Related papers: What Powers Ultra-luminous IRAS Galaxies?
We have studied the dynamics and masses of a sample of ten nearby luminous and ultraluminous infrared galaxies (LIRGS and ULIRGs), using 2.3 micron CO absorption line spectroscopy and near-infrared H- and Ks-band imaging. By combining…
We present high quality (high signal-to-noise ratio and moderate spectral resolution) near-infrared (near-IR) spectroscopic observations of 23 well-known broad-emission line active galactic nuclei (AGN). Additionally, we obtained…
The extreme infrared (IR) luminosity of local luminous and ultra-luminous IR galaxies (U/LIRGs; 11 < log LIR /Lsun < 12 and log LIR /Lsun > 12, respectively) is mainly powered by star-formation processes triggered by mergers or…
Context. Active galactic nuclei (AGN) of galaxies play an important role in the life and evolution of galaxies due to the impact they exert on certain properties and the evolutionary path of galaxies. It is well known that infrared (IR)…
We present high spatial resolution H and K'-band images of a complete sample of ultraluminous infrared galaxies selected to have warm mid-infrared colors known to be characteristic of active galaxies. The extended underlying galaxy is…
It is not yet clear what triggers the activity of active galactic nuclei (AGNs), but galaxy merging has been suspected to be one of the main mechanisms fuelling the activity. Using deep optical images taken at various ground-based…
(Abridged) We report on an accounting of the star formation and accretion driven energetics of 24um detected sources in GOODS North. For sources having infrared (IR; 8-1000um) luminosities >3x10^12 L_sun when derived by fitting local SEDs…
The luminous electromagnetic emission from distant active galactic nuclei (AGNs) including quasars is believed to be powered by accretion onto super-massive black holes (SMBHs). In the standard unification model for AGNs a dusty torus…
We explore the relationship between gas, dust and star formation in a sample of 12 ultra-luminous infrared galaxies (ULIRGs) at high redshift compared to a similar sample of local galaxies. We present new CO observations and/or Spitzer…
We report on the results of 3--4 $\mu$m spectroscopy of the ultra-luminous infrared galaxy (ULIRG) UGC 5101. It has a cool far-infrared color and a LINER-type optical spectrum, and so, based on a view gaining some currency, would be…
Near-infrared spectroscopy using the new Palomar Integral Field Spectrograph indicates the presence of an AGN (active galactic nucleus) in the ultraluminous infrared galaxy IRAS 08311-2459. The high-velocity wings of the Paschen-alpha…
The study of the dominant population of high redshift IR-luminous galaxies (10^11 - 10^12 Lsun at 1<z<3), requires observation of sources at the ~0.1 mJy level in the mid-IR. We present the deepest spectra taken to date with the Infrared…
We present J and K-band near-infrared photometry of a sample of mid-infrared sources detected by the Infrared Space Observatory (ISO) as part of the European Large Area ISO-Survey (ELAIS) and study their classification and star-forming…
(Abridged) We present high spatial resolution ultraviolet and optical spectroscopy, obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, of nuclear structures within four `warm' Ultraluminous Infrared…
Surveys have revealed a class of object displaying both high X-ray luminosities (Lx > 10^42 erg/s), and a lack of a discernible active galactic nucleus (AGN) in the optical band. If these sources are powered by star formation activity…
Ultraluminous infrared galaxies (ULIRGs) show on average three times more emission in the rotational transitions of molecular hydrogen than expected based on their star formation rates. Using Spitzer archival data we investigate the origin…
Starting from a sample of 24 \micron\ sources in the Extended Groth Strip, we use 3.6 to 8 \micron\ color criteria to select ultraluminous infrared galaxies (ULIRGs) at $z\sim2$. Spectroscopy from 20-38 \micron\ of 14 objects verifies their…
We present a sample of mid-infrared detected sources from the European Large Area ISO Survey (ELAIS) regions characterised by strong mid-IR radiation with faint near-IR and optical counterparts. These extreme mid-to-near-IR objects (EMNOs)…
Nuclear starbursts and AGN activity are the main heating processes in luminous infrared galaxies (LIRGs) and their relationship is fundamental to understand galaxy evolution. In this paper, we study the star-formation and AGN activity of a…
We present a new diagnostic diagram for mid-infrared spectra of infrared galaxies based on the equivalent width of the 6.2 micron PAH emission feature and the strength of the 9.7 micron silicate feature. Based on the position in this…