THE ROLE OF STARBURST–ACTIVE GALACTIC NUCLEUS COMPOSITES IN LUMINOUS INFRARED GALAXY MERGERS: INSIGHTS FROM THE NEW OPTICAL CLASSIFICATION SCHEME

By T. Yuan, Lisa J. Kewley, D. Sanders. 2009

175 citations recorded by the source corpus.

We investigate the fraction of starbursts, starburst–active galactic nucleus (AGN) composites, Seyferts, and low-ionization narrow emission-line region galaxies (LINERs) as a function of infrared luminosity (LIR) and merger progress for ∼500 infrared (IR)-selected galaxies. Using the new optical classifications afforded by the extremely large data set of the Sloan Digital Sky Survey, we find that the fraction of LINERs in IR-selected samples is rare (<5%) compared with other spectral types. The lack of strong IR emission in LINERs is consistent with recent optical studies suggesting that LINERs contain AGN with lower accretion rates than in Seyfert galaxies. Most previously classified IR-luminous LINERs are classified as starburst–AGN composite galaxies in the new scheme. Starburst–AGN composites appear to “bridge” the spectral evolution from starburst to AGN in ULIRGs. The relative strength of the AGN versus starburst activity shows a significant increase at high IR luminosity. In ULIRGs (LIR > 1012 L☉), starburst–AGN composite galaxies dominate at early–intermediate stages of the merger, and AGN galaxies dominate during the final merger stages. Our results are consistent with models for IR-luminous galaxies where mergers of gas-rich spirals fuel both starburst and AGN, and where the AGN becomes increasingly dominant during the final merger stages of the most luminous IR objects.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/722478ea44564336ece9a907de6df0967e936272

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In Astronomy and Astrophysics

1. Lisa J. Kewley
2. D. M. Alexander
3. P. Hopkins
4. L. Hernquist
5. Naveen A. Reddy
6. D. Rupke
7. A. Shapley
8. R. Dav'e

In Atomic and Molecular Physics, and Optics

1. Naveen A. Reddy
2. C. Steidel
3. M. Pettini
4. Julia Gutkin
5. J. Barnes
6. Daniel Stern
7. C. Casey
8. Sylvain Veilleux

In Instrumentation

1. Naveen A. Reddy
2. C. Steidel
3. Lisa J. Kewley
4. A. Shapley
5. M. Pettini
6. D. Rupke
7. D. Erb
8. D. M. Alexander

Citations in the corpus

• A NEW DIAGNOSTIC OF ACTIVE GALACTIC NUCLEI: REVEALING HIGHLY ABSORBED SYSTEMS AT REDSHIFT >0.3 (2011, unknown): “This was suggested by, e.g., Kewley et al. (2006), who introduced a parameter to measure the distance from the star-forming sequence on the BPT diagram (also see Yuan et al. 2010).”
• THE MULTIPHASE STRUCTURE AND POWER SOURCES OF GALACTIC WINDS IN MAJOR MERGERS (2013, background): “Previous optical spectral types of LINER (Veilleux et al. 1999a) or Seyfert 2 (Yuan et al. 2010) in each nucleus were based on shallow spectra that did not significantly detect [O III] 5007 Å or Hβ (Kim et al. 1998).”
• SPECTRAL ENERGY DISTRIBUTIONS OF LOCAL LUMINOUS AND ULTRALUMINOUS INFRARED GALAXIES (2012, methodology): “Yuan et al. (2010) applied an SDSS-based semi-empirical optical spectral classification scheme to a large sample of local infrared galaxies, 57 of which are in our current sample.”
• Nuclear activity versus star formation: emission-line diagnostics at ultraviolet and optical wavelengths (2015, background): “…nearby galaxies from the Sloan Digital Sky Survey Data Release 7 (SDSS MNRAS 000, 1–21 (2015) DR7; Abazajian et al. 2009).1 By analogy with Juneau et al. (2014, see also Kewley et al. 2006; Yuan et al. 2010), we select all primary targets (SCIENCEPRIMARY = 1) in the redshift range 0.04 ≤ z ≤ 0.2.”
• Growing supermassive black holes in the late stages of galaxy mergers are heavily obscured (2017, background): “NGC3110 is classified as a HII-region by Yuan et al. (2010), and no trace of an AGN is evident for NGC3110 and MCG−01−26−013 from any of the multi-wavelength properties.”
• The subarcsecond mid-infrared view of local active galactic nuclei – I. The N- and Q-band imaging atlas (2013, unknown): “1 Véron-Cetty & Véron (2010); 2 Yuan et al. (2010); 3 Ho et al. (1997); 4 Hernán-Caballero & Hatziminaoglou (2011); 5 Hameed & Devereux (1999) 4.2.”
• Nebular Emission Line Ratios in z ≃ 2–3 Star-forming Galaxies with KBSS-MOSFIRE: Exploring the Impact of Ionization, Excitation, and Nitrogen-to-Oxygen Ratio (2016, background): “…densities (ne ∼ 10 2 cm−3) exhibit higher log([N II]/Hα) and log([O III]/Hβ) than typical SDSS galaxies (e.g. Brinchmann et al. 2008; Liu et al. 2008; Yuan et al. 2010), often associated with higher inferred ionization parameters and differences in ISM pressure (Lehnert et al. 2009; Kewley et…”
• GALAXY-WIDE SHOCKS IN LATE-MERGER STAGE LUMINOUS INFRARED GALAXIES (2011, background): “Finally, these become dominated by a powerful AGN as their star formation becomes quenched as the available gas reservoir becomes depleted (Genzel et al. 1998; Yuan et al. 2010).”