Overzier, Roderik A. and Heckman, Timothy M. and Tremonti, Christy and Armus, Lee and Basu-Zych, Antara and Gonçalves, Thiago and Rich, R. Michael and Martin, D. Christopher and Ptak, Andy and Schiminovich, David and Ford, Holland C. and Madore, Barry and Seibert, Mark (2009) Local Lyman Break Galaxy Analogs: The Impact of Massive Star-Forming Clumps on the Interstellar Medium and the Global Structure of Young, Forming Galaxies. Astrophysical Journal, 706 (1). pp. 203-222. ISSN 0004-637X http://resolver.caltech.edu/CaltechAUTHORS:20091124-113044359
- Published Version
Restricted to Repository administrators only
See Usage Policy.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20091124-113044359
We report on the results of Hubble Space Telescope optical and UV imaging, Spitzer mid-IR photometry, and optical spectroscopy of a sample of 30 low-redshift (z ~ 0.1 to 0.3) galaxies chosen from the Sloan Digital Sky Survey and Galaxy Evolution Explorer surveys to be accurate local analogs of the high-redshift Lyman break galaxies. The Lyman break analogs (LBAs) are similar in stellar mass, metallicity, dust extinction, star formation rate (SFR), physical size, and gas velocity dispersion, thus enabling a detailed investigation of many processes that are important in star-forming galaxies at high redshift. The main optical emission-line properties of LBAs, including evidence for outflows, are also similar to those typically found at high redshift. This indicates that the conditions in their interstellar medium are comparable. In the UV, LBAs are characterized by complexes of massive clumps of star formation, while in the optical they most often show evidence for (post-)mergers and interactions. In six cases, we find a single extremely massive (up to several ×10^9 M_☉) compact (radius ~10^2 pc) dominant central object (DCO). The DCOs are preferentially found in LBAs with the highest mid-IR luminosities (L_(24 μm) = 10^(10.3)-10^(11.2) L_☉) and correspondingly high SFRs (15-100 M_☉ yr^(–1)). We show that the massive star-forming clumps (including the DCOs) have masses much larger than the nuclear super star clusters seen in normal late-type galaxies. However, the DCOs do have masses, sizes, and densities similar to the excess light/central cusps seen in typical elliptical galaxies with masses similar to the LBA galaxies. We suggest that the DCOs form in the present-day examples of the dissipative mergers at high redshift that are believed to have produced the central cusps in local ellipticals (consistent with the disturbed optical morphologies of the LBAs). More generally, the properties of the LBAs are consistent with the idea that instabilities in a gas-rich disk lead to very massive star-forming clumps that eventually coalesce to form a spheroid. Finally, we comment on the apparent lack of energetically significant active galactic nuclei in the DCOs. We speculate that the DCOs are too young at present to grow a supermassive black hole because they are still in a supernova-dominated outflow phase (age less than 50 Myr).
|Additional Information:||© 2009 American Astronomical Society. Print publication: Issue 1 (2009 November 20); received 2009 June 18; accepted for publication 2009 October 7; published 2009 October 28. We are very grateful to Frederic Bournaud, Rychard Bouwens, Jarle Brinchmann, Bruce Elmegreen, Guinevere Kauffmann, Lisa Kewley, Isa Oliveira, Francesco Shankar, and the anonymous referee for useful suggestions and discussions. We thank Brent Groves for generating the optically thin models referred to in Section 4. We thank Anne Pellerin for her help with the WFPC2 reductions. We thank the support staff at ESO Paranal for their assistance with the FLAMES observations.|
|Subject Keywords:||galaxies: active; galaxies: bulges; galaxies: high-redshift; galaxies: peculiar; galaxies: starburst|
|Official Citation:||Local Lyman Break Galaxy Analogs: The Impact of Massive Star-Forming Clumps on the Interstellar Medium and the Global Structure of Young, Forming Galaxies Roderik A. Overzier, Timothy M. Heckman, Christy Tremonti, Lee Armus, Antara Basu-Zych, Thiago Gonçalves, R. Michael Rich, D. Christopher Martin, Andy Ptak, David Schiminovich, Holland C. Ford, Barry Madore, and Mark Seibert 2009 ApJ 706 203-222 doi: 10.1088/0004-637X/706/1/203|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Jason Perez|
|Deposited On:||24 Nov 2009 22:26|
|Last Modified:||26 Dec 2012 11:34|
Repository Staff Only: item control page