GALEX catalogs of UV sources: statistical properties and sample science applications: hot white dwarfs in the Milky Way
GALEX catalogs of UV sources: statistical properties and sample science applications: hot white dwarfs in the Milky Way
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DOI：
10.1007/s10509-010-0581-x
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发表时间：
2011-01
影响因子：
1.9
通讯作者：
L. Bianchi;J. Herald;B. Efremova;Léo Girardi;A. Zabot;P. Marigo;Alberto Conti;B. Shiao
中科院分区：
文献类型：
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作者：
L. Bianchi;J. Herald;B. Efremova;Léo Girardi;A. Zabot;P. Marigo;Alberto Conti;B. Shiao
我们描述了GALEX的全天成像调查(AIS，AB系统中的5σDepth≈19.9(FUV)/20.8(NUV)MAG)和中深度成像调查(MIS5σDepth≈22.6(FUV)/22.7(NUV)MAG)的紫外线源星表的内容和性质。不。R·阿斯特龙。SoC。(2010年，在媒体上)。这些目录包含6,530/1,260万(美国信息系统/信息系统)独特的紫外源，其近紫外光度误差小于0.5M，超过21 435(美国信息系统)/1,579(信息系统)平方度。来自GSC-II的匹配光学数据为最亮的光源提供了额外的B、R、I光度测量，而SDSS提供了7325(AIS)/1103(MIS)平方度重叠区域的I光度测量。在这些星表的潜在科学应用中，我们讨论了与理解样本选择偏差和完整性相关的统计性质。FUV(1344-1786年)和NUV(1771-2831年)光度学独特地使我们能够选择最热的恒星物体，特别是热白矮星(WD)，它们在光学波长下是难以捉摸的，因为它们的温度很高，亮度很弱。从GALEX-SDSS匹配源中，我们选择了比约18FUV 000K(∼- <； −0.13)更热的FUV 40NUV 000银河系(MW)恒星。它们的密度在银河系低纬度方向增加，但由于尘埃消亡而在兆瓦圆盘中下降。用银河系模型分析了银河系不同纬度的热WD密度，限制了初始-最终质量关系(IFMR)，这与理解中等质量恒星的化学元素产量和银河系的化学丰度有关。
We describe the content and properties of UV source catalogs from GALEX’s All-Sky Imaging Survey (AIS, 5σdepth ≈19.9(FUV)/20.8(NUV) mag, in the AB system) and Medium-depth Imaging Survey (MIS, 5σdepth ≈22.6(FUV)/22.7(NUV) mag), constructed by Bianchi L., et al.: Mon. Not. R. Astron. Soc. (2010, in press). The catalogs contain 65.3/12.6 million (AIS/MIS) unique UV sources with photometric error in NUV less than 0.5 mag, over 21 435(AIS)/1579(MIS) square degrees. Matched optical data from GSC-II provide additionalB,R,Iphotometry for the brightest sources, and SDSS providesu g r i zphotometry over 7325(AIS)/1103(MIS) square degrees overlap areas. We discuss statistical properties that are relevant for understanding sample selection biases and completeness, in potential science applications of these catalogs. The FUV (1344–1786 Å) and NUV (1771–2831 Å) photometry uniquely enable selection of the hottest stellar objects, in particular hot white dwarfs (WD), which are elusive at optical wavelengths because of their hot temperatures and faint luminosities. From the GALEX-SDSS matched sources we selected ∼40 000 Milky Way (MW) stars hotter than about 18 000 K (FUV-NUV < −0.13). Their density increases towards low Galactic latitudes, but drops in the MW disk due to dust extinction. The hot-WD density at different Galactic latitudes, analyzed with Milky Way models, constrains the Initial-Final Mass Relation (IFMR), relevant for understanding the yield of chemical elements from intermediate-mass stars and the chemical enrichment of the Galaxy.