J/AJ/114/2381ivo://CDS.VizieR/J/AJ/114/2381doi:10.26093/cds/vizier.51142381CDSMiller B.W.Whitmore B.C.Schweizer F.Fall S.M.2023-04-06T16:50:26Z2000-02-19T21:10:38ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiesphotometryinfrared-photometryvisible-astronomybroad-band-photometryglobular-star-clustersWe present new U, B, V, and I images of the prototypical merger remnant NGC 7252 obtained with the WFPC2 instrument of the Hubble Space Telescope. The photometry reaches about 3 mag deeper than the previous observations with WF/PCI and we detect 499 cluster candidates, most of them previously undiscovered. We can distinguish three populations of star clusters. We confirm the existence of a very luminous, blue population of clusters with a narrow range in color. Comparisons with Bruzual & Charlot (1996, in preparation) models incorporating a Salpeter stellar IMF show that the mean ages of these clusters are 650Myr for [Fe/H]=0.0 and 750 Myr if [Fe/H]=-0.3. Therefore, these are the clusters that formed during the merger event. The upper limit to the effective radii of these objects is 4.8+/-0.4pc (for D=64.4Mpc, H_0_=75), suggesting that they have physical properties like Galactic globular clusters. The second population of clusters is associated with the inner disk. Their (U-B) colors and reddening-free Q values indicate that their light is dominated by O stars and that they have ages less than 10Myr. However, with <R_eff_>=8.3+/-0.6pc, these objects may be more like stellar associations and they may not survive for a significant time. Finally, there is also evidence for the presence of the most luminous of the old, metal-poor globular clusters that belonged to the progenitor galaxies. The cluster luminosity function is a single power law with slope {alpha}~-1.8 down to a limiting magnitude of V=26. The current specific cluster frequency is S_N_=0.6+/-0.3 for old clusters and young clusters with M>10^5^M_{sun}_, but after the remnant has faded for about 15Gyr S_N_ will have increased to about 2.5. The central disk is now resolved into much finer detail than in earlier WF/PCI observations and the light profile of the nuclear region is consistent with a single power law with slope {gamma}=-1.26+/-0.03. After both the main body and the cluster system of NGC 7252 have aged, for several Gyr it may have the properties of a field elliptical.1997AJ....114.2381Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/114/2381CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/114/2381https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/114/2381http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/114/2381https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/114/2381https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/114/2381http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/114/2381GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/114/2381/tables (Cluster candidates in NGC 7252)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/114/2381/tables?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/114/2381/tables?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/114/2381/tables?GETtext/xml+votable180.050000true335.17502944-24.662725560.0055555555555555566/47078https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/114/2381?format=asciiOpticalInfrareddefaultJ/AJ/114/2381/tablesCluster candidates in NGC 7252recnoRecord number assigned by the VizieR team. Should Not be used for identification.intMWS97Sequential number ([MWS97] NN in simbad)intoRAOffset from right ascension (1)arcsecfloatoDEOffset from declination (1)arcsecfloatrprojProjected radiusarcsecfloatVmagV magnitude corrected for foreground extinctionmagfloate_Vmagrms uncertainty on CmagmagfloatU-B? U-B colour index corrected for foreground extinctionmagfloatnullablee_U-B? rms uncertainty on U-BmagfloatnullableB-V? B-V colour index corrected for foreground extinctionmagfloatnullablee_B-V? rms uncertainty on B-VmagfloatnullableV-I? V-I colour index corrected for foreground extinctionmagfloatnullablee_V-I? rms uncertainty on V-ImagfloatnullableQ? Reddening-free index Q=(U-B)-0.72(B-V)magfloatnullablee_Q? rms uncertainty on QmagfloatnullableReff? Effective radiuspcfloatnullable_RAComputed Right Ascension for Equinox: J2000deg_DEComputed Declination for Equinox: J2000deg