Dark Matter in the Central Region of NGC 3256

• Main Authors: Ali, Israa Abdulqasim Mohammed, Hwang, Chorng-Yuan, Abidin, Zamri Zainal, Plunkett, Adele Laurie
• Format: Article
• Published: Penerbit Universiti Kebangsaan Malaysia 2018
• Subjects: Q Science (General); QC Physics
• Online Access: http://eprints.um.edu.my/22560/; https://doi.org/10.17576/jsm-2018-4706-20

We investigated the central mass distribution of the luminous infrared galaxy NGC 3256 at a distance of 35 Mpc by using CO(1-0) observations of the Atacama Large Millimeter and sub-millimeter Array (ALMA) and near-IR data of the Two Micron Sky Survey (2MASS). We found that there is a huge amount of invisible dynamical mass (4.48 × 1010 ) in the central region of the galaxy. The invisible mass is likely caused by some dark matter, which might have a cuspy dark matter profile. We note that this dark matter is difficult to explain with the conventional Modified Newtonian Dynamics (MOND) model, which is only applicable at a low acceleration regime, whereas the acceleration at the central region of the galaxy is relatively strong. Therefore, this discovery might pose a challenge to the conventional MOND models.