We report on a long-term monitoring of a newly discovered X-ray nova, MAXI J1910-057 (= Swift J1910.2-0546), by MAXI and Swift. The new X-ray transient was first detected on 2012 May 31 by MAXI Gas Slit Camera (GSC) and Swift Burst Alert Telescope (BAT) almost simultaneously. We analyzed X-ray and UV data for 270 days since the outburst onset taken by repeated MAXI scans and Swift pointing observations. The obtained X-ray light curve for the inital 90 days is roughly represented by a fast-rise and exponential-decay profile. However, it re-brightened on the ~110 days after the onset and finally went down below both GSC and BAT detec- tion limits on the 240 day. All the X-ray energy spectra are fitted well with a model consisting of a multi-color-disk blackbody and its Comptonized hard tail. During the soft-state periods, the inner-disk radius of the best-fit model were almost constant. If the radius represents the innermost stable circular orbit of a non-spinning black hole and the soft-to-hard transitions occur at 1-4% of the Eddington luminosity, the mass of the compact object is estimated to be > 2.9Mo and the distance to be > 1.70 kpc. The inner-disk radius became larger in the hard / hard-intermediate state. This suggests that the accretion disk would be truncated. We detected an excess of the UV flux over the disk blackbody component extrapolated from the X-ray data, which can be modelled as reprocessed emission irradiated by the inner disk. We also found that the UV light curve mostly traced the X-ray curve, but a short dipping event was observed in both the UV and the X-ray bands with a 3.5-day X-ray time lag. This can be interpreted as the radial inflow of accreting matter from the outer UV region to the inner X-ray region.
A Self-Consistent Model for a Full Cycle of Recurrent Novae -- Wind Mass Loss Rate and X-Ray Luminosity
在重现期非常短的新星M31 N 2008- 12 a中，前光学最大阶段的演化速度出乎意料地缓慢。为了获得合理的新星光变曲线，我们改进了我们的计算方法，一贯结合光学厚风解决方案的富氢信封白矮星（WD）的结构计算的Henyey型演化代码。风的质量损失率是正确的，具有较高的精度。我们计算了1.2和1.38Msun的WDs的光变曲线模型，质量吸积率分别对应于10年和1年的重现周期。爆发持续时间为590/29天，其中光学极大前位相为82/16天，分别对应于1.2/1.38M_sun。光学厚风开始于X射线闪光的末尾，并在超软X射线阶段的开始时停止。我们还提出了超软X射线光变曲线，包括一个提示X射线闪光和后来的超软X射线阶段。
An Optically Motivated Gamma-ray Study of Fermi-LAT Novae
Department of Astrophysics, American Museum of Natural History（美国自然历史博物馆天体物理系）；Department of Earth & Physical Sciences, York College, City University of New York（纽约市立大学约克学院地球与物理科学系）；Department of Natural Sciences, LaGuardia Community College, City University of New York（纽约市立大学拉瓜迪亚社区学院自然科学系）
A phenomenological model for the X-ray spectrum of Nova V2491 Cygni
Nova V2491 Cyg的X射线通量在光学极大值后约40天达到最大值。当时的X射线光谱，用XMM-牛顿的RGS获得，显示出深，蓝移吸收的离子的电离范围很广。我们表明，深吸收线的X射线光谱在最大值，9天后，很好地描述了以下的唯象模型与发射从中央黑体和碰撞电离等离子体（CIE）。黑体光谱（BB）被三个主要的高度电离的膨胀壳层吸收; CIE和BB被包括尘埃在内的冷的星周和星际物质吸收。出流密度并不随距离单调减小。这些壳的丰度表明它们是从一颗O-Ne白矮星中喷射出来的。我们表明，在X射线光谱的时间尺度上的变化是由中央源的变化和电离壳层的柱密度的组合。我们的唯象模型给出了最好的描述，到目前为止的超软X射线光谱的新星V2491天鹅座，但低估了，由一个很大的因素，光学和紫外线通量。光谱中的X射线部分必须来自膨胀包层中的一个非常不同的层，大概比负责光学/紫外光谱的层更接近白矮星。这一点通过X射线和UV/光学观测通量之间不存在任何相关性得到证实。
