Ultra-diffuse Galaxies at Ultraviolet Wavelengths
Ultra-diffuse Galaxies at Ultraviolet Wavelengths
复制标题
DOI：
10.3847/1538-3881/ab16f2
复制
发表时间：
2019-04
期刊：
影响因子：
--
通讯作者：
Pranjal Rajendra Singh;D. Zaritsky;R. Donnerstein;K. Spekkens
中科院分区：
文献类型：
--
作者：
Pranjal Rajendra Singh;D. Zaritsky;R. Donnerstein;K. Spekkens
我们测量近紫外线（NUV）孔径大小从星系演化探测器图像的258超扩散星系（UDG）的候选人从最初的系统测量超扩散星系（SMUDG）调查的300平方度周围，包括后发星系团。对于其中的绝大多数，242，我们目前的通量上限，由于缺乏显着的通量在光圈或混淆与其他物体投射在光圈内。这些限制经常对UDG候选者施加有趣的限制，表明它们是非恒星形成或静止的。特别是，我们确定领域，静态UDG候选人，这是一个挑战，形成模型，因此，引人注目的前景，光谱的后续行动和距离测定。我们目前的远紫外（FUV）和NUV的星等为16个检测到的UDG候选人，并比较这些星系的颜色星等和特定的星星形成率图上的当地人口的星系。NUV探测到的UDG候选者主要是向恒星形成星系序列的较低恒星质量的延伸，并且没有一个位于高局部星系密度的区域内。UDG候选者跨越了一系列的属性，尽管几乎所有的都是静止的，低表面亮度的星系，无论环境如何。
We measure near-ultraviolet (NUV) aperture magnitudes from Galaxy Evolution Explorer images for 258 ultra-diffuse galaxy (UDG) candidates drawn from the initial Systematically Measuring Ultra-Diffuse Galaxies (SMUDGes) survey of ∼300 square degrees surrounding, and including, the Coma galaxy cluster. For the vast majority, 242 of them, we present flux upper limits due either to a lack of significant flux in the aperture or confusion with other objects projected within the aperture. These limits often place interesting constraints on the UDG candidates, indicating that they are non-star-forming or quiescent. In particular, we identify field, quiescent UDG candidates, which are a challenge for formation models and are, therefore, compelling prospects for spectroscopic follow-up and distance determinations. We present far-ultraviolet (FUV) and NUV magnitudes for 16 detected UDG candidates and compare those galaxies to the local population of galaxies on color–magnitude and specific star formation rate diagrams. The NUV-detected UDG candidates form mostly an extension toward lower stellar masses of the star-forming galaxy sequence, and none of these lie within regions of high local galaxy density. UDG candidates span a range of properties, although almost all are consistent with being quiescent, low surface brightness galaxies, regardless of environment.