- ID:
- ivo://CDS.VizieR/J/MNRAS/423/2917
- Title:
- Radial velocities in Pal 4
- Short Name:
- J/MNRAS/423/2917
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We obtained precise line-of-sight radial velocities of 23 member stars of the remote halo globular cluster Palomar 4 (Pal 4) using the High Resolution Echelle Spectrograph at the Keck I telescope. We also measured the mass function of the cluster down to a limiting magnitude of V~28mag using archival Hubble Space Telescope/Wide Field Planetary Camera 2 (WFPC2) imaging. We derived the cluster's surface brightness profile based on the WFPC2 data and on broad-band imaging with the Low Resolution Imaging Spectrometer at the Keck II telescope.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/573/A115
- Title:
- Radial velocities in seven globular clusters
- Short Name:
- J/A+A/573/A115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Gaia-ESO survey is a large public spectroscopic survey aimed at investigating the origin and formation history of our Galaxy by collecting spectroscopy of representative samples (about 10^5^ Milky Way stars) of all Galactic stellar populations, in the field and in clusters.The survey uses globular clusters as intra- and inter-survey calibrators, deriving stellar atmospheric parameters and abundances of a significant number of stars in clusters, along with radial velocity determinations. We used precise radial velocities of a large number of stars in seven globular clusters (NGC 1851, NGC 2808, NGC 4372, NGC 4833, NGC 5927, NGC 6752, and NGC 7078) to validate pipeline results and to preliminarily investigate the cluster internal kinematics. Radial velocity measurements were extracted from FLAMES/GIRAFFE spectra processed by the survey pipeline as part of the second internal data release of data products to ESO. We complemented our sample with ESO archival data obtained with different instrument configurations. Reliable radial velocity measurements for 1513 bona fide cluster star members were obtained in total. We measured systemic rotation, estimated central velocity dispersions, and present velocity dispersion profiles of all the selected clusters, providing the first velocity dispersion curve and the first estimate of the central velocity dispersion for the cluster NGC 5927. Finally, we explore the possible link between cluster kinematics and other physical parameters. The analysis we present here demonstrates that Gaia-ESO survey data are sufficiently accurate to be used in studies of kinematics of stellar systems and stellar populations in the Milky Way.
- ID:
- ivo://CDS.VizieR/J/AJ/115/708
- Title:
- Radial Velocities in the Field of M15
- Short Name:
- J/AJ/115/708
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- These tables give the mean radial velocities for 591 stars in the vicinity of the globular cluster M15 (NGC 7078). 230 of these are members of the cluster, the remaining 361 are most likely non-members, although the membership, or otherwise, of the faintest stars with velocities near that of the cluster was impossible to determine. The radial velocities were measured using the Hydra multi-object spectrograph on the WIYN telescope. For cluster members, the median uncertainty is 0.3 km/s.
- ID:
- ivo://CDS.VizieR/J/A+A/528/A127
- Title:
- Radial velocities in the globular NGC 2808
- Short Name:
- J/A+A/528/A127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The formation mechanism of hot horizontal branch (HB) stars is still one of the most uncertain points of stellar evolution theories. In the past decade, models based on their binary origin have been very successful in reproducing the properties of field subdwarf-B stars, but the observations of their analogues in globular clusters has posed new problems. In addition, the discovery of multiple populations offered an appealing alternative scenario for the formation of these stars. We search for binaries of period P<=200days among a sample of 83 blue horizontal branch stars (Teff=12000-22000K) in NGC 2808, a cluster known to host three distinct stellar populations and a multimodal horizontal branch. The final sample, after the rejection of stars with incomplete observations or poor quality data, consists of 64 targets. The radial velocity of the targets was measured in fourteen epochs, spanning a temporal interval of ~75days. The significant variations were identified by means of a detailed error analysis and a statistical study.
- ID:
- ivo://CDS.VizieR/J/A+A/525/A148
- Title:
- Radial velocities in two globular clusters
- Short Name:
- J/A+A/525/A148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Globular clusters are useful for testing the validity of Newtonian dynamics in the low acceleration regime typical of galaxies, without the complications of non-baryonic dark matter. In the absence of disturbing effects, such as tidal heating, the velocity dispersion of globular clusters is expected to vanish at large radii. If this is not observed, and in particular if, as observed in elliptical galaxies, the dispersion is found to be constant at large radii below a certain threshold acceleration, this might indicate a breakdown of Newtonian dynamics. To minimize the effects of tidal heating that can increase the velocity dispersion at large radii, we study the velocity dispersion profile of two distant globular clusters, NGC 1851 and NGC 1904. The velocity dispersion profile is derived from accurate radial velocity measurements, obtained at the ESO 8m VLT telescope with the FLAMES multi-object spectrograph. Reliable data for 184 and 146 bona fide cluster star members were obtained for NGC 1851 and NGC 1904, respectively.
- 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.
- ID:
- ivo://CDS.VizieR/J/PASP/111/1233
- Title:
- Radial Velocities of Globular Cluster Giants
- Short Name:
- J/PASP/111/1233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Velocities are given for 303 giant stars in the globular clusters M3, M13, M15, and M92 from spectra obtained with the 3.5-m WIYN Telescope at the Kitt Peak National Observatory using the Hydra multi-fiber positioner and bench spectrograph. The tables provide the individual identifications, HJD, and velocity for each star observed. The uncertainties in the velocity measurements are typically 1 km.s^-1^ or less.
- ID:
- ivo://CDS.VizieR/J/A+A/448/155
- Title:
- Radial velocities of Leo I globular clusters
- Short Name:
- J/A+A/448/155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- VLT/FLAMES radial velocities for 50 Globular Clusters (GCs), 37 field stars and 21 unclassified objects around the Leo I group galaxies NGC 3379 and NGC 3384 are presented. Object Id and BVR photometry are from Rhode & Zepf (2004AJ....127..302R). Positions (J2000.0) should be accurate to ~0"2 or better w.r.t. the GSC2.1 catalogue. Heliocentric radial velocities and their errors were estimated by fitting the peak (see the width, heigh, and Tonry & Davies (1979AJ.....84.1511T) coefficient) of the cross-correlation function (CCF) with the IRAF/RV package task FXCOR, using simulatenous and ELODIE library stellar templates. Objects have been assigned three quality class, class A being the most secure velocity determination, and class C the least secure; the latter objects require confirmation, and such GCs were not considered for the dynamical analysis presented in the paper.
- ID:
- ivo://CDS.VizieR/J/A+A/456/985
- Title:
- Radial velocities of 76 M31 candidate clusters
- Short Name:
- J/A+A/456/985
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results of a large spectroscopic survey of globular clusters and candidate globular clusters in the nearby M31 galaxy. The survey is aimed at the classification of known candidate M31 clusters and at the study of their kinematic properties. We obtained low-resolution spectroscopy for 133 targets, including 76 yet-to-be-confirmed candidate clusters (i.e. with no previous spectroscopic information), 55 already-confirmed genuine M31 clusters, and 2 uncertain candidates. Our observations allowed a reliable estimate of the target radial velocity, within a typical accuracy of ~+/-20Km/s. The observed candidates have been robustly classified according to their radial velocity and shape parameters that allowed us to confidently discriminate between point sources and extended objects even from low-spatial-resolution imagery. In our set of 76 candidate clusters we found: 42 newly-confirmed bona-fide M31 clusters, 12 background galaxies, 17 foreground Galactic stars, 2 HII regions belonging to M31 and 3 unclassified (possibly M31 clusters or foreground stars) objects. The classification of a few other candidates not included in our survey has been also reassessed on various observational bases. All the sources of radial velocity estimates for M31 known globular clusters available in the literature have been compared and checked, and a homogeneous general list has been obtained for 349 confirmed clusters with radial velocity. Our results suggest that a significant number of genuine clusters (~>100) is still hidden among the plethora of known candidates proposed by various authors. Hence our knowledge of the globular cluster system of the M31 galaxy is still far from complete even in terms of simple membership.
- ID:
- ivo://CDS.VizieR/J/ApJ/591/850
- Title:
- Radial velocities of M49 globular clusters
- Short Name:
- J/ApJ/591/850
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the Low Resolution Imaging Spectrometer on the Keck I and II telescopes, we have measured radial velocities for 196 globular clusters (GCs) around M49 (NGC 4472), the brightest member of the Virgo Cluster. Combined with published data, they bring the total number of GCs with measured radial velocities in this galaxy to 263. In terms of sample size, spatial coverage, velocity precision, and the availability of metallicity estimates from Washington photometry, this radial velocity database resembles that presented recently for M87 (NGC 4486), Virgo's cD galaxy and its second-ranked member. We extract the projected kinematics of the full sample of GCs and of separate subsamples of 158 metal-poor and 105 metal-rich GCs.
