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- ID:
- ivo://CDS.VizieR/J/A+A/423/833
- Title:
- Photometry in elliptical galaxies
- Short Name:
- J/A+A/423/833
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Morphological peculiarities, as defined from isophote asymmetries and number of detected shells, jets or similar features, have been estimated in a sample of 117 E classified galaxies, and qualified by an ad hoc S_2_ index. Objects with S_2_<1 are "normal" (Nop subsample), the other are "peculiar" (Pec subsample). The two subsamples are intercompared as regards the Fundamental Plane, Faber-Jackson relation, dust content from IRAS fluxes, occurence of Kinematically Distinct Cores and stellar populations. The Nop subsample objects displays tight correlations between central velocity dispersion (or mass) and the population indices U-B, B-V, B-R, V-I, Mg_2_, Hbeta, <Fe>, Mg_b_. Part of the Pec objects deviate from these correlations, with blue "residuals" indicating a Younger Population mixed with the old one. This does not occur for other Pec objects. This subsample is thus classified in two families: i.e. the 'YP', or NGC 2865 family, and the 'NP' or NGC 3923 one. This distinction is quantified by a Mean Index of a Younger Population, or 'MIYP' with near zero values for the 'NP' objects and relatively large negative values for the 'YP'.
- ID:
- ivo://CDS.VizieR/J/A+A/429/819
- Title:
- Photometry in elliptical galaxies. II.
- Short Name:
- J/A+A/429/819
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As a complement to the data collected and discussed in Paper I of this series (Michard & Prugniel, 2004, <J/A+A/423/833>) 2MASS near-IR images have been used, in connection with available V-light aperture photometry to derive the colours V-J, V-K, J-H and J-K within the effective aperture Ae: nearly the same complete sample of 110 E-type galaxies is treated. In Paper I these were classified, based on morphological criteria, into the "peculiar'' (or Pec) and "normal'' (or Nop) subsamples. The data included here supersede the previous catalog <J/A+A/423/833>.
- ID:
- ivo://CDS.VizieR/J/A+A/389/439
- Title:
- Photometry in field of RX J004404.8+411820
- Short Name:
- J/A+A/389/439
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We propose the first association of an optical counterpart with a luminous supersoft X-ray source in M31, RX J0044.0+4118, observed with ROSAT in July 1991. The PSPC position is at 1.644 angular distance from a candidate nova in outburst in September of 1990. This is interesting because the incidence of classical novae among supersoft X-ray sources is an open question. The proposed optical counterpart was measured at R~=17.7 in September of 1990, and it had faded to R>19.2 when it was observed again after 70 days. The light curve was too sparsely monitored for definite conclusions on the speed class of the nova. No other variable objects with V<23.5 were found in the ROSAT spatial error box. We evaluate that the probability that a classical or recurrent nova was in outburst in the ROSAT error box in the few years preceding the observation is very small, so the proposed identification is meaningful. We also show evidence that the associated supersoft X-ray source turned off in the third year after the outburst.
- ID:
- ivo://CDS.VizieR/J/PAZh/36/16
- Title:
- Photometry in 6 galactic open star clusters
- Short Name:
- J/PAZh/36/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of our BVRcIc CCD photometry for six Galactic open star clusters toward the Perseus spiral arm performed at the Special Astrophysical Observatory of the Russian Academy of Sciences.
- ID:
- ivo://CDS.VizieR/J/AJ/101/1699
- Title:
- Photometry in globular cluster NGC 6229
- Short Name:
- J/AJ/101/1699
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD-based BV photometry for over 1100 stars in and around the globular cluster NGC 6229. For the first time, the cluster's entire giant branch and its horizontal branch are delineated, from which metallicity ([Fe/H]~-1.4) and distance (d__{sun}_~28kpc; d_GC_~27kpc) estimates ensue. NGC 6229 is found to have a relatively blue horizontal branch for its intermediate metallicity, which is unusual for an outer halo cluster. Its low R value (defined as N_HB_/N_RG_) hints that the blue color of its horizontal branch is due to a lower than average helium abundance. Three possible new variable stars are identified, including one RR Lyrae and two long-period variables. We present a brief review of our knowledge of basic data for the 13 globular clusters lying more than 24 kpc from the Galactic center. The unusually red horizontal branch phenomenon is common only among the outermost clusters. An average R value for these clusters suggests the effect is not caused by an overabundance of helium. The Oosterhoff dichotomy apparently persists into the outer halo, although the number of clusters with RR Lyrae variables is small.
- ID:
- ivo://CDS.VizieR/J/AJ/148/27
- Title:
- Photometry in globular clusters. I. NGC 1851
- Short Name:
- J/AJ/148/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The analysis of multiple populations (MPs) in globular clusters (GCs) has become a forefront area of research in astronomy. Multiple red giant branches (RGBs), subgiant branches (SGBs), and even main sequences (MSs) have now been observed photometrically in many GCs, while broad abundance distributions of certain elements have been detected spectroscopically in most, if not all, GCs. UV photometry has been crucial in discovering and analyzing these MPs, but the Johnson U and the Stromgren and Sloan u filters that have generally been used are relatively inefficient and very sensitive to reddening and atmospheric extinction. In contrast, the Washington C filter is much broader and redder than these competing UV filters, making it far more efficient at detecting MPs and much less sensitive to reddening and extinction. Here, we investigate the use of the Washington system to uncover MPs using only a 1 m telescope. Our analysis of the well-studied GC NGC 1851 finds that the C filter is both very efficient and effective at detecting its previously discovered MPs in the RGB and SGB. Remarkably, we have also detected an intrinsically broad MS best characterized by two distinct but heavily overlapping populations that cannot be explained by binaries, field stars, or photometric errors. The MS distribution is in very good agreement with that seen on the RGB, with ~30% of the stars belonging to the second population. There is also evidence for two sequences in the red horizontal branch, but this appears to be unrelated to the MPs in this cluster. Neither of these latter phenomena have been observed previously in this cluster. The redder MS stars are also more centrally concentrated than the blue MS. This is the first time MPs in an MS have been discovered from the ground, and using only a 1 m telescope. The Washington system thus proves to be a very powerful tool for investigating MPs, and holds particular promise for extragalactic objects where photons are limited.
5058. Photometry in NGC 2516
- ID:
- ivo://CDS.VizieR/J/A+A/375/863
- Title:
- Photometry in NGC 2516
- Short Name:
- J/A+A/375/863
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a 0.86 square degree CCD photometric survey of the open cluster NGC 2516, which has an age of about 150Myr and may have a much lower metallicity than the similarly-aged Pleiades. Our BVI_c_ survey of cluster members is complete to V~20 and is used to select a preliminary catalogue of 1254 low mass (0.<M<2.0M_{sun}_) cluster candidates, of which about 70-80 percent are expected to be genuine. After applying corrections for contamination by non-members and adding data for higher mass stars from the literature, we investigate the cluster binarity, luminosity and mass function, mass segregation and total mass. We find a binary fraction of 26+/-5%, for A to M-type systems with mass ratios between 0.6 and 1, which is very similar to the Pleiades.
- ID:
- ivo://CDS.VizieR/J/PASP/105/78
- Title:
- Photometry in open cluster NGC 5822
- Short Name:
- J/PASP/105/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study presents photoelectric photometry of stars in NGC 5822 on the UBVR and DDO systems. The BV data are employed to calibrate a photographic survey of the cluster, while UBV and DDO data are used to constrain the cluster reddening and metallicity. Taken in conjunction with previous photometric analysis, it is found that the cluster has a reddening of 0.15+/-0.015(pe) as defined for the stars at the turnoff, and a metallicity relative to the sun of -0.15+/-0.05(pe).
- ID:
- ivo://CDS.VizieR/J/AJ/127/660
- Title:
- Photometry in southern tail of the Antennae
- Short Name:
- J/AJ/127/660
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Hubble Space Telescope and Wide Field Planetary Camera 2 to image the putative tidal dwarf galaxy located at the tip of the Southern tidal tail of NGC 4038/4039, the Antennae. We resolve individual stars and identify two stellar populations. Hundreds of massive stars are present, concentrated into tight OB associations on scales of 200pc, with ages ranging from 2 to 100Myr. An older stellar population is distributed roughly following the outer contours of the neutral hydrogen in the tidal tail; we associate these stars with material ejected from the outer disks of the two spirals. The older stellar population has a red giant branch tip at I=26.5+/-0.2 from which we derive a distance modulus (m-M)_0_=30.7+/-0.25. The implied distance of 13.8+/-1.7Mpc is significantly smaller than commonly quoted distances for NGC 4038/4039. In contrast to the previously studied core of the merger, we find no superstar clusters (SSCs).
