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arXiv 1609.01162astro-ph.GAastro-ph.IM
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星系和质量集合体(GAMA):从SDSS数据探测低表面亮度星系

Galaxy And Mass Assembly (GAMA): detection of low-surface-brightness galaxies from SDSS data

R. P. Williams, I. K. Baldry, L. S. Kelvin, P. A. James, S. P. Driver, M. Prescott, S. Brough, M. J. I. Brown, L. J. M. Davies, B. W. Holwerda, J. Liske, P. Nor… 展开作者

R. P. Williams, I. K. Baldry, L. S. Kelvin, P. A. James, S. P. Driver, M. Prescott, S. Brough, M. J. I. Brown, L. J. M. Davies, B. W. Holwerda, J. Liske, P. Norberg, A. J. Moffett, A. H. Wright

摘要:

我们报告的搜索新的低表面亮度星系(LSBG)使用斯隆数字巡天(SDSS)的数据在GAMA赤道领域。搜索方法包括掩蔽SDSS照片检测到的物体,结合加权的gri图像以最大化预期的信噪比(SNR),并平滑图像。然后,处理后的图像通过检测算法运行,该算法找到所有高于设定阈值的像素,并根据它们彼此的接近程度将它们分组。探测列表中的杂质被清除,比如衍射尖峰和被遮蔽物体的微弱翅膀。从这些中,选择可能最亮的总通量,产生了343个LSBG的列表,这些LSBG已经使用VISTA Kilo degree Infrared Galaxy Survey(VIKING)成像确认。使用更深的VIKING Z带作为孔径定义带,对该样品的光度测定进行了改进。测量它们的$g-i$和$J-K$的颜色表明,大多数是一致的,在红移小于0.2。测光进行使用的每个检测给出表面亮度的$μ_{r} \ge 25 \, \mathrm{mag} \, \mathrm{arcsec}^{-2}$和幅度的$r > 19.8$ MAG的一个光圈。这些星系都没有足够的亮度是在GAMA的主要调查限制,但可能是未来更深的调查的一部分,以测量低质量的星系恒星质量函数的结束。

英文摘要:

We report on a search for new low-surface-brightness galaxies (LSBGs) using Sloan Digital Sky Survey (SDSS) data within the GAMA equatorial fields. The search method consisted of masking objects detected with SDSS photo, combining gri images weighted to maximise the expected signal-to-noise ratio (SNR), and smoothing the images. The processed images were then run through a detection algorithm that finds all pixels above a set threshold and groups them based on their proximity to one another. The list of detections was cleaned of contaminants such as diffraction spikes and the faint wings of masked objects. From these, selecting potentially the brightest in terms of total flux, a list of 343 LSBGs was produced having been confirmed using VISTA Kilo-degree Infrared Galaxy Survey (VIKING) imaging. The photometry of this sample was refined using the deeper VIKING Z band as the aperture-defining band. Measuring their $g-i$ and $J-K$ colours shows that most are consistent with being at redshifts less than 0.2. The photometry is carried out using an AUTO aperture for each detection giving surface brightnesses of $μ_{r} \ge 25 \, \mathrm{mag} \, \mathrm{arcsec}^{-2}$ and magnitudes of $r > 19.8$ mag. None of these galaxies are bright enough to be within the GAMA main survey limit but could be part of future deeper surveys to measure the low-mass end of the galaxy stellar mass function.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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