Figure 1

(Color online) Chandra HETG spectrum of NGC 3783. From 479.Reuse & Permissions

Figure 2

HETG spectrum of Capella. Insets: The regions of the spectrum in the vicinity of the lines of He-like ${\mathrm{Ne}}^{8+}$ and ${\mathrm{O}}^{6+}$. In the left inset panel the two curves are the data from the two arms of the dispersed image. The thin line is data from the higher energy arm (HEG) and the thick line is the data from the medium energy arm (MEG). From 179.Reuse & Permissions

Figure 3

(Color online) Composite spectrum of galaxy clusters where cooling gas is expected. Solid curve shows data from the RGS on XMM-Newton and dashed vertical lines show the predicted locations of various coronal emission lines. From 633.Reuse & Permissions

Figure 4

(Color online) Spectrum of the Seyfert 2 galaxy NGC 1068, taken with the LETG on the Chandra satellite. The solid jagged curve shows the data taken of the nuclear region of the galaxy, and the smooth (red) curve shows a model (472). From 141.Reuse & Permissions

Figure 5

Ionization balance comparison for coronal plasmas. Left panel: Ionization balance for iron in a coronal gas, calculated using rate coefficients described in the text. Right panel: Ionization balance calculated using perturbed rate coefficients as described in the text. Curves correspond to various ions of iron: in the left panel ${\mathrm{Fe}}^{+}$ dominates at $\log \left(T\right)=4$, ${\mathrm{Fe}}^{+5}$ dominates at $\log \left(T\right)=5.2$, ${\mathrm{Fe}}^{+8}$ dominates at $\log \left(T\right)=5.9$, ${\mathrm{Fe}}^{+12}$ dominates at $\log \left(T\right)=6.3$, ${\mathrm{Fe}}^{+16}$ dominates at $\log \left(T\right)=6.6$, and ${\mathrm{Fe}}^{+24}$ dominates at $\log \left(T\right)=7.5$. In the right panel, the temperature of maximum abundance of ${\mathrm{Fe}}^{+8}–{\mathrm{Fe}}^{+23}$ is displaced to lower temperature by $\simeq 0.1$ in $\log \left(T\right)$.Reuse & Permissions

Figure 6

(Color online) Fit to a $3\times {10}^4\mathrm{s}$ Chandra HETG observation of the active star Capella in the $10–18\mathrm{\AA }$ region using the baseline ionization balance shown in the left panel of Fig. 5.Reuse & Permissions

Figure 7

(Color online) Same as Fig. 6 except using ionization balance shown in Fig. 5 derived from perturbed rate coefficients as described in the text and displayed in the right panel of Fig. 5.Reuse & Permissions

Figure 8

Cross section for electron-impact ionization of ${\mathrm{O}}^{5+}$ in the vicinity of the $1s2s^2$ ${}^{3}S^o$ EA threshold. The DI contribution has been subtracted off. Data points are crossed beam measurements (593); the solid curve is the $R$-matrix calculation.Reuse & Permissions

Figure 9

${\mathrm{Fe}}^{18+}–{\mathrm{Fe}}^{17+}$ rate coefficient for recombination. Left panel (a): The thick solid curve represents the experimentally derived rate coefficient from 706. The thick error bars show the estimated experimental uncertainty of 20%. Symbols show tokamak results of 412 (filled circles) and 793 (open squares). Curves are DR rate coefficients calculated by 419 as fitted by 731, 732 (dotted curve), 676 (short-dashed curve), and of 231 (long-dashed curve), and recommended DR rate coefficient of 547 (dot-long-dashed curve), and recommended RR rate coefficient of 25 (thin solid curve). None of the experimental or theoretical DR rate coefficients include RR. The range of temperatures at which these processes are likely to occur in equilibrium are denoted for photoionized and collisionally ionized plasmas. Right panel (b): As in (a) the thick solid curve represents the rate coefficient derived from the storage ring experiment of 705, and the thin solid curve shows the recommended RR rate. Dotted curve shows the MCBP calculations and the dashed curve shows the MCDF calculations of the DR rate coefficents calculated by 705. Both calculations are for capture into states including capture states for all values of $nl$ (i.e., $n_{\max }=\infty$) and both include DR via $1\to 2$, $2\to 2$, and $2\to 3$ core excitations. None of the experimental or theoretical DR rate coefficients in (a) or (b) include RR. From 705.Reuse & Permissions

Figure 10

The effective collision strength for the $3s^{21}{S}_0\to 3s3p^3{P}_1^o$ transition in ${\mathrm{Fe}}^{14+}$ as a function of temperature for close-coupling (circles) and DW calculations (squares). From 275.Reuse & Permissions

Figure 11

Comparison of the collision strength for the $2s^{2}2p^2\left({}^{3}P_0^{\mathrm{e}}\right)\to 2s^{2}2p^2\left({}^{1}D_2^{\mathrm{e}}\right)$ transition in ${\mathrm{Fe}}^{20+}$ calculated using BPRM (solid curve; 172) with calculated using MCDF by 2 (dashed curve) as a function of temperature. From 172.Reuse & Permissions

Figure 12

Comparison of the collision strength for the $3s^2{}^{1}P_0\to 3s3p{}^{3}D$ transition in ${\mathrm{Ar}}^{6+}$ calculated using an $R$-matrix calculation (solid curve) (364), an isolated-resonance DW calculation (dashed curve), and experimental merged beam measurements (734). From 734.Reuse & Permissions

Figure 13

Comparison of BPRM calculation of the photoionization of ${\mathrm{O}}^{4+}$ with experiment (181) in the energy range $90–130\mathrm{eV}$. Below $103\mathrm{eV}$ the cross section is due to ionization from the $2s2p$ excited configuration, and $2s^2$ above. From 598.Reuse & Permissions

Figure 14

High-energy total photoabsorption cross sections of the ground level of (a) ${\mathrm{Fe}}^{16+}$ including radiative and Auger damping effects; (b) ${\mathrm{Fe}}^{16+}$ excluding damping effects for resonances with $n>2$; (c) ${\mathrm{Fe}}^{22+}$ including damping; and (d) ${\mathrm{Fe}}^{22+}$ excluding damping for resonances with $n>2$. This demonstrates that when damping is included the resonance widths are constant for high $n$ leading to a smearing of the $K$ edge. From 66.Reuse & Permissions