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arXiv 1401.7773astro-ph.GAastro-ph.CO
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赫歇尔参考巡天的冷气性质。I. 12 CO(1-0)和HI数据

Cold gas properties of the Herschel Reference Survey. I. 12CO(1-0) and HI data

A. Boselli, L. Cortese, M. Boquien

摘要:

我们对赫歇尔参考巡天(HRS)中的59个晚型星系进行了新的~(12)CO(1-0)观测,HRS是一个完整的K波段选择的体积有限(15 <D< 25 Mpc)的邻近星系样本,其形态类型和光度范围很广。我们研究了不同的配方,以纠正不同大小和倾角的附近星系的孔径效应的单光束观测。这是通过比较沿长轴的单光束和多光束观测来完成的,这些观测使用不同的经验或分析处方进行了孔径效应校正,并将其与几个附近星系的综合地图进行了比较,包括通过不同的调查观察到的边缘系统。由此得到的配方是一个分析函数,它是通过假设晚型星系是三维指数衰减盘来确定的,其特征标度长度r_CO} = 0.2 r_24.5,其中r_24.5是24.5 mag arcsec^-2处的光学g(或B)带等照度线半径(25 mag arcsec^-2),以及标度高度z_CO = 1/100 r_24.5。我们的新的CO数据,然后结合那些在文献中产生的最新目录的HRS的CO观测,现在包括225的322个星系的完整样本。应用三维指数圆盘积分法测量样品中所有星系的总CO通量,然后利用常数和依赖于光度的XCO转换因子将其转换为分子气体质量。我们还收集HI数据的315 HRS星系从文献中,并提出它在一个均匀的形式。

英文摘要:

We present new 12CO(1-0) observations of 59 late-type galaxies belonging to the Herschel Reference Survey (HRS), a complete K-band-selected, volume-limited (15 <D< 25 Mpc) sample of nearby galaxies spanning a wide range in morphological type and luminosity. We studied different recipes to correct single-beam observations of nearby galaxies of different sizes and inclinations for aperture effects. This was done by comparing single-beam and multiple-beam observations along the major axis, which were corrected for aperture effects using different empirical or analytical prescriptions, to integrated maps of several nearby galaxies, including edge-on systems observed by different surveys. The resulting recipe is an analytical function determined by assuming that late-type galaxies are 3D exponentially declining discs with a characteristic scale length r_CO} = 0.2 r_24.5, where r_24.5 is the optical, g- (or B-) band isophotal radius at the 24.5 mag arcsec^-2 (25 mag arcsec^-2), as well as a scale height z_CO = 1/100 r_24.5. Our new CO data are then combined with those available in the literature to produce the most updated catalogue of CO observations for the HRS, now including 225 out of the 322 galaxies of the complete sample. The 3D exponential disc integration is applied to all the galaxies of the sample to measure their total CO fluxes, which are later transformed into molecular gas masses using a constant and a luminosity-dependent X_CO conversion factor. We also collect HI data for 315 HRS galaxies from the literature and present it in a homogenised form.

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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