Table 1: Convection zone mass (log q = log M(CVZ)/M ) and diffusion timescales (log tau[yrs]) in hydrogen-rich white dwarfs. Data refer to the depth tau(Ross) = 2/3, if there is no convection zone in the hotter (>~ 14000 K) stars. Source: Detlev Koester, University of Kiel, Germany (Jan 2013) ---------------------------------------------------------------------------------------------------------- Teff/K log g log q C O Na Mg Al Si Ca Fe ---------------------------------------------------------------------------------------------------------- 6000. 7.50 -6.885 5.3131 5.3636 5.2214 5.1460 5.0838 5.0128 5.1640 4.9403 7000. 7.50 -7.532 4.8315 4.8883 4.7187 4.6504 4.5826 4.5198 4.6835 4.4615 8000. 7.50 -8.159 4.4038 4.4667 4.2638 4.2050 4.1317 4.0823 4.2230 4.0354 9000. 7.50 -9.077 3.7879 3.8611 3.5683 3.5283 3.4247 3.4512 3.5745 3.3995 10000. 7.50 -10.854 2.6616 2.5431 2.2449 2.1645 2.1983 2.2966 2.2369 2.1358 11000. 7.50 -13.826 0.3373 0.0756 -0.2479 0.0132 0.2189 0.2300 -0.1355 -0.1145 12000. 7.50 -15.573 -1.6035 -2.0814 -1.6753 -1.3277 -1.5292 -1.6280 -1.4543 -1.7739 13000. 7.50 -15.945 -2.0275 -2.6747 -2.0069 -1.7367 -1.9767 -2.0649 -1.7949 -2.2075 14000. 7.50 -16.019 -2.0559 -2.6919 -2.0567 -1.7819 -2.0203 -2.1057 -1.8454 -2.2472 15000. 7.50 -16.030 -2.3178 -2.7102 -2.3463 -2.2125 -2.3136 -2.3572 -2.2459 -2.4369 16000. 7.50 -16.012 -1.9259 -2.4136 -2.0104 -1.6376 -1.8535 -1.9480 -1.7677 -2.0862 17000. 7.50 -15.911 -1.7758 -2.1334 -1.9129 -1.4818 -1.6359 -1.7245 -1.6568 -1.8985 18000. 7.50 -15.858 -1.7051 -1.9985 -1.8779 -1.4226 -1.5408 -1.6098 -1.6162 -1.8173 19000. 7.50 -15.808 -1.6405 -1.8959 -1.8467 -1.3780 -1.4724 -1.5205 -1.5810 -1.7562 20000. 7.50 -15.709 -1.5194 -1.7695 -1.7814 -1.3018 -1.3680 -1.4073 -1.5140 -1.6663 21000. 7.50 -15.650 -1.4248 -1.6990 -1.7481 -1.2638 -1.3042 -1.3462 -1.4793 -1.6156 22000. 7.50 -15.658 -1.3981 -1.6948 -1.7615 -1.2746 -1.2995 -1.3452 -1.4911 -1.6183 23000. 7.50 -15.607 -1.2890 -1.6397 -1.7349 -1.2459 -1.2419 -1.2957 -1.4635 -1.5714 24000. 7.50 -15.561 -1.1806 -1.5834 -1.7114 -1.2208 -1.1778 -1.2457 -1.4393 -1.5211 25000. 7.50 -15.504 -1.0643 -1.5027 -1.6802 -1.1901 -1.0960 -1.1772 -1.4083 -1.4504 ---------------------------------------------------------------------------------------------------------- 6000. 8.00 -7.722 4.4522 4.5018 4.2952 4.2328 4.1499 4.1127 4.2924 4.0605 7000. 8.00 -8.432 3.9168 3.9746 3.7254 3.6822 3.5864 3.5762 3.7125 3.5262 8000. 8.00 -8.954 3.5425 3.6051 3.3387 3.3028 3.1998 3.2031 3.3303 3.1571 9000. 8.00 -9.607 3.1054 3.1689 2.8702 2.8264 2.7238 2.7616 2.8725 2.6995 10000. 8.00 -10.738 2.3608 2.2932 2.0401 1.9431 1.9199 2.0001 1.9997 1.8844 11000. 8.00 -12.715 1.0720 0.8386 0.4911 0.5117 0.6158 0.7357 0.4845 0.4592 12000. 8.00 -15.618 -1.6600 -1.9448 -1.9495 -1.4940 -1.6024 -1.6223 -1.6941 -1.8662 13000. 8.00 -16.408 -2.5114 -3.0186 -2.5617 -2.2466 -2.4516 -2.5500 -2.3590 -2.6977 14000. 8.00 -16.672 -2.8265 -3.4494 -2.8171 -2.5668 -2.7873 -2.8787 -2.6305 -3.0258 15000. 8.00 -16.698 -2.8048 -3.3978 -2.8216 -2.5511 -2.7709 -2.8628 -2.6277 -3.0057 16000. 8.00 -16.744 -2.7893 -3.3450 -2.8325 -2.5256 -2.7473 -2.8420 -2.6220 -2.9817 17000. 8.00 -16.634 -2.5918 -2.9979 -2.7040 -2.3115 -2.4864 -2.5829 -2.4688 -2.7421 18000. 8.00 -16.586 -2.5140 -2.8452 -2.6670 -2.2412 -2.3832 -2.4592 -2.4213 -2.6470 19000. 8.00 -16.538 -2.4477 -2.7273 -2.6337 -2.1871 -2.3029 -2.3574 -2.3804 -2.5745 20000. 8.00 -16.439 -2.3285 -2.5836 -2.5652 -2.1005 -2.1849 -2.2274 -2.3077 -2.4725 21000. 8.00 -16.383 -2.2442 -2.5053 -2.5322 -2.0604 -2.1170 -2.1585 -2.2713 -2.4186 22000. 8.00 -16.392 -2.2244 -2.4984 -2.5453 -2.0695 -2.1147 -2.1542 -2.2821 -2.4206 23000. 8.00 -16.342 -2.1259 -2.4414 -2.5184 -2.0383 -2.0602 -2.1027 -2.2527 -2.3754 24000. 8.00 -16.297 -2.0238 -2.3864 -2.4946 -2.0113 -2.0001 -2.0538 -2.2271 -2.3294 25000. 8.00 -16.241 -1.9067 -2.3132 -2.4640 -1.9800 -1.9212 -1.9906 -2.1953 -2.2655 ---------------------------------------------------------------------------------------------------------- 6000. 8.50 -8.473 3.6554 3.7012 3.4460 3.4036 3.2838 3.3036 3.4810 3.2497 7000. 8.50 -9.373 2.9723 3.0294 2.7113 2.6600 2.5580 2.6154 2.7340 2.5607 8000. 8.50 -9.819 2.6403 2.6710 2.3732 2.3211 2.2256 2.2838 2.3910 2.2143 9000. 8.50 -10.327 2.2940 2.2937 2.0156 1.9610 1.8766 1.9381 2.0110 1.8550 10000. 8.50 -11.070 1.8005 1.7454 1.4867 1.3993 1.3633 1.4386 1.4487 1.3251 11000. 8.50 -12.334 0.9782 0.8327 0.5125 0.4421 0.5018 0.6021 0.4914 0.4099 12000. 8.50 -14.261 -0.4058 -0.6530 -0.9657 -0.8801 -0.7469 -0.6167 -0.9836 -0.9709 13000. 8.50 -16.562 -2.6778 -2.9793 -2.9068 -2.4795 -2.6199 -2.6551 -2.6595 -2.8692 14000. 8.50 -17.149 -3.3170 -3.8078 -3.3748 -3.0688 -3.2654 -3.3627 -3.1896 -3.5187 15000. 8.50 -17.372 -3.5806 -4.1582 -3.5872 -3.3340 -3.5416 -3.6361 -3.4126 -3.7876 16000. 8.50 -17.353 -3.4888 -4.0103 -3.5313 -3.2363 -3.4403 -3.5370 -3.3401 -3.6864 17000. 8.50 -17.350 -3.4187 -3.8721 -3.5033 -3.1569 -3.3463 -3.4454 -3.2945 -3.5994 18000. 8.50 -17.308 -3.3297 -3.7017 -3.4616 -3.0721 -3.2367 -3.3156 -3.2350 -3.4892 19000. 8.50 -17.265 -3.2582 -3.5704 -3.4249 -3.0053 -3.1447 -3.2051 -3.1858 -3.4040 20000. 8.50 -17.167 -3.1358 -3.4064 -3.3528 -2.9043 -3.0101 -3.0578 -3.1051 -3.2866 21000. 8.50 -17.176 -3.1231 -3.3848 -3.3634 -2.9079 -2.9950 -3.0397 -3.1114 -3.2803 22000. 8.50 -17.124 -3.0431 -3.3096 -3.3327 -2.8688 -2.9364 -2.9707 -3.0751 -3.2274 23000. 8.50 -17.077 -2.9549 -3.2478 -3.3053 -2.8337 -2.8815 -2.9145 -3.0431 -3.1815 24000. 8.50 -17.033 -2.8619 -3.1914 -3.2815 -2.8049 -2.8234 -2.8642 -3.0155 -3.1379 25000. 8.50 -16.978 -2.7503 -3.1221 -3.2514 -2.7719 -2.7478 -2.8036 -2.9823 -3.0795 ---------------------------------------------------------------------------------------------------------- Remarks: Except for the correction of the errors mentioned on the WEBsite, the following changes have been made in comparison to the paper Koester (2009, AA 498, 517): - The atmosphere models use ML2/(l/Hp=0.8) (=ML2/0.8) as mixing length parameters in the atmosphere models used as boundary condition for the envelope calculations. - The model parameters for the variable DA G29-38 = WD2326+049, which were used to "calibrate" the MLT description in the envelope calculation, have changed to Teff = 11830 K, log g = 8.40 (Xu et al. in preparation). With these values, the thermal timescale of the convection zone becomes ~100s, if the same description (ML2/0.8) is used in the envelope. There is no need to use a different value. It should be noted, that there is no homogeneous reservoir in the absence of a convection zone. The concept of a diffusion timescale is not very useful in that case, except to demonstrate that diffusion is extremely fast (order of days). In this case it is more plausible to assume a steady state with constant diffusion flux throughout the atmosphere, which leads to a stratified abundance structure. The relative abundances in the accreted material can be obtained from the diffusion fluxes.