- ID:
- ivo://CDS.VizieR/J/ApJ/682/135
- Title:
- CCD photometry of M60
- Short Name:
- J/ApJ/682/135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a photometric study of the globular clusters (GCs) in the giant elliptical galaxy M60 in the Virgo Cluster, based on deep, relatively wide field Washington CT_1_ CCD images. The CMD reveals a significant population of GCs in M60 and a large number of young luminous clusters in NGC 4647, a small companion spiral northwest of M60. The color distribution of the GCs in M60 is clearly bimodal, with a blue peak at (C-T_1_)=1.37 and a red peak at (C-T_1_)=1.87. We derive two new transformation relations between the (C-T_1_)_0_ color and [Fe/H] using the data for the GCs in our Galaxy and M49. Using these relations, we derive the metallicity distribution of the GCs in M60, which is also bimodal: a dominant metal-poor component with center at [Fe/H]=-1.2, and a weaker metal-rich component with center at [Fe/H]=-0.2. We estimate the total number of the GCs in M60 to be 3600+/-500 and the specific frequency to be S_N_=3.8+/-0.4.
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- ID:
- ivo://CDS.VizieR/J/PASP/127/31
- Title:
- CCD photometry of NGC 2482
- Short Name:
- J/PASP/127/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present BV and u'g'r'i' CCD photometry of the central region of NGC 2482. We also present BVu'g' CCD photometry of five clusters that have been poorly studied in the past: Ruprecht 42, Ruprecht 51, Ruprecht 153, Ruprecht 154, and AH03 J0748-26.9, which to our knowledge has not been studied before. Using a global optimization technique that eliminates much of the subjectivity previously inherent in main-sequence fitting studies, we obtain values of the distances, ages, and metallicities of the clusters, with robust estimates of the uncertainties of these fundamental parameters. Four of our clusters are less than ~1.3kpc beyond the Sun's distance from the Galactic center and have essentially solar metallicity. The metallicities of those clusters more distant from the Galactic center are consistent with a 0.3dex step to lower [Fe/H] found in other studies.
- ID:
- ivo://CDS.VizieR/J/AJ/98/2086
- Title:
- CCD photometry of NGC 2257 RR Lyrae
- Short Name:
- J/AJ/98/2086
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- B and V band CCD photometry is used to study 33 cluster and nine field RR Lyrae variables near the LMC cluster, NGC 2257. It is found that the mean magnitudes for the two groups differ by 0.17 mag. The cluster and field variables both have an Fe/H abundance ratio of -1.8+/-0.1. The results are compared used to compare NGC 2257 with galactic globular clusters, showing that NGC 2257 is indistinguishable from its local counterparts.
- ID:
- ivo://CDS.VizieR/J/AJ/106/181
- Title:
- CCD photometry of open cluster M67
- Short Name:
- J/AJ/106/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a CCD photometric survey of the central one-half degree of the old open cluster, M67, in U, B, V, and I colors to magnitude V=20. Extensive comparison of our photometry with other published datasets shows excellent agreement, indicating that CCD photometry is capable of producing a uniform set of measurements consistent with the photometric system defined primarily by the Landolt standard sequence. The color-magnitude diagram of the cluster shows a well-defined main sequence extending at least to the limit of the photometry at M(V)=10.55 and a substantial binary sequence. At least 38 percent of cluster stars are binaries. The observations were performed on 3 nights on 15-18 February 1990 with the 1.09m telescope at Kitt Peak National Observatory with a Tektronix 512^2^ CCD camera; a standard KPNO UBVRI filter set was used, with BVR filters being the Harris et, and I the "nearly Mould" filter.
- ID:
- ivo://CDS.VizieR/J/MNRAS/450/2122
- Title:
- CCD photometry of star clusters in the LMC
- Short Name:
- J/MNRAS/450/2122
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Washington system colour-magnitude diagrams (CMDs) for 17 practically unstudied star clusters located in the bar as well as in the inner disc and outer regions of the Large Magellanic Cloud (LMC). Cluster sizes were estimated from star counts distributed throughout the entire observed fields. Based on the best fits of theoretical isochrones to the cleaned (C-T_1_, T_1_) CMDs, as well as on the {delta}T_1_ parameter and the standard giant branch method, we derive ages and metallicities for the cluster sample. Four objects are found to be intermediate-age clusters (1.8-2.5 Gyr), with [Fe/H] ranging from -0.66 to -0.84. With the exception of SL 263, a very young cluster (~16 Myr), the remaining 12 objects are aged between 0.32 and 0.89 Gyr, with their [Fe/H] values ranging from -0.19 to -0.50. We combined our results with those for other 231 clusters studied in a similar way using the Washington system. The resulting age-metallicity relationship shows a significant dispersion in metallicities, whatever age is considered. Although there seems to exist a clear tendency for the younger clusters to be more metal rich than the intermediate ones, we believe that none of the chemical evolution models currently available in the literature reasonably well represents the recent chemical enrichment processes in the LMC clusters. The present sample of 17 clusters is part of our ongoing project of generating a data base of LMC clusters homogeneously studied using the Washington photometric system and applying the same analysis procedure.
- ID:
- ivo://CDS.VizieR/J/AJ/112/618
- Title:
- CCD photometry of variable stars in M9
- Short Name:
- J/AJ/112/618
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD observations have been used to derive precise light curves for six of the previously known RR Lyrae variables in the Oosterhoff type II globular cluster M9 and to search for additional variables. Nine variables have been discovered, eight of the RR Lyrae type. As a result, the total number of RR Lyrae variables has been revised from 9 to 17 (9 RRc and 8 RRab), the mean period of the RRc stars has been revised from 0.341d to 0.342d and that of the RRab stars from 0.621d to 0.638d. Simon's method that relates physical properties of RRc stars to the pulsation period and Fourier phase parameter {phi}_31_ has been used to determine the mass, luminosity, and temperature for one of the RRc stars. Published observations of RR Lyrae stars in M15 have been used to test Simon's method (1993ApJ...410..526S, 1993, IAUCo, 139, 315) and the results are promising. The formulae of Jurcsik and Kovacs (1996A&A...312..111J) for relating Fourier parameters of RRab stars to [Fe/H] have been used to derive a metal abundance for M9.
- ID:
- ivo://CDS.VizieR/J/A+AS/118/407
- Title:
- CCD photometry & velocities of NGC 3680 stars
- Short Name:
- J/A+AS/118/407
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new CCD photometry in the b and y colours of the Stroemgren uvby system for 310 stars in a 13'x13' field centered on the intermediate-age open cluster NGC 3680. Careful cross-checks indicate that previously published BV photometry of NGC 3680 is affected by random and/or systematic errors precluding its use in critical comparison with theoretical isochrone computations. Detailed notes on several individual stars are given. In addition, we present =~400 new photoelectric radial-velocity observations of 109 stars obtained with the CORAVEL scanner during the period 1988-1994. These data allow substantially complete identification of member and non-member stars in the field, and of spectroscopic binaries in both groups. Rotational velocities have also been derived for the programme stars, and our velocity variability criteria for stars of all rotations are described. The further astrophysical discussion of the data, including the definition of radial-velocity membership criteria, theoretical isochrone fitting, and the dynamical state of the cluster and the origin of its "bimodal turnoff", will appear in a separate paper (Nordstroem et al. 1996).
- ID:
- ivo://CDS.VizieR/J/PAZh/27/403
- Title:
- CCD R photometry in the UMa supercluster
- Short Name:
- J/PAZh/27/403
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric parameters for 98 early-type galaxies in the central for 11 clusters, belonging to the Ursa Major supercluster, are presented. Galaxies in the following clusters have been observed: A1270, A1291, A1377, A1318, A1383, A1436, Anon1, Anon2, Anon3, Anon4, Sh166. The derivation of the effective parameters takes the seeing into account.
- ID:
- ivo://CDS.VizieR/J/A+A/382/389
- Title:
- CCD R photometry of 17 clusters of galaxies
- Short Name:
- J/A+A/382/389
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a study of streaming motion of galaxy clusters around the Giant Void (RA~13h, DE~40{deg}, z~0.11 and a diameter of 150/hMpc) in the distribution of rich Abell clusters. We used the Kormendy relation as a distance indicator taking into account galaxy luminosities. Observations were carried out in Kron-Cousins R_c_ system on the 6m and 1m telescopes of SAO RAS. For 17 clusters in a spherical shell of 25/hMpc in thickness centered on the void no significant diverging motion (expected to be generated by the mass deficit in the void) has been detected. This implies that cosmological models with low {Omega}_m_ are preferred. To explain small mass underdensity inside the Giant Void, a mechanism of void formation with strong biasing is required.
- ID:
- ivo://CDS.VizieR/J/A+A/390/863
- Title:
- CCD R Photometry of WHISP Dwarf Galaxies
- Short Name:
- J/A+A/390/863
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- R-band surface photometry is presented for 171 late-type dwarf and irregular galaxies. For a subsample of 46 galaxies B-band photometry is presented as well. We present surface brightness profiles as well as isophotal and photometric parameters including magnitudes, diameters and central surface brightnesses. Absolute photometry is accurate to 0.1 mag or better for 77% of the sample. For over 85% of the galaxies the radial surface brightness profiles are consistent with published data within the measured photometric uncertainty. For most of the galaxies in the sample HI data have been obtained with the Westerbork Synthesis Radio Telescope. The galaxies in our sample are part of the WHISP project (Westerbork HI Survey of Spiral and Irregular Galaxies), which aims at mapping about 500 nearby spiral and irregular galaxies in HI. The availability of HI data makes this data set useful for a wide range of studies of the structure, dark matter content and kinematics of late-type dwarf galaxies.
