Polarimetric and Photometric Investigation of the Dark Globule LDN 1225: Distance, Extinction Law, and Magnetic Fields
文献类型：期刊论文
| 作者 | Eswaraiah, Chakali1,2,3,4; Lai, Shih-Ping2; Ma, Yuehui5,6,7; Pandey, Anil K.8; Jose, Jessy9; Chen, Zhiwei5,6; Samal, Manash R.10; Wang, Jia-Wei1; Sharma, Saurabh8; Ojha, D. K.11 |
| 刊名 | ASTROPHYSICAL JOURNAL
 |
| 出版日期 | 2019-04-10 |
| 卷号 | 875期号:1页码:24 |
| ISSN号 | 0004-637X |
| 关键词 | dust, extinction ISM: clouds local interstellar matter magnetic fields polarization |
| DOI | 10.3847/1538-4357/ab0a0c |
| 通讯作者 | Eswaraiah, Chakali(eswaraiahc@nao.cas.cn) |
| 英文摘要 | We present results based on the optical R-band observations of the polarization of 280 stars distributed toward the dark globule LDN 1225. Parallaxes from Gaia data release 2 along with the polarization data of -200 stars have been used to (a) constrain the distance of LDN 1225 as 830 +/- 83 pc, (b) determine the contribution of interstellar polarization, and (c) characterize the dust properties and delineate the magnetic field (B-field) morphology of LDN 1225. We find that B-fields are more organized and exhibit a small dispersion of 12 degrees. Using the (CO)-C-12 molecular line data from the Purple Mountain Observatory, along with the column density and dispersion in B-fields, we estimate the B-field strength to be similar to 56 +/- 10 mu G, the ratio of magnetic to turbulent pressure to be similar to 3 +/- 2, and the ratio of mass to magnetic flux (in units of the critical value) to be <1. These results indicate the dominant role of B-fields in comparison to turbulence and gravity in rendering the cloud support. B-fields are aligned parallel to the low-density parts (traced by a (CO)-C-12 map) of the cloud; in contrast, they are neither parallel nor perpendicular to the high-density core structures (traced by (CO)-C-13 and (CO)-O-18 maps). LDN 1225 hosts two 70 mu m sources, which seem to be low-mass Class 0 sources. The ratio of total to selective extinction derived using optical and near-infrared photometric data is found to be anomalous (R-v = 3.4), suggesting the growth of dust grains in LDN 1225. The polarization efficiency of dust grains follows a power law with an index of -0.7, implying that optical polarimetry traces B-fields in the outer parts of the cloud. |
| WOS关键词 | LATITUDE MOLECULAR CLOUD ; STAR-FORMATION ; INTERSTELLAR EXTINCTION ; INFRARED POLARIMETRY ; GRAIN ALIGNMENT ; CO SURVEY ; STELLAR CONTENTS ; STANDARD STARS ; OPEN CLUSTERS ; DENSE CORES |
| WOS研究方向 | Astronomy & Astrophysics |
| 语种 | 英语 |
| 出版者 | IOP PUBLISHING LTD |
| WOS记录号 | WOS:000464984900018 |
| 源URL | [http://libir.pmo.ac.cn/handle/332002/24468]  |
| 专题 | 中国科学院紫金山天文台 |
| 通讯作者 | Eswaraiah, Chakali |
| 作者单位 | 1.Natl Tsing Hua Univ, Inst Astron, 101,Sect 2,Kuang Fu Rd, Hsinchu 30013, Taiwan 2.Chinese Acad Sci, CAS Key Lab FAST, NAOC, Beijing 100101, Peoples R China 3.Chinese Acad Sci, Natl Astron Observ, Datun Rd, Beijing 100101, Peoples R China 4.Indian Inst Astrophys, Koramangala 2nd Block, Bengaluru 560034, India 5.Chinese Acad Sci, Purple Mt Observ, 2 West Beijing Rd, Nanjing 210008, Jiangsu, Peoples R China 6.Chinese Acad Sci, Key Lab Radio Astron, 2 West Beijing Rd, Nanjing 210008, Jiangsu, Peoples R China 7.Univ Chinese Acad Sci, 19A Yuquan Rd, Beijing 100049, Peoples R China 8.Aryabhatta Res Inst Observat Sci ARIES, Naini Tal 263002, Uttarakhand Sta, India 9.Indian Inst Sci Educ & Res Tirupati, Karakambadi Rd,Mangalam PO, Tirupati 517507, Andhra Pradesh, India 10.Phys Res Lab, Ahmadabad 380009, Gujarat, India |
| 推荐引用方式 GB/T 7714 | Eswaraiah, Chakali,Lai, Shih-Ping,Ma, Yuehui,et al. Polarimetric and Photometric Investigation of the Dark Globule LDN 1225: Distance, Extinction Law, and Magnetic Fields[J]. ASTROPHYSICAL JOURNAL,2019,875(1):24. |
| APA | Eswaraiah, Chakali.,Lai, Shih-Ping.,Ma, Yuehui.,Pandey, Anil K..,Jose, Jessy.,...&Ojha, D. K..(2019).Polarimetric and Photometric Investigation of the Dark Globule LDN 1225: Distance, Extinction Law, and Magnetic Fields.ASTROPHYSICAL JOURNAL,875(1),24. |
| MLA | Eswaraiah, Chakali,et al."Polarimetric and Photometric Investigation of the Dark Globule LDN 1225: Distance, Extinction Law, and Magnetic Fields".ASTROPHYSICAL JOURNAL 875.1(2019):24. |
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来源：紫金山天文台
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