A global view on star formation: The GLOSTAR Galactic plane survey. II. Supernova Remnants in the first quadrant of the Milky Way
Rohit Dokara, A. Brunthaler, K. M. Menten, S. A. Dzib, W. Reich, W. D. Cotton, L. D. Anderson, C. -H. R. Chen, Y. Gong, S. -N. X. Medina, G. N. Ortiz-León, M. R… 展开作者
Rohit Dokara, A. Brunthaler, K. M. Menten, S. A. Dzib, W. Reich, W. D. Cotton, L. D. Anderson, C. -H. R. Chen, Y. Gong, S. -N. X. Medina, G. N. Ortiz-León, M. Rugel, J. S. Urquhart, F. Wyrowski, A. Y. Yang, H. Beuther, S. J. Billington, T. Csengeri, C. Carrasco-González, N. Roy
备注：
To be published in A&A. 36 pages, 22 figures in text, 80 figures in Appendix. Revision 1: grammar, position information of one object, other minor changes. Revision 2: added arXiv link to the main GLOSTAR paper
Context. The properties of the population of Galactic supernova remnants (SNRs) are essential to our understanding of the dynamics of the interstellar medium (ISM) in the Milky Way. However, the completeness of the catalog of Galactic SNRs is expected to be only ${\sim}30\%$, with on order 700 SNRs yet to be detected. Deep interferometric radio continuum surveys of the Galactic plane help in rectifying this apparent deficiency by identifying low surface brightness SNRs and compact SNRs that have not been detected in previous surveys. However, SNRs are routinely confused with H II regions, which can have similar radio morphologies. Radio spectral index, polarization, and emission at mid-infrared (MIR) wavelengths can help distinguish between SNRs and H II regions. Aims. We aim to identify SNR candidates using continuum images from the Karl G. Jansky Very Large Array GLObal view of the STAR formation in the Milky Way (GLOSTAR) survey. Methods. GLOSTAR is a C-band (4--8 GHz) radio wavelength survey of the Galactic plane covering $358^{\circ} \leq l \leq 60^{\circ}, |b| \leq 1^{\circ}$. The continuum images from this survey, which resulted from observations with the most compact configuration of the array, have an angular resolution of $18''$. We searched for SNRs in these images to identify known SNRs, previously identified SNR candidates, and new SNR candidates. We study these objects in MIR surveys and the GLOSTAR polarization data to classify their emission as thermal or nonthermal. Results. We identify 157 SNR candidates, of which 80 are new. Polarization measurements provide evidence of nonthermal emission from 9 of these candidates. We find that two previously identified candidates are filaments. We also detect emission from 91 of the 94 known SNRs in the survey region. Four of these are reclassified as H II regions following detection in MIR surveys. (Abridged)
Context. While over 1000 supernova remnants (SNRs) are estimated to exist in the Milky Way, only less than 400 have been found to date. In the context of this apparent deficiency, more than 150 SNR candidates were recently identified in the D-configuration Very Large Array (VLA-D) continuum images of the 4--8 GHz global view on star formation (GLOSTAR) survey, in the Galactic longitude range $-2^\circ<l<60^\circ$. Aims. We attempt to find evidence of nonthermal synchrotron emission from 35 SNR candidates in the region of Galactic longitude range $28^\circ<l<36^\circ$, and also to study the rad…
We take advantage of the red clump stars to build the relation of the optical extinction (AV) and distance in each direction of supernova remnants (SNRs) with known extinction in the fourth Galactic quadrant. The distances of 9 SNRs are well determined by this method. Their uncertainties range from 10% to 30%, which is significantly improved for 8 SNRs, G279.0+1.1, G284.3-1.8, G296.1-0.5, G299.2-2.9, G308.4-1.4, G309.2-0.6, G309.8- 2.6, G332.4-0.4. In addition, SNR G284.3-1.8 with the new distance of 5.5 kpc is not likely associated with the PSR J1016-5857 at 3 kpc.
A global view on star formation: The GLOSTAR Galactic plane survey XII. Effelsberg's continuum view and data release
Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；National Radio Astronomy Observatory（国家射电天文台）；Center for Astrophysics | Harvard & Smithsonian（哈佛史密森尼天体物理中心）
We report the detection of near-infrared (NIR) [Fe II] (1.644 $μ$m) and H$_{2}$ 1-0 S(1) (2.122 $μ$m) line features associated with Galactic supernova remnants (SNRs) in the first quadrant using two narrowband imaging surveys, UWIFE and UWISH2. Among the total of 79 SNRs fully covered by both surveys, we found 19 [Fe II]-emitting and 19 H$_{2}$-emitting SNRs, giving a detection rate of 24% for each. Eleven SNRs show both emission features. The detection rate of [Fe II] and H$_{2}$ peaks at the Galactic longitude ($l$) of $40^{\circ}$-$50^{\circ}$ and $30^{\circ}$-$40^{\circ}$, respectively, an…
We carry out a project to independently measure the distances of supernova remnants (SNRs) in the first quadrant of the Galaxy. In this project, red clump (RC) stars are used as standard candles and extinction probes to build the optical extinction (A$_V$) - distance(D) relation in each direction of extinction-known SNRs. 15 SNRs' distances are well determined. Among them, the distances of G65.8-0.5, G66.0-0.0 and G67.6+0.9 are given for the first time. We also obtain 32 upper/lower limits of distances, and the distances to G5.7-0.1, G15.1-1.6, G28.8+1.5 and G78.2+2.1 are constrained. Most of …
Young Supernova remnants (SNRs) with smaller angular sizes are likely missing from existing radio SNR catalogues, caused by observational constraints and selection effects. In order to find new compact radio SNR candidates, we searched the high angular resolution (25") THOR radio survey of the first quadrant of the galaxy. We selected sources with non-thermal radio spectra. HI absorption spectra and channel maps were used to identify which sources are galactic and to estimate their distances. Two new compact SNRs were found: G31.299$-$0.493 and G18.760$-$0.072, of which the latter was a previo…
Seoul National University（首尔大学）；Korea Astronomy and Space Science Institute（韩国天文学与宇宙科学研究所）；Subaru Telescope, National Astronomical Observatory of Japan (NAOJ), National Institutes of Natural Sciences (NINS)（昴星团望远镜，日本国立天文台（NAOJ），国立自然科学研究院（NINS））；School of Mathematical and Physical Science, SOKENDAI (The Graduate University for Advanced Studies)（数学与物理科学学院，SOKENDAI（高级研究大学院大学））；University of Kent（肯特大学）；Korea University of Science and Technology (UST)（韩国科学技术院（UST））；Samsung SDS（三星SDS）；Department of Earth Science Education, Kongju National University（公州国立大学地球科学教育系）；UKIRT Observatory, Institute for Astronomy, University of Hawaii（夏威夷大学天文学研究所英国红外望远镜观测台）
Radio continuum emission in the northern Galactic plane: Sources and spectral indices from the THOR survey
银河平面的射电连续巡天可以发现和表征HII区、超新星遗迹（SNRs）、行星状星云（PNe）和河外源。在不同波长的高角分辨率（<25”）下，存在许多调查来研究星际介质（ISM），但在21厘米左右的长射电波长下，没有可比的高分辨率和高灵敏度调查。我们用Karl G. Jansky甚大阵列（VLA）在C配置覆盖六个连续光谱窗口。这些数据提供了我们银河系和数千个河外背景源的紧凑和扩展无线电发射的详细视图。我们使用BLOBCAT软件，提取了10916个源。在去除由合成波束的旁瓣引起的杂散源检测后，我们将10387个源分类为可靠检测。我们将图像平滑到25”的公共分辨率，并提取每个光谱窗口（SPW）中每个源的峰值通量密度，以确定光谱指数$α$（假设$I(ν)\proptoν^α$）。通过与HII区、SNRs、PNE和PNAR的目录交叉匹配，我们发现了840个HII区、52个SNRs、164个PNE和38个PNAR的射电对应物。我们发现了79个与X射线源相关的连续谱源。我们确定了699个可能是高红移星系的超陡光谱源（$α< -1.3$）。我们提取的大约9000个源没有被具体分类，但根据它们的空间和光谱分布，其中很大一部分可能是河外背景源。超过7750个来源在SIMBAD数据库中没有对应物，超过3760个来源在NED数据库中没有对应物。
