DGSAT: Dwarf Galaxy Survey with Amateur Telescopes I. Discovery of low surface brightness systems around nearby spiral galaxies
DGSAT: Dwarf Galaxy Survey with Amateur Telescopes I. Discovery of low surface brightness systems around nearby spiral galaxies
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DGSAT：用业余望远镜进行矮星系巡天 I. 发现附近螺旋星系周围的低表面亮度系统
DOI：
10.1051/0004-6361/201527745
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
F. Neyer
中科院分区：
文献类型：
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作者：
B. Javanmardi;B. Javanmardi;D. Martinez;Pavel Kroupa;Christian Henkel;C. Henkel;Ken Crawford;Karel Teuwen;R. J. Gabany;M. Hanson;T. Chonis;F. Neyer
背景：我们介绍了用业余望远镜观测矮星系(DGSAT)项目，并报告在附近星系NGC2683、NGC3628、NGC4594(M104)、NGC4631、NGC5457(M101)和NGC7814的视野中发现了11个低表面亮度(LSB)星系。目标：DGSAT项目旨在利用小型望远镜的潜力探测大星系周围的LSB特征，并增加局部体积中矮小卫星星系的样本大小。方法：利用长曝光图像，探索目标旋涡星系的视场，以寻找延伸的低表面亮度物体。在确定候选矮小星系后，通过将模型与其光线轮廓进行拟合来提取它们的观测属性。结果：我们在NGC2683、3628、4594、4631、5457和7814区域分别发现了3个、1个、3个、1个、1个和2个新的LSB星系。除了新发现的星系外，我们还分析了九个已知星系的结构性质。所有这20个候选矮小星系的有效表面亮度都在$25.3\less sim\Mu_{e}\less_im28.8$mag.arcsec$^{-2}$范围内，并符合指数为$n\less sim 1$的SERSIC轮廓。假设它们位于上述大质量星系附近，它们的$r带绝对星等、有效半径和光度分别在$-15.6\less sim M_r\less sim-7.8$、160pC$\less sim R_e\less sim$4.1kpc和$0.1\x 10^6\lesssim\left(\frac{L}{L_{\odot}}\right)_r\lesssim127\x 10^6$之间。要确定这些LSB星系是否真的是上述大质量星系的卫星，需要通过进一步的观测来确定它们的距离。结论：使用小型望远镜，我们可以很容易地探测到LSB星系，它的性质与本地群中已知的矮星系相似。
Context: We introduce the Dwarf Galaxy Survey with Amateur Telescopes (DGSAT) project and report the discovery of eleven low surface brightness (LSB) galaxies in the fields of the nearby galaxies NGC 2683, NGC 3628, NGC 4594 (M104), NGC 4631, NGC 5457 (M101), and NGC 7814. Aims: The DGSAT project aims to use the potential of small-sized telescopes to probe LSB features around large galaxies and to increase the sample size of the dwarf satellite galaxies in the Local Volume. Methods: Using long exposure images, fields of the target spiral galaxies are explored for extended low surface brightness objects. After identifying dwarf galaxy candidates, their observed properties are extracted by fitting models to their light profiles. Results: We find three, one, three, one, one, and two new LSB galaxies in the fields of NGC 2683, 3628, 4594, 4631, 5457, and 7814, respectively. In addition to the newly found galaxies, we analyse the structural properties of nine already known galaxies. All of these 20 dwarf galaxy candidates have effective surface brightnesses in the range $25.3\lesssim\mu_{e}\lesssim28.8$ mag.arcsec$^{-2}$ and are fit with Sersic profiles with indices $n\lesssim 1$. Assuming that they are in the vicinity of the above mentioned massive galaxies, their $r$-band absolute magnitudes, their effective radii, and their luminosities are in the ranges $-15.6 \lesssim M_r \lesssim -7.8$, 160 pc $\lesssim R_e \lesssim$ 4.1 kpc, and $0.1\times 10^6 \lesssim\left(\frac{L}{L_{\odot}}\right)_r\lesssim127 \times 10^6$, respectively. To determine whether these LSB galaxies are indeed satellites of the above mentioned massive galaxies, their distances need to be determined via further observations. Conclusions: Using small telescopes, we are readily able to detect LSB galaxies with similar properties to the known dwarf galaxies of the Local Group.