of short-period ( 3 h)systems of this sample is 1.3, much smaller compared to the ratio of 2.7 found for all known dwarf novae. The HQS dwarf novae display typically infrequent or low-amplitude outburst activity, underlining the strength of spectroscopic selection in identifying new CVs independently of their variability. The spectroscopic properties of short-period CVs in the HQS, newly identified and previously known, suggest that most, or possibly all of them are still evolving towards the minimum period. Their total number agrees with the predictions of population models within an order of magnitude. However, the bulk of all CVs is predicted to have evolved past the minimum period, and those systems remain unidentified. This suggests that those post-bounce systems have markedly weaker Hβ emission lines compared to the average known short-period CVs, and undergo no or extremely rare outbursts.