Astronomy and Astrophysics – Astronomy
Scientific paper
Feb 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009aipc.1094..908b&link_type=abstract
COOL STARS, STELLAR SYSTEMS AND THE SUN: Proceedings of the 15th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun.
Astronomy and Astrophysics
Astronomy
Stellar Activity, Faint Blue Stars, White Dwarfs, Degenerate Stars, Nuclei Of Planetary Nebulae, Astronomical And Space-Research Instrumentation
Scientific paper
We present observations of the X-ray and ultraviolet emission from a sample of dwarf stars in the Arcturus Moving Group. The Arcturus Moving Group is very likely a remnant of the merger of a dwarf galaxy with the Milky Way Galaxy in the distant past. This kinematically distinct group has members located very close to the Sun, allowing study of stellar activity on very old (7-8 Gyr), low metallicity stars that would typically not be possible. Our sample has metallicities between 0.4 and 0.04 solar, spectral types F9-mid-M, and distances less than 25 pc from the Sun. We have detected X-ray emission from five AMG dwarfs with the Chandra ACIS-S S3 back-illuminated detector and for four stars have measured or placed upper limits on the C IV UV1 emission flux using GALEX GRISM spectra. The measured X-ray luminosities are comparable to the minimum solar Lx (range 6-20 1026 erg s-1 for 0.24-2.0 keV) and for the late G/early K stars are also similar to that of the inactive, more metal rich ([Fe/H] = -0.42] G8 dwarf Tau Cet. However, a major difference from the Sun and Tau Cet is that the soft X-ray emitting plasma is far cooler. The detected source X-rays are generally very soft with energies of 0.2-0.3 keV, and the bulk of this emission originates from upper transition region emission lines, such as C V, rather than a conventional solar-like corona.
Ayres Thomas R.
Brown Alexander
Harper Graham M.
Hodges-Kluck Edmund
No associations
LandOfFree
Chandra and GALEX Observations of Stellar Activity on the 7 Gyr Old Arcturus Moving Group Dwarfs does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Chandra and GALEX Observations of Stellar Activity on the 7 Gyr Old Arcturus Moving Group Dwarfs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chandra and GALEX Observations of Stellar Activity on the 7 Gyr Old Arcturus Moving Group Dwarfs will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-836163