论文标题
用VVV绘制银河系的恒星时代。 iii。高分辨率红色地图
Mapping the stellar age of the Milky Way bulge with the VVV. III. High resolution reddening map
论文作者
论文摘要
对银河膨胀恒星种群的详细研究必然需要对星际灭绝的准确表示，尤其是在银河平面和中心，在那里，预计严重和差异的红色会在亚氨基酸尺度上有所不同。尽管最近的红外调查通过在整个银河凸出区域提供灭绝图来解决了这个问题，但平面附近的derdenden颜色磁性图和中心似乎系统地校正了，这表明需要更高的分辨率。这些不足会影响对颜色敏感的任何恒星研究（例如，通过颜色刻度图拟合的恒星形成历史分析），使其不准确或将其限制在该值可以更好地限制的小型低/稳定灭绝窗口中。我们旨在为VVV Bulge区域提供高分辨率（2 arcmin至$ \ sim $ 10 arcsec）颜色多余的地图，in $ \ mathrm {j} - \ mathrm {k} _s _s $ color。我们使用MW-Bulge-PSFPHOT目录$ \ sim $ 300度$^2 $在银河凸起（$ | l | l | <10^\ circ $和$ -10^\ circ <b <5^\ circ $）来隔离红色和红色的巨大的分支星星，我们将平均$ \ $ \ \ \ k \ k \ k \ k \ k \ k \ k \ k {在$（l，b）$空间的精细空间网格中。我们获得了e $（\ mathrm {j} - \ mathrm {k} _s）$地图，跨越了大约300度$^2 $的VVV凸起面积，相当于$ \ sim $ \ sim $ 1 $ 1 arcmin for Bulge utge to Bulge utgeirts（$ l <-6^\ circe $）incternall in connection unterncter in Contranct in countermece in incternal in connection unterncter concect unnectern carcsec c cysec in incternal in connect carcsec l | l | <1^\ circ $，最终区域的10个arcsec（$ | l | <1^\ circ $和$ | b | <3^\ circ $）。结果可在http://basti-iac.oa-teramo.inaf.it/vvvexmap/上公开获取。
The detailed study of the Galactic bulge stellar population necessarily requires an accurate representation of the interstellar extinction particularly toward the Galactic plane and center, where the severe and differential reddening is expected to vary on sub-arcmin scales. Although recent infrared surveys have addressed this problem by providing extinction maps across the whole Galactic bulge area, dereddened color-magnitude diagrams near the plane and center appear systematically undercorrected, suggesting the need for higher resolutions. These undercorrections affect any stellar study sensitive to color (e.g. star formation history analysis via color-magnitude diagram fitting), either making them inaccurate or limiting them to small low/stable extinction windows where this value is better constrained. We aim at providing a high-resolution (2 arcmin to $\sim$ 10 arcsec) color excess map for the VVV bulge area, in $\mathrm{J}-\mathrm{K}_s$ color. We use the MW-BULGE-PSFPHOT catalogs sampling $\sim$ 300 deg$^2$ across the Galactic bulge ($|l| < 10^\circ$ and $-10^\circ < b < 5^\circ$) to isolate a sample of red clump and red giant branch stars, for which we calculate average $\mathrm{J}-\mathrm{K}_s$ color in a fine spatial grid in $(l, b)$ space. We obtain a E$(\mathrm{J}-\mathrm{K}_s)$ map spanning the VVV bulge area of roughly 300 deg$^2$, with the equivalent to a resolution between $\sim$ 1 arcmin for bulge outskirts ($l < -6^\circ$) to below 20 arcsec within the central $|l| < 1^\circ$, and below 10 arcsec for the innermost area ($|l| < 1^\circ$ and $|b| < 3^\circ$). The result is publicly available at http://basti-iac.oa-teramo.inaf.it/vvvexmap/
