2007A&A...468..443T


C.D.S. - SIMBAD4 rel 1.7 - 2020.01.29CET05:53:34

2007A&A...468..443T - Astronomy and Astrophysics, volume 468, 443-462 (2007/6-3)

High-resolution X-ray spectroscopy of T Tauri stars in the Taurus-Auriga complex.

TELLESCHI A., GUEDEL M., BRIGGS K.R., AUDARD M. and SCELSI L.

Abstract (from CDS):

Differences have been reported between the X-ray emission of accreting and non-accreting stars. Some observations have suggested that accretion shocks could be responsible for part of the X-ray emission in classical T Tauri stars (CTTS). We present high-resolution X-ray spectroscopy for nine pre-main sequence stars in order to test the proposed spectroscopic differences between accreting and non-accreting pre-main sequence stars. We used X-ray spectroscopy from the XMM-Newton Reflection Grating Spectrometers and the EPIC instruments. We interpret the spectra using optically thin thermal models with variable abundances, together with an absorption column density. For BP Tau and AB Aur we derive electron densities from the OVII triplets. Using the OVII/OVIII count ratios as a diagnostic for cool plasma, we find that CTTS display a soft excess (with equivalent electron temperatures of ≃2.5-3MK) when compared with WTTS or zero-age main-sequence stars. Although the OVII triplet in BP Tau is consistent with a high electron density (3.4x1011cm–3), we find low density for the accreting Herbig star AB Aur (ne<1010cm–3). The element abundances of accreting and non-accreting stars are similar. The Ne abundance is found to be high (4-6 times the Fe abundance) in all K and M-type stars. In contrast, for the three G-type stars (SU Aur, HD 283572, and HP Tau/G2), we find an enhanced Fe abundance (0.4-0.8 times solar photospheric values) compared to later-type stars. Adding the results from our sample to former high-resolution studies of T Tauri stars, we find a soft excess in all accreting stars, but in none of the non-accretors. On the other hand, high electron density and high Ne/Fe abundance ratios do not seem to be present in all accreting pre-main sequence stars.

Abstract Copyright:

Journal keyword(s): stars: coronae - stars: formation - stars: pre-main sequence - X-rays: stars - stars: flare

Simbad objects: 28

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Number of rows : 28

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 * 47 Cas PM* 02 05 07.4242273 +77 16 52.824198   5.590 5.268     F0V 104 1
2 V* VY Ari RS* 02 48 43.7283572894 +31 06 54.592580835   7.72   6.4   G9 205 0
3 V* UX Ari RS* 03 26 35.3764089427 +28 42 54.211100955 7.76 7.28 6.37     K0IV 659 0
4 HD 22468 RS* 03 36 47.2911034958 +00 35 15.938962144 7.09 6.63   5.4   K2:Vnk 1119 0
5 HD 283447 TT* 04 14 12.9232870093 +28 12 12.378540314 13.17 12.07 10.68 9.45 8.67 K3Ve 377 0
6 V* V410 Tau TT* 04 18 31.1083261392 +28 27 16.155411536   12.13 10.75 8.45 9.408 K3Ve 422 0
7 V* BP Tau TT* 04 19 15.8342975037 +29 06 26.929456808   13.13 12.12 11.89   K5/7Ve 592 0
8 HD 283572 TT* 04 21 58.8482823933 +28 18 06.511915195   9.80 9.03 9.14   G5IVe 266 0
9 V* DH Tau TT* 04 29 41.558 +26 32 58.27 15.14 14.62 13.10 13.01   M1Ve 257 1
10 NAME Tau-Aur Region SFR 04 30 +25.0           ~ 1189 1
11 V* DN Tau TT* 04 35 27.3776240781 +24 14 58.908761629 13.56 12.88 11.50 11.79   M1:Ve 342 0
12 CoKu HP Tau G3 TT* 04 35 53.4991854163 +22 54 09.000431829 18.21   14.8     M0.6 56 0
13 CoKu HP Tau G2 TT* 04 35 54.1553246504 +22 54 13.404170652 13.63 12.31 11.158 10.14 9.172 G2e 111 0
14 V* AB Aur Ae* 04 55 45.8459978418 +30 33 04.293281305 7.20 7.16 7.05 6.96 6.70 A0Ve 912 2
15 V* SU Aur TT* 04 55 59.3861369488 +30 34 01.499800471   10.33 9.30 9.17   G2IIIne 527 0
16 * alf Aur SB* 05 16 41.35871 +45 59 52.7693 1.33 0.88 0.08 -0.52 -0.96 G3III: 1135 0
17 HD 36705 TT* 05 28 44.8916324761 -65 26 55.289846904 8.259 7.856 6.999 6.496 5.993 K0V 920 0
18 Hen 3-545 TT* 10 59 06.9712894449 -77 01 40.309036535   12.91 11.136   9.596 K4Ve 185 0
19 V* TW Hya TT* 11 01 51.9054298616 -34 42 17.031550898   11.94 10.50 10.626 9.18 K6Ve 1476 1
20 CD-33 7795 TT* 11 31 55.2603055856 -34 36 27.214242128   12.97 11.524 11.150 9.150 M2Ve 172 0
21 V* V851 Cen RS* 13 44 00.9207917868 -61 21 59.167786170   8.74 7.798   6.638 K0III 74 0
22 V* EK Dra BY* 14 39 00.2109485496 +64 17 29.977371998   8.243 7.604     G1.5V 372 0
23 * sig CrB RS* 16 14 40.85557 +33 51 30.9497           F6V+G0V 474 0
24 HD 319139 BY* 18 14 10.4818974563 -32 47 34.516106830   11.47 10.68   9.11 K5+K7 280 0
25 V* PZ Tel BY* 18 53 05.8733807460 -50 10 49.901380086   9.22 8.342   7.464 G9IV 240 0
26 V* AR Lac RS* 22 08 40.8180372773 +45 44 32.104045703 7.09 6.83 6.11     K0IVe+G5IV 693 0
27 * lam And RS* 23 37 33.8426114 +46 27 29.337984 5.54 4.84 3.82 3.04 2.47 G8IVk 639 0
28 HD 224085 RS* 23 55 04.0516465022 +28 38 01.248194500 8.88 8.20   6.9   K2+IVeFe-1 675 0

    Equat.    Gal    SGal    Ecl

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2020.01.29-05:53:34

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