1. Recent Highlights from the High Resolution Transmission Grating X-ray Spectrometer on the Chandra X-ray Observatory Michael A. Nowak (MIT-CXC) on behalf of Claude Canizares and the Chandra- HETG Group* (* Anything intelligent that I say, full credit to the group; idiotic statements wholly my own!)

2. The Chandra X-ray Observatory:

3. Chandra History and Specs: Third of NASA’s “Great Observatories”. Launched July 1999 High Altitude Orbit (132,000 km); 63.5 hour orbit Up to 160 ksec viewing windows Superb Spatial Resolution; 0.5” ACIS-I (0.8-10 keV), ACIS-S (0.3-10 keV), HRC Superb Spectral Resolution; E/ΔE = 2300-150 (0.1-6.4 keV) HETG (HEG, MEG): 3 cm 2 @23 Å, 40 cm Å; LETGcm

4. Imaging Improvement: Cas A Supernova Remnant ROSAT

5. Spectral Improvement: Protostar, TW Hydrae Wavelength (Å) 261014182226 10 20 30 Counts/ Bin Wavelength (Å) ASCA

6. Chandra HETG: The Most Sensitive 0.9-7 keV Instrument for Line Studies

7. Why We Want High Resolution: Spectroscopy Tells us the Composition of the Universe Abundances (see J. Drake’s talk); Phases, e.g., Warm, Hot, Cold, Solid (see J. Lee’s talk) Spectroscopy is the Best Means to Study the Kinematics of Astrophysical Plasmas Capella, SS 433, MCG--6-30-15, GRO J1655-40, SN1987A Line Ratios can yield Temperatures, Densities, & Heating Mechanisms, e.g., Photo- or Collisional Ionization? M81*, is it Advection Dominated?

8. Stellar Physics: Capella 42.2 lightyears from Earth, 6 th Brightest “Star” in the Sky Actually, 4 stars, with a Spectroscopic Binary - Capella Aa/Ab Capella Aa 2.7 M sun, variable, beginning ascent to Red Giant Phase Capella Ab 2.6 M sun, faster rotating, 104 day orbit System is used to Study Stellar Physics and Chandra Calibration Excellent Example of the Accuracy and Power of HETG!

9. Stellar Physics: Capella MEG -1 st Order Spectra can be fit with a 3 Temperature Plasma Model

10. Stellar Physics: Capella Capella Shows 10’s of km/sec velocity residuals Real Effect! Barycenter & Space-craft Corrections need to be applied! (Ishibashi et al. 2006)

11. Stellar Physics: Capella Remaining Velocity Shifts Indicate X-ray Dominated by Capella Aa Orbital Variability Also Seen in Line Fluxes (Ishibashi et al. 2006)

12. Stellar Physics: Capella Some lines indicate emission from both stars. Mg XII Doublet fitted velocity indicates 2:1 Aa:Ab ratio Statistics and instrument resolution/stability allow us to carefully model other blends (Ishibashi et al. 2006)

13. Higher Orders Allow Line Separation: MEG 1 st HEG 1 st MEG 3 rd Ne X Lyα Doublet Fe XVII Fe XXIII Ni XX (Huenemoerder et al., in prep.)

14. More Extreme Kinematics - SS 433: Two sided, relativistic jet with velocity 0.25 c Orbital period of 13 days Jet/disk precessing with 162 day period Baryonic jet, as evidenced by emission (Migliari et al., 2002) (Animation by L. Boroson, MIT)

15. Blue/Redshift Velocities Accurately Measured (Lopez et al. 2006)

16. Recent Observation, Exiting Eclipse, fit with 5 Temperature APED Model

17. Stacking Lines to Perform Detailed Kinematic Modeling Aug. 18Aug. 16Aug. 12 Velocity (km/s) 50,000 -30,000 Time (ks) 25 ks Aug. 8 0 (Marshall et al., in prep.)

18. The Interstellar Medium: Just as Quasars + Optical/UV Spectroscopy Probed the Structure of the Intergalactic Medium (IGM), X-ray Spectroscopy + X-ray Binaries Probes the Interstellar Medium (ISM) Probes the Cold, Warm, and Hot Phases of the ISM Driving Models of the ISM Distribution Driving us to Improve Modeling of Edge/Resonance Line Structure Testing/Calibrating Theoretical Models of Edge & Lines

19. Various Sight Lines Probed

20. 4U 1636-53 Oxygen & Neon Edges Require 20 mÅ Shifts from Theoretical Values Ne IX is Detection of the Hot Phase of ISM O/Ne = 5.4 ± 1.6, Fe/Ne = 0.20 ± 0.03, Ne II /Ne I ≈ 0.3, Ne III /Ne I ≈ 0.07 The Interstellar Medium: (Juett et al., 2004, 2006)

21. Model of Disk Distribution: z (kpc) log(N H sin(b)) 0.11.010100 18 19 20 21 22 (Yao & Wang 2005, 2006) The gas ( ∼ 10 8 M sun ) is primarily concentrated around the Galactic disk within several kpc. n H = 5.0 x 10 -3 cm - 3 exp[- |z|/1.1kpc] Total N H ∼ 1.6 x10 19 cm -2

22. The Active Galactic Nuclei: MCG--6-30-15 Image: CXO ≈100 R G Seyfert 1 Active Galactic Nucleus (AGN), offering an unobscured view of nucleus Powered by efficient accretion through a “cold”, dense accretion disk Powerful, compact central source of X-rays Reflection Spectrum:

23. Broad Iron Line: Heavily binned 522 ksec Chandra HEG (red) XMM-Newton EPIC-pn (black) (Young et al., in prep.)

24. MCG-6-30-15 : O I - O VIII (O 0+ - O 7+ ), Fe I - Fe XXVI (Fe 0+ - Fe 25+ ) ! Potential of tying our X-ray observations to a large body of work in UV, IR... Ability to probe sources with high extinction in the X-rays Kinematic associations between UV and X-ray absorbers More options for probing the ISM? Both in AGN & our own Galaxy Inner Shell Resonance Lines: Probing Low Ionization (UV, IR) Processes in the X-rays (J. Lee et al., in prep.) MCG−6-30-15 Galactic O V O VI O VII He α O IV O III O II or Fe n O m Atomic O I 1s-2p O VI

25. The KLL (1s2s2p) Resonance of Li- like O VI (1s 2 2s) 1s 2 2s ● Atomic Calculation : Pradhan 2000 ● Discovered in MCG-6-30-15 : J. Lee et al. 2001 O VI in MCG--6-30-15 : N OVI ~ 3 x 10 17 cm -2 ; EW ~ 32 mÅ Inner Shell Resonance Lines: Probing Low Ionization (UV, IR) Processes in the X-rays O V O VI O VII He α O IV O VI

26. 540 ksec MEG Spectra: Ne IX at High τ (J. Lee et al., in prep.)

27. Winds Seen in X-ray Binaries: (Miller et al., 2006)

28. GRO J1655-40: Binary in Outburst (Miller et al., 2006) Typical Blueshifts of 500 km s -1. Modeled as a constant ρ slab, with T=0.2-1 x 10 6 K, log ξ = 4.2- 4.7 Argued that low velocity, high ionization mean magnetic driving Note that a fair number of lines remain unidentified

29. M81*: Low Luminosity AGN M81* ULX Imaging Allows us to Separate Faint Source from Its Surroundings; Spectra Allows us to Study the Accretion Flow onto the Nucleus

30. Closest extra-Galactic AGN with observable nucleus: 3.6 Mpc Bolometric luminosity: L ≈ 10 41 erg s -1 HST STIS spectroscopy MBH = 7.0 x 10 7 M sun Low-luminosity AGN: L ≈ 10 -5 L Edd Has jet, similar to Sgr A*, but brighter M81*: Low Luminosity AGN

31. Portion of the MEG Spectra: Si XIV Si Kα Mg XII Ne X Si XIII (Young et al., in prep.) Si XIII G = (f+i)/r = 0.8 Hybrid collisionally- and photo-ionized plasma [?]

32. Advection Dominated Accretion Flow? ADAF outer radius, disk inner radius Difficult to get strong Fe Kα Even harder to get strong Si Kα Expect Line Emission from Transition Regions & Hot Plasma Weak Fluorescence Features

33. Close-up of the Fe Region: Fe Kβ? Fe XXV Fe XXVI Fe Kα Fe XXVI redshifted by 3000 km s -1 Fe Kα, Fe XXVI consistent with 2000 km s -1 widths Si Kα consistent with 600 ± 300 km s -1 widths (Young et al., in prep.)

34. Supernova 1987A

35. Existing LETG Spectra (Zhekov et al. 2005)

36. SN1987A: Getting Brighter & Bigger! MEG -1 st Order Simulation Shown 270 ksec Observation with HETG (Canizares, PI), and 300 ksec with LETG (McCray, PI) Spatial Information Available, both Via Image and Via Line Widths

37. Summary: The Imaging Improvement by Chandra is Incredibly Impressive! Spectral Resolution Improvement is Equally Impressive! HETG is the Best Instrument for Studying Narrow Absorption & Emission Features in the 0.9-7 keV range HETG is Used to Study a Wide Array of Astrophysics Stars, X-ray Binaries, AGN, ISM, Supernovae... Data Leading us More Sophisticated Models, with Better Atomic Physics Data can Help to Calibrate & Test Atomic Physics Models We are Embarking Upon More Ambitious Observations that Combine Chandra’s Unique Spectroscopy and Imaging