标题： XMM-Newton对极化星EV UMa、RX J1002-19和RX J1007-20的观测 显示英文标题

标题： XMM-Newton observations of the polars EV UMa, RX J1002-19 and RX J1007-20

摘要： 我们呈现三个强磁场灾变变星（极性星）EV UMa、RX J1002-19 和 RX J1007-20 的 XMM-Newton 数据。 这些包括轨道周期最短的极性星（EV UMa）和磁場強度最高的極性星之一（RX J1007-20）。 它们表现出一系列與其已知磁場強度一致的 X 射線光譜特性。 我們發現其中兩個系統在軟 X 射線中顯示出吸收凹陷的證據。 它們的輪廓非常明確，表明流體高度集中。 我們測定了兩個已知距離的系統的質量轉移率。 我們確定 EV UMa 和 RX J1007-20 中白矮星的質量約為 1Msun，而在 RX J1002-19 中則接近約 0.5Msun。 显示英文摘要

摘要： We present XMM-Newton data of three strongly magnetic cataclysmic variables (polars) EV UMa, RX J1002-19 and RX J1007-20. These include the polar with the shortest orbital period (EV UMa) and the polar with one of the highest magnetic field strengths (RX J1007-20). They exhibit a range of X-ray spectral characteristics which are consistent with their known magnetic field strength. We find that two of the systems show evidence for an absorption dip in soft X-rays. Their profiles are well defined, implying that the stream is highly collimated. We determine the mass transfer rate for the two systems with known distances. We determine that the mass of the white dwarf in EV UMa and RX J1007-20 is ~1Msun while in RX J1002-19 it is closer to ~0.5Msun.