- ID:
- ivo://CDS.VizieR/J/ApJ/883/175
- Title:
- First release of the MaNGA Stellar Library (MaStar)
- Short Name:
- J/ApJ/883/175
- Date:
- 29 Nov 2021 07:46:33
- Publisher:
- CDS
- Description:
- We present the first release of the MaNGA Stellar Library (MaStar), which is a large, well-calibrated, high-quality empirical library covering the wavelength range 3622-10354{AA} at a resolving power of R~1800. The spectra were obtained using the same instrument as used by the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) project, by piggybacking on the Sloan Digital Sky Survey (SDSS-IV)/Apache Point Observatory Galaxy Evolution Experiment 2-N (APOGEE-2N) observations. Compared to previous empirical libraries, the MaStar library will have a higher number of stars and a more comprehensive stellar-parameter coverage, especially of cool dwarfs, low-metallicity stars, and stars with different [{alpha}/Fe], achieved by a sophisticated target-selection strategy that takes advantage of stellar-parameter catalogs from the literature. This empirical library will provide a new basis for stellar-population synthesis and is particularly well suited for stellar-population analysis of MaNGA galaxies. The first version of the library contains 8646 high-quality per-visit spectra for 3321 unique stars. Compared to photometry, the relative flux calibration of the library is accurate to 3.9% in g-r, 2.7% in r-i, and 2.2% in i-z. The data are released as part of SDSS Data Release 15. We expect the final release of the library to contain more than 10000 stars.
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- ID:
- ivo://CDS.VizieR/J/other/PASA/18.232
- Title:
- FLAIR II spectroscopy of DENIS samples
- Short Name:
- J/other/PASA/18.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As a pilot survey for the forthcoming 6dF Galaxy Redshift Survey, spectroscopy of galaxies selected in the 1.2 micron J waveband with the DENIS imaging survey was performed at the UKST using the FLAIR II multi-object spectroscope. Sixty-nine galaxy redshifts were obtained in a high galactic latitude field and an additional 12 redshifts in a low galactic latitude (b=-17{deg}), obscured field. This spectroscopic follow-up of NIR selected galaxies illustrates the feasibility of obtaining redshifts with optical spectra on galaxies selected at much longer wavelengths. It validated a very preliminary algorithm for star/galaxy separation for high galactic latitude DENIS objects, with 99% reliability for J<13.9. The FLAIR II redshifts are in excellent agreement with those, previously published, of 20 common galaxies. However, the FLAIR II redshift determinations presented here required substantially longer integration times to achieve 90% completeness than expected from previous optical surveys at comparable depth. This is mainly due to a degradation in overall fibre throughput due to known problems with ageing of the prism- cement-fibre interface with exposure to UV light. In comparison to our high galactic latitude field, our low latitude (high extinction) field required 2.5 times more exposure time for less than 50% of successful redshift measurements. Among the J<=13.9 galaxies with measured redshifts, only 37+/-6% display emission lines, in comparison with 60% of emission line galaxies in optical samples of comparable depth. These galaxies are, on average, half a magnitude bluer in B-J than galaxies of the same luminosity without emission fines. We confirm a previous optically-based result that the fraction of galaxies with emission lines increases rapidly with decreasing galaxy luminosity. The J band luminosity function is estimated. Our high latitude field displays a concentration of galaxies at cz~=38000km/s suggesting a possible supercluster. A radial velocity is reported for a galaxy lying near the projected centre of the Abell 1434 cluster of galaxies, for which no cluster redshift is currently available.
- ID:
- ivo://CDS.VizieR/J/ApJ/805/65
- Title:
- FLAMES observations of NGC 5128's globular clusters
- Short Name:
- J/ApJ/805/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the dynamical properties of 125 compact stellar systems (CSSs) in the nearby giant elliptical galaxy NGC 5128, using high-resolution spectra (R~26000) obtained with Very Large Telescope/FLAMES. Our results provide evidence for a new type of star cluster, based on the CSS dynamical mass scaling relations. All radial velocity (v_r_) and line-of-sight velocity dispersion ({sigma}_los_) measurements are performed with the penalized pixel fitting (ppxf) technique, which provided {sigma}_ppxf_ estimates for 115 targets. The {sigma}_ppxf_ estimates are corrected to the 2D projected half-light radii, {sigma}_1/2_, as well as the cluster cores, {sigma}_0_, accounting for observational/aperture effects and are combined with structural parameters, from high spatial resolution imaging, in order to derive total dynamical masses (M_dyn_) for 112 members of NGC5128's star cluster system. In total, 89 CSSs have dynamical masses measured for the first time along with the corresponding dynamical mass-to-light ratios ({sigma}_1/2_). We find two distinct sequences in the {gamma}^dyn^_V_-M_dyn_ plane, which are well approximated by power laws of the forms {gamma}^dyn^_V_{propto}M_dyn_^0.33+/-0.04^ and {gamma}^dyn^_V_{propto}M_dyn_^0.79+/-0.04^. The shallower sequence corresponds to the very bright tail of the globular cluster luminosity function (GCLF), while the steeper relation appears to be populated by a distinct group of objects that require significant dark gravitating components such as central massive black holes and/or exotically concentrated dark matter distributions. This result would suggest that the formation and evolution of these CSSs are markedly different from the "classical" globular clusters in NGC 5128 and the Local Group, despite the fact that these clusters have luminosities similar to the GCLF turnover magnitude. We include a thorough discussion of myriad factors potentially influencing our measurements.
- ID:
- ivo://CDS.VizieR/J/A+A/561/A87
- Title:
- FLAMES observations of Terzan 8
- Short Name:
- J/A+A/561/A87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Massive globular clusters (GCs) contain at least two generations of stars with slightly different ages and clearly distinct light elements abundances. The Na-O anticorrelation is the best studied chemical signature of multiple stellar generations. Low-mass clusters appear instead to be usually chemically homogeneous. We are investigating low-mass GCs to understand what is the lower mass limit where multiple populations can form, mainly using the Na and O abundance distribution. We used VLT/FLAMES spectra of giants in the low-mass, metal-poor GC Terzan 8, belonging to the Sagittarius dwarf galaxy, to determine abundances of Fe, O, Na, alpha-, Fe-peak, and neutron-capture elements in six stars observed with UVES and 14 observed with GIRAFFE. The average metallicity is [Fe/H]=-2.27+/-0.03 (rms=0.08), based on the six high-resolution UVES spectra. Only one star, observed with GIRAFFE, shows an enhanced abundance of Na and we tentatively assign it to the second generation. In this cluster, at variance with what happens in more massive GCs, the second generation seems to represent at most a small minority fraction. We discuss the implications of our findings, comparing Terzan 8 with the other Sgr dSph GCs, to GCs and field stars in the Large Magellanic Cloud, Fornax, and in other dwarfs galaxies.
- ID:
- ivo://CDS.VizieR/J/AJ/144/19
- Title:
- Follow-up photometry for HAT-P-34 through HAT-P-37
- Short Name:
- J/AJ/144/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of four transiting extrasolar planets (HAT-P-34b-HAT-P-37b) with masses ranging from 1.05 to 3.33M_J_ and periods from 1.33 to 5.45days. These planets orbit relatively bright F and G dwarf stars (from V=10.16 to V=13.2). Of particular interest is HAT-P-34b which is moderately massive (3.33M_J_), has a high eccentricity of e=0.441+/-0.032 at a period of P=5.452654+/-0.000016days, and shows hints of an outer component. The other three planets have properties that are typical of hot Jupiters.
- ID:
- ivo://CDS.VizieR/J/A+A/555/A12
- Title:
- Foreground Galactic stars properties
- Short Name:
- J/A+A/555/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the chemical and kinematic properties of roughly a thousand FLAMES-GIRAFFE LR8 spectra of faint magnitude foreground Galactic stars observed serendipitously during extra-galactic surveys in four lines-of-sight: three in the southern Galactic hemisphere (surveys of the Carina, Fornax and Sculptor dwarf spheroidal galaxies) and one in the northern Galactic hemisphere (a survey of the Sextans dwarf spheroidal galaxy). The foreground stars span distances up to ~3kpc from the Galactic plane and Galactocentric radii up to 11kpc. The stellar atmospheric parameters (effective temperature, surface gravity, metallicity) are obtained by an automated parameterisation pipeline and the distances of the stars are then derived by a projection of the atmospheric parameters on a set of theoretical isochrones using a Bayesian approach. The metallicity gradients are estimated for each line-of-sight and compared with predictions from the Besancon model of the Galaxy, in order to test the chemical structure of the thick disc. Finally, we use the radial velocities in each line-of-sight to derive a proxy for either the azimuthal or the vertical component of the orbital velocity of the stars. Only three lines-of-sight have a sufficient number of foreground stars for a robust analysis. Towards Sextans in the Northern Galactic hemisphere and Sculptor in the South, we measure a consistent decrease in mean metallicity with height from the Galactic plane, suggesting a chemically symmetric thick disc. This decrease can either be due to an intrinsic thick disc metallicity gradient, or simply due to a change in the thin disc/thick disc population ratio and no intrinsic metallicity gradients for the thick disc. We favour the latter explanation. In contrast, we find evidence of an unpredicted metal-poor population in the direction of Carina. This population was earlier detected by Wyse et al. (2006ApJ...639L..13W), but our more detailed analysis provides robust estimates of its location (|Z|<1kpc), metallicity (-2<[M/H]<-1dex) and azimuthal orbital velocity (V_phi_~120km/s).
- ID:
- ivo://CDS.VizieR/J/A+A/646/A131
- Title:
- Four Jovian planets RV and activity indexes
- Short Name:
- J/A+A/646/A131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of planetary companions orbiting four low-luminosity giant stars with M* between 1.04 and 1.39M_{sun}_. All four host stars have been independently observed by the EXoPlanets aRound Evolved StarS (EXPRESS) program and the Pan-Pacific Planet Search (PPPS). The companion signals were revealed by multi-epoch precision radial velocities obtained in nearly a decade. The planetary companions exhibit orbital periods between ~1.2 and 7.1 years, minimum masses of m_p_*sini~1.8-3.7M_Jup_, and eccentricities between 0.08 and 0.42. With these four new systems, we have detected planetary companions to 11 out of the 37 giant stars that are common targets in the EXPRESS and PPPS. After excluding four compact binaries from the common sample, we obtained a fraction of giant planets (m_p_~1-2M_Jup_) orbiting within 5AU from their parent star of f=33.3^+9.0^_-7.1_%. This fraction is slightly higher than but consistent at the 1{sigma} level with previous results obtained by different radial velocity surveys. Finally, this value is substantially higher than the fraction predicted by planet formation models of gas giants around stars more massive than the Sun.
- ID:
- ivo://CDS.VizieR/J/AJ/156/140
- Title:
- Four new eclipsing mid M-dwarf systems from MEarth
- Short Name:
- J/AJ/156/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using data from the MEarth-North and MEarth-South transit surveys, we present the detection of eclipses in four mid M-dwarf systems: LP 107-25, LP 261-75, LP 796-24, and LP 991-15. Combining the MEarth photometry with spectroscopic follow-up observations, we show that LP 107-25 and LP 796-24 are short-period (1.388 and 0.523 day, respectively) eclipsing binaries in triple-lined systems with substantial third-light contamination from distant companions. LP 261-75 is a short-period (1.882 day) single-lined system consisting of a mid M-dwarf eclipsed by a probable brown dwarf secondary, with another distant visual brown dwarf companion. LP 991-15 is a long-period (29.3 day) double-lined eclipsing binary on an eccentric orbit with a geometry that produces only primary eclipses. A spectroscopic orbit is given for LP 991-15, and initial orbits for LP 107-25 and LP 261-75.
- ID:
- ivo://CDS.VizieR/J/A+A/572/A93
- Title:
- Four new transiting planets
- Short Name:
- J/A+A/572/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The characterization of four new transiting extrasolar planets is presented here. KOI-188b and KOI-195b are bloated hot Saturns, with orbital periods of 3.8 and 3.2-days, and masses of 0.25 and 0.34M_Jup_, respectively. They are located in the low-mass range of known transiting, giant planets. KOI-192b has a similar mass (0.29M_Jup_) but a longer orbital period of 10.3 days. This places it in a domain where only few planets are known. KOI-830b, finally, with a mass of 1.27M_Jup_ and a period of 3.5-days, is a typical hot Jupiter. The four planets have radii of 0.98, 1.09, 1.2, and 1.08R_Jup_, respectively. We detected no significant eccentricity in any of the systems, while the accuracy of our data does not rule out possible moderate eccentricities. The four objects were first identified by the Kepler Team as promising candidates from photometry of the Kepler satellite. We establish here their planetary nature thanks to the radial velocity follow-up we secured with the HARPS-N spectrograph at the Telescopio Nazionale Galileo. The combined analyses of the whole datasets allow us to fully characterize the four planetary systems. These new objects increase the number of well-characterized exoplanets for statistics, and provide new targets for individual follow-up studies. The pre-screening we performed with the SOPHIE spectrograph at the Observatoire de Haute-Provence as part of that study also allowed us to conclude that a fifth candidate, KOI-219.01, is not a planet but is a false positive.
- ID:
- ivo://CDS.VizieR/J/A+A/549/A134
- Title:
- Four new WASP transiting close-in giant planets
- Short Name:
- J/A+A/549/A134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of four new transiting hot jupiters, detected mainly from SuperWASP-North and SOPHIE observations. These new planets, WASP-52b, WASP-58b, WASP-59b, and WASP-60b, have orbital periods ranging from 1.7 to 7.9-days, masses between 0.46 and 0.94M_Jup_, and radii between 0.73 and 1.49 R_Jup_.