THE THICK DISK IN THE GALAXY NGC 4244 FROM S(4)G IMAGING

Sebastien Comeron , Johan H. Knapen , Kartik Sheth , Michael W. Regan , Joannah L. Hinz , Armando Gil De Paz , Karin Menendez-Delmestre , Juan-Carlos Munoz-Mateos , Mark Seibert , Taehyun Kim , E. Athanassoula (1) , Albert Bosma , Ronald J. Buta , Bruce G. Elmegreen , Luis C. Ho , Benne W. Holwerda , Eija Laurikainen , Heikki Salo , Eva Schinnerer

1 LAM - Laboratoire d'Astrophysique de Marseille

If thick disks are ubiquitous and a natural product of disk galaxy formation and/or evolution processes, all undisturbed galaxies that have evolved during a significant fraction of a Hubble time should have a thick disk. The late-type spiral galaxy NGC 4244 has been reported as the only nearby edge-on galaxy without a confirmed thick disk. Using data from the Spitzer Survey of Stellar Structure in Galaxies (S(4)G) we have identified signs of two disk components in this galaxy. The asymmetries between the light profiles on both sides of the mid-plane of NGC 4244 can be explained by a combination of the galaxy not being perfectly edge-on and a certain degree of opacity of the thin disk. We argue that the subtlety of the thick disk is a consequence of either a limited secular evolution in NGC 4244, a small fraction of stellar material in the fragments which built the galaxy, or a high amount of gaseous accretion after the formation of the galaxy.

Domaines: Astrophysique [astro-ph]

Sebastien Comeron, Johan H. Knapen, Kartik Sheth, Michael W. Regan, Joannah L. Hinz, et al.. THE THICK DISK IN THE GALAXY NGC 4244 FROM S(4)G IMAGING. The Astrophysical Journal, 2011, 729 (1), ⟨10.1088/0004-637X/729/1/18⟩. ⟨hal-01438878⟩