arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1005.2563astro-ph.CO
收藏

M33的PACS和SPIRE光度计图:Herschel M33扩展巡天(HERM33ES)的第一批结果

PACS and SPIRE photometer maps of M33: First results of the Herschel M33 extended survey (HERM33ES)

C. Kramer, C. Buchbender, E. M. Xilouris, M. Boquien, J. Braine, D. Calzetti, S. Lord, B. Mookerjea, G. Quintana-Lacaci, M. Relano, G. Stacey, F. S. Tabatabaei,… 展开作者

C. Kramer, C. Buchbender, E. M. Xilouris, M. Boquien, J. Braine, D. Calzetti, S. Lord, B. Mookerjea, G. Quintana-Lacaci, M. Relano, G. Stacey, F. S. Tabatabaei, S. Verley, S. Aalto, S. Akras, M. Albrecht, S. Anderl, R. Beck, F. Bertoldi, F. Combes, M. Dumke, S. Garcia-Burillo, M. Gonzalez, P. Gratier, R. Gueusten, C. Henkel, F. P. Israel, B. Koribalski, A. Lundgren, J. Martin-Pintado, M. Roellig, E. Rosolowsky, K. F. Schuster, K. Sheth, A. Sievers, J. Stutzki, R. P. J. Tilanus, F. van der Tak, P. van der Werf, M. C. Wiedner

摘要:

在HERM 33 ES重点项目的框架内,我们正在研究附近贫金属螺旋星系M33中的恒星形成星际介质,利用Herschel的高分辨率和灵敏度。我们使用PACS和SPIRE地图在100,160,250,350,和500微米波长,研究的光谱能量分布(SED)的变化与银河系的中心距离。详细的SED建模进行使用方位角平均通量在椭圆环的2千秒差距的宽度,出8千秒差距的银河系为中心的距离。简单的等温和两个组件的灰体模型,与固定的灰尘发射率指数,安装到SED之间的24和500微米,也使用MIPS/斯皮策数据,以获得第一次估计的灰尘的物理条件。远红外和亚毫米波段的图像揭示了M33的分支、打结的螺旋结构。在所有SPIRE图(250-500微米)中都可以看到下面的扩散盘。两个组件适合的SED同意比等温模型与观察到的,总的和径向平均的通量密度。β固定为1.5的双组分模型最适合全局和径向SED。冷尘埃成分明显占主导地位;温暖的成分的相对质量小于0.3%的所有拟合。热分量的温度没有得到很好的约束,发现约为60 K ± 10 K。对于最佳拟合模型,冷组分的温度从2kpc半径内的约24 K显著下降到6 kpc径向距离外的13 K。在β =1.5的情况下,整个星系的平均气尘比是太阳值的1.5倍,与M33的太阳下金属丰度大致一致。

英文摘要:

Within the framework of the HERM33ES key project, we are studying the star forming interstellar medium in the nearby, metal-poor spiral galaxy M33, exploiting the high resolution and sensitivity of Herschel. We use PACS and SPIRE maps at 100, 160, 250, 350, and 500 micron wavelength, to study the variation of the spectral energy distributions (SEDs) with galacto-centric distance. Detailed SED modeling is performed using azimuthally averaged fluxes in elliptical rings of 2 kpc width, out to 8 kpc galacto-centric distance. Simple isothermal and two-component grey body models, with fixed dust emissivity index, are fitted to the SEDs between 24 and 500 micron using also MIPS/Spitzer data, to derive first estimates of the dust physical conditions. The far-infrared and submillimeter maps reveal the branched, knotted spiral structure of M33. An underlying diffuse disk is seen in all SPIRE maps (250-500 micron). Two component fits to the SEDs agree better than isothermal models with the observed, total and radially averaged flux densities. The two component model, with beta fixed at 1.5, best fits the global and the radial SEDs. The cold dust component clearly dominates; the relative mass of the warm component is less than 0.3% for all the fits. The temperature of the warm component is not well constrained and is found to be about 60K plus/minus 10K. The temperature of the cold component drops significantly from about 24K in the inner 2 kpc radius to 13K beyond 6 kpc radial distance, for the best fitting model. The gas-to-dust ratio for beta=1.5, averaged over the galaxy, is higher than the solar value by a factor of 1.5 and is roughly in agreement with the subsolar metallicity of M33.

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。

↑