Star formation and nuclear activity in luminous infrared galaxies: an infrared through radio review

AbstractWe conducted a Spitzer Space Telescope survey of 28 Luminous (11 < log (LIR/L⊙) < 12, LIRGs) and Ultra-Luminous Infrared Galaxies (log (LIR/L⊙) > 12, ULIRGs). Many of these galaxies are found in pairs or associations and are powered by either nuclear activity or star-formation (Sanders & Mirabel 1996). Our main goal is to understand the relative importance of starbursts and AGNs in interacting systems. Is the frequency of AGN and starbursts in these interacting galaxies related to their luminosities? What is the importance of the merger stage and the frequency of AGNs? We present our conclusions and diagnostic diagrams based in the observed near infrared lines and compare to studies based solely in optical data.

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Molecules as tracers of galaxy evolution

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313001105 ◽

2012 ◽

Vol 8 (S292) ◽

pp. 199-208 ◽

Cited By ~ 2

Author(s):

Susanne Aalto

Keyword(s):

Black Holes ◽

Star Formation ◽

High Resolution ◽

Galaxy Evolution ◽

Large Scale ◽

Short Review ◽

Stimulated Emission ◽

Molecular Gas ◽

Infrared Galaxies ◽

Luminous Infrared Galaxies

AbstractStudying the molecular phase of the interstellar medium in galaxies is fundamental for the understanding of the onset and evolution of star formation and the growth of supermassive black holes. We can use molecules as observational tools exploiting them as tracers of chemical, physical and dynamical conditions. In this short review, key molecules (e.g. HCN, HCO+, HNC, HC3N, CN, H3O+) in identifying the nature of buried activity and its evolution are discussed including some standard astrochemical scenarios. Furthermore, we can use IR excited molecular emission to probe the very inner regions of luminous infrared galaxies (LIRGs) allowing us to get past the optically thick dust barrier of the compact obscured nuclei, e.g. in the dusty LIRG NGC4418. High resolution studies are often necessary to separate effects of excitation and radiative transport from those of chemistry - one example is absorption and effects of stimulated emission in the ULIRG Arp220. Finally, molecular gas in large scale galactic outflows is briefly discussed.

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Recent Star Formation in Very Luminous Infrared Galaxies

QSO Hosts and Their Environments ◽

10.1007/978-1-4615-0695-9_28 ◽

2001 ◽

pp. 171-176 ◽

Cited By ~ 5

Author(s):

Alessandro Bressan ◽

Bianca Poggianti ◽

Alberto Franceschini

Keyword(s):

Star Formation ◽

Infrared Galaxies ◽

Luminous Infrared Galaxies

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Luminous IR Galaxies in a Merger Sequence: Bima Co Imaging

Symposium - International Astronomical Union ◽

10.1017/s0074180900112677 ◽

1999 ◽

Vol 186 ◽

pp. 227-230

Author(s):

Y. Gao ◽

R.A. Gruendl ◽

C.-Y. Hwang ◽

K.Y. Lo

Keyword(s):

Star Formation ◽

Power Output ◽

Infrared Galaxies ◽

Physical Processes ◽

Luminous Infrared Galaxies ◽

Bolometric Luminosity

The power output in luminous infrared galaxies (LIGs, LIR ≳ 1011L⊙, H0 = 75 kms−1 Mpc−1) can approach the bolometric luminosity of quasars and can be provided by either starbursts or dust-enshouded QSOs, or both. Most LIGs appear to comprise of mergers of gas-rich galaxies. So, intense bursts of star formation apparently result from interaction and merging of galaxies, but the exact physical processes involved in collecting the large amount of gas involved and in initiating the starbursts are not well understood.

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Star-formation histories of local luminous infrared galaxies

Astronomy and Astrophysics ◽

10.1051/0004-6361/201425359 ◽

2015 ◽

Vol 577 ◽

pp. A78 ◽

Cited By ~ 14

Author(s):

Miguel Pereira-Santaella ◽

Almudena Alonso-Herrero ◽

Luis Colina ◽

Daniel Miralles-Caballero ◽

Pablo G. Pérez-González ◽

...

Keyword(s):

Star Formation ◽

Infrared Galaxies ◽

Luminous Infrared Galaxies ◽

Star Formation Histories

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Evolution of Very Luminous Infrared Galaxies

Symposium - International Astronomical Union ◽

10.1017/s0074180900113117 ◽

1999 ◽

Vol 186 ◽

pp. 364-364

Author(s):

H. Wu ◽

Z.L. Zou ◽

X.Y. Xia ◽

Z. G. Deng

Keyword(s):

Spectral Classification ◽

Dynamical Friction ◽

Infrared Galaxies ◽

Nuclear Activity ◽

Classification Schemes ◽

Luminous Infrared Galaxies ◽

Luminous Galaxies ◽

Class 1 ◽

Nuclear Separation ◽

Last Stage

We have completed spectroscopic observations (Wu et al. 1997a) of a sample of 73 very luminous infrared galaxies (log(LIR/L⊙) ≥ 11.5;H0 = 50 km s−1 Mpc−1) from the 2-Jy catalogue (Strauss et al. 1992) using the 2.16m telescope at the Beijing Astronomical Observatory. Spectral and interacting classifications are performed for the sample (Wu et al. 1997b). These statistical results provide strong evidence for the idea that interactions trigger nuclear activity and enhance the infrared luminosity. With the decrease of nuclear separation, relative velocity and specific angular momentum decrease rapidly, while on the contrary, both infrared luminosity and Hα equivalent width increase. Dynamical friction plays an important role even when two galaxies have large separation. This provides a favorable condition for strong star formation. We construct a simple merger sequence, from interaction class 1 to 4, to class 5 and 6 and then to the class 0 regarded as being in the stage of advanced merger. Along this sequence, spectral types change from HII-like to AGN-like. Considering the strong correlation of very luminous infrared galaxies in spectral classification schemes, it is reliable that infrared luminous galaxies evolve from HII-like galaxies to AGN-like galaxies. The different properties of infrared luminous Seyfert 1s and optically selected Seyfert 1s suggest that infrared luminous galaxies could evolve into optical Seyfert 1s in the last stage.

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Massive star formation in local luminous infrared galaxies

Astrophysics and Space Science ◽

10.1007/s10509-009-0089-4 ◽

2009 ◽

Vol 324 (2-4) ◽

pp. 333-336

Author(s):

Almudena Alonso-Herrero ◽

Tanio Díaz-Santos ◽

Macarena García-Marín ◽

Luis Colina ◽

Santiago Arribas ◽

...

Keyword(s):

Star Formation ◽

Massive Star ◽

Infrared Galaxies ◽

Massive Star Formation ◽

Luminous Infrared Galaxies

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A 3D view of galactic winds in luminous infrared galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314010084 ◽

2014 ◽

Vol 10 (S309) ◽

pp. 312-312

Author(s):

P. Martín-Fernández ◽

J. Jiménez-Vicente ◽

A. Zurita ◽

E. Mediavilla ◽

A. Castillo-Morales

Keyword(s):

Star Formation ◽

Emission Lines ◽

Host Galaxy ◽

Infrared Galaxies ◽

Ionized Gas ◽

Luminous Infrared Galaxies ◽

Galactic Winds ◽

Star Formation Activity ◽

Galaxy Type ◽

Multi Phase

AbstractGalactic winds and outflows are an ubiquitous phenomenon in galaxies with active star formation and/or active nuclei. They constitute the main mechanism for redistributing dust and metals on large scales and are therefore a key ingredient to understand the life cycle of galaxies. Among galaxies, ULIRGs are of particular interest in this context, as they host intense starbursts and are likely to be the dominant star formers at z > 1. These objects have been shown to host important winds, but it is not yet known what is the frequency of galactic winds and their properties in galaxies with lower star formation rates (SFR). We are studying galactic winds in a sample of 21 galaxies with different SFRs (including ULIRGs) from observations with the INTEGRAL fiber spectrograph on the 4.2m WHT. In order to be able to address the complex multi–phase nature of the wind phenomenon, we have used the Na I D doublet absorption lines to trace cold gas, and a few emission lines (Hα, [N ii] and [S ii]) to trace the warmer ionized gas of the wind. The distribution and kinematics of both components in these objects is then analysed. Preliminary results show strong spatial correlation between regions with high non–circular velocities, areas with high star formation activity and regions with two different components in the emission lines. This set of data will help us to characterise the distribution and kinematics of the winds and their relation with the host galaxy type.

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