Near Infrared Photometry of Galactic Globular Clusters M56 and M15. Extending the Red Giant Branch vs. Metallicity Calibration Towards Metal Poor Systems
| dc.creator | Ivanov, Valentin D. | |
| dc.creator | Borissova, Jordanka | |
| dc.creator | Alonso-Herrero, Almudena | |
| dc.creator | Russeva, Tatiana | |
| dc.date | 2000-02-04 | |
| dc.date.accessioned | 2026-07-25T17:39:36Z | |
| dc.description | Infrared JKs-band photometry of the Galactic globular clusters M15 and, for the first time, M56 is presented. We estimated the reddening (E(B-V)=0.18+/-0.08 mag) and distance modulus ((m-M)_V=15.43+/-0.30 mag) towards the poorly studied globular cluster M56. We combined our data with observations of other clusters from the literature (12 in total) to extend the [Fe/H] vs. Red Giant Branch (RGB) slope relation towards metal-poor clusters. Our best fit yields to [Fe/H]=-3.40(+/-0.22)-27.74(+/-2.35)x(RGB Slope), with an r.m.s.=0.20. The broader metallicity baseline greatly reduced the uncertainties compared to other existing calibrations. We confirmed a previously obtained calibration of the relation between the RGB color (J-Ks)_0(RGB) at M_Ks=-5.5 vs. [Fe/H]: [Fe/H]=-6.90(+/-0.99)+6.63(+/-1.05)x(J-Ks)_0(RGB) with an r.m.s.=0.33. Finally, using the new RGB slope calibration we estimated the abundance of the super metal-rich cluster Liller 1 [Fe/H]=+0.34+/-0.22. | |
| dc.description | 22 pages, 5 figures. accepted to AJ; scheduled for May 2000 | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0002118 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0002118 | |
| dc.identifier.uri | https://dspace.dare.co.zw/handle/123456789/49282 | |
| dc.subject | Astrophysics | |
| dc.title | Near Infrared Photometry of Galactic Globular Clusters M56 and M15. Extending the Red Giant Branch vs. Metallicity Calibration Towards Metal Poor Systems | |
| dc.type | text |