- ID:
- ivo://CDS.VizieR/J/A+A/494/1137
- Title:
- K-band spectral catalog of Quintuplet cluster
- Short Name:
- J/A+A/494/1137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Three very massive clusters are known to reside in the Galactic center region, the Arches cluster, the Quintuplet cluster, and the central parsec cluster, each of them rich in young hot stars. With new infrared instruments, this region is no longer obscured for the observer. For understanding these very massive clusters, it is essential to know their stellar inventory. We provide comprehensive spectroscopic data for the stellar population of the Quintuplet cluster that will form the basis of subsequent spectral analyses. Spectroscopic observations of the Quintuplet cluster were obtained with the Integral Field Spectrograph SINFONI-SPIFFI at the ESO-VLT, with the ESO VLT UT4 (Yepun) telescope between May and July 2006. The inner part of the Quintuplet cluster covered by 22 slightly overlapping fields, each of them of 8"x8" in size. The spectral range comprises the near-IR K-band from 1.94 to 2.45um. The 3D data cubes of the individual fields were flux-calibrated and combined to one contiguous cube, from which the spectra of all detectable point sources were extracted.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/568/L13
- Title:
- K-band spectrum of the very massive star W49nr1
- Short Name:
- J/A+A/568/L13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Very massive stars (M>100M_{sun}_) are very rare objects, but have a strong influence on their environment. The formation of this kind of objects is of prime importance in star formation, but observationally still poorly constrained. We report on the identification of a very massive star in the central cluster of the star-forming region W49. We investigate near-infrared K-band spectroscopic observations of W49 from VLT/ISAAC together with JHK images obtained with NTT/SOFI and LBT/LUCI. We derive a spectral type of W49nr1, the brightest star in the dense core of the central cluster of W49.
- ID:
- ivo://CDS.VizieR/II/211
- Title:
- K-band survey in high galactic latitude
- Short Name:
- II/211
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The survey is a high galactic latitude, large area (552 square arcmin) blank-field sample to a 5{sigma} limit of K=17.3mag. Star-galaxy discrimination is performed. The infrared observations were made over the period 1987-1988, using the infrared camera IRCAM at the 3.8m UKIRTelescope at Mauna Kea, Hawai. The pixel size is 1.2arcsec. The redshift survey (spectro.dat) concerns 124 galaxies of the survey, and was carried out on the Anglo-Australian telescope and the William Herschel telescope at La Palma over the period 1990-1992, with a multi-fibre spectrograph for the brighter objects (R<19), long and multi-slit spectrographs for fainter objects.
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/2652
- Title:
- Keck Aperture Masking Experiment. Red giants
- Short Name:
- J/MNRAS/426/2652
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- While the importance of dusty asymptotic giant branch (AGB) stars to galactic chemical enrichment is widely recognized, a sophisticated understanding of the dust formation and wind-driving mechanisms has proven elusive due in part to the difficulty in spatially resolving the dust-formation regions themselves. We have observed 20 dust-enshrouded AGB stars as part of the Keck Aperture Masking Experiment, resolving all of them in multiple near-infrared bands between 1.5 and 3.1um.
- ID:
- ivo://CDS.VizieR/J/AJ/157/71
- Title:
- Keck/NIRC2 astrometry for GSC 6214-210 b
- Short Name:
- J/AJ/157/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Direct-imaging exoplanet surveys have discovered a class of 5-20 M_Jup_ substellar companions at separations >100 au from their host stars, which present a challenge to planet and star formation models. Detailed analysis of the orbital architecture of these systems can provide constraints on possible formation mechanisms, including the possibility that they were dynamically ejected onto a wide orbit. We present astrometry for the wide planetary-mass companion GSC 6214-210 b (240 au; ~14 M_Jup_) obtained using NIRC2 with adaptive optics at the Keck telescope over 10 years. Our measurements achieved astrometric uncertainties of ~1 mas per epoch. We determined a relative motion of 1.12+/-0.15 mas/yr (0.61+/-0.09 km/s), the first detection of orbital motion for this companion. We compute the minimum periastron for the companion due to our measured velocity vector and derive constraints on the orbital parameters through our modified implementation of the Orbits for the Impatient rejection sampling algorithm. We find that close periastron orbits, which could indicate that the companion was dynamically scattered, are present in our posterior but have low likelihoods. For all orbits in our posterior, we assess the detectability of close-in companions that could have scattered GSC 6214-210 b from a closer orbit, and find that most potential scatterers would have been detected in previous imaging. We conclude that formation at small orbital separation and subsequent dynamical scattering through interaction with another potential close-in object is an unlikely formation pathway for this companion. We also update stellar and substellar properties for the system using the new parallax from Gaia DR2 (Cat. I/345).
- ID:
- ivo://CDS.VizieR/J/ApJ/873/65
- Title:
- Keck/NIRC2 obs. of the Galactic Center
- Short Name:
- J/ApJ/873/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Precision measurements of the stars in short-period orbits around the supermassive black hole at the Galactic Center are now being used to constrain general relativistic effects, such as the gravitational redshift and periapse precession. One of the largest systematic uncertainties in the measured orbits has been errors in the astrometric reference frame, which is derived from seven infrared-bright stars associated with SiO masers that have extremely accurate radio positions, measured in the Sgr A*-rest frame. We have improved the astrometric reference frame within 14" of the Galactic Center by a factor of 2.5 in position and a factor of 5 in proper motion. In the new reference frame, Sgr A* is localized to within a position of 0.645mas and proper motion of 0.03mas/yr. We have removed a substantial rotation (2.25{deg} per decade), that was present in the previous less-accurate reference frame used to measure stellar orbits in the field. With our improved methods and continued monitoring of the masers, we predict that orbital precession predicted by general relativity will become detectable in the next ~5yr.
- ID:
- ivo://CDS.VizieR/J/ApJ/751/132
- Title:
- Keck observations of the Arches cluster
- Short Name:
- J/ApJ/751/132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the first detection of the intrinsic velocity dispersion of the Arches cluster - a young (~2Myr), massive (10^4^M_{sun}_) starburst cluster located only 26pc in projection from the Galactic center. This was accomplished using proper motion measurements within the central 10"x10" of the cluster, obtained with the laser guide star adaptive optics system at Keck Observatory over a three-year time baseline (2006-2009). This uniform data set results in proper motion measurements that are improved by a factor ~5 over previous measurements from heterogeneous instruments. By careful, simultaneous accounting of the cluster and field contaminant distributions as well as the possible sources of measurement uncertainties, we estimate the internal velocity dispersion to be 0.15+/-0.01mas/yr, which corresponds to 5.4+/-0.4km/s at a distance of 8.4kpc. Collateral benefits of our data and analysis include: (1) cluster membership probabilities, which may be used to extract a clean-cluster sample for future photometric work; (2) a refined estimate of the bulk motion of the Arches cluster with respect to the field, which we find to be 172+/-15km/s, which is slightly slower than suggested by previous measurements using one epoch each with the Very Large Telescope and the Keck telescope; and (3) a velocity dispersion estimate for the field itself, which is likely dominated by the inner Galactic bulge and the nuclear disk.
- ID:
- ivo://CDS.VizieR/IV/34
- Title:
- K2 Ecliptic Plane Input Catalog (EPIC)
- Short Name:
- IV/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The K2 Mission (Howell+, 2014PASP..126..398H) uses the Kepler spacecraft to obtain high-precision photometry over ~80 day campaigns in the ecliptic plane. The Ecliptic Plane Input Catalog (EPIC) provides coordinates, photometry, and kinematics based on a federation of all-sky catalogs to support target selection and target management for the K2 mission.
- ID:
- ivo://CDS.VizieR/J/ApJ/799/105
- Title:
- KELT light curve of the M82 SN 2014J
- Short Name:
- J/ApJ/799/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report observations of the bright M82 supernova 2014J serendipitously obtained with the Kilodegree Extremely Little Telescope (KELT). The supernova (SN) was observed at high cadence for over 100 days, from pre-explosion, to early rise and peak times, through the secondary bump. The high cadence KELT data with high signal-to-noise ratio is completely unique for SN 2014J and for any other SNIa, with the exception of the (yet) unpublished Kepler data. Here, we report determinations of the SN explosion time and peak time. We also report measures of the "smoothness" of the light curve on timescales of minutes/hours never before probed, and we use this to place limits on energy produced from short-lived isotopes or inhomogeneities in the explosion or the circumstellar medium. From the non-observation of significant perturbations of the light curves, we derive a 3{sigma} upper limit corresponding to 8.7x10^36^erg/s for any such extra sources of luminosity at optical wavelengths.
- ID:
- ivo://CDS.VizieR/J/ApJ/761/123
- Title:
- KELT-1 photometry and spectroscopy follow-up
- Short Name:
- J/ApJ/761/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of KELT-1b, the first transiting low-mass companion from the wide-field Kilodegree Extremely Little Telescope-North (KELT-North) transit survey. A joint analysis of the spectroscopic, radial velocity, and photometric data indicates that the V=10.7 primary is a mildly evolved mid-F star with T_eff_=6516+/-49K, logg=4.228^+0.014^_-0.021_, and [Fe/H]=0.052+/-0.079, with an inferred mass M_*_=1.335+/-0.063M_{sun}_ and radius R_*_=1.471^+0.045^_-0.035_R_{sun}_. The companion is a low-mass brown dwarf or a super-massive planet with mass M_P_=27.38+/-0.93M_Jup_ and radius R_P_=1.116^+0.038^_-0.029_R_Jup_. The companion is on a very short (~29 hr) period circular orbit, with an ephemeris T_c_ (BJD_TDB_)=2455909.29280+/-0.00023 and P=1.217501+/-0.000018 days. KELT-1b receives a large amount of stellar insolation, resulting in an estimated equilibrium temperature assuming zero albedo and perfect redistribution of T_eq_=2423^+34^_-27_K. Comparison with standard evolutionary models suggests that the radius of KELT-1b is likely to be significantly inflated. Adaptive optics imaging reveals a candidate stellar companion to KELT-1 with a separation of 588+/-1mas, which is consistent with an M dwarf if it is at the same distance as the primary. Rossiter-McLaughlin measurements during transit imply a projected spin-orbit alignment angle {lambda}=2+/-16deg, consistent with a zero obliquity for KELT-1. Finally, the vsinI_*_=56+/-2km/s of the primary is consistent at ~2{sigma} with tidal synchronization. Given the extreme parameters of the KELT-1 system, we expect it to provide an important testbed for theories of the emplacement and evolution of short-period companions, as well as theories of tidal dissipation and irradiated brown dwarf atmospheres.
