Spiral and dwarf galaxies' kinematics and optical instrumentation

螺旋星系和矮星系的运动学和光学仪器

• 批准号: 90037-2006
• 负责人: Carignan, Claude
• 金额: $ 2.91万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=390764
• 关键词: Spiral; dwarf; galaxies; kinematics; optical

The main goal of our different research projects is to determine the physical parameters (e.g. density laws, total extent) of the Dark Matter present in spiral and dwarf galaxies. The methodology used is the following. First, from 21cm HI observations obtained at the Very Large Array (New-Mexico), Westerbork (Holland), the Australia Telescope, and at DRAO (Penticton, BC), it is possible to derive the rotation curves of those galaxies over 2 to 5 times their optical diameters and thus to measure the mass present out to the last measured velocity point (kinematical mass). Those observations also give us the gas mass, which can sometimes be more important than the stellar mass in certain dwarf galaxies. Then, the light distribution (surface photometry) allows us to derive the stellar mass (using near infrared data, e.g. Spitzer). The difference between the kinematical mass and the luminous mass (stars & gas) is thus a measure of the Dark Matter component. Since the mass models are very sensitive to the rising part of the rotation curves, higher resolution 3D data, obtained from Fabry-Perot interferometry, must be combined to the HI data for the inner parts (to avoid the beam smearing effect of HI data). This is especially important if someone wants to determine whether the dark matter density profiles are flat (e.g. isothermal) or cuspy (e.g. NFW) in the very inner parts, as predicted by Cold Dark Matter cosmological simulations. In order to get the highest Signal-to-Noise data possible in the very critical inner parts, we built our own Image Photon Counting System (IPCS) called FaNTOmM, which we used not only on the 1,6m telescope of the Observatoire du mont Mégantic, but also on the 3,6m telescopes of the Canada-France-Hawaii (CFHT) and of the ESO (La Silla). The first generation of FaNTOmM used a GaAs intensifier tube which gives a DQE ~ 30% (meaning that 30% of the incoming photons are detected), as compared to ~4-5% for the old IPCS and we are working on the second generation camera based on a L3CCD chip which should provide a DQE > 80%.

我们不同研究项目的主要目标是确定螺旋和矮星系中存在的暗物质的物理参数（例如密度法，总范围）。所使用的方法是以下内容。首先，从在非常大的阵列（New-Mexico），Westerbork（荷兰），澳大利亚望远镜和Drao（BC Penticton，BC）中获得的21cm HI观测值，可以在2至5倍的光直径上得出这些星系的旋转曲线，从而使质量量的质量量度高于最终测量值（kin）。这些观察结果还给我们带来了气体，有时比某些矮星系中的恒星质量更重要。然后，光分布（表面光度法）使我们能够得出恒星质量（使用近红外数据，例如Spitzer）。因此，运动质量质量和发光质量（恒星和气体）之间的差异是对暗物质成分的度量。由于质量模型对旋转曲线的上升部分非常敏感，因此必须将从Fabry-Perot干扰获得的更高分辨率3D数据组合到内部部件的HI数据（以避免HI数据的光束涂抹效果）。如通过冷暗物质宇宙学模拟所预测的那样，如果某人想确定暗物质密度曲线是平坦的（例如等温）还是cuspy（例如等温）或cuspy（例如NFW），这一点尤其重要。为了在非常关键的内部部分中获得最高的信噪数据，我们构建了称为Fantomm的图像光子计数系统（IPC），我们不仅在梅尼加西大西洋的1,60万望远镜上使用了它，而且在3,6M望远镜的望远镜的望远镜上使用了3,600万望远镜，而且在加拿大 - 弗朗西 - 弗朗西 - 弗朗西 - 弗朗西 - 弗朗西 - 弗朗西·赫瓦伊（Canca-France-Hawaii）（CFHT）（CFHT）（CFHT）和eSON（cfht）（cfhaii and）上。第一代FANTOMM使用了GAAS增强器管，该管的DQE 〜30％（这意味着检测到30％的传入照片），相比之下，旧IPC的〜4-5％，我们正在基于L3CCD芯片的第二代摄像头，该摄像头应提供DQE> 80％。