A MeerKAT Survey of Nearby Novalike Cataclysmic Variables
D. M. Hewitt, M. L. Pretorius, P. A. Woudt, E. Tremou, J. C. A. Miller-Jones, C. Knigge, N. Castro Segura, D. R. A. Williams, R. P. Fender, R. Armstrong, P. Gro… 展开作者
D. M. Hewitt, M. L. Pretorius, P. A. Woudt, E. Tremou, J. C. A. Miller-Jones, C. Knigge, N. Castro Segura, D. R. A. Williams, R. P. Fender, R. Armstrong, P. Groot, I. Heywood, A. Horesh, A. J. van der Horst, E. Koerding, V. A. McBride, K. P. Mooley, A. Rowlinson, B. Stappers, R. A. M. J. Wijers
We present the results of MeerKAT radio observations of eleven nearby novalike cataclysmic variables. We have detected radio emission from IM Eri, RW Sex, V3885 Sgr and V603 Aql. While RW Sex, V3885 Sgr and V603 Aql had been previously detected, this is the first reported radio detection of IM Eri. Our observations have doubled the sample of non-magnetic CVs with sensitive radio data. We observe that at our radio detection limits, a specific optical luminosity $\gtrsim 2.2\times 10^{18}$ erg/s/Hz (corresponding to $M_V \lesssim 6.0$) is required to produce a radio detection. We also observe that the X-ray and radio luminosities of our detected novalikes are on an extension of the $L_{X} \propto L_{R}^{\sim 0.7}$ power law originally proposed for non-pulsating neutron star low-mass X-ray binaries. We find no other correlations between the radio emission and emission in other wavebands or any other system parameters for the existing sample of radio-detected non-magnetic CVs. We measure in-band (0.9-1.7 GHz) radio spectral indices that are consistent with reports from earlier work. Finally, we constructed broad spectral energy distributions for our sample from published multi-wavelength data, and use them to place constraints on the mass transfer rates of these systems.
The eclipsing novalike cataclysmic variable CRTS SSS100505 J093417-174421
Universidade Federal de Santa Catarina（圣卡塔琳娜联邦大学）；Laboratório Nacional de Astrofísica（国家天体物理学实验室）；Universidade Federal de Sergipe（塞尔希培联邦大学）；Observatório Nacional（国家天文台）；Instituto de Astronomia, Geofísica e Ciências Atmosféricas da USP（圣保罗大学天文、地球物理和大气科学研究所）；Instituto Nacional de Pesquisas Espacias（国家空间研究 institute）；Universidade do Vale do Paraíba（帕拉伊巴河谷大学）；Universidade Estadual Paulista（圣保罗州立大学）
Modifying the Standard Disk Model for the Ultraviolet Spectral Analysis of Disk-dominated Cataclysmic Variables. I. The Novalikes MV Lyrae, BZ Camelopardalis, and V592 Cassiopeiae
标准圆盘通常不足以对圆盘主导的激变变量（CV）进行建模，并产生比观察到的紫外光谱更蓝的光谱[Puebla et al 2007]。这些系统的X射线观测揭示了一个光学薄的边界层（BL），预计将出现在磁盘中的内孔。因此，我们截断了内盘。然而，而不是删除内部磁盘，我们施加的截断半径的无剪切边界条件，从而降低磁盘温度和产生的光谱，更好地适合紫外线数据。与我们修改后的磁盘，我们分析档案紫外光谱的三个novalikes，不能与标准磁盘。对于VY Scl系统MV Lyr和BZ Cam，我们将热膨胀的白矮星WD与冷修改的盘（$\dot{M} \sim $几个$10^{-9}M_{\odot}$ /年）安装在一起。对于V592 Cas，略微改变的圆盘（$\dot{M} \sim 6 \times 10^{-9}M_{\odot}$ /年）完全主导UV。这些结果与这些系统的Swift X射线观测结果一致[Balman et al 2014]，揭示了与ADAF样流动和/或热日冕合并的BL，其中能量的平流可能会引发外流并加热WD，从而解释了VY Scl系统中的高WD温度。这是进一步支持的事实，即X射线硬度比增加与浅的UV斜率在一个小的CV样品，我们检查。此外，对于105个盘主导的系统，国际紫外探测器（IUE）光谱UV斜率以与X射线通量与光学/UV通量的比率相同的顺序减小：从SU UMa的，到U Gem的，…
A MeerKAT survey of nearby dwarf novae: I. New detections
Radboud University（拉德堡德大学）；University of Cape Town（开普敦大学）；South African Astronomical Observatory（南非天文台）；Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester（曼彻斯特大学物理与天文学学院乔德雷尔银行天体物理学中心）；University of Oxford（牛津大学）；Rhodes University（罗德岛大学）；South African Radio Astronomy Observatory（南非射电天文台）；University of Warwick（华威大学）；University of Southampton（南安普顿大学）
SRG/eROSITA X-ray selected cataclysmic variable candidates observed in SDSS-V DR20
Leibniz-Institut für Astrophysik Potsdam (AIP)（波茨坦阿诺德·爱因斯坦天文研究所）；University of Potsdam（波茨坦大学）；Max-Planck-Institut für extraterrestrische Physik（马普地外物理研究所）；University of Washington（华盛顿大学）；Tel Aviv University（特拉维夫大学）；The Pennsylvania State University（宾夕法尼亚州立大学）
