UIT: Ultraviolet Observations of the Small Magellanic Cloud
UIT: Ultraviolet Observations of the Small Magellanic Cloud
复制标题
UIT：小麦哲伦星云的紫外线观测
DOI：
--
复制
发表时间：
1996
期刊：
影响因子：
--
通讯作者：
NASA
中科院分区：
文献类型：
--
作者：
R. Cornett;M. Greason;J. K. Hill;J. Wm. Parker;W. Waller;R. Bohlin;K. Cheng;S. Neff;R. O’Connell;M. S. Roberts;Andrew M. Smith;T. P. S. H. S. Corp;Laboratory for Astronomy;Solar Physics;NASA
一个马赛克的四个UIT远紫外（FUV; 1620 A）的图像，其中包括大部分的SMC酒吧，推导出恒星和HII区域测光。Bar的紫外线形态显示，最近的星星形成留下了惊人的特征，包括：a）四个集中的紫外线明亮的恒星从东北到西南以几乎相等的间距（约30弧分=0.5千秒差距）分布; B）一个定义明确的8弧分的紫外线明亮的恒星环，周围环绕着一个更大的H-α环，表明连续的星星形成。对11，306颗恒星进行了FUV PSF测光，并导出了FUV光度函数。195颗已确认的超巨星的（FUV-V，V）色星等图，以及导出的光谱图;每种光谱类型中最蓝（最少变红）的恒星的FUV-V色与模型一致。FUV测光获得42 H-α-选定的HII区域，无论是恒星和Kennicutt和霍奇定义的光圈内的总发射。总FUV通量与恒星FUV通量的通量加权平均比为2.15;恒星FUV光度函数表明，大部分多余的总通量是由于散射的FUV辐射，而不是暗淡的恒星。恒星和总排放量都与H-α通量相关，并产生FUV/H-α比率，与SMC金属量，年龄从1-5百万年，和中等（E（B-V）=0.0-0.1等）内部SMC灭绝的单次爆发集群模型一致。
A mosaic of four UIT far-UV (FUV; 1620A) images, which covers most of the SMC bar, is presented, with derived stellar and HII region photometry. The UV morphology of the Bar shows that recent star formation there has left striking features including: a) four concentrations of UV-bright stars spread from northeast to southwest at nearly equal (~30 arcmin=0.5 kpc) spacings; b) a well-defined 8-arcmin ring of UV-bright stars surrounded by a larger H-alpha ring, suggesting sequential star formation. FUV PSF photometry is obtained for 11,306 stars, and a FUV luminosity function is derived. A (FUV-V,V) color-magnitude diagram for 195 identified supergiants, with derived extinctions; the bluest (least-reddened) stars of each spectral type have FUV-V colors consistent with models. FUV photometry is obtained for 42 H-alpha-selected HII regions, both for the stars and for the total emission within the apertures defined by Kennicutt&Hodge. The flux-weighted average ratio of total to stellar FUV flux is 2.15; the stellar FUV luminosity function indicates that most of the excess total flux is due to scattered FUV radiation, rather than faint stars. Both stellar and total emission are well correlated with H-alpha fluxes, and yield FUV/H-alpha ratios that are consistent with models of single-burst clusters with SMC metallicity, ages from 1-5 Myr, and moderate (E(B-V)=0.0-0.1 mag) internal SMC extinction.