AtomDB: X-ray Diagnostics of Astrophysical Plasmas Randall Smith Smithsonian Astrophysical Observatory
Collaborators and Thanks AtomDB Collaborators: Adam Foster, Nancy Brickhouse, John Raymond, Li Ji, Tim Kallman, Mike Witthoeft, Hiroya Yamaguchi, Joern Wilms Thanks to: ADAS team, CHIANTI team, ITAMP, Kate Kirby, Verne Jacobs, Ulyana Safronova, Guo- Xin Chen, Brendan McLaughlin, Brad Wargelin, and many others
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Introduction Unexpectedly strong solar X-rays were first detected on an August 5, 1948 flight (Burnight 1949, Phys Rev 76, 165). Combined with optical observations of the corona, models assuming it was a plasma at ~10 6 K were entertained"
X-ray Line Emission from Capella Abstract: X-ray emission-line components from Mg, Si, S, and Fe are unambiguously detected from Capella with the solidstate spectrometer onboard the Einstein Observatory. The X-ray spectrum is inconsistent with an isothermal corona, and requires components between 6- million K and at least 24-million K for an adequate fit. An inhomogeneous corona in which the X-ray emitting plasma is confined to magnetically contained loops appears to be reconcilable with all of the experimental evidence. Flux (cts/s/kev) 10 1 0.1 10-2 10-3 10-4 0.6 Introduction 1.0 2.0 3.0 Energy (kev) 7 ksec exposure with the Einstein Solid State Spectrometer (Holt et al. 1979)!
Introduction Coronal Structure and Abundances of Capella from EUVE and ASCA Spectroscopy! Abstract: (edited)! The plasma spectral emission models (Raymond-Smith, MEKAL, SPEX) around 1.2 kev appear to have flux deficits relative to the observed ASCA count spectrum. " New atomic models by Liedahl and Brickhouse dramatically improves the spectral model fits to the data, allowing reliable determination of elemental abundances." While a two-temperature model actually provides a better fit to the ASCA spectrum than the EUVE-derived continuous model, the EUVE data are not well fitted with only two temperatures. " We find that the abundances of Mg, Si, S, and Fe are consistent with solar photospheric values, while Ne appears to be underabundant by a factor of ~3 to 4." 21 ksec obs. w/asca Silicon Imaging Spectrometer (Brickhouse et al. 2000)
In this case, the poor fit between 9-12 Å is likely due to missing lines, not bad modeling. Introduction
Introduction High-Resolution X-Ray Spectra of Capella: Initial Results from the Chandra High- Energy Transmission Grating Spectrometer" 89 ksec w/chandra HETG (Canizares et al. 2000) Abstract (edited): Capella has plasma with a broad range of temperatures, from log T = 6.3 to 7.2, generally consistent with recent results from EUV/ASCA The electron density is determined from He-like O VII lines, giving the value of Ne 10 10 cm -3 at Te 2 10 6 K. The density and emission measure from O VII lines together indicate that the coronal loops are significantly smaller than the stellar radius.
A Few Words about X-ray Needs "Major needs are H-like, He-like, and Fe (and to a lesser extent Ni) L-shell line data." 400 Counts 200 Si XIV Si XIII Mg XII Mg XI Ne X Ne IX Ne IX Ne X Ne IX Fe XVII O VIII TW Hya, Chandra HETG Fe XVII O VII O VIII O VII 0 5 10 15 20 Wavelength (Angstroms) Brickhouse et al. 2010
A Few Words about X-ray Needs Photoionized plasmas are more complex as both collisional and photon cross sections are relevant. " However, H-like, He-like, and Fe ions are still key (although other ions play a larger role)." NGC 3783 X-ray bright Seyfert galaxy; 900 ksec HETG, 280 ksec RGS observations Krongold et al. 2003; also Netzer et al. 2003 and Behar et al. 2003
http://www.atomdb.org
AtomDB Astrophysical Models Theoretical and Laboratory Atomic Data (various formats) XSTAR PHASE APEC Wavelengths Atomic Structure Collisional Rate Coefficients AtomDB standard formats, evaluated data, accessible Sherpa/ CIAO XSPEC ISIS Analysis Tools Radiative Transition Rates Profit Photon Cross Sections Level Bundling Tool Database Tools WebGUIDE
http://www.atomdb.org
Advertisement: AtomDB WorkWeek 3 rd Annual Work Week @ CfA August 19 23 (M-F) August 19, 20, 23: Informal daily collaborations August 21-22: 1.5 day conference on latest results Attendees include X-ray astrophysicists Atomic physicists (theory & experiment) AtomDB maintainers
Wavelengths Fit using raw HULLAC wavelengths Fit using lab (Brown et al. 1998) wavelengths Fit using newly calculated wavelengths Kotochigova et al 2010 By combining laboratory measurements and theoretical structure calculations, can get highly accurate (few må) wavelengths. Detectors with R>1000 require this kind of accuracy!
Current Problems: He-like "Data updated for He-like ions using an R-Matrix calculation for the levels up to n=5, and then extending that to n=10 using a distorted wave calculation. " Smith et al. 2009; Foster et al 2012
Current Problems: H-like 456776)6.8019/:.:,707 0;5 % 3 "# "# #&#" <*0=0(.0"#70> 2.:5@A0)"&%&"?8 2.:5@A0)$&#&# Bandpass for Mg XI?8?8?8?8?8?8?8?8! "# "" "$ "% '()*+*,-./0123 Going to higher n-shell is needed and still an outstanding problem for all but H-like, He-like ions.
Current Problems: Fe XVII & 4C1-D:1/D121 EFFGH.I23-/D121 % Raymond-Smith AtomDB v1.3.1 +,-./012,3/$45$6 $ # AtomDB v2.0.0 Chen 2008 41=.881 " 3C 2p53d 1P1 gnd (15.014 Å) 3D 2p53d 3D1 gnd (15.261 Å)! ' '(# '(% '(' '() * *(# 78.92:3-/;.<=.:12>:./83?@;5AB Fe XVII 3C/3D from the point of view of observational data and various calculations
Current Problems: Fe XVII Gillaspy et al. 2010 Fe XVII 3C/3D from the point of view of laboratory data and various calculations
Current Problems: Ionization Balance Fractional Ion Population T=107K % Error in Ion Population 70 60 50 40 30 20 10 T=107K C N O Ne Mg Al Si S Ar Ca Fe Ni 0 C N O Ne Mg Al Si S Ar Ca Fe Ni 30% errors on the ionization & recombination rates leads to ~30% errors in the ion population. However, at the limits of an ion s population, these errors are increased up to 60%.
Low Abundance Elements Flux (cts/s/kev) 0.5 0.2 4 Tamagawa+ 2009 Ca XIX n=3 1 4.56±0.04 kev Tycho SNR observed with Suzaku XIS CCDs 5.48±0.02 kev Cr K Neutral Cr K 5.95±0.05 kev Mn K 5 6 Energy (kev) Neutral Mn K FeK Suzaku 100ks Tycho observation shows Mn and Cr fluorescence lines from partiallyionized material. Relevent atomic parameters had to be estimated. (Tamagawa+08) Badenes+(2008) considered model SNIa explosions with different neutron excesses and various classes of explosions For the progenitor of Tycho's SN, the data requires a near-solar or supersolar metallicity Badenes et al 2008
Wavelengths Mkn 421 Chandra LETG/HRC-S Flux (counts/0.0125å bin) Balucinska-Church & McCammon (1992) This work Hasoglu+ 2010 Lee et al 09 Wavelength (Å) Absorption edges and related features still need a lot of work
Fluorescent Line Data Bandler et al. 2010 The fluorescent lines from radioactive sources are not simple Lorentzians, but complex combinations of many lines. Line widths measured by current calorimeters are dominated by the natural line widths which are not known for many useful elements! Hoelzer et al 1997
Conclusions Send lawyers, guns, and money We need a balanced program of focused Laboratory Measurements Theoretical Calculations Data Curation of Both Astro-H will usher in a new world of highresolution spectra, especially in the 2-10 kev band. We must be ready for it!