The Cepheid Distance to NGC 5236 (M 83) with the VLT

• Main Authors: Thim, Frank, Tammann, G. A, Saha, A, Dolphin, A, Sandage, Allan, Tolstoy, E, Labhardt, Lukas
• Format: Journal Article
• Language: English
• Published: 04.03.2003
• Subjects: Physics - Astrophysics of Galaxies; Physics - Cosmology and Nongalactic Astrophysics; Physics - Earth and Planetary Astrophysics; Physics - High Energy Astrophysical Phenomena; Physics - Instrumentation and Methods for Astrophysics; Physics - Solar and Stellar Astrophysics
• DOI: 10.48550/arxiv.astro-ph/0303101

Astrophys.J. 590 (2003) 256-270 Cepheids have been observed in NGC 5236 (M 83) using the ANTU (UT1) 8.2 meter telescope of the ESO VLT with FORS1. Observations over 34 epochs in V and I have been made between January 2000 and July 2001. Twelve Cepheid candidates have periods between 12 and 55 days. The true distance modulus is adopted to be (m-M)_0 = 28.25 +/- 0.15, which corresponds to a distance of 4.5 +/- 0.3 Mpc. The distance of NGC 5253 has been rediscussed. The mean distance of (m-M)_0 = 28.01 +/- 0.15 (based on SN 1972E) shows the galaxy to be a close neighbor of M 83 (separation = 0.5 +/- 0.4 Mpc), suggesting that the two galaxies may have interacted in the past and thus possibly explaining the amorphous morphology of NGC 5253. M 83 is the principal member of the nearby M 83 group containing also, besides NGC 5253, several dwarf members, for five of which TRGB distances are available (Karachentsev et al. 2002a, A&A, 385, 21). The adopted group distance of (m-M)_0 = 28.28 +/- 0.10 (4.5 +/- 0.2 Mpc) together with its mean recession velocity of v_LG = 249 +/- 42 km/s shows again the extreme quietness of the local (1 Mpc to 10 Mpc) expansion field. M 83 fits onto the local mean Hubble flow line of the velocity-distance relation (with H_0 ~ 60) with no significant deviation, supporting the earlier conclusion that the local velocity expansion field is remarkably cold on a scale of 10 Mpc, contrary to the predictions of the simplest cold dark matter model for large scale structure. The role of a cosmological constant has been invoked as a possible solution in providing a nearly uniform force field everywhere in the presence of a lumpy galaxy distribution. (abridged)