- ID:
- ivo://CDS.VizieR/J/MNRAS/483/299
- Title:
- Local Bubble & Gould Belt polarization
- Short Name:
- J/MNRAS/483/299
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We create and analyse the largest up-to-date all-sky compilation of the interstellar optical polarization data supplemented by the reddening data This compilation includes 13 data sources with optical interstellar linear polarization for 3871 Gaia DR2 and Hipparcos stars within 500pc, which do not exhibit a considerable intrinsic polarization. These data are analysed together with five 3D maps and models of the reddening E(B-V). We consider variations of the polarization degree P, position angle theta, and polarization efficiency P/E(B-V) with Galactic coordinates, distance R, and dereddened colour. P shows a maximum at the Gould Belt mid-plane. P/R drops in the Local Bubble by several times defining a boundary of the Bubble at P=0.1 per cent. All the data sources of the reddening, except Lallement et al., show a drop of P/E(B-V) in the Bubble. The spatial- and colour-dependent variations of P and E(B-V) outside the Bubble compensate each other, resulting in a nearly constant P/E(B-V). A giant envelope of aligned dust dominates at middle and high latitudes outside the Bubble. The Markkanen's cloud, the North Polar Spur, and some other filaments are parts of this envelope.
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- ID:
- ivo://CDS.VizieR/J/AJ/158/122
- Title:
- Local structure & star formation history of the MW
- Short Name:
- J/AJ/158/122
- Date:
- 09 Mar 2022 22:00:00
- Publisher:
- CDS
- Description:
- Gaia DR2 (Cat. I/345) provides unprecedented precision in measurements of the distance and kinematics of stars in the solar neighborhood. Through applying unsupervised machine learning on DR2's 5D data set (3D position + 2D velocity), we identify a number of clusters, associations, and comoving groups within 1 kpc and |b|<30{deg} (many of which have not been previously known). We estimate their ages with the precision of ~0.15 dex. Many of these groups appear to be filamentary or string-like, oriented in parallel to the Galactic plane, and some span hundreds of parsec in length. Most of these string lack a central cluster, indicating that their filamentary structure is primordial, rather than the result of tidal stripping or dynamical processing. The youngest strings (<100 Myr) are orthogonal to the Local Arm. The older ones appear to be remnants of several other arm-like structures that cannot be presently traced by dust and gas. The velocity dispersion measured from the ensemble of groups and strings increase with age, suggesting a timescale for dynamical heating of ~300 Myr. This timescale is also consistent with the age at which the population of strings begins to decline, while the population in more compact groups continues to increase, suggesting that dynamical processes are disrupting the weakly bound string populations, leaving only individual clusters to be identified at the oldest ages. These data shed a new light on the local galactic structure and a large-scale cloud collapse.
- ID:
- ivo://CDS.VizieR/J/ApJ/847/123
- Title:
- Local velocity substructures in the Milky Way disk
- Short Name:
- J/ApJ/847/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We confirm, quantify, and provide a table of the coherent velocity substructure of the Milky Way disk within 2kpc of the Sun toward the Galactic anticenter, with a 0.2kpc resolution. We use the radial velocities of ~340000 F-type stars obtained with the Guoshoujing Telescope (also known as the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, LAMOST), and proper motions derived from the PPMXL catalog. The PPMXL proper motions have been corrected to remove systematic errors by subtracting the average proper motions of galaxies and QSOs that have been confirmed in the LAMOST spectroscopic survey, and that are within 2.5{deg} of the star's position. We provide the resulting table of systematic offsets derived from the PPMXL proper motion measurements of extragalactic objects identified in the LAMOST spectroscopic survey. Using the corrected phase-space stellar sample, we find statistically significant deviations in the bulk disk velocity of 20km/s or more in the three-dimensional velocities of Galactic disk stars. The bulk velocity varies significantly over length scales of half a kiloparsec or less. The rotation velocity of the disk increases by 20km/s from the Sun's position to 1.5kpc outside the solar circle. Disk stars in the second quadrant, within 1kpc of the Sun, are moving radially toward the Galactic center and vertically toward a point a few tenths of a kiloparsec above the Galactic plane; looking down on the disk, the stars appear to move in a circular streaming motion with a radius of the order of 1kpc.
- ID:
- ivo://CDS.VizieR/J/A+A/623/A71
- Title:
- LOTSS HETDEX Faraday depth cube
- Short Name:
- J/A+A/623/A71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Faraday tomography allows us to map diffuse polarized synchrotron emission from our Galaxy and use it to interpret the magnetic field in the interstellar medium (ISM). We have applied Faraday tomography to 60 observations from the LOFAR Two-Meter Sky Survey (LOTSS) and produced a Faraday depth cube mosaic covering 568 square degrees at high Galactic latitudes, at 4.3 angular resolution and 1rad/m^2^ Faraday depth resolution, with a typical noise level of 50-100uJy per point spread function (PSF) per rotation measure spread function (RMSF) (40-80mK/RMSF). While parts of the images are strongly affected by instrumental polarization, we observe diffuse polarized emission throughout most of the field, with typical brightness between 1 and 6K/RMSF, and Faraday depths between -7 and +25rad/m^2^. We observe many new polarization features, some up to 15deg in length. These include two regions with very uniformly structured, linear gradients in the Faraday depth; we measured the steepness of these gradients as 2.6 and 13rad/m^2^/deg. We also observe a relationship between one of the gradients and an HI filament in the local ISM. Other ISM tracers were also checked for correlations with our polarization data and none were found, but very little signal was seen in most tracers in this region. We conclude that the LOTSS data are very well suited for Faraday tomography, and that a full-scale survey with all the LOTSS data has the potential to reveal many new Galactic polarization features and map out diffuse Faraday depth structure across the entire northern hemisphere.
- ID:
- ivo://CDS.VizieR/J/PASP/107/846
- Title:
- LSE stars, extension of Case-Hamburg surveys.
- Short Name:
- J/PASP/107/846
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Case-Hamburg OB-star surveys (Luminous Stars in the Milky Way, Catalogs III/76 and III/43) have been extended to galactic latitude b=+/-30 for l=+/-60 using the Curtis Schmidt telescope and 4{deg} objective prism at the Cerro Tololo Inter-American Observatory. A catalog of 234 OB stars and other objects with peculiar spectra is presented along. The positions were revisited by B. Skiff in May 2002, using the finding charts; additional notes and cross-identifications have been added in the course of this examination (see the "notes.dat" file).
- ID:
- ivo://CDS.VizieR/III/76A
- Title:
- Luminous Stars in the Northern Milky Way (LS)
- Short Name:
- III/76A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains a series of works published in the period 1959 to 1965, resulting from a joint survey of the Hamburg and Warner and Swasey Observatories for early-type stars of high luminosity. This survey was conducted using objective-prism plates taken with the Schmidt telescopes of the Hamburg, Warner and Swasey, and University of Michigan Observatories. The catalog contains all stars of the six source publications in a single file; the notes and remarks published in Volumes II, IV, and VI are included in the separate file "notes.dat".
- ID:
- ivo://CDS.VizieR/III/43
- Title:
- Luminous Stars in the Southern Milky Way
- Short Name:
- III/43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
338. MAGPIS 20cm survey
- ID:
- ivo://CDS.VizieR/J/AJ/131/2525
- Title:
- MAGPIS 20cm survey
- Short Name:
- J/AJ/131/2525
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Multi-Array Galactic Plane Imaging Survey (MAGPIS), which maps portions of the first Galactic quadrant with an angular resolution, sensitivity, and dynamic range that surpass existing radio images of the Milky Way by more than an order of magnitude. The source detection threshold at 20cm is in the range 12mJy over the 85% of the survey region (5{deg}<l<32{deg}, |b|<0.8{deg}) not covered by bright extended emission; the angular resolution is ~6". We catalog over 3000 discrete sources (diameters mostly <30") and present an atlas of ~400 diffuse emission regions. New and archival data at 90cm for the whole survey area are also presented. Comparison of our catalogs and images with the Midcourse Space Experiment mid-infrared data allows us to provide preliminary discrimination between thermal and nonthermal sources. We identify 49 high-probability supernova remnant candidates, increasing by a factor of 7 the number of known remnants with diameters smaller than 5' in the survey region; several are pulsar wind nebula candidates and/or very small diameter remnants (D<45").
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/2344
- Title:
- MALT-45, a 7mm survey of the southern Galaxy
- Short Name:
- J/MNRAS/448/2344
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from the MALT-45 (Millimetre Astronomer's Legacy Team-45GHz) Galactic Plane survey. We have observed 5 square degrees (l=330{deg}-335{deg}, b=+/-0.5{deg}) for spectral lines in the 7mm band (42-44 and 48-49GHz), including CS (1-0), class I CH_3_OH masers in the 7(0,7)-6(1,6) A^+^ transition and SiO (1-0) v=0,1,2,3. MALT-45 is the first unbiased, large-scale, sensitive spectral line survey in this frequency range. In this paper, we present data from the survey as well as a few intriguing results; rigorous analyses of these science cases are reserved for future publications. Across the survey region, we detected 77 class I CH_3_OH masers, of which 58 are new detections, along with many sites of thermal and maser SiO emission and thermal CS. We found that 35 class I CH_3_OH masers were associated with the published locations of class II CH_3_OH, H_2_O and OH masers but 42 have no known masers within 60 arcsec. We compared the MALT-45 CS with NH_3_ (1,1) to reveal regions of CS depletion and high opacity, as well as evolved star-forming regions with a high ratio of CS to NH_3_. All SiO masers are new detections, and appear to be associated with evolved stars from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE). Generally, within SiO regions of multiple vibrational modes, the intensity decreases as v=1, 2, 3, but there are a few exceptions where v=2 is stronger than v=1.
- ID:
- ivo://CDS.VizieR/J/MNRAS/471/3915
- Title:
- MALT-45, 44 GHz class I methanol masers
- Short Name:
- J/MNRAS/471/3915
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We detail interferometric observations of 44GHz class I methanol masers detected by MALT-45 (a 7mm unbiased auto-correlated spectral-line Galactic-plane survey) using the Australia Telescope Compact Array. We detect 238 maser spots across 77 maser sites. Using high-resolution positions, we compare the class I CH_3_OH masers to other star formation maser species, including CS (1-0), SiO v=0 and the H53{alpha} radio-recombination line. Comparison between the cross- and auto-correlated data has allowed us to also identify quasi-thermal emission in the 44GHz class I methanol maser line. We find that the majority of class I methanol masers have small spatial and velocity ranges (<0.5pc and <5km/s), and closely trace the systemic velocities of associated clouds. Using 870{mu}m dust continuum emission from the ATLASGAL survey, we determine clump masses associated with class I masers, and find that they are generally associated with clumps between 1000 and 3000M_{sun}_. For each class I methanol maser site, we use the presence of OH masers and radio recombination lines to identify relatively evolved regions of high-mass star formation; we find that maser sites without these associations have lower luminosities and preferentially appear towards dark infrared regions.
