The Bolocam Galactic Plane Survey -- II. Catalog of the Image Data
Erik Rosolowsky, Miranda K. Dunham, Adam Ginsburg, Eric Todd Bradley, James Aguirre, John Bally, Cara Battersby, Claudia Cyganowski, Darren Dowell, Meredith Dro… 展开作者
Erik Rosolowsky, Miranda K. Dunham, Adam Ginsburg, Eric Todd Bradley, James Aguirre, John Bally, Cara Battersby, Claudia Cyganowski, Darren Dowell, Meredith Drosback, Neal J. Evans, Jason Glenn, Paul Harvey, Guy S. Stringfellow, Josh Walawender, Jonathan P. Williams
We present a catalog of 8358 sources extracted from images produced by the Bolocam Galactic Plane Survey (BGPS). The BGPS is a survey of the millimeter dust continuum emission from the northern Galactic plane. The catalog sources are extracted using a custom algorithm, Bolocat, which was designed specifically to identify and characterize objects in the large-area maps generated from the Bolocam instrument. The catalog products are designed to facilitate follow-up observations of these relatively unstudied objects. The catalog is 98% complete from 0.4 Jy to 60 Jy over all object sizes for which the survey is sensitive (<3.5'). We find that the sources extracted can best be described as molecular clumps -- large dense regions in molecular clouds linked to cluster formation. We find the flux density distribution of sources follows a power law with dN/dS ~S^(-2.4 +/- 0.1) and that the mean Galactic latitude for sources is significantly below the midplane: <b>=(-0.095 +/- 0.001) deg.
We present an expanded distance catalog for 1,710 molecular cloud structures identified in the Bolocam Galactic Plane Survey (BGPS) version 2, representing a nearly threefold increase over the previous BGPS distance catalog. We additionally present a new method for incorporating extant data sets into our Bayesian distance probability density function (DPDF) methodology. To augment the dense-gas tracers (e.g., HCO+(3-2), NH3(1,1)) used to derive line-of-sight velocities for kinematic distances, we utilize the Galactic Ring Survey 13CO(1-0) data to morphologically extract velocities for BGPS sou…
The Bolocam Galactic Plane Survey. X. A Complete Spectroscopic Catalog of Dense Molecular Gas Observed toward 1.1 mm Dust Continuum Sources with 7.5 <= l <= 194 degrees
Bolocam Galactic Plane Survey（BGPS）是一个1.1毫米的连续测量，覆盖整个银河系170平方度的密集尘埃团。我们使用Heinrich Hertz亚毫米波望远镜的稠密气体示踪剂HCO+和N2 H + 3-2，对Bolocam银河系平面巡天v1.0.1目录中7.5 <= 1 <= 194度之间的所有6194个源进行了光谱观测。这是迄今为止对银河系致密分子气体进行的最大规模的有针对性的光谱调查。我们发现独特的速度为3126（50.5%）的BGPS v1.0.1源观察。没有HCO+ 3 - 2发射的强N2 H + 3 -2发射（T_{mb} > 0.5 K）在该星表中没有出现。我们表征了致密分子气体向整个样品发射的性质。HCO+是非常亚热填充和3-2过渡是光学厚朝向大多数BGPS团块。观测到的线宽中值为3.3 km/s，与BGPS团块内的超音速湍流一致。我们发现致密分子气体的积分强度和1.1毫米的峰值通量和气体动力学温度来自以前发表的NH3观测之间的强相关性。这些强度相关性是由3-2跃迁对激发条件的敏感性驱动的，而不是由分子柱密度或丰度的变化驱动的。我们确定了一个子集的113个来源与更强的N2 H+比HCO+的综合强度，但我们发现N2 H + / HCO+比和1.1毫米的连续通量密度，气体动力学温度，或线宽之间没有相关性。自我专注的情况很少（1.3%）。
We present 107 maps of continuum emission at 350 microns from Galactic molecular clumps. Observed sources were mainly selected from the Bolocam Galactic Plane Survey (BGPS) catalog, with 3 additional maps covering star forming regions in the outer Galaxy. The higher resolution of the SHARC-II images (8.5" beam) compared with the 1.1 mm images from BGPS (33" beam) allowed us to identify a large population of smaller substructures within the clumps. A catalog is presented for the 1386 sources extracted from the 350 micron maps. The color temperature distribution of clumps based on the two wavele…
The Bolocam Galactic Plane Survey. VIII. A Mid-Infrared Kinematic Distance Discrimination Method
我们提出了一种新的距离估计方法尘埃连续识别分子云团块。最近的（亚）毫米银河平面调查已经编目了数万个这样的物体，但对其物理特性的详细研究需要可靠的距离测定。我们推导出贝叶斯距离概率密度函数（DPDF）的770个对象从Bolocam银河平面调查在经度范围7.5 < l < 65。DPDF形式主义是基于运动学距离，并使用外部数据集放置先验距离概率，以解决运动学距离模糊（KDA）的对象在银河系内部。我们目前的先验知识与致密分子区尘埃的中红外吸收和分子气体的银河系分布有关。通过假设银河系中红外辐射的数值模型和简单的辐射转移，我们匹配的毫米热尘埃发射的形态与中红外吸收计算距离歧视的先验DPDF。首先从（亚）毫米源目录中选择对象，避免了对最暗红外暗云（IRDC）的偏见，并扩展了中红外消光探测的日心距离和对比度范围。我们推导出618个分子云团簇的约束良好的KDA分辨率，其中大约15%位于切向距离或超出切向距离。暗到足以被编目为IRDC的天体通常位于近运动学距离处。与银河环巡天KDA分辨率的距离比较产生了92%的一致性，银河正面视图显示了人马座和盾牌-半人马座臂的部分。这种KDA分辨率的方法，通过结合（亚）毫米和中红外观测的分子云团块的大目录的来源，一般适用于其他尘埃连续星系平面调查。
We use the distance probability density function (DPDF) formalism of Ellsworth-Bowers et al. (2013, 2015) to derive physical properties for the collection of 1,710 Bolocam Galactic Plane Survey (BGPS) version 2 sources with well-constrained distance estimates. To account for Malmquist bias, we estimate that the present sample of BGPS sources is 90% complete above 400 $M_\odot$ and 50% complete above 70 $M_\odot$. The mass distributions for the entire sample and astrophysically motivated subsets are generally fitted well by a lognormal function, with approximately power-law distributions at hig…
We sort $4683$ molecular clouds between $10^\circ< \ell <65^\circ$ from the Bolocam Galactic Plane Survey based on observational diagnostics of star formation activity: compact $70$ $μ{\rm m}$ sources, mid-IR color-selected YSOs, ${\rm H_2O}$ and ${\rm CH_3OH}$ masers, and UCHII regions. We also present a combined ${\rm NH_3}$-derived gas kinetic temperature and ${\rm H_2O}$ maser catalog for $1788$ clumps from our own GBT 100m observations and from the literature. We identify a subsample of $2223$ ($47.5\%$) starless clump candidates, the largest and most robust sample identified from a blind…
Recent Galactic plane surveys of dust continuum emission at long wavelengths have identified a population of dense, massive clumps with no evidence for on-going star formation. These massive starless clump candidates are excellent sites to search for the initial phases of massive star formation before the feedback from massive star formation effects the clump. In this study, we search for the spectroscopic signature of inflowing gas toward starless clumps, some of which are massive enough to form a massive star. We observed 101 starless clump candidates identified in the Bolocam Galactic Plane…
The Purple Mountain Observatory 13.7 m radio telescope has been used to search for 95 GHz (8$_0$--7$_1$A$^+$) class I methanol masers towards 1020 Bolocam Galactic Plane Survey (BGPS) sources, leading to 213 detections. We have compared the line width of the methanol and HCO$^+$ thermal emission in all of the methanol detections and on that basis we find 205 of the 213 detections are very likely to be masers. This corresponds to an overall detection rate of 95 GHz methanol masers towards our BGPS sample of 20%. Of the 205 detected masers 144 (70%) are new discoveries. Combining our results wit…
We examined the relations between molecular gas surface density and star formation rate surface density in a 11 square degree region of the Galactic Plane. Dust continuum at 1.1 mm from the Bolocam Galactic Plane Survey and 22 micron emission from the WISE All-sky survey were used as tracers of molecular gas and star formation rate, respectively, across Galactic longitude of 31.5 > l > 20.5 and Galactic latitude of 0.5 > b > -0.5. The relation was studied over a range of resolutions from 33 arcsecond to 20 arcminute by convolving images to larger scales. The pixel-by-pixel correlation between …
An updated catalog of 205 observed tangents to the spiral arms (in Galactic longitudes) since 1980 is presented. This represents an addition of 80 arm tangents in 6 years (since 2016). Most arm tangents are observed at telescopes in the radio regime. In this study, the separation of each arm tracer from the dust lane is analyzed to obtain the relative speed away from the dust lane (an age gradient). Each arm tracer is observed to be separated from the dust lane, showing an age gradient of about 11.3 +/- 2 Myr/kpc across the spiral arm; this gives a relative speed away from the dust lane of abo…
We have studied a sample of more than 25 000 young stars with proper motions and trigonometric parallaxes from the Gaia DR2 catalogue. The relative errors of their parallaxes do not exceed 10\%. The selection of stars belonging to active star-forming regions was made by Marton et al. based on data from the Gaia DR2 catalogue by invoking infrared measurements from the WISE and Planck catalogues. Low-mass T Tauri stars constitute the majority of sample stars. The following parameters of the angular velocity of Galactic rotation have been found from them: $Ω_0 =28.40\pm0.11$ km s$^{-1}$ kpc$^{-1}…
As the precursors to stellar clusters, it is imperative that we understand the distribution and physical properties of dense molecular gas clouds and clumps. Such a study has been done with the ground-based Bolocam Galactic Plane Survey (BGPS). Now the Herschel infrared GALactic plane survey (Hi-GAL) allows us to do the same with higher quality data and complete coverage of the Galactic plane. We have made a pilot study comparing dense molecular gas clumps identified in the Hi-GAL and BGPS surveys, using six $2^\circ \times 2^\circ$ regions centered at Galactic longitudes of $\ell = 11^\circ$,…
Near-Infrared Counterparts to Chandra X-ray Sources toward the Galactic Center. I. Statistics and a Catalog of Candidates
我们提出了一个目录的5184个候选红外对应的X射线源检测到对银河系中心。X射线样本包含9017个点源，由钱德拉X射线天文台在该地区检测到，包括最近对银河平面中心2 x 0.8度的深度调查数据。这些源中共有6760个具有硬X射线颜色，其中大多数位于银河系中心附近，而其余2257个软X射线源中的大多数位于前景。我们将X射线源的位置与2 MASS和SIRIUS近红外星表进行了交叉关联，这两个星表共同包含10 σ极限通量为K_s<=15.6等的恒星。为了区分银河系中心附近的吸收红外源和前景中的吸收红外源，我们将红源和蓝源分别定义为H-K_s>=0.9和<=0.9等的源。我们发现5.8%（1.5%）的硬X射线源具有真实的红外对应物，其中228（99）个是红色的，166（27）个是蓝色的。红色对应物可能由WR/O型恒星、HMXB和银河系中心附近的共生体组成。我们还发现，39.4%（1.0%）的软X射线源有蓝红外对应物，其中大部分可能是日冕活动的矮星在前景。在人马座-B H II区域附近有一个值得注意的大约20个与硬X射线源对应的红色双星，它们可能是在最近几个百万年内形成的大质量双星。对于每个红外匹配到我们的目录中的X射线源，我们推导出的概率，该协会是真实的，基于互相关分析的结果。该目录将用于光谱调查，以确定银河系中心附近的X射线源的红外对应物。
Passing through the Galactic disk, a massive object such as a globular cluster, can trigger star formation process leading to the birth of open clusters. Here, we analyze such possible evolutionary relationship between globular and open clusters. To search for the closest rapprochement between objects we computed backwards the orbits of 150 Galactic globular and 232 open clusters (younger than 100 Myr) with proper motions, derived from the Gaia DR2 Catalog. The orbits were computed using the recently modified three-component (disk, bulge and halo) axisymmetric Navarro-Frenk-White potential, wh…
The eJWST active galactic nucleus observation catalogue
Zentrum für Astronomie der Universität Heidelberg, Astronomisches Rechen-Institut（海德堡大学天文中心，天文计算研究所）；European Space Agency (ESA), European Space Astronomy Centre (ESAC)（欧洲空间局（ESA），欧洲空间天文中心（ESAC））；Telespazio UK S.L. for ESA, ESAC（为ESA和ESAC服务的泰雷兹英国有限公司）；Institut de Radioastronomie Millimétrique (IRAM)（毫米波射电天文学研究所（IRAM））；Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心（CAB），西班牙国家科学研究委员会-国家航空航天技术研究所）
The {\it Herschel} Astrophysical Terahertz Large Area Survey (H-ATLAS) is a survey of 660 deg$^2$ with the PACS and SPIRE cameras in five photometric bands: 100, 160, 250, 350 and 500\mic. This is the second of three papers describing the data release for the large fields at the south and north Galactic poles (NGP and SGP). In this paper we describe the catalogues of far-infrared and submillimetre sources for the NGP and SGP, which cover 177 deg$^2$ and 303 deg$^2$, respectively. The catalogues contain 153,367 sources for the NGP field and 193,527 sources for the SGP field detected at more tha…
As part of the Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters, 110 parallel fields were observed with the Wide Field Channel of the Advanced Camera for Surveys, in the outskirts of 48 globular clusters, plus the open cluster NGC 6791. Totalling about $0.3$ square degrees of observed sky, this is the largest homogeneous Hubble Space Telescope photometric survey of Galalctic globular clusters outskirts to date. In particular, two distinct pointings have been obtained for each target on average, all centred at about $6.5$ arcmin from the cluster centre, thus covering a mean…
The spatial velocities of the stars with high-precision positions, proper motions and parallaxes from the Gaia TGAS catalog and line-of-sight velocities from the RAVE5 catalog are considered. From the sample of 92395 stars with the age estimates we have obtained the following kinematic parameters: (U,V,W)=(9.42,20.34,7.21)+/-0.12,0.10,0.09) km/s, Ω=26.29+/-0.39 km/s/kpc and Ω'=-3.89+/-0.08 km/s/kpc^2, where V0=210+/-6 km/s (for adopted R0=8.0+/-0.2 kpc), and the Oort constants A=15.57+/-0.31 km/s/kpc and B=-10.72+/-0.50 km/s/kpc. It is shown that the parameters Ωand Ω' are stable to the star a…
Class II methanol (CH$_{3}$OH) masers are amongst the clearest signposts of recent high-mass star formation (HMSF). A complete catalogue outlines the distribution of star formation in the Galaxy, the number of young star-forming cores, and the physical conditions of their environment. The Global View on Star Formation (GLOSTAR) survey, which is a blind survey in the radio regime of 4$-$8 GHz, maps the Galactic mid-plane in the radio continuum, 6.7 GHz methanol line, the 4.8 GHz formaldehyde line, and several radio recombination lines. We present the analysis of the observations of the 6.7 GHz …
We used four-year baseline HST/WFC3 IR observations of the Galactic Centre in the F153M band (1.53 micron) to identify variable stars in the central ~2.3'x2.3' field. We classified 3845 long-term (periods from months to years) and 76 short-term (periods of a few days or less) variables among a total sample of 33070 stars. For 36 of the latter ones, we also derived their periods (<3 days). Our catalog not only confirms bright long period variables and massive eclipsing binaries identified in previous works, but also contains many newly recognized dim variable stars. For example, we found δScuti…
We present the results of a large-scale proper motion study of the central ~36'x16' of the Milky Way, based on our high angular resolution GALACTICNUCLEUS survey (epoch 2015) combined with the HST Paschen-alpha survey (epoch 2008). Our catalogue contains roughly 80,000 stars, an unprecedented kinematic data set for this region. We describe the data analysis and the preparation of the proper motion catalogue. We verify the catalogue by comparing our results with measurements from previous work and data. We provide a preliminary analysis of the kinematics of the studied region. Foreground stars …
We present two catalogues of active galactic nucleus (AGN) candidates selected from the latest data of two all-sky surveys -- Data Release 2 (DR2) of the \emph{Gaia} mission and the unWISE catalogue of the \emph{Wide-field Infrared Survey Explorer} (\emph{WISE}). We train a random forest classifier to predict the probability of each source in the \emph{Gaia}-unWISE joint sample being an AGN, $P_{\rm RF}$, based on \emph{Gaia} astrometric and photometric measurements and unWISE photometry. The two catalogues, which we designate C75 and R85, are constructed by applying different $P_{\rm RF}$ thr…
We collected radial velocities of more than 50.000 individual stars in 156 Galactic globular clusters (GGC) and matched them with HST photometry and Gaia DR2 proper motions. This allowed us to derive the GGC's mean proper motions and space velocities. By fitting a large set of N-body simulations to their velocity dispersion and surface density profiles, combined with new measurements of their internal radially dependent mass functions, we have determined their present-day masses and structural parameters, and for 144 GGCs their internal kinematics. We also derive the initial cluster masses by …
Using the Murchison Widefield Array (MWA), the low-frequency Square Kilometre Array (SKA1 LOW) precursor located in Western Australia, we have completed the GaLactic and Extragalactic All-sky MWA (GLEAM) survey, and present the resulting extragalactic catalogue, utilising the first year of observations. The catalogue covers 24,831 square degrees, over declinations south of $+30^\circ$ and Galactic latitudes outside $10^\circ$ of the Galactic plane, excluding some areas such as the Magellanic Clouds. It contains 307,455 radio sources with 20 separate flux density measurements across 72--231MHz,…
The SCUBA-2 Ambitious Sky Survey (SASSy) is composed of shallow 850-$\umu$m imaging using the Sub-millimetre Common-User Bolometer Array 2 (SCUBA-2) on the James Clerk Maxwell Telescope. Here we describe the extraction of a catalogue of beam-sized sources from a roughly $120\,{\rm deg}^2$ region of the Galactic plane mapped uniformly (to an rms level of about 40\,mJy), covering longitude 120\degr\,$<$\,\textit{l}\,$<$\,140\degr\ and latitude $\abs{\textit{b}}$\,$<$\,2.9\degr. We used a matched-filtering approach to increase the signal-to-noise (S/N) ratio in these noisy maps and tested the eff…
The Southern HII Region Discovery Survey (SHRDS) is a 900 hour Australia Telescope Compact Array 4-10 GHz radio continuum and radio recombination line (RRL) survey of Galactic HII regions and infrared-identified HII region candidates in the southern sky. For this data release, we reprocess all previously published SHRDS data and include an additional ~450 hours of observations. The search for new HII regions is now complete over the range 259 deg < Galactic longitude < 346 deg, |Galactic latitude| < 4 deg for HII region candidates with predicted 6 GHz continuum peak brightnesses >30 mJy/beam. …
Open star clusters from the MWSC (Milky Way Star Clusters) catalogue have been used to determine the Galactic rotation parameters. The circular rotation velocity of the solar neighborhood around the Galactic center has been found from data on more than 2000 clusters of various ages to be V_0=236+/-6 km s^{-1} for the adopted Galactocentric distance of the Sun R_0=8.3+/-0.2 kpc. The derived angular velocity parameters are Ω_0=28.48+/-0.36 km s^{-1} kpc^{-1}, Ω'_0=-3.50+/-0.08 km s^{-1} kpc^{-2}, and Ω"_0= 0.331+/-0.037 km s^{-1} kpc^{-3}. The influence of the spiral density wave has been detect…
The Hubble Space Telescope (HST) UV Legacy Survey of Galactic Globular Clusters (GO-13297) has been specifically designed to complement the existing F606W and F814W observations of the Advanced Camera for Surveys (ACS) Globular Cluster Survey (GO-10775) by observing the most accessible 47 of the previous survey's 65 clusters in three WFC3/UVIS filters F275W, F336W, and F438W. The new survey also adds super-solar metallicity open cluster NGC 6791 to increase the metallicity diversity. The combined survey provides a homogeneous 5-band data set that can be used to pursue a broad range of scientif…
