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Gas Dynamics in Planetary Nebulae: From Macro-structures to FLIERs

Perinotto, Mario

Purpose of this paper is to clarify how Planetary Nebulae (PNe) are very interesting laboratories to study cosmic gas dynamics. I first recall the history of PNe which are generated from low and intermediate mass stars through successive mass loss processes starting in the Reg Giant phase of evolution and continuing also after the termination of t…

The Influence of Fluctuations of the Solar Emission Line Profileon the Doppler Shift of Interplanetary HLyα Lines Observed by the Hubble–Space–Telescope

Scherer, H.; Fahr, H. J.; Bzowski, M. +1 more

In an earlier research the employment of a radiation transport model with angle-dependent partial frequency redistribution, self-absorption by interplanetary hydrogen, realistic solar H_Lyαemission profile, and a time dependent `hot' hydrogen model to analyze 5 interplanetary H_Lyα glow spectra obtained with theHubble–Space–Tel…

Faint field galaxies: an explanation of the faint blue excess using number evolution models

Zhang, Yuan-Zhong; He, Ping; Zou, Zhen-Long

Pure luminosity evolution models for galaxies provide an unacceptable fit to the redshifts and colors of faint galaxies. In this paper we demonstrate, using HST morphological number counts derived both from the I₈₁₄-band of WFPC2 in the Medium Deep Survey (MDS) and the Hubble Deep Field (HDF) and from the H_1.6-band of NICMOS,…

A Search for Warm Neutral Gas Associated with the Giant HII Region NGC 604

Beckman, J.; Gómez de Castro, A. I.; Sanz, L.

The characteristics of the halo gas and its interaction with the galactic disk in spiral galaxies are poorly known; this is particularly true for the warm neutral gas associated with HVCs and galactic chimneys. The detection of absorption features such as the NaI D or the CaII (H,K)lines is instrumental to study its detailed physical properties bu…