论文标题
调查对南部HII地区RCW 42的恒星形成活性
Investigating star-formation activity towards the southern HII region RCW 42
论文作者
论文摘要
使用多个波段从近红外到无线电波长，研究了HII区域RCW 42中的星形活性。该南部地区位于5.8 kpc的距离为5.8 kpc，其辐射光度为1.8 $ \ times $ 10 $^6 $ l $ _ {\ odot} $。使用巨大的Metrewave射电望远镜，印度的巨型无线电频率以610和1280 MHz的低无线电频率成像，并显示了HII地区的大量范围，涉及$ 20 \ times 15 $ pc $^2 $。该地区的平均电子数量密度估计为$ \ sim70 $ cm $^{ - 3} $，这表明该云的平均电离分数为$ 11 \％$。使用来自2Mass和Spitzer调查的数据，在该地区发现了扩展的绿色对象EGO G274.0649-01.1460和几个年轻的恒星对象。使用Herschel空间望远镜探测了相关分子云的尘埃发射，该望远镜揭示了该区域中5个团块C1-C5的存在。质量380和390 m $ _ {\ odot} $朝向无线电发射峰的两个毫米排放核心已从1.4 mm的ALMA地图上鉴定出C1。根据与各种恒星形成示踪剂的关联，研究了团块的进化阶段，我们发现所有团块都处于活跃/进化阶段。
The star-forming activity in the HII region RCW 42 is investigated using multiple wavebands, from near-infrared to radio wavelengths. Located at a distance of 5.8 kpc, this southern region has a bolometric luminosity of 1.8 $\times$ 10$^6$ L$_{\odot}$. The ionized gas emission has been imaged at low radio frequencies of 610 and 1280 MHz using the Giant Metrewave Radio Telescope, India and shows a large expanse of the HII region, spanning $20\times 15$ pc$^2$. The average electron number density in the region is estimated to be $\sim70$ cm$^{-3}$, which suggests an average ionization fraction of the cloud to be $11\%$. An extended green object EGO G274.0649-01.1460 and several young stellar objects have been identified in the region using data from the 2MASS and Spitzer surveys. The dust emission from the associated molecular cloud is probed using Herschel Space Telescope, which reveals the presence of 5 clumps, C1-C5, in this region. Two millimetre emission cores of masses 380 and 390 M$_{\odot}$ towards the radio emission peak have been identified towards C1 from the ALMA map at 1.4 mm. The clumps are investigated for their evolutionary stages based on association with various star-formation tracers, and we find that all the clumps are in active/evolved stage.
