ar X iv : a st ro - p h / 99 02 23 3 v 2 2 J un 1 99 9 Dust lanes causing structure in the extended narrow line region of early - type Seyfert galaxies

ar X iv : a st ro - p h / 97 08 23 1 v 1 2 5 A ug 1 99 7 ASCA observations of type - 2 Seyfert Galaxies : III Orientation and X - ray Absorption

We discuss the spectral properties of a sample of type-2 Seyfert galaxies based upon the analysis of ASCA data. In this paper we consider the sources for which the X-ray spectra appear to be dominated by the nuclear continuum, transmitted through a large column of absorbing material. We find that both Seyfert-2 galaxies and NELGs show iron Kα line profiles indicative of reprocessing of nuclear ...

ar X iv : a st ro - p h / 99 02 29 8 v 2 1 3 A pr 1 99 9 New limits on Ω Λ and Ω M from old galaxies at high redshift

ar X iv : a st ro - p h / 93 05 00 2 v 1 6 M ay 1 99 3 Visibility of Gravitational Lenses and the Cosmological Constant Problem

Recent observations suggest appreciable star formation activity in early-type galaxies down to redshift z ∼ 0.5. If so, there is likely to be dust in these galaxies. We consider the possibility that obscuration by dust can reconcile the observed frequency of gravitational lensing of quasar images with the considerably larger rate predicted in a low density cosmologically flat universe dominated...

Dust lanes causing structure in the extended narrow line region of early-type Seyfert galaxies

We construct near-infrared to visible broad band NICMOS/WFPC color maps for 4 early-type Seyfert galaxies with S-shaped or one-sided ionization cones. We find that dust lanes are near or connected to many of the features seen in the [OIII] and Hα+[NII] line emission maps. This suggests that much of the structure of line emission in these ionization cones is determined by the distribution of amb...

ar X iv : a st ro - p h / 99 07 02 5 v 1 2 J ul 1 99 9 Properties of High Redshift Galaxies

I review the characteristics of high redshift galaxies, with particular attention to the effects of dust obscuration on the observed light. Galaxies at redshift z∼1 and at z>2 are discussed separately, as the accessible information for each redshift range are different. In the z≤1–2 redshift region, data on the Hα and mid/far-IR luminosity of the galaxies are becoming increasingly available, ef...