- ID:
- ivo://CDS.VizieR/J/MNRAS/464/1247
- Title:
- VVV high proper motion stars. I. Ks<=13.5 stars
- Short Name:
- J/MNRAS/464/1247
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Knowledge of the stellar content near the Sun is important for a broad range of topics ranging from the search for planets to the study of Milky Way (MW) structure. The most powerful method for identifying potentially nearby stars is proper motion (PM) surveys. All old optical surveys avoid, or are at least substantially incomplete, near the Galactic plane. The depth and breadth of the 'VISTA Variables in Via Lactea' (VVV) near-IR survey significantly improves this situation. Taking advantage of the VVV survey data base, we have measured PMs in the densest regions of the MW bulge and southern plane in order to complete the census of nearby objects. We have developed a custom PM pipeline based on VVV catalogues from the Cambridge Astronomy Survey Unit, by comparing the first epoch of JHKs with the multi-epoch Ks bands acquired later. Taking advantage of the large time baseline between the Two Micron All Sky Survey (2MASS) and the VVV observations, we also obtained 2MASS-VVV PMs. We present a near-IR PM catalogue for the whole area of the VVV survey, which includes 3003 moving stellar sources. All of these have been visually inspected and are real PM objects. Our catalogue is in very good agreement with the PM data supplied in IR catalogues outside the densest zone of the MW. The majority of the PM objects in our catalogue are nearby M-dwarfs, as expected. This new data base allows us to identify 57 common PM binary candidates, among which are two new systems within 30 pcof the Sun.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/136/1667
- Title:
- VV Vir BVRI differential photometry
- Short Name:
- J/AJ/136/1667
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- VV Vir is a near-contact but detached mid-G-type eclipsing binary with an asymmetrical light curve due to a weak but regular mass exchange. The binary is apparently approaching contact and has a stream impact spot on the secondary component that is responsible for a quadratically [dP/P=(-7.8+/-0.2)x10^-11^] decreasing period. Our period study included more than 140 minima observed over the past 60 years. We explore other possible near-contact configurations for this binary.
- ID:
- ivo://CDS.VizieR/J/ApJ/889/56
- Title:
- VVV survey microlensing events; -3.7<b{<}-3.9{deg}
- Short Name:
- J/ApJ/889/56
- Date:
- 17 Jan 2022 11:50:08
- Publisher:
- CDS
- Description:
- We search for microlensing events in fields along the Galactic minor axis, ranging from the Galactic center to -3.7{deg}<b<3.9{deg} using the VISTA Variables in the Via Lactea (VVV) survey near-IR photometry. The new search is made across VVV tiles b291, b305, b319, b347, b361, and b375, covering a total area of about 11.5deg^2^. We find a total of N=238 new microlensing events in this new area, N=74, which are classified as bulge red clump (RC) giant sources. Combining them with N=122 events that we had previously reported in the Galactic center (VVV tile b333), allows us to study the latitude distribution of the microlensing events reaching the Galactic plane at b=00 for the first time. We find a very strong dependence of the number of microlensing events with Galactic latitude, a number that increases rapidly toward the Galactic center by one order of magnitude from |b|=2{deg} to b=0{deg} with a much steeper gradient than with Galactic longitude. The microlensing event population shows a flattened distribution (axial ratio b/a~1.5). The final sample shows a shorter mean timescale distribution than the Galactic plane sample for both the complete population and RC stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/893/65
- Title:
- VVV Survey microlensing events in the Gal. Bulge
- Short Name:
- J/ApJ/893/65
- Date:
- 19 Jan 2022 11:43:07
- Publisher:
- CDS
- Description:
- We search for microlensing events in the zero-latitude area of the Galactic Bulge using the VVV Survey near-IR data. We have discovered a total sample of N=630 events within an area covering 20.68deg^2^ between the years 2010 and 2015. In this paper, we describe the search and present the data for the final sample, including near-IR magnitudes, colors, and proper motions, as well as the standard microlensing parameters. We use the near-IR color-magnitude and color-color diagrams to select NRC=290 events with red-clump sources to analyze the extinction properties of the sample in the central region of the Galactic plane. The timescale distribution and its dependence in the longitude axis is presented. The mean timescale decreases as we approach the Galactic minor axis (b=0{deg}). Finally, we give examples of special microlensing events, such as binaries, short-timescale events, and events with a strong parallax effect.
- ID:
- ivo://CDS.VizieR/J/A+A/647/A169
- Title:
- VVV survey near-infrared colour catalogue
- Short Name:
- J/A+A/647/A169
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Vista Variables in the Via Lactea (VVV) near-infrared (IR) variability survey explores some of the most complicated regions of the Milky Way bulge and disk in terms of high extinction and high crowding. We add a new wavelength dimension to the optical information available at the American Association of Variable Star Observers International Variable Star Index (VSX-AAVSO) catalogue to test the VVV survey near-IR photometry to better characterise these objects. We cross-match the VVV and the VSX-AAVSO catalogues along with Gaia Data Release 2 photometry and parallax. We present a catalogue that includes accurate individual coordinates, near-IR magnitudes (ZYJHKs), extinctions AKs, and distances based on Gaia parallaxes. We also show the near-IR CMDs and spatial distributions for the different VSX types of variable stars, including important distance indicators, such as RR Lyrae, Cepheids and Miras. By analysing the photometric flags in our catalogue, we found that around 20% of the stars with measured and verified variability are flagged as "non-stellar source", even when they are outside of the saturation and/or noise regimes. Additionally, we pair-matched our sample with the VIVA catalogue and found that more than half of our sources are missing from the VVV variability list, mostly due to low signal-to-noise observations or photometric problems with a small percentage due to failures in the selection process. Conclusions. Our results suggest that the current knowledge about variability in the Galaxy is biased to the nearby, low extincted stars. The present catalogue also provides the groundwork to characterise the results of future large variability surveys like the Vera C. Rubin Observatory's Legacy Survey of Space and Time in the heavily crowded and reddened regions of the Galactic plane, as wellas follow-up campaigns to characterise specific types of variables. The analysis of the miss-flagged stars can be used to improve the photometric classification of the VVV data allowing to expand the amount of data considered useful for science purposes. Besides, we provide an additional list of stars missed by the VIVA procedures for which the observations are actually good and they were missed due to some failure in the VIVA selection process.
- ID:
- ivo://CDS.VizieR/J/AJ/153/179
- Title:
- VVV Survey RR Lyr stars in Southern Galactic plane
- Short Name:
- J/AJ/153/179
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep near-IR images from the VISTA Variables in the Via Lactea (VVV) Survey were used to search for RR Lyrae stars in the Southern Galactic plane. A sizable sample of 404 RR Lyrae of type ab stars was identified across a thin slice of the fourth Galactic quadrant (295{deg}<l<350{deg}, -2.24{deg}<b<-1.05{deg}). The sample's distance distribution exhibits a maximum density that occurs at the bulge tangent point, which implies that this primarily Oosterhoff type I population of RRab stars does not trace the bar delineated by their red clump counterparts. The bulge RR Lyrae population does not extend beyond l~340{deg}, and the sample's spatial distribution presents evidence of density enhancements and substructure that warrants further investigation. Indeed, the sample may be employed to evaluate Galactic evolution models, and is particularly lucrative since half of the discovered RR Lyrae are within reach of Gaia astrometric observations.
- ID:
- ivo://CDS.VizieR/J/ApJ/697/1741
- Title:
- Warped disks of YSOs in Galactic center
- Short Name:
- J/ApJ/697/1741
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The central parsec around the supermassive black hole in the Galactic center (GC) hosts more than 100 young and massive stars. Outside the central cusp (R~1") the majority of these O and Wolf-Rayet (W-R) stars reside in a main clockwise system, plus a second, less prominent disk or streamer system at large angles with respect to the main system. Here we present the results from new observations of the GC with the AO-assisted near-infrared imager NACO and the integral field spectrograph SINFONI on the ESO/VLT. These include the detection of 27 new reliably measured W-R/O stars in the central 12" and improved measurements of 63 previously detected stars, with proper motion uncertainties reduced by a factor of 4 compared to our earlier work. Based on the sample of 90 well measured W-R/O stars, we develop a detailed statistical analysis of their orbital properties and orientations. We show that half of the W-R/O stars are compatible with being members of a clockwise rotating system.
- ID:
- ivo://CDS.VizieR/J/A+A/625/A80
- Title:
- WASP-121b secondary eclipse in 2MASS K band
- Short Name:
- J/A+A/625/A80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ground-based observations of the secondary eclipse in the 2MASS K band are presented for the hot Jupiter WASP-121b. These are the first occultation observations of an extrasolar planet that were carried out with an instrument attached to a 1m class telescope (the SMARTS 1.3m). We find a highly significant eclipse depth of (0.228+/-0.023)%. Together with other planet atmosphere measurements, including the Hubble Space Telescope near-infrared emission spectrum, current data support more involved atmosphere models with species producing emission and absorption features, rather than simple smooth blackbody emission. Analysis of the time difference between the primary and secondary eclipses and the durations of these events yields an eccentricity of e=0.0207+/-0.0153, which is consistent with the earlier estimates of low or zero eccentricity, but with a smaller error. Comparing the observed occultation depth in the K band with the one derived under the assumption of zero Bond albedo and full heat redistribution, we find that WASP-121b has a deeper observed occultation depth than predicted. Together with the sample of 31 systems with K-band occultation data, this observation lends further support to the idea of inefficient heat transport between the day and night sides for most of the hot Jupiters.
- ID:
- ivo://CDS.VizieR/J/AJ/154/118
- Title:
- WD+dMs from the SUPERBLINK proper motion survey
- Short Name:
- J/AJ/154/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an activity and kinematic analysis of high proper motion white dwarf-M dwarf binaries (WD+dMs) found in the SUPERBLINK survey, 178 of which are new identifications. To identify WD+dMs, we developed a UV-optical-IR color criterion and conducted a spectroscopic survey to confirm each candidate binary. For the newly identified systems, we fit the two components using model white dwarf spectra and M dwarf template spectra to determine physical parameters. We use H{alpha} chromospheric emission to examine the magnetic activity of the M dwarf in each system, and investigate how its activity is affected by the presence of a white dwarf companion. We find that the fraction of WD+dM binaries with active M dwarfs is significantly higher than their single M dwarf counterparts at early and mid-spectral types. We corroborate previous studies that find high activity fractions at both close and intermediate separations. At more distant separations, the binary fraction appears to approach the activity fraction for single M dwarfs. Using derived radial velocities and the proper motions, we calculate 3D space velocities for the WD+dMs in SUPERBLINK. For the entire SUPERBLINK WD+dMs, we find a large vertical velocity dispersion, indicating a dynamically hotter population compared to high proper motion samples of single M dwarfs. We compare the kinematics for systems with active M dwarfs and those with inactive M dwarfs, and find signatures of asymmetric drift in the inactive sample, indicating that they are drawn from an older population.
- ID:
- ivo://CDS.VizieR/J/ApJS/243/15
- Title:
- WERGS. II. SED fitting with optical, IR & radio data
- Short Name:
- J/ApJS/243/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present physical properties of radio galaxies (RGs) with f_1.4GHz_>1mJy discovered by Subaru Hyper Suprime-Cam (HSC) and Very Large Array Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. For 1056 FIRST RGs at 0<z<=1.7 with HSC counterparts in about 100deg^2^, we compiled multi-wavelength data of optical, near-infrared (IR), mid-IR, far-IR, and radio (150MHz). We derived their color excess (E(B-V)_*_), stellar mass, star formation rate (SFR), IR luminosity, the ratio of IR and radio luminosity (q_IR_), and radio spectral index ({alpha}_radio_) that are derived from the spectral energy distribution (SED) fitting with CIGALE. We also estimated Eddington ratio based on stellar mass and integration of the best-fit SEDs of active galactic nucleus (AGN) component. We found that E(B-V)_*_, SFR, and IR luminosity clearly depend on redshift while stellar mass, q_IR_, and {alpha}_radio_ do not significantly depend on redshift. Since optically faint (i_AB_>=21.3) RGs that are newly discovered by our RG survey tend to be high redshift, they tend to not only have a large dust extinction and low stellar mass but also have high SFR and AGN luminosity, high IR luminosity, and high Eddington ratio compared with optically bright ones. The physical properties of a fraction of RGs in our sample seem to differ from a classical view of RGs with massive stellar mass, low SFR, and low Eddington ratio, demonstrating that our RG survey with HSC and FIRST provides us curious RGs among entire RG population.
