Chandra and ASCA Observations of the X-ray-brightest T-Tauri Stars in the Rho Ophiuchi Cloud

Details Chandra and ASCA Observations of the X-ray-brightest T-Tauri Stars in the Rho Ophiuchi Cloud Chandra and ASCA Observations of the X-ray-brightest T-Tauri Stars in the Rho Ophiuchi Cloud

2002-02-15

arxiv.org/abs/astro-ph/0202287v1

Astronomy and Astrophysics

Astrophysics

13 pages, 18 figures, accepted for publication in ApJ

Scientific paper

10.1086/340306

We present the Chandra ACIS and ASCA GIS results for a series of four long-term observations on DoAr 21, ROXs 21 and ROXs 31; the X-ray brightest T-Tauri stars (TTSs) in the Rho Ophiuchi cloud. In the four observations with a net exposure of ~600 ksec, we found six, three and two flares from DoAr 21, ROXs 21 and ROXs 31, respectively; hence the flare rate is fairly high. The spectra of DoAr 21 are well fitted with a single-temperature plasma model, while those of ROXs 21 and ROXs 31 need an additional soft plasma component. Since DoAr 21 is younger (~10^5 yr) than ROXs 21 and ROXs 31 (~10^6 yr), these results may indicate that the soft component gradually increases as T-Tauri stars age. The abundances are generally sub-solar and vary from element to element. Both high-FIP (first ionization potential) and low-FIP elements show enhancement over the mean abundances. An unusual giant flare is detected from ROXs 31. The peak luminosity and temperature are ~10^33 ergs s^-1 and ~10 keV, respectively. The temperature reaches its peak value before the flux maximum, and is nearly constant (4--5 keV) during the decay phase, indicating successive energy release during the flare. The abundances and absorption show dramatic variability from the quiescent to flare phase.

Affiliated with

Also associated with

No associations

Rating

Chandra and ASCA Observations of the X-ray-brightest T-Tauri Stars in the Rho Ophiuchi Cloud 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 ASCA Observations of the X-ray-brightest T-Tauri Stars in the Rho Ophiuchi Cloud, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chandra and ASCA Observations of the X-ray-brightest T-Tauri Stars in the Rho Ophiuchi Cloud will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-709800