Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · astro-ph/0211577

Results from a VLT-ISAAC survey of ices and gas around young stellar objects

K. M. Pontoppidan·H. Fraser·F. L. Schoeier·E. Dartois·W. -F. Thi·E. F. van Dishoeck
View original source ↗Read source document ↗Export metadata ↓

Abstract

General results from a 3-5 micron spectroscopic survey of nearby low-mass young stellar objects are presented. L and M-band spectra have been obtained of \~50 low mass embedded young stars using the ISAAC spectrometer mounted on UT1-Antu at Paranal Observatory. For the first time, a consistent census of the CO, H2O ices and the minor ice species CH3OH and OCN- and warm CO gas present around young stars is obtained, using large number statistics and resolving powers of up to R=10000. The molecular structure of circumstellar CO ices, the depletion of gaseous CO onto grains in protoplanetary disks, the presence of hot gas in the inner parts of circumstellar disks and in outflows and infalls are studied. Furthermore, the importance of scattering effects for the interpretation of the spectra have been addressed.

Explore related subjects

astro-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

K. M. Pontoppidan, H. Fraser, F. L. Schoeier, E. Dartois, W. -F. Thi, E. F. van Dishoeck. 2002-11-28. Results from a VLT-ISAAC survey of ices and gas around young stellar objects. https://arxiv.org/abs/astro-ph/0211577

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2022

Two 3-Branes in Randall-Sundrum Setup and Current Acceleration of the Universe

Five-dimensional spacetimes of two orbifold 3-branes are studied, by assuming that {\em the two 3-branes are spatially homogeneous, isotropic, and independent of time}, following the so-called "bulk-based" approach. The most general form of the metric is obtained, and the corresponding field equations are divided into three groups, one is valid on each of the two 3-branes, and the third is valid in the bulk. The Einstein tensor on the 3-branes is expressed in terms of the discontinuities of the first-order derivatives of the metric coefficients. Thus, once the metric is known in the bulk, the distribution of the Einstein tensor on the two 3-branes is uniquely determined. As applications, we consider two different cases, one is in which the bulk is locally $AdS_{5}$, and the other is where it is vacuum. In some cases, it is shown that the universe is first decelerating and then accelerating. The global structure of the bulk as well as the 3-branes is also studied, and found that in some cases the solutions may represent the collision of two orbifold 3-branes. The applications of the formulas to the studies of the cyclic universe and the cosmological constant problem are also pointed out.

astro-ph↗
arXiv2022

A Revolution in Science: the Eclipse Expeditions of 1919

The first direct experimental test of Einstein's theory of general relativity involved a pair of expeditions to measure the bending of light at a total solar eclipse that took place one hundred years ago, on 29 May 1919. So famous is this experiment, and so dramatic was the impact on Einstein himself, that history tends not to recognise the controversy that surrounded the results at the time. In this article, I discuss the experiment in its scientific and historical background context and explain why it was, and is, such an important episode in the development of modern physics.

astro-ph↗
arXiv2022

State Vector Determination By A Single Tracking Satellite

Using only a single tracking satellite capable of only range measurements to an orbiting object in an unknown Keplerian orbit, it is theoretically possible to calculate the orbit and a current state vector. In this paper we derive an algorithm that can perform this calculation.

astro-ph↗