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arXiv 1002.2475astro-ph.GA
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6-GHz甲醇多束脉泽星表I:银河系中心区,345 - 6

The 6-GHz methanol multibeam maser catalogue I: Galactic Centre region, longitudes 345 to 6

J. L. Caswell, G. A. Fuller, J. A. Green, A. Avison, S. L. Breen, K. J. Brooks, M. G. Burton, A. Chrysostomou, J. Cox, P. J. Diamond, S. P. Ellingsen, M. D. Gra… 展开作者

J. L. Caswell, G. A. Fuller, J. A. Green, A. Avison, S. L. Breen, K. J. Brooks, M. G. Burton, A. Chrysostomou, J. Cox, P. J. Diamond, S. P. Ellingsen, M. D. Gray, M. G. Hoare, M. R. W. Masheder, N. M. McClure-Griffiths, M. R. Pestalozzi, C. J. Phillips, L. Quinn, M. A. Thompson, M. A. Voronkov, A. J. Walsh, D. Ward-Thompson, D. Wong-McSweeney, J. A. Yates, R. J. Cohen

摘要:

我们用帕克斯望远镜上的7光束接收器对6668兆赫的甲醇脉泽进行了银河平面巡天。在这里,我们提出的结果,从第一部分,它提供了一个大的区域周围的银河系中心的敏感无偏覆盖。本文给出了从银心345 $^{\circ}$到6 $^{\circ}$经度范围内183个甲醇脉泽站点的详细资料。在该中心的6个$^{\circ}$内,我们发现了88个脉泽地点,其中一半以上(48个)是新发现的。脉泽被限制在一个狭窄的银河系纬度范围内,这表明在银河系中心距离和更远的地方有许多源,并且被限制在一个薄的盘人口中;没有可能归因于银河系隆起的高纬度人口。在银河系中心2 $^{\circ}$范围内,脉泽速度都在-60到+77 \kms之间,这个范围比在CO观测到的540 \kms范围小得多。在其他地方,具有最高正速度(+107 \kms)的脉泽令人惊讶地出现在经度355 $^{\circ}$附近,很可能归因于银河系棒。具有最大负速度(-127 \kms)的脉泽位于经度346 $^{\circ}$附近,在“3千秒差距臂”近侧的超速轨迹内。它具有与3千秒差距臂的近侧和远侧相关的脉泽群中最极端的速度,靠近银河系中心的脉泽空间密度通常较低,除了在中心本身的0.25千秒差距以内的“银河系中心区”,那里的脉泽空间密度高50倍,这一点由经度分布暗示,并由不寻常的速度证实。

英文摘要:

We have conducted a Galactic plane survey of methanol masers at 6668 MHz using a 7-beam receiver on the Parkes telescope. Here we present results from the first part, which provides sensitive unbiased coverage of a large region around the Galactic Centre. Details are given for 183 methanol maser sites in the longitude range 345$^{\circ}$ through the Galactic Centre to 6$^{\circ}$. Within 6$^{\circ}$ of the Centre, we found 88 maser sites, of which more than half (48) are new discoveries. The masers are confined to a narrow Galactic latitude range, indicative of many sources at the Galactic Centre distance and beyond, and confined to a thin disk population; there is no high latitude population that might be ascribed to the Galactic Bulge. Within 2$^{\circ}$ of the Galactic Centre the maser velocities all lie between -60 and +77 \kms, a range much smaller than the 540 \kms range observed in CO. Elsewhere, the maser with highest positive velocity (+107 \kms) occurs, surprisingly, near longitude 355$^{\circ}$ and is probably attributable to the Galactic bar. The maser with the most negative velocity (-127 \kms) is near longitude 346$^{\circ}$, within the longitude-velocity locus of the near side of the `3-kpc arm'. It has the most extreme velocity of a clear population of masers associated with the near and far sides of the 3-kpc arm. Closer to the Galactic Centre the maser space density is generally low, except within 0.25 kpc of the Centre itself, the `Galactic Centre Zone', where it is 50 times higher, which is hinted at by the longitude distribution, and confirmed by the unusual velocities.

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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