- ID:
- ivo://CDS.VizieR/J/AJ/122/3155
- Title:
- Peculiar HI cloud near galactic plane
- Short Name:
- J/AJ/122/3155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An H I cloud with a double-lobed structure and a radial velocity of +50km/s has been found near l=92{deg}, b=-4{deg} in a low-resolution H I survey carried out at the Dominion Radio Astrophysical Observatory (DRAO). This velocity is forbidden for circular Galactic rotation. Because of its unusual morphology and small variation in radial velocity over the cloud, further observations of the area were made with the DRAO Synthesis Telescope, both in the H I line and in the radio continuum. The cloud has dimensions of about 3.3{deg}x0.5{deg}, and has a morphology somewhat similar to high-velocity H I clouds (HVCs). Several possible associations with other objects are examined in this paper. A variable inverted-spectrum radio continuum source exists near the morphological center of the H I cloud. It is probably a rare example of a gigahertz peaked spectrum (GPS) extragalactic source having a peak above 5GHz. A luminous B star is found close to the peculiar H I cloud, and the cloud is also located near the center of an H I supershell, supposedly located at a distance of about 9kpc. Energetic and other considerations lead to the conclusion that the cloud is probably not related to the HVC phenomenon nor to any of the above objects but is a relic of a nearby (D~1kpc) supernova event, all other evidence of which has now dissipated. Maps of continuum radio emission (at 1420 and 408MHz) in the area around the cloud are presented, as well as lists of continuum radio sources. A few isolated high-velocity knots of H I emission have also been detected in the vicinity of the cloud.
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- ID:
- ivo://CDS.VizieR/J/A+A/632/A58
- Title:
- Physical properties of CHIMPS clumps
- Short Name:
- J/A+A/632/A58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The latest generation of high-angular-resolution unbiased Galactic plane surveys in molecular-gas tracers are enabling the interiors of molecular clouds to be studied across a range of environments. The CO Heterodyne Inner Milky Way Plane Survey (CHIMPS) simultaneously mapped a sector of the inner Galactic plane, within 27.8<l<46.2{deg} and |b|<0.5{deg}, in ^13^CO (3-2) and C^18^O (3-2) at an angular resolution of 15 arcsec. The combination of the CHIMPS data with ^12^CO (3-2) data from the CO High Resolution Survey (COHRS) has enabled us to perform a voxel-by-voxel local-thermodynamic-equilibrium (LTE) analysis, determining the excitation temperature, optical depth, and column density of ^13^CO at each l,b,v position. Distances to discrete sources identified by FellWalker in the ^13^CO (3-2) emission maps were determined, allowing the calculation of numerous physical properties of the sources, and we present the first source catalogues in this paper. We find that, in terms of size and density, the CHIMPS sources represent an intermediate population between large-scale molecular clouds identified by CO and dense clumps seen in thermal dust continuum emission, and therefore represent the bulk transition from the diffuse to the dense phase of molecular gas. We do not find any significant systematic variations in the masses, column densities, virial parameters, mean excitation temperature, or the turbulent pressure over the range of Galactocentric distance probed, but we do find a shallow increase in the mean volume density with increasing Galactocentric distance. We find that inter-arm clumps have significantly narrower linewidths, and lower virial parameters and excitation temperatures than clumps located in spiral arms. When considering the most reliable distance-limited subsamples, the largest variations occur on the clump-to-clump scale, echoing similar recent studies that suggest that the star-forming process is largely insensitive to the Galactic-scale environment, at least within the inner disc.
- ID:
- ivo://CDS.VizieR/J/PASP/118/1639
- Title:
- Proper motions of faint UV-bright sources
- Short Name:
- J/PASP/118/1639
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Proper motions with values >=10 or <=10mas/yr have been extracted from the USNOB1.0 and Tycho2 catalogs for all Lanning UV-bright sources identified in the Sandage Two-Color Survey of the Galactic Plane and presented in Papers I-VI (Cat. <II/257>. Of the 572 sources examined, we find at least 213 that exhibit a significantly large proper motion. Based on the location of the sources in a reduced proper motion diagram, we demonstrate that about two-thirds of the high proper motion sources are likely or very likely to be heretofore unidentified white dwarfs.
- ID:
- ivo://CDS.VizieR/J/A+A/632/A85
- Title:
- PSF photometric catalog of VVV survey data
- Short Name:
- J/A+A/632/A85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Vista Variables in the Via Lactea (VVV) survey has performed a multi-epoch near-infrared imaging of the inner Galactic plane. High-fidelity photometric catalogs are needed to utilize the data. We aim at producing a deep, point-spread-function (PSF) photometric catalog for the VVV survey J, H, and Ks band data. Specifically, we aim at taking advantage of all the epochs of the survey to reach high limiting magnitudes. We develop an automatic PSF-fitting pipeline based on the DaoPHOT algorithm and perform photometry on the stacked VVV images in J, H, and Ks bands. We present a PSF photometric catalog in the Vega system that contains about 926 million sources in the J, H, and Ks filters. About 10% of the sources are flagged as possible spurious detections. The 5 sigma limiting magnitudes of the sources with high reliability are about 20.8, 19.5, and 18.7mag in the J, H, and Ks band, respectively, depending on the local crowding condition. Our photometric catalog reaches on average about one magnitude deeper than the previously released PSF DoPHOT photometric catalog. It also includes less spurious detections. There are significant differences in the brightnesses of faint sources between our catalog and the previously released one. The likely origin of these differences is in the different photometric algorithms that are utilized; it is not straightforward to assess which catalog is more accurate in which situations. Our new catalog is beneficial especially for science goals that require high limiting magnitudes; our catalog reaches such in fields that have a relatively uniform source number density. Overall, the limiting magnitudes and completeness are different in the fields with different crowding conditions.
- ID:
- ivo://CDS.VizieR/III/172
- Title:
- Radial Velocities from Objective Prism Plates
- Short Name:
- III/172
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate positions and radial velocities are determined from 32 objective-prism plates for two areas. Each field is observed twice with opposite dispersion, allowing adjustment of coordinates for spectra not at the plate centers. From the adjusted coordinates and plate overlap, positions are determined with average mean errors: 0.0135 s in RA and 0.177 arcsec in Dec for Area I (near the South Galactic Pole); 0.0315 s in RA, 0.144 arcsec in Dec for Area II (near the galactic plane). Observations were taken by J.D. MacConnell and G. Araya with a six degree prism on the Curtis Schmidt telescope at Cerro Tololo.
- ID:
- ivo://CDS.VizieR/J/A+A/473/143
- Title:
- Radial velocities of C stars near Galactic plane
- Short Name:
- J/A+A/473/143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The availability, from 2MASS, of a large homogeneous sample of Galactic C stars and the recognition that their absolute magnitude can be accurately determined offer the possibility to use them as kinematical probes to investigate motions in the thin or thick disks. Our aims is to determine the radial velocities for 70 C stars, a few degrees from the Galactic plane and distributed in longitudes from 60{deg} to 220{deg}.
- ID:
- ivo://CDS.VizieR/J/ApJS/237/27
- Title:
- Radio Ammonia Mid-plane Survey (RAMPS) pilot survey
- Short Name:
- J/ApJS/237/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Radio Ammonia Mid-Plane Survey (RAMPS) is a molecular line survey that aims to map a portion of the Galactic midplane in the first quadrant of the Galaxy (l=10{deg}-40{deg}, |b|<=0.4{deg}) using the Green Bank Telescope. We present results from the pilot survey, which has mapped approximately 6.5 square degrees in fields centered at l=10{deg}, 23{deg}, 24{deg}, 28{deg}, 29{deg}, 30{deg}, 31{deg}, 38{deg}, 45{deg}, and 47{deg}. RAMPS observes the NH3 inversion transitions NH_3_(1,1)-(5,5), the H_2_O 6_1,6_-5_2,3_ maser line at 22.235GHz, and several other molecular lines. We present a representative portion of the data from the pilot survey, including NH_3_(1,1) and NH_3_(2,2) integrated intensity maps, H_2_O maser positions, maps of NH_3_ velocity, NH_3_ line width, total NH_3_ column density, and NH_3_ rotational temperature.
- ID:
- ivo://CDS.VizieR/J/ApJ/755/21
- Title:
- Rotation measures of extragalactic radio sources
- Short Name:
- J/ApJ/755/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the Milky Way disk and halo magnetic field, determined from observations of Faraday rotation measure (RM) toward 641 polarized extragalactic radio sources in the Galactic longitude range 100{deg}-117{deg}, within 30{deg} of the Galactic plane. For |b|<15{deg}, we observe a symmetric RM distribution about the Galactic plane. This is consistent with a disk field in the Perseus arm of even parity across the Galactic mid-plane. In the range 15{deg}<|b|<30{deg}, we find median RMs of -15+/-4rad/m2 and -62+/-5rad/m2 in the northern and southern Galactic hemispheres, respectively. If the RM distribution is a signature of the large-scale field parallel to the Galactic plane, then this suggests that the halo magnetic field toward the outer Galaxy does not reverse direction across the mid-plane. The variation of RM as a function of Galactic latitude in this longitude range is such that RMs become more negative at larger |b|. This is consistent with an azimuthal magnetic field of strength 2{mu}G (7{mu}G) at a height 0.8-2kpc above (below) the Galactic plane between the local and the Perseus spiral arm. We propose that the Milky Way could possess spiral-like halo magnetic fields similar to those observed in M51.
- ID:
- ivo://CDS.VizieR/J/ApJ/874/30
- Title:
- RRab stars toward Baade's window with Blanco/DECam
- Short Name:
- J/ApJ/874/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained repeated images of six fields toward the Galactic bulge in five passbands (u, g, r, i, z) with the DECam imager on the Blanco 4m telescope at CTIO. From more than 1.6 billion individual photometric measurements in the field centered on Baade's window, we have detected 4877 putative variable stars. A total of 474 of these have been confirmed as fundamental mode RR Lyrae stars, whose colors at minimum light yield line-of-sight reddening determinations, as well as a reddenning law toward the Galactic Bulge, which differs significantly from the standard R_V_=3.1 formulation. Assuming that the stellar mix is invariant over the 3 square-degree field, we are able to derive a line-of-sight reddening map with sub-arcminute resolution, enabling us to obtain de-reddened and extinction corrected color-magnitude diagrams (CMDs) of this bulge field using up to 2.5 million well-measured stars. The corrected CMDs show unprecedented detail and expose sparsely populated sequences: for example, delineation of the very wide red giant branch, structure within the red giant clump, the full extent of the horizontal branch, and a surprising bright feature that is likely due to stars with ages younger than 1Gyr. We use the RR Lyrae stars to trace the spatial structure of the ancient stars and find an exponential decline in density with Galactocentric distance. We discuss ways in which our data products can be used to explore the age and metallicity properties of the bulge, and how our larger list of all variables is useful for learning to interpret future LSST alerts.
- ID:
- ivo://CDS.VizieR/V/132
- Title:
- SAI Open Clusters Catalog
- Short Name:
- V/132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The automated search for star clusters of J,H,K_s data from the Two Micron All-Sky Survey (2MASS) was made using a new method based on the convolution with density functions (Koposov et al. 2008A&A...486..771K). In two papers (this one and Koposov et al. 2008A), 168 new clusters were found and verified in the range of galactic latitude |b|<24 degrees. The new method to estimate main physical parameters of clusters was developed, which involves three different techniques: Hess-diagram, color-magnitude diagrams in (J,J-H) and (K_s,J-K_s), and radial density distribution. Color excesses E(B-V), distance moduli and ages were determined for 141 new and 27 known, but poorly studied clusters. We present the Sternberg Astronomical Institute Open Clusters Catalog (SAI OCL Catalog) of coordinates, diameters and main physical parameters of these clusters. The parameters for 9 clusters were determined using J,H,K data from UKIDSS GPS. For 26 new embedded clusters, we publish the coordinates and diameters only. To facilitate the access to these data and its scientific analysis, we have developed a dedicated web-site of the catalog available at http://ocl.sai.msu.ru/
