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- ID:
- ivo://CDS.VizieR/J/AJ/139/59
- Title:
- Milky Way halo velocity dispersion profile
- Short Name:
- J/AJ/139/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic sample of 910 distant halo stars from the Hypervelocity Star survey from which we derive the velocity dispersion profile of the Milky Way halo. The sample is a mix of 74% evolved horizontal branch stars and 26% blue stragglers. We estimate distances to the stars using observed colors, metallicities, and stellar evolution tracks. Our sample contains twice as many objects with R>50kpc as previous surveys. We compute the velocity dispersion profile in two ways: with a parametric method based on a Milky Way potential model and with a non-parametric method based on the caustic technique originally developed to measure galaxy cluster mass profiles. The resulting velocity dispersion profiles are remarkably consistent with those found by two independent surveys based on other stellar populations: the Milky Way halo exhibits a mean decline in radial velocity dispersion of -0.38+/-0.12km/s/kpc over 15<R<75kpc. This measurement is a useful basis for calculating the total mass and mass distribution of the Milky Way halo.
- ID:
- ivo://CDS.VizieR/J/AJ/162/137
- Title:
- Minerva-Australis radial velocity of AU Mic
- Short Name:
- J/AJ/162/137
- Date:
- 14 Mar 2022 08:18:00
- Publisher:
- CDS
- Description:
- We report measurements of the sky-projected spin-orbit angle for AU Mic b, a Neptune-size planet orbiting a very young (~20Myr) nearby pre-main-sequence M-dwarf star, which also hosts a bright, edge-on, debris disk. The planet was recently discovered from preliminary analysis of radial-velocity observations and confirmed to be transiting its host star from photometric data from the NASA's TESS mission. We obtained radial-velocity measurements of AU Mic over the course of two partially observable transits and one full transit of planet b from high-resolution spectroscopic observations made with the MINERVA-Australis telescope array. Only a marginal detection of the Rossiter-McLaughlin effect signal was obtained from the radial velocities, in part due to AU Mic being an extremely active star and the lack of full transit coverage plus sufficient out-of-transit baseline. As such, a precise determination of the obliquity for AU Mic b is not possible in this study and we find a sky-projected spin-orbit angle of {lambda}=47_-54_^+26^deg . This result is consistent with both the planet's orbit being aligned or highly misaligned with the spin axis of its host star. Our measurement independently agrees with, but is far less precise than observations carried out on other instruments around the same time that measure a low-obliquity orbit for the planet. AU Mic is the youngest exoplanetary system for which the projected spin-orbit angle has been measured, making it a key data point in the study of the formation and migration of exoplanets-particularly given that the system is also host to a bright debris disk.
- ID:
- ivo://CDS.VizieR/J/A+AS/135/231
- Title:
- Mining in the Hipparcos raw data
- Short Name:
- J/A+AS/135/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We give 139 reprocessed problem double stars using Hipparcos data
- ID:
- ivo://CDS.VizieR/J/ApJS/247/44
- Title:
- Mira-like variables from the KELT survey
- Short Name:
- J/ApJS/247/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 4132 Mira-like variables (red variables with long periods and high amplitudes) in the Kilodegree Extremely Little Telescope (KELT) survey. Of these, 376 are new Mira-like detections. We used Two Micron All Sky Survey (2MASS) colors to identify candidate asymptotic giant branch stars. We searched for photometric variability among the candidate asymptotic giant branch stars and identified stars that show periodic variability. We selected variables with high amplitudes and strong periodic behavior using a Random Forest classifier. Of the sample of 4132 Mira-like variables, we estimate that 70% are Miras and 30% are semiregular (SR) variables. We also adopt the method of using (W_RP_-W_Ks_) versus (J-Ks) colors in distinguishing between O-rich and C-rich Miras and find it to be an improvement over 2MASS colors.
- ID:
- ivo://CDS.VizieR/J/ApJ/800/80
- Title:
- MIR properties of galaxies in A2199 at z~0.03
- Short Name:
- J/ApJ/800/80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the mid-infrared (MIR) properties of the galaxies in the A2199 supercluster at z=0.03 to understand the star formation activity of galaxy groups and clusters in the supercluster environment. Using the Wide-field Infrared Survey Explorer (WISE) data, we find no dependence of mass-normalized integrated star formation rates of galaxy groups/clusters on their virial masses. We classify the supercluster galaxies into three classes in the MIR color-luminosity diagram: MIR blue cloud (massive, quiescent, and mostly early-type), MIR star-forming sequence (mostly late-type), and MIR green valley galaxies. These MIR green valley galaxies are distinguishable from the optical green valley galaxies in the sense that they belong to the optical red sequence. We find that the fraction of each MIR class does not depend on the virial mass of each group/cluster. We compare the cumulative distributions of surface galaxy number density and cluster/group-centric distance for the three MIR classes. MIR green valley galaxies show the distribution between MIR blue cloud and MIR star-forming (SF) sequence galaxies. However, if we fix galaxy morphology, early- and late-type MIR green valley galaxies show different distributions. Our results suggest a possible evolutionary scenario of these galaxies: (1) late-type MIR SF sequence galaxies --> (2) late-type MIR green valley galaxies --> (3) early-type MIR green valley galaxies --> (4) early-type MIR blue cloud galaxies. In this sequence, the star formation of galaxies is quenched before the galaxies enter the MIR green valley, and then morphological transformation occurs in the MIR green valley.
- ID:
- ivo://CDS.VizieR/J/ApJ/791/113
- Title:
- MIR-selected quasar parameters
- Short Name:
- J/ApJ/791/113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We provide a catalog of 391 mid-infrared-selected (MIR; 24 {mu}m) broad-emission-line (BEL; type 1) quasars in the 22 deg^2^ SWIRE Lockman Hole field. This quasar sample is selected in the MIR from Spitzer MIPS with S_24_> 400 {mu}Jy, jointly with an optical magnitude limit of r(AB) < 22.5 for broad line identification. The catalog is based on MMT and Sloan Digital Sky Survey (SDSS) spectroscopy to select BEL quasars, extending the SDSS coverage to fainter magnitudes and lower redshifts, and recovers a more complete quasar population. The MIR-selected quasar sample peaks at z ~ 1.4 and recovers a significant and constant (20%) fraction of extended objects with SDSS photometry across magnitudes, which were not included in the SDSS quasar survey dominated by point sources. This sample also recovers a significant population of z < 3 quasars at i > 19.1. We then investigate the continuum luminosity and line profiles of these MIR quasars, and estimate their virial black hole masses and the Eddington ratios. The supermassive black hole mass shows evidence of downsizing, although the Eddington ratios remain constant at 1 < z < 4. Compared to point sources in the same redshift range, extended sources at z < 1 show systematically lower Eddington ratios. The catalog and spectra are publicly available online.
- ID:
- ivo://CDS.VizieR/J/MNRAS/463/1831
- Title:
- M67 Kepler/K2 variable stars
- Short Name:
- J/MNRAS/463/1831
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the third paper of this series we continue the exploitation of Kepler/K2 data in dense stellar fields using our PSF-based method. This work is focused on a ~720-arcmin^2^ region centred on the Solar-metallicity and Solar-age open cluster M 67. We extracted light curves for all detectable sources in the Kepler channels 13 and 14, adopting our technique based on the usage of a high-angular-resolution input catalogue and target-neighbour subtraction. We detrended light curves for systematic errors, and searched for variables and exoplanets using several tools. We found 451 variables, of which 299 are new detection. Three planetary candidates were detected by our pipeline in this field. Raw and detrended light curves, catalogues, and K2 stacked images used in this work will be released to the community.
- ID:
- ivo://CDS.VizieR/V/69
- Title:
- MK, UBV Time and Latitude Stars
- Short Name:
- V/69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- MK spectral classifications are given for 591 stars which are used for time and latitude observations at Mizusawa and Washington. The classifications in the MK system were made by slit spectrograms of dispersion 73 A/mm at H-gamma which were taken with the 91cm reflector at the Okayama Astrophysical Observatory. Photometric observations in UBV were made with the 1-meter reflector at the Flagstaff Station of U.S. Naval Observatory.
- ID:
- ivo://CDS.VizieR/J/ApJS/154/623
- Title:
- M31 Long Period Variables : Photometry
- Short Name:
- J/ApJS/154/623
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A significant fraction of the disk of M31 has been surveyed for long-period variable stars. We report the results, including near-infrared photometry of almost 2000 variables, and light curves in the i band. The period-luminosity relation suggests that most of the variables are asymptotic giant branch stars, and their luminosity function can be understood in terms of mass-loss rates, which increase with increasing luminosity on the giant branch, and star formation rates, which were a few times higher a billion years ago in M31 than they are today. We see some supergiant long-period variables, but somewhat fewer than expected based on their frequency in M33, and confined to the ring of star formation in M31 seen in the IRAS and 2MASS surveys.
