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Population effects on the red giant clump absolute magnitude, and distance determinations to nearby galaxies
The red giant clump has been recently argued to be a reliable distance indicator for the galaxies in the Local Group. The accuracy of distance determinations based on this method, however, depends on
A Unified, Merger-driven Model of the Origin of Starbursts, Quasars, the Cosmic X-Ray Background, Supermassive Black Holes, and Galaxy Spheroids
We present an evolutionary model for starbursts, quasars, and spheroidal galaxies in which mergers between gas-rich galaxies drive nuclear inflows of gas, producing starbursts and feeding the buried
A merger-driven scenario for cosmological disk galaxy formation
The hierarchical nature of the ?CDM cosmology poses serious difficulties for the formation of disk galaxies. To help resolve these issues, we describe a new, merger-driven scenario for the
Unification of X-ray winds in Seyfert galaxies: from ultra-fast outflows to warm absorbers
The existence of ionized X-ray absorbing layers of gas along the line of sight to the nuclei of Seyfert galaxies is a well established observational fact. This material is systematically outflowing
Nitrogen Abundances in Giant Stars of the Globular Cluster NGC 6752
We present N abundances for 21 bright giants in the globular cluster NGC 6752 based on high-resolution UVES spectra of the 3360 A NH lines. We confirm that the Stromgren -->c1 index traces the N
The Evolution of the M-sigma Relation
(Abridged) We examine the evolution of the black hole mass - stellar velocity dispersion (M-sigma) relation over cosmic time using simulations of galaxy mergers that include feedback from
Detection of two power-law tails in the probability distribution functions of massive GMCs
We report the novel detection of complex high-column density tails in the probability distribution functions (PDFs) for three high-mass star-forming regions (CepOB3, MonR2, NGC6334), obtained from
Evolution of planetary nebulae II. Population effects on the bright cut-off of the PNLF
We investigate the bright cut-off of the (O ) λ5007 planetary nebula luminosity function (PNLF), that has been sug- gested as a powerful extragalactic distance indicator in virtue of its observed
Spectrum formation in superluminous supernovae (Type I)
The near-maximum spectra of most superluminous supernovae (SLSNe) that are not dominated by interaction with a H-rich circum-stellar medium (SLSN-I) are characterized by a blue spectral peak and a
Mixing of CNO-cycled matter in massive stars
Aims. We test predictions of evolution models on mixing of CNO-cycled products in massive stars from a fundamental perspective. Relative changes within the theoretical C:N:O abundance ratios and the