论文标题
外星系II中恒星形成的人口普查：GLIMPSE360场
A Census of Star Formation in the Outer Galaxy II: The GLIMPSE360 Field
论文作者
论文摘要
我们已经从65 \ degr $ <l <$ <$ 265 \ degr〜中对恒星形成的研究进行了研究。此{\ it Spitzer}温暖的任务计划映射了IRAC的外部银河系平面，为3.6和4.5〜 $μ$ m。我们将IRAC，{\ it Wise}和2个MASS目录结合在一起，以及我们先前来自另一个外部星系调查的结果，并确定了整个田地上的47,338个年轻恒星对象（YSO），跨越了$> $ 180 \ degr \ degr \ degr \。使用合并后的目录中的$ dbscan $方法，我们确定具有5个或更多成员的YSO的618个群集或聚合。我们确定10,476级I类，29,604级和7,325级II类/III级YSO。确定为群集成员的YSO的比率为25,528/47,338，或54 \％。我们发现已确定的100个群集以前在{\ it Wise} \ ion {H} {2}调查中测量了距离。我们在这些簇中YSO的光谱能分布（SED）拟合中使用了这些距离，其中96个具有$ <3σ$拟合的YSO。我们使用拟合SED模型的派生质量来估计内部和外星系簇中的初始质量函数（IMF）：将簇除以式中心距离，斜率为$γ= 1.87 \ pm 0.31 \ pm 0.31 $ 0.31 $ 3〜m $ $ $ $ $ $ _ {\ odot} $ $ _ {\ odot} $ $ r_ $ r_ pm = 1.5 $ r_ {gal} <11.5 $ {gal} <11.5 kpc， 0.24 $以上3〜m $ _ {\ odot} $ for $ r_ {gal}> 11.5 $ 〜kpc。发现合并的IMF的坡度为$γ= 1.92 \ pm 0.42 $上方3〜m $ _ {\ odot} $。这些值在不确定性中彼此一致，并且与内部星系高质量星形成区域中的文献值是一致的。这些斜率也可能与通用的Salpeter IMF一致。
We have conducted a study of star formation in the outer Galaxy from 65\degr$< l <$265\degr~in the region observed by the GLIMPSE360 program. This {\it Spitzer} warm mission program mapped the plane of the outer Milky Way with IRAC at 3.6 and 4.5~$μ$m. We combine the IRAC, {\it WISE}, and 2MASS catalogs and our previous results from another outer Galaxy survey and identify a total of 47,338 Young Stellar Objects (YSOs) across the field spanning $>$180\degr\ in Galactic longitude. Using the $DBSCAN$ method on the combined catalog, we identify 618 clusters or aggregations of YSOs having 5 or more members. We identify 10,476 Class I, 29,604 Class II, and 7,325 anemic Class II/Class III YSOs. The ratio of YSOs identified as members of clusters was 25,528/47,338, or 54\%. We found 100 of the clusters identified have previously measured distances in the {\it WISE} \ion{H}{2} survey. We used these distances in our spectral energy distribution (SED) fitting of the YSOs in these clusters, of which 96 had YSOs with $<3σ$ fits. We used the derived masses from the SED model fits to estimate the initial mass function (IMF) in the inner and outer Galaxy clusters: dividing the clusters by Galactocentric distances, the slopes were $Γ= 1.87 \pm 0.31$ above 3~M$_{\odot}$ for $R_{Gal} < 11.5$~kpc and $Γ= 1.15 \pm 0.24$ above 3~M$_{\odot}$ for $R_{Gal} > 11.5$~kpc. The slope of the combined IMF was found to be $Γ= 1.92 \pm 0.42$ above 3~M$_{\odot}$. These values are consistent with each other within the uncertainties, and with literature values in the inner Galaxy high-mass star formation regions. The slopes are likely also consistent with a universal Salpeter IMF.
