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261. Local velocity substructures in the Milky Way disk
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.
262. LOFAR long baselines at 140MHz Calibrators
ID:
ivo://CDS.VizieR/J/A+A/574/A73
Title:
LOFAR long baselines at 140MHz Calibrators
Short Name:
J/A+A/574/A73
Date:
21 Oct 2021
Publisher:
CDS
Description:
An efficient means of locating calibrator sources for international LOw Frequency ARray (LOFAR) is developed and used to determine the average density of usable calibrator sources on the sky for subarcsecond observations at 140MHz. We used the multi-beaming capability of LOFAR to conduct a fast and computationally inexpensive survey with the full international LOFAR array. Sources were preselected on the basis of 325MHz arcminute-scale flux density using existing catalogues. By observing 30 different sources in each of the 12 sets of pointings per hour, we were able to inspect 630 sources in two hours to determine if they possess a sufficiently bright compact component to be usable as LOFAR delay calibrators.
263. Lowell Proper Motion Survey 8991 Northern Stars
ID:
ivo://CDS.VizieR/I/79
Title:
Lowell Proper Motion Survey 8991 Northern Stars
Short Name:
I/79
Date:
21 Oct 2021
Publisher:
CDS
Description:
The catalog contains a summary of many individual papers published in the Lowell Observatory Bulletins in the years 1958 to 1970. The data in the machine-readable version include observed positions, proper motions, estimated photographic magnitudes and colors, and references to identifications in other catalogs. Photoelectric data on the UBV system are included for many stars, but no attempt was made to find all existing photometry. The notes.dat file was computerized at the ADC by keying the notes directly to disk storage.
264. Lowell Proper Motion Survey - Southern Hemisphere
ID:
ivo://CDS.VizieR/I/112A
Title:
Lowell Proper Motion Survey - Southern Hemisphere
Short Name:
I/112A
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog contains a summary of the Lowell Proper Motion Survey for the southern hemisphere. The catalog gives the position, motion, magnitude, and color of 2827 stars from the Lowell program.
265. low-ionization structures around NGC 1360
ID:
ivo://CDS.VizieR/J/MNRAS/473/2275
Title:
low-ionization structures around NGC 1360
Short Name:
J/MNRAS/473/2275
Date:
21 Oct 2021
Publisher:
CDS
Description:
Whether planetary nebulae (PNe) are predominantly the product of binary stellar evolution as some population synthesis models (PSM) suggest remains an open question. Around 50 short-period binary central stars (P~1d) are known, but with only four with measured orbital periods over 10 d, our knowledge is severely incomplete. Here we report on the first discovery from a systematic Southern African Large Telescope (SALT) High Resolution Spectrograph (HRS) survey for long-period binary central stars. We find a 142d orbital period from radial velocities of the central star of NGC 1360, HIP 16566. NGC 1360 appears to be the product of common-envelope (CE) evolution, with nebula features similar to post-CE PNe, albeit with an orbital period considerably longer than expected to be typical of post-CE PSM. The most striking feature is a newly identified ring of candidate low-ionization structures. Previous spatiokinematic modelling of the nebula gives a nebula inclination of 30{deg}+/-10{deg}, and assuming the binary nucleus is coplanar with the nebula, multiwavelength observations best fit a more massive, evolved white dwarf (WD) companion. A WD companion in a 142d orbit is not the focus of many PSM, making NGC 1360 a valuable system with which to improve future PSM work. HIP 16566 is amongst many central stars in which large radial velocity variability was found by low-resolution surveys. The discovery of its binary nature may indicate long-period binaries may be more common than PSM models predict.
266. Low-z BQS Quasars
ID:
ivo://CDS.VizieR/J/MNRAS/263/425
Title:
Low-z BQS Quasars
Short Name:
J/MNRAS/263/425
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
267. LQRF: Large Quasar Reference Frame
ID:
ivo://CDS.VizieR/I/313
Title:
LQRF: Large Quasar Reference Frame
Short Name:
I/313
Date:
21 Oct 2021
Publisher:
CDS
Description:
The LQRF (Large Quasar Reference Frame) was built with the care of avoiding wrong matches of its constituents quasars, of homogenizing the astrometry from the different catalogs and lists from which the constituent quasars are gathered, and of attaining the milli-arcsec global alignment to the ICRF (International Celestial Reference Frame), as well as typical individual source position accuracies even to better than 100 milli-arcsec. Starting from the updated and presumably complete LQAC (Large Quasar Astrometric Catalog) list of QSOs, initial optical positions for those quasars are found in the USNO B1.0 and GSC2.3 catalogs, and from the SDSS Data Release 5. The initial positions are next placed onto UCAC2 based reference frames, following by an alignment to the ICRF, as well as of the most precise sources from the VLBA calibrator list and from the VLA calibrator list - when reliable optical counterparts exist. Finally the LQRF axes are inspected through spherical harmonics, contemplating right ascension, declination and magnitude terms.
268. LUT Survey Catalogue Data Release 1
ID:
ivo://CDS.VizieR/I/335
Title:
LUT Survey Catalogue Data Release 1
Short Name:
I/335
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an near-ultraviolet star catalogue extracted from the Lunar-based Ultraviolet Telescope (LUT) survey program. LUT's observable sky area is a circular belt around the Moon's north pole, and the survey program covers a preferred area for about 2400 square degrees which includes a region of the Galactic plane. All the sources have signal-to-noise ratio larger than 5, and the corresponding magnitude limit is typically 14.4mag, which can be deeper as ~16 mag if the stray light contamination is in the lowest level. A total number of 86,467 stars are recorded in the catalogue.
269. MAP observations of the position of Procyon
ID:
ivo://CDS.VizieR/J/AJ/131/1015
Title:
MAP observations of the position of Procyon
Short Name:
J/AJ/131/1015
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on the analysis of observations of Procyon obtained with the Multichannel Astrometric Photometer during the years 1986-2004. While the results significantly increase the precision of the estimated characteristics of the components of the system, they are generally in good agreement with the most recent studies.
270. Mars Express astrometric observations of Phobos
ID:
ivo://CDS.VizieR/J/A+A/488/361
Title:
Mars Express astrometric observations of Phobos
Short Name:
J/A+A/488/361
Date:
21 Oct 2021
Publisher:
CDS
Description:
New astrometric measurements for Phobos are reported on the basis of 69 SRC (Super Resolution Channel) images obtained during 28 Mars Express Phobos flybys executed between 2004 and 2007. The measurements have been made using a newly developed technique which involves positional measurements of surface control points and verification of camera pointing by background stars. The astrometric positions are in excellent agreement with currently available Phobos orbit models. However, we find remaining systematic offsets of 1.5-2.6km, with Phobos ahead of the predicted position along its track. Our observations will be a basis for further improvements in the Phobos ephemeris. The methods we have developed will be useful for astrometric tracking of planetary or asteroidal targets and spacecraft optical navigation in future planetary missions.

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