TY - JOUR

T1 - Isochrone fitting of Galactic globular clusters - I. NGC 5904

AU - Gontcharov, George A.

AU - Mosenkov, Aleksandr V.

AU - Khovritchev, Maxim Yu

N1 - Publisher Copyright: © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.

PY - 2019/3/11

Y1 - 2019/3/11

N2 - We present new isochrone fits to colour-magnitude diagrams of the Galactic globular cluster NGC 5904 (M5). We utilize 29 photometric bands from the ultraviolet to mid-infrared by the use of the data from the Hubble Space Telescope, Gaia DR2, Wide-field Infrared Survey Explorer, Sloan Digital Sky Survey (SDSS), and other photometric data. In our isochrone fitting we use the Padova and TRieste Stellar Evolution Code, the MESA Isochrones and Stellar Tracks, the Dartmouth Stellar Evolution Program, and a Bag of Stellar Tracks and Isochrones for both the solar-scaled and enhanced He and α abundances with a metallicity about [Fe/H]=-1.33 adopted from the literature. All tools provide us with estimates of the distance, age, and extinction law to the cluster. The best-fitting distance, true distance modulus, and age are 7.4 ± 0.3 kpc, 14.34 ± 0.09 mag, and 12.15 ± 1.00 Gyr, respectively. The derived distance agrees with the literature, including the Gaia DR2 parallax with its known global zero-point correction. All the data and models, except some UV and SDSS data, agree with the extinction law of Cardelli-Clayton-Mathis with R V = 3.60 ± 0.05 and A V = 0.20 ± 0.02 mag. This extinction is twice as high as generally accepted due to a rather high extinction between 625 and 2000 nm. An offset of the model colours instead of the high extinction in this range is a less likely, yet possible explanation of the discovered large deviations of the isochrones from the data.

AB - We present new isochrone fits to colour-magnitude diagrams of the Galactic globular cluster NGC 5904 (M5). We utilize 29 photometric bands from the ultraviolet to mid-infrared by the use of the data from the Hubble Space Telescope, Gaia DR2, Wide-field Infrared Survey Explorer, Sloan Digital Sky Survey (SDSS), and other photometric data. In our isochrone fitting we use the Padova and TRieste Stellar Evolution Code, the MESA Isochrones and Stellar Tracks, the Dartmouth Stellar Evolution Program, and a Bag of Stellar Tracks and Isochrones for both the solar-scaled and enhanced He and α abundances with a metallicity about [Fe/H]=-1.33 adopted from the literature. All tools provide us with estimates of the distance, age, and extinction law to the cluster. The best-fitting distance, true distance modulus, and age are 7.4 ± 0.3 kpc, 14.34 ± 0.09 mag, and 12.15 ± 1.00 Gyr, respectively. The derived distance agrees with the literature, including the Gaia DR2 parallax with its known global zero-point correction. All the data and models, except some UV and SDSS data, agree with the extinction law of Cardelli-Clayton-Mathis with R V = 3.60 ± 0.05 and A V = 0.20 ± 0.02 mag. This extinction is twice as high as generally accepted due to a rather high extinction between 625 and 2000 nm. An offset of the model colours instead of the high extinction in this range is a less likely, yet possible explanation of the discovered large deviations of the isochrones from the data.

KW - dust, extinction

KW - globular clusters: general

KW - globular clusters: individual: NGC5904 (M5)

KW - Hertzsprung - Russell and colour-magnitude diagrams

UR - http://www.scopus.com/inward/record.url?scp=85062280901&partnerID=8YFLogxK

U2 - 10.1093/mnras/sty3439

DO - 10.1093/mnras/sty3439

M3 - Article

AN - SCOPUS:85062280901

VL - 483

SP - 4949

EP - 4967

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -