Two Pseudobulges In The "Boxy Bulge" Galaxy NGC 5746
MetadataShow full item record
Galaxy formation and growth under the Lambda CDM paradigm is expected to proceed in a hierarchical, bottom-up fashion by which small galaxies grow into large galaxies; this mechanism leaves behind large "classical bulges" kinematically distinct from "pseudobulges" grown by internal, secular processes. We use archival data (Spitzer Space Telescope 3.6 mu m wavelength, Hubble Space Telescope H-band, Two Micron All Sky Survey K-s-band, and Sloan Digital Sky Survey gri-band) to measure composite minor-and major-axis surface brightness profiles of the almost-edge-on spiral galaxy NGC 5746. These light profiles span a large range of radii and surface brightnesses to reveal an inner, high surface brightness stellar component that is distinct from the well-known boxy bulge. It is well fitted by Sersic functions with indices n = 0.99 +/- 0.08 and 1.17 +/- 0.24 along the minor and major axes, respectively. Since n < 2, we conclude that this innermost component is a secularly evolved pseudobulge that is distinct from the boxy pseudobulge. This inner pseudobulge makes up 0.136 +/- 0.019 of the total light of the galaxy. It is therefore considerably less luminous than the boxy structure, which is now understood to be a bar seen nearly end-on. The infrared imagery shows further evidence for secular evolution in the form of a bright inner ring of inner radius 9.1 kpc and width 1.6 kpc. NGC 5746 is therefore a giant, pure-disk SB(r) bc galaxy with no sign of a merger-built bulge. We do not understand how such galaxies form in a Lambda DM universe.
CitationBarentine, John C., and John Kormendy. "Two Pseudobulges in the 'Boxy Bulge' Galaxy NGC 5746." The Astrophysical Journal 754, No. 2 (Aug., 2012): 140.
Showing items related by title, author, creator and subject.
Papovich, Casey; Bassett, Robert; Lotz, Jennifer M.; van der Wel, A.; Tran, K. V.; Finkelstein, Steven L.; Bell, Eric F.; Conselice, Christopher J.; Dekel, Avishai; Dunlop, J. S.; Guo, Y. C.; Faber, S. M.; Farrah, D.; Ferguson, Henry C.; Finkelstein, Keely D.; Haussler, Boris; Kocevski, D. D.; Koekemoer, A. M.; Koo, D. C.; McGrath, E. J.; McLure, R. J.; McIntosh, Daniel H.; Momcheva, I.; Newman, Jeffrey A.; Rudnick, Gregory; Weiner, B.; Willmer, Christopher N. A.; Wuyts, S. (2012-05)We discuss the structural and morphological properties of galaxies in a z = 1.62 proto-cluster using near-IR imaging data from Hubble Space Telescope Wide Field Camera 3 data of the Cosmic Assembly Near-IR Deep Extragalactic ...
The Structure Of Classical Bulges And Pseudobulges: The Link Between Pseudobulges And Sersic Index Fisher, David B.; Drory, Niv (2008-08)In this paper, we study the properties of pseudobulges (bulges that appear similar to disk galaxies) and classical bulges (bulges which appear similar to E-type galaxies) in bulge-disk decompositions. We show that the ...
Konstantopoulos, I. S.; Gallagher, S. C.; Fedotov, K.; Durrell, P. R.; Heiderman, Amanda; Elmegreen, D. M.; Charlton, J. C.; Hibbard, J. E.; Tzanavaris, P.; Chandar, R.; Johnson, K. E.; Maybhate, A.; Zabludoff, A. E.; Gronwall, Caryl; Szathmary, D.; Hornschemeier, Ann E.; English, J.; Whitmore, B.; de Oliveira, C. M.; Mulchaey, J. S. (2010-11)The environment where galaxies are found heavily influences their evolution. Close groupings, like the ones in the cores of galaxy clusters or compact groups, evolve in ways far more dramatic than their isolated counterparts. ...