Stellar Variability and Distance Indicators in the Near-infrared in Nearby Galaxies. II. Pulsating Stars in the Carina Dwarf Spheroidal
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arXiv
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| Autori principali: | , , , |
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| Natura: | Preprint |
| Pubblicazione: |
2026
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| _version_ | 1866910072275206144 |
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| author | Ngeow, Chow-Choong Bhardwaj, Anupam Nishad, Prashant Susmita, Das |
| author_facet | Ngeow, Chow-Choong Bhardwaj, Anupam Nishad, Prashant Susmita, Das |
| contents | We present homogeneous, near-infrared ($JHK_s$ bands) time-series observations of the classical Carina dwarf Spheroidal (dSph) galaxy to determine accurate and precise distances using the pulsating stars as standard candles. These observations cover two Carina dSph fields ($\sim10.8'\times10.8'$) obtained with the FourStar infrared camera mounted on the 6.5-m Magellan Telescope. We collected precise photometric measurements of 43 RR Lyrae, 11 anomalous Cepheids (ACep), and 102 dwarf Cepheids (DCep) in Carina dSph. Using RR Lyrae, we obtained a distance modulus of $20.079\pm0.028\mathrm{(statistical)}\pm0.045\mathrm{(systematic)}$~mag, or a distance to Carina of $103.7\pm1.3\mathrm{(statistical)}\pm2.2\mathrm{(systematic)}$~kpc. The literature calibrations based on SX Phoenicis or delta-Scuti stars were used to anchor the $JHK_s$ period-luminosity relations for DCep. This resulted in a distance modulus that is in excellent agreement with RR Lyrae based determination. Finally, the distance moduli estimates using the ACep were found to be systematically smaller than the RR Lyrae-based distance modulus, suggesting a metallicity dependence on the ACep period-luminosity relation. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2603_24249 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Stellar Variability and Distance Indicators in the Near-infrared in Nearby Galaxies. II. Pulsating Stars in the Carina Dwarf Spheroidal Ngeow, Chow-Choong Bhardwaj, Anupam Nishad, Prashant Susmita, Das Solar and Stellar Astrophysics Astrophysics of Galaxies We present homogeneous, near-infrared ($JHK_s$ bands) time-series observations of the classical Carina dwarf Spheroidal (dSph) galaxy to determine accurate and precise distances using the pulsating stars as standard candles. These observations cover two Carina dSph fields ($\sim10.8'\times10.8'$) obtained with the FourStar infrared camera mounted on the 6.5-m Magellan Telescope. We collected precise photometric measurements of 43 RR Lyrae, 11 anomalous Cepheids (ACep), and 102 dwarf Cepheids (DCep) in Carina dSph. Using RR Lyrae, we obtained a distance modulus of $20.079\pm0.028\mathrm{(statistical)}\pm0.045\mathrm{(systematic)}$~mag, or a distance to Carina of $103.7\pm1.3\mathrm{(statistical)}\pm2.2\mathrm{(systematic)}$~kpc. The literature calibrations based on SX Phoenicis or delta-Scuti stars were used to anchor the $JHK_s$ period-luminosity relations for DCep. This resulted in a distance modulus that is in excellent agreement with RR Lyrae based determination. Finally, the distance moduli estimates using the ACep were found to be systematically smaller than the RR Lyrae-based distance modulus, suggesting a metallicity dependence on the ACep period-luminosity relation. |
| title | Stellar Variability and Distance Indicators in the Near-infrared in Nearby Galaxies. II. Pulsating Stars in the Carina Dwarf Spheroidal |
| topic | Solar and Stellar Astrophysics Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2603.24249 |