导致低表面亮度星系（LSB）存在的确切形成场景和演化过程尚未完全了解。由于LSB的环境以前只在小尺度（低于2 Mpc）上进行过研究，因此在更大尺度上研究LSB星系附近的星系内容可以为我们对这类星系起源的理解增加很多。我们使用SDSS DR 4的光谱主星系样本来研究LSB星系的环境星系密度，并与高表面亮度星系（HSB）附近的星系密度进行比较。环境研究，分为两个红移箱，表明低质量和更大质量的LSB都拥有比HSB更低的星系密度的环境。在2和5百万秒差距之间的尺度上，集团和细丝的尺度上，LSB和HSB之间的星系密度的差异是显着的。为了量化这一点，我们首次推出了LSB-HSB抗偏置器件。得到的LSB-HSB抗偏参数值为10%~ 15%。从这些结果中，我们得出结论，LSB形成于初始宇宙的低密度区域，直到现在一直漂移到大尺度结构的细丝和壁的外部。此外，我们的研究结果以及实际的宇宙学模拟表明，LSB是由先天和后天的混合造成的。
英文摘要：
The exact formation scenarios and evolutionary processes that led to the existence of the class of low surface brightness galaxies (LSBs) have not yet been understood completely. Since the environment of LSBs has been studied before only on small scales (below 2 Mpc), a study of the galaxy content in the vicinity of LSB galaxies on larger scales could add a lot to our understanding of the origin of this galaxy class. We used the spectroscopic main galaxy sample of the SDSS DR4 to investigate the environmental galaxy density of LSB galaxies compared to the galaxy density in the vicinity of high surface brightness galaxies (HSBs). The environment studies, divided into two redshift bins, show that both the low mass, and the more massive LSBs possess an environment with a lower galaxy density than HSBs. The differences in the galaxy density between LSBs and HSBs are significant on scales between 2 and 5 Mpc, the scales of groups and filaments. To quantify this, we have introduced for the first time the LSB-HSB Antibias. The obtained LSB-HSB Antibias parameter has a value of 10%-15%. From these results we conclude that LSBs formed in low-density regions of the initial universe and have drifted until now to the outer parts of the filaments and walls of the large-scale structure. Furthermore, our results, together with actual cosmological simulations, show that LSBs are caused by a mixture of nature and nurture.
We built r-band surface brightness profiles by SDSS data for 16 Seyfert galaxies observed in Crimean Astrophysical Observatory. Obtained profiles can be used for finding more accurate lightcurves for these galaxies.
The Rastall gravity is a modification of Einstein's general relativity, in which the energy-momentum conservation is not satisfied and depends on the gradient of the Ricci curvature. It is in dispute whether the Rastall gravity is equivalent to the general relativity (GR). In this work, we constrain the theory using the rotation curves of Low Surface Brightness (LSB) spiral galaxies. Through fitting the rotation curves of LSB galaxies, we obtain the parameter $β$ of the Rastall gravity. The $β$ values of LSB galaxies satisfy Weak Energy Condition (WEC) and Strong Energy Condition(SEC). Combini…
We conduct a survey of low surface brightness (LSB) satellite galaxies around the Local Volume massive spirals using long exposures with small amateur telescopes. We identified 27 low and very low surface brightness objects around the galaxies NGC,672, 891, 1156, 2683, 3344, 4258, 4618, 4631, and 5457 situated within 10 Mpc from us, and found nothing new around NGC,2903, 3239, 4214, and 5585. Assuming that the dwarf candidates are the satellites of the neighboring luminous galaxies, their absolute magnitudes are in the range of -8.6 > M_B > -13.3, their effective diameters are 0.4-4.7 kpc, and…
The low surface brightness galaxies are gas-rich and yet have a low star formation rate, this is a well-known puzzle. The spiral features in these galaxies are weak and difficult to trace, although this aspect has not been studied much. These galaxies are known to be dominated by the dark matter halo from the innermost regions. Here we do a stability analysis for the galactic disc of UGC 7321, a low surface brightness, superthin galaxy, for which the various observational input parameters are available. We show that the disc is stable against local, linear axisymmetric and non-axisymmetric per…
Cosmological surface brightness dimming of the form $(1+z)^{-4}$ affects all sources. The strong dependence of surface brightness dimming on redshift z suggests the presence of a selection bias when searching for high-redshift galaxies, i.e. we tend to detect only those galaxies with a high surface brightness (SB). However, unresolved knots of emission are not affected by SB dimming, thus providing a way to test the clumpiness of high-z galaxies. Our strategy relies on the comparison of the total flux detected for the same source in surveys characterized by different depth. For all galaxies, d…
We introduce a method for producing a galaxy sample unbiased by surface brightness and stellar mass, by selecting star-forming galaxies via the positions of core-collapse supernovae (CCSNe). Whilst matching $\sim$2400 supernovae from the SDSS-II Supernova Survey to their host galaxies using IAC Stripe 82 legacy coadded imaging, we find $\sim$150 previously unidentified low surface brightness galaxies (LSBGs). Using a sub-sample of $\sim$900 CCSNe, we infer CCSN-rate and star-formation rate densities as a function of galaxy stellar mass, and the star-forming galaxy stellar mass function. Result…
A central question regarding Ultra Diffuse Galaxies (UDGs) is whether they are a separate category to Low Surface Brightness (LSB) galaxies, or just their natural continuation towards low stellar masses. In this letter, we show that the rotation curve of the gas rich UDG AGC 242019 is well fit by a dark matter halo with inner slope that asymptotes to -0.54, and that such fit provides a concentration parameter that matches theoretical expectations. This finding, together with previously works in which shallow inner profiles are derived for UDGs, shows that the structural properties of these gal…
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 brightnes…
Testing Modified Newtonian Dynamics with Rotation Curves of Dwarf and Low Surface Brightness Galaxies
矮星系和低表面亮度星系是测试修正牛顿动力学（MOND）的理想对象，因为在大多数这些星系中，加速度低于MOND适用的阈值。我们从文献中选取了27个矮星系和低表面亮度星系的样本。MOND成功地解释了在这里提供的样本中大约四分之三的星系的观测旋转曲线的一般形状。然而，对于剩下的四分之一，MOND不能充分解释观察到的旋转曲线。考虑到我们样本中星系的距离和倾角的不确定性，一小部分糟糕的MOND预测是可以预料的，这不一定是MOND的问题。我们还采用MOND加速度常数a_0作为自由参数进行拟合，以确定任何系统趋势。我们发现，似乎有一个中心表面亮度和最佳拟合值的a_0之间的相关性，在这个意义上说，较低的表面亮度星系往往有较低的a_0。然而，这种相关性强烈地依赖于少数星系，其旋转曲线可能是不确定的，因为无论是酒吧或翘曲。如果没有这些星系，那么这种趋势的证据就更少了，但是我们发现的a_0 ~ 0.7*10^-8 cm s^-2的平均值比以前的研究结果要低一些。如果外部引力场很重要，那么a_0的拟合值可能会更低。
This work uses observed galaxy surface brightness profiles at high redshifts to determine the cosmological model best suited to interpret these observations. Theoretical predictions of galactic surface brightness profiles are compared to observational data in two cosmological models, $Λ$CDM and Einstein-de Sitter, to calculate the evolutionary effects of different spacetime geometries in these profiles in order to try to find out if the available data is capable of indicating the cosmology that best represents actual galactic brightness profiles observations. Starting from the connection betwe…
