The Stellar Structures around Disk Galaxies

I. Drozdovsky; N. Tikhonov; A. Aparicio; C. Gallart; M. Monelli; S. Hidalgo; E. J. Bernard; O. Galazutdinova; The LCID Team

doi:10.1007/978-1-4020-6933-8_67

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arXiv · astro-ph/0702118

The Stellar Structures around Disk Galaxies

I. Drozdovsky·N. Tikhonov·A. Aparicio·C. Gallart·M. Monelli·S. Hidalgo·E. J. Bernard·O. Galazutdinova·The LCID Team

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Abstract

We present a brief summary of our current results on the stellar distribution and population gradients of the resolved stars in the surroundings of ~50 nearby disk galaxies, observed with space- (Hubble & Spitzer) and ground-based telescopes (Subaru, VLT, BTA, Palomar, CFHT & INT). We examine the radial (in-plane) and vertical (extraplanar) distributions of resolved stars as a function of stellar age and metallicity by tracking changes in the color-magnitude diagram of face-on and edge-on galaxies. Our data show, that the scale length and height of a stellar population increases with age, with the oldest detected stellar populations identified at a large galactocentric radius or extraplanar height, out to typically a few kpc. In the most massive of the studied galaxies there is evidence for a break in number density and color gradients of evolved stars, which plausibly correspond to the thick disk and halo components of the galaxies. The ratio of intermediate-age to old stars in the outermost fields correlate with the gas fraction, while relative sizes of the thick-to-thin disks anticorrelate with galactic circular velocity.

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BibTeX RIS

I. Drozdovsky, N. Tikhonov, A. Aparicio, C. Gallart, M. Monelli, S. Hidalgo, E. J. Bernard, O. Galazutdinova, The LCID Team. 2007-02-05. The Stellar Structures around Disk Galaxies. https://doi.org/10.1007/978-1-4020-6933-8_67

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