- ID:
- ivo://CDS.VizieR/J/AJ/125/1598
- Title:
- New high proper motion stars in the northern sky
- Short Name:
- J/AJ/125/1598
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We define an enhanced spectral classification scheme for M dwarf stars and use it to derive spectral classification of 104 northern stars with proper motions larger than 0.5"/yr that we discovered in a survey of high proper motion stars at low Galactic latitudes. The final tally is as follows: 54 M dwarfs, 25 sdK and sdM subdwarfs, 14 esdK and esdM extreme subdwarfs, and 11 DA and DC white dwarfs. Among the most interesting cases, we find one star to be the coolest subdwarf ever reported (LSR 2036+5059, with spectral type sdM7.5), a new M9.0 dwarf only about 6 pc distant (LSR 1835+3259), and a new M6.5 dwarf only 7 pc from the Sun (LSR 2124+4003). Spectroscopic distances suggests that 27 of the M dwarfs, three of the white dwarfs, and one of the subdwarfs (LSR 2036+5059) are within 25 pc of the Sun, making them excellent candidates for inclusion in the solar neighborhood census. Estimated sky-projected velocities suggest that most of our subdwarfs and extreme subdwarfs have halo kinematics. We find that several white dwarfs and nonmetal-poor M dwarfs also have kinematics consistent with the halo, and we briefly discuss their possible origin.
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Search Results
1752. New MnII energy levels
- ID:
- ivo://CDS.VizieR/J/A+A/580/A10
- Title:
- New MnII energy levels
- Short Name:
- J/A+A/580/A10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The NIST database lists several MnI lines that were observed in the laboratory but not classified. They cannot be used in spectrum synthesis because their atomic line data are unknown. These lines are concentrated in the 2380-2700{AA} interval. We aimed to assign energy levels and loggf values to these lines. Semi-empirical line data for MnII computed by Kurucz were used to synthesize the ultraviolet spectrum of the slow-rotating, HgMn star HD 175640. The spectrum was compared with the high-resolution spectrum observed with the HST-STIS equipment. A UVES spectrum covering the 3050-10000{AA} region was also examined.
- ID:
- ivo://CDS.VizieR/J/ApJ/670/92
- Title:
- New sample of low-mass black holes in AGN
- Short Name:
- J/ApJ/670/92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an expanded sample of low-mass black holes (BHs) found in galactic nuclei. Using standard virial mass techniques to estimate BH masses, we select from the Fourth Data Release of the Sloan Digital Sky Survey all broad-line active galaxies with masses <2x10^6^M_{sun}_ BHs in this mass regime provide unique tests of the relationship between BHs and galaxies, since their late-type galaxy hosts do not necessarily contain classical bulges. Furthermore, they provide observational analogs of primordial seed BHs and are expected, when merging, to provide strong gravitational signals for future detectors such as LISA. From our preliminary sample of 19, we have increased the total sample by an order of magnitude to 174, as well as an additional 55 (less secure) candidates.
- ID:
- ivo://CDS.VizieR/J/A+AS/128/35
- Title:
- New Sample of OH/IR stars
- Short Name:
- J/A+AS/128/35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Tables 2 and 3 present the positional and kinematic, and physical data for OH/IR stars found within 37 arcmin of the Galactic center (Sgr A*) respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/623/A129
- Title:
- New satellites of the LMC search
- Short Name:
- J/A+A/623/A129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A wealth of tiny galactic systems populates the surroundings of the Milky Way. However, some of these objects might have originated as former satellites of the Magellanic Clouds, in particular of the Large Magellanic Cloud (LMC). Examples of the importance of understanding how many systems are genuine satellites of the Milky Way or the LMC are the implications that the number and luminosity-mass function of satellites around hosts of different mass have for dark matter theories and the treatment of baryonic physics in simulations of structure formation. Here we aim at deriving the bulk motions and estimates of the internal velocity dispersion and metallicity properties in four recently discovered distant southern dwarf galaxy candidates, Columba I, Reticulum III, Phoenix II, and Horologium II. We combined Gaia DR2 astrometric measurements, photometry, and new FLAMES/GIRAFFE intermediate-resolution spectroscopic data in the region of the near-IR CaII triplet lines; this combination is essential for finding potential member stars in these low-luminosity systems. We find very likely member stars in all four satellites and are able to determine (or place limits on) the bulk motions and average internal properties of the systems. The systems are found to be very metal poor, in agreement with dwarf galaxies and dwarf galaxy candidates of similar luminosity. Of these four objects, we can only firmly place Phoenix II in the category of dwarf galaxies because of its resolved high velocity dispersion (9.5^+6.8^_-4.4_km/s) and intrinsic metallicity spread (0.33dex). For Columba I we also measure a clear metallicity spread. The orbital pole of Phoenix II is well constrained and close to that of the LMC, suggesting a prior association. The uncertainty on the orbital poles of the other systems is currently very large, so that an association cannot be excluded, except for Columba I. Using the numbers of potential former satellites of the LMC identified here and in the literature, we obtain for the LMC a dark matter mass of M_200_=1.9^+1.3^_-0.9_x10^11^M_{sun}_
- ID:
- ivo://CDS.VizieR/J/PAZh/34/21
- Title:
- New spectral types for Tycho2 stars
- Short Name:
- J/PAZh/34/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compare the spectroscopic and trigonometric parallaxes of common stars from the Tycho-2 Spectral Type and Hipparcos Catalogues. This comparison has revealed that the distance estimations for the overwhelming majority of stars by both methods yield very similar results. However, there is a small fraction of stars for which the distance estimates differences.
- ID:
- ivo://CDS.VizieR/J/PAZh/24/343
- Title:
- New spectroscopic components
- Short Name:
- J/PAZh/24/343
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on the correlation radial-velocity measurement, we discovered new spectroscopic subsystems in the components of six visual multiple stars and determined the elements of their spectroscopic orbits.
- ID:
- ivo://CDS.VizieR/J/A+A/578/A3
- Title:
- New survey of supergiants in the MCs
- Short Name:
- J/A+A/578/A3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this study, we conduct a pilot program aimed at the red supergiant population of the Magellanic Clouds. We intend to extend the current known sample to the unexplored low end of the brightness distribution of these stars, building a more representative dataset with which to extrapolate their behaviour to other Galactic and extra-galactic environments. We select candidates using only near infrared photometry, and with medium resolution multi-object spectroscopy, we perform spectral classification and derive their line-of-sight velocities, confirming the nature of the candidates and their membership to the clouds. Around two hundred new RSGs have been detected, hinting at a yet to be observed large population. Using near and mid infrared photometry we study the brightness distribution of these stars, the onset of mass-loss and the effect of dust in their atmospheres. Based on this sample, new a priori classification criteria are investigated, combining mid and near infrared photometry to improve the observational efficiency of similar programs as this.
- ID:
- ivo://CDS.VizieR/J/AJ/158/54
- Title:
- New Taurus members from stellar to planetary masses
- Short Name:
- J/AJ/158/54
- Date:
- 06 Dec 2021 11:31:43
- Publisher:
- CDS
- Description:
- We present a large sample of new members of the Taurus star-forming region that extend from stellar to planetary masses. To identify candidate members at substellar masses, we have used color-magnitude diagrams and proper motions measured with several wide-field optical and infrared (IR) surveys. At stellar masses, we have considered the candidate members that were found in a recent analysis of high-precision astrometry from the Gaia mission. Using new and archival spectra, we have measured spectral types and assessed membership for these 161 candidates, 79 of which are classified as new members. Our updated census of Taurus now contains 519 known members. According to Gaia data, this census should be nearly complete for spectral types earlier than M6-M7 at A_J_<1. For a large field encompassing ~72% of the known members, the census should be complete for K<15.7 at A_J_<1.5, which corresponds to ~5-13 M_Jup_ for ages of 1-10 Myr based on theoretical evolutionary models. Our survey has doubled the number of known members at >=M9 and has uncovered the faintest known member in M_K_, which should have a mass of ~3-10 M_Jup_ for ages of 1-10 Myr. We have used mid-IR photometry from the Spitzer Space Telescope and the Wide-field Infrared Survey Explorer to determine whether the new members exhibit excess emission that would indicate the presence of circumstellar disks. The updated disk fraction for Taurus is ~0.7 at =<M3.5 and ~0.4 at >M3.5.
1760. New ultracool subdwarfs
- ID:
- ivo://CDS.VizieR/J/A+A/598/A92
- Title:
- New ultracool subdwarfs
- Short Name:
- J/A+A/598/A92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We developed an efficient method to search for late-type subdwarfs. We carried out a search cross-matching SDSS, 2MASS, and UKIDSS with VO tools. We considered different photometric and proper motion criteria for our selection. We identified 100 late-type subdwarf candidates. We obtained our own low-resolution optical spectra for 71 of our candidates and retrieved Sloan spectra for 30 of them (9 in common to the 71). We classified 92 candidates based on optical spectra. Our new discoveries include 49 subdwarfs, 25 extreme subdwarfs, six ultrasubdwarfs, one subdwarf/extreme subdwarf, and two dwarfs/subdwarfs. In addition, we discovered three early-L subdwarfs. We double the numbers of cool subdwarfs and derived a surface density of late-type subdwarfs.
