Science-advisor
REGISTER info/FAQ
Login
username
password
     
forgot password?
register here
 
Research articles
  search articles
  reviews guidelines
  reviews
  articles index
My Pages
my alerts
  my messages
  my reviews
  my favorites
 
 
Stat
Members: 3662
Articles: 2'599'751
Articles rated: 2609

11 December 2024
 
  » arxiv » astro-ph/0701587

 Article overview



Collimation, Proper Motions, and Physical Conditions in the HH 30 Jet From HST Slitless Spectroscopy
P. Hartigan ; J. Morse ; PostScript ; PDF ; Other formats ; SLAC-SPIRES HEP ; to ; by ; NASA ADS ;
Date 20 Jan 2007
AbstractWe present Space Telescope Imaging Spectrograph (STIS) spectral images of the HH~30 stellar jet taken through a wide slit over two epochs. The jet is unresolved spectrally, so the observations produce emission-line images for each line in the spectrum. This rich dataset shows how physical conditions in the jet vary with distance and time, produces precise proper motions of knots within the jet, resolves the jet width close to the star, and gives a spectrum of the reflected light from the disk over a large wavelength range at several positions. We introduce a new method for analyzing a set of line ratios based on minimizing a quadratic form between models and data. The method generates images of the density, temperature and ionization fraction computed using all the possible line ratios appropriately weighted. In HH 30, the density declines with distance from the source in a manner consistent with an expanding flow, and is larger by a factor of two along the axis of the jet than it is at the periphery. Ionization in the jet ranges from ~ 5% to 40%, and high ionization/excitation knots form at about 100 AU from the star and propagate outward with the flow. These high-excitation knots are not accompanied by corresponding increases in the density, so if formed by velocity variations the knots must have a strong internal magnetic pressure to smooth out density increases while lengthening recombination times.
Source arXiv, astro-ph/0701587
Services Forum | Review | PDF | Favorites   
 
Visitor rating: did you like this article? no 1   2   3   4   5   yes

No review found.
 Did you like this article?

This article or document is ...
important:
of broad interest:
readable:
new:
correct:
Global appreciation:

  Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.






ScienXe.org
» my Online CV
» Free

home  |  contact  |  terms of use  |  sitemap
Copyright © 2005-2024 - Scimetrica