The relationship of an AGN to its host galaxy is one crucial question in the study of galaxy evolution. We present a method to estimate the stellar contribution in active galactic nuclei. We perform stellar population synthesis in the central regions of a sample of 12 galaxies of different levels of activity: normal galaxies, starburst galaxies, LINERs, Seyfert 2 and Seyfert 1 galaxies. Quantif...

We report our recent progress on extragalactic spectroscopic and continuum observations, including HCN(J=1–0), HCO(J=1–0), and CN(N=1–0) imaging surveys of local Seyfert and starburst galaxies using the Nobeyama Millimeter Array, high-J CO observations (J=3–2 observations using the Atacama Submillimeter Telescope Experiment (ASTE) and J=2–1 observations with the Submillimeter Array) of galaxies...

We have carried out a spectropolarimetric search for hidden broad-line quasars in three ultraluminous infrared galaxies (ULIRGs) discovered in the positional correlations between sources detected in deep radio surveys and the IRAS Faint Source Catalog. Only the high-ionization Seyfert 2 galaxy TF J1736+1122 is highly polarized, displaying a broad-line spectrum visible in polarized light. The ot...

A handful of nearby supernovae (SNe) with visual extinctions of a few magnitudes have recently been discovered. However, an undiscovered population of much more highly extinguished (AV > 10) core-collapse supernovae (CCSNe) is likely to exist in the nuclear (central kpc) regions of starburst galaxies. The high dust extinction means that optical searches for such SNe are unlikely to be successfu...

Loeb and Waxman have argued that high energy neutrinos from the decay of pions produced in interactions of cosmic rays with interstellar gas in starburst galaxies would be produced with a large enough flux to be observable. Here we obtain an upper limit to the diffuse neutrino flux from starburst galaxies which is a factor of ∼5 lower than the flux which they predict. Compared with predicted fl...

Radio imaging of ULIR galaxies is ideal to explore the connection between the starburst and the AGN phenomenon since it is unaffected by dust obscuration, and provides the required high angular resolution to distinguish between an AGN and starburst emission. We have made combined 18cm radio continuum, EVN and MERLIN observations of 13 ULIRGs that have the parsec and deci-parsec scale resolution...

We present spectra of nine low-luminosity early-type galaxies (MB > −17.5) in the Coma cluster. The spectra, which were obtained with the Multiple Mirror Telescope and cover the spectral region 3300-5350 Å, exhibit a large variation in Balmer line strengths. In fact the line strength variation among the Coma low-luminosity galaxies is as large as that found among a sample of low-luminosity elli...

We investigate the emission-line properties of galaxies with red rest-frame colors (compared to the g− r color bimodality) using spectra from Data Release 4 of the Sloan Digital Sky Survey (SDSS). Emission lines are detected in more than half of the red galaxies. We focus on the relationship between two emission lines commonly used as star formation rate indicators: Hα and [O II] λ3727. Since [...

A sample of local galaxies for which far infrared and uv fluxes are available is used to estimate the characteristic dust extinction in galaxies and to test whether standard dust properties are plausible. Assuming galaxies can be characterized by a single dust optical depth (certainly not valid for galaxies with a dominant starburst component), the infrared excess and ultraviolet colours of loc...

Chandra is detecting a significant population of normal and starburst galaxies in extremely deep X-ray exposures. For example, approximately 15% of the sources arising in the 2 Ms Chandra Deep Field-North survey are fairly normal galaxies, where “normal” means “Milky Way-type” X-ray emission rather than simply exhibiting an “optically normal” spectrum. Many of these galaxies are being detected ...