- ID:
- ivo://CDS.VizieR/J/ApJ/798/23
- Title:
- Radial velocities of giant stars in NGC 6388
- Short Name:
- J/ApJ/798/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new radial velocity measurements for 82 stars, members of the Galactic globular cluster (GC) NGC 6388, obtained from ESO-VLT K-band Multi Object Spectrograph (KMOS) spectra acquired during the instrument Science Verification. The accuracy of the wavelength calibration is discussed and a number of tests of the KMOS response are presented. The cluster systemic velocity obtained (81.3+/-1.5km/s) is in very good agreement with previous determinations. While a hint of ordered rotation is found between 9" and 20" from the cluster center, where the distribution of radial velocities is clearly bimodal, more data are needed before drawing any firm conclusions. The acquired sample of radial velocities has also been used to determine the cluster velocity dispersion (VD) profile between ~9" and 70", supplementing previous measurements at r<2" and r>60" obtained with ESO-SINFONI and ESO-FLAMES spectroscopy, respectively. The new portion of the VD profile nicely matches the previous ones, better defining the knee of the distribution. The present work clearly shows the effectiveness of a deployable integral field unit in measuring the radial velocities of individual stars for determining the VD profile of Galactic GCs. It represents the pilot project for an ongoing large program with KMOS and FLAMES at the ESO-VLT, aimed at determining the next generation of VD and rotation profiles for a representative sample of GCs.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/580/A14
- Title:
- Radial Velocities of 3 giant stars with planets
- Short Name:
- J/A+A/580/A14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of two giant planets around the intermediate-mass evolved star HIP65891 and HIP107773. The best Keplerian fit to the HIP65891 and HIP107773 radial velocities leads to the following orbital parameters: P=1084.5d; Mpsini=6.0M_Jup_; e=0.13 and P=144.3d; Mpsini=2.0M_Jup_; e=0.09, respectively. In addition, we confirm the planetary nature of the outer object orbiting the giant star HIP67851. The orbital parameters of HIP67851c are: P=2131.8d, Mpsini=6.0M_Jup_, and e=0.17.
- ID:
- ivo://CDS.VizieR/J/AJ/135/196
- Title:
- Radial velocities of 45 metal-poor field stars
- Short Name:
- J/AJ/135/196
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report 349 radial velocities for 45 metal-poor field red giant branch (RGB) and red horizontal branch (RHB) stars, with time coverage ranging from 1 to 21 years. We have identified one new spectroscopic binary, HD 4306, and one possible such system, HD 184711. We also provide 57 radial velocities for 11 of the 91 stars reported in our previous work. All but one of the 11 stars had been found to have variable radial velocities.
- ID:
- ivo://CDS.VizieR/J/MNRAS/462/3376
- Title:
- Radial velocities of NGC 6822 carbon stars
- Short Name:
- J/MNRAS/462/3376
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using spectra taken with the AAOmega spectrograph, we measure the radial velocities of over 100 stars, many of which are intermediate age carbon stars, in the direction of the dwarf irregular galaxy NGC 6822. Kinematic analysis suggests that the carbon stars in the sample are associated with NGC 6822, and estimates of its radial velocity and galactic rotation are made from a star-by-star analysis of its carbon star population. We calculate a heliocentric radial velocity for NGC 6822 of -51+/-3km/s and show that the population rotates with a mean rotation speed of 11.2+/-2.1km/s at a mean distance of 1.1kpc from the galactic centre, about a rotation axis with a position angle of 26{deg}+/-13{deg}, as projected on the sky. This is close to the rotation axis of the HI gas disc and suggests that NGC 6822 is not a polar ring galaxy, but is dynamically closer to a late-type galaxy. However, the rotation axis is not aligned with the minor axis of the AGB isodensity profiles and this remains a mystery.
- ID:
- ivo://CDS.VizieR/J/A+A/399/105
- Title:
- Radial velocities of red giants in NGC 1817
- Short Name:
- J/A+A/399/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radial-velocity and BV CCD observations of 29 red-giant candidates in the central part of the intermediate-age open cluster NGC 1817 have confirmed the membership of 21 stars. In addition, we have used radial velocities and new UBVR photoelectric photometry to investigate the membership of 59 new candidates located in an outer corona surrounding NGC 1817, identified from the POSS plates. We have confirmed 18 new members out to a distance of 27' from the centre, thus doubling the previous cluster radius. Ten definite spectroscopic-binary members have been discovered, corresponding to a binary frequency of 25.6% and four orbits have been determined so far. Three additional stars have been identified as possible spectroscopic-binary members. We derive a cluster mean velocity of +65.33+/-0.09 (0.52 s.e.) km/s based on 29 members with no detected velocity variations plus the 3 binary members with orbital solutions.
- ID:
- ivo://CDS.VizieR/J/MNRAS/396/2183
- Title:
- Radial velocities of red giants in {omega} Cen
- Short Name:
- J/MNRAS/396/2183
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a survey of radial velocities over a wide region extending from r~=10 out to 80' (~1.5 tidal radii) within the massive star cluster omega Centauri (omega Cen). The survey was performed with FLAMES@VLT, to study the velocity dispersion profile in the outer regions of this stellar system. We derived accurate radial velocities for a sample of 2557 newly observed stars, identifying 318 bona fide cluster red giants. Merging our data with those provided by our previous survey, we assembled a final homogeneous sample of 946 cluster members that allowed us to trace the velocity dispersion profile from the centre out to r~32'.
- ID:
- ivo://CDS.VizieR/J/AJ/131/2514
- Title:
- Radial velocities of red giants in the SMC
- Short Name:
- J/AJ/131/2514
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic survey of 2079 red giant stars, distributed over the central 4kpcx2kpc of the Small Magellanic Cloud (SMC). After fitting and removing a small velocity gradient across the SMC (8.3km/s/{deg} oriented at 23.4{deg} east of north), we measure an rms velocity scatter of 27.5+/-0.5km/s.
- ID:
- ivo://CDS.VizieR/J/AJ/145/134
- Title:
- Radial velocities of 108 stars in Ruprecht 147
- Short Name:
- J/AJ/145/134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ruprecht 147 is a hitherto unappreciated open cluster that holds great promise as a standard in fundamental stellar astrophysics. We have conducted a radial velocity survey of astrometric candidates with Lick, Palomar, and MMT observatories and have identified over 100 members, including 5 blue stragglers, 11 red giants, and 5 double-lined spectroscopic binaries (SB2s). We estimate the cluster metallicity from spectroscopic analysis, using Spectroscopy Made Easy (SME), and find it to be [M/H]=+0.07+/-0.03. We have obtained deep CFHT/MegaCam g'r'i'z' photometry and fit Padova isochrones to the (g'-i') and Two Micron All Sky Survey (J-K_S_) color-magnitude diagrams, using the {tau}^2^ maximum-likelihood procedure of Naylor, and an alternative method using two-dimensional cross-correlations developed in this work. We find best fits for Padova isochrones at age t=2.5+/-0.25Gyr, m-M=7.35+/-0.1, and A_V_=0.25+/-0.05, with additional uncertainty from the unresolved binary population and possibility of differential extinction across this large cluster. The inferred age is heavily dependent on our choice of stellar evolution model: fitting Dartmouth and PARSEC models yield age parameters of 3Gyr and 3.25Gyr, respectively. At ~300pc and ~3Gyr, Ruprecht 147 is by far the oldest nearby star cluster.
- ID:
- ivo://CDS.VizieR/J/ApJ/661/L155
- Title:
- Radial velocities RGB stars in omega Cen
- Short Name:
- J/ApJ/661/L155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first result of the Ital-FLAMES survey of red giant branch (RGB) stars in omega Cen. Radial velocities with a precision of ~0.5km/s are presented for 650 members of omega Cen observed with FLAMES-GIRAFFE at the Very Large Telescope.
- ID:
- ivo://CDS.VizieR/J/A+A/509/A24
- Title:
- Radial velocity curve of {gamma}^1^ Leo
- Short Name:
- J/A+A/509/A24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our primary goal is to search for planets around intermediate mass stars. We are also interested in studying the nature of radial velocity (RV) variations of K giant stars. We selected about 55 early K giant (K0-K4) stars brighter than fifth magnitude that were observed using BOES, a high resolution spectrograph attached to the 1.8m telescope at BOAO (Bohyunsan Optical Astronomy Observatory). BOES is equipped with I_2_ absorption cell for high precision RV measurements. We detected a periodic radial velocity variations in the K0 III star gamma1 Leo with a period of P=429-days. An orbital fit of the observed RVs yields a period of P=429-days, a semi-amplitude of K=208m/s, and an eccentricity of e=0.14. To investigate the nature of the RV variations, we analyzed the photometric, Ca II {lambda} 8662 equivalent width, and line-bisector variations of gamma1 Leo. We conclude that the detected RV variations can be best explained by a planetary companion with an estimated mass of msini=8.78M_{Jupiter}_ and a semi-major axis of a=1.19AU, assuming a stellar mass of 1.23M_{sun}_.
